Merge branch 'master' into context-request-keyboard

.gitignore

@@ -106,6 +106,9 @@ _NCrunch_*/
 *.ncrunchsolution.user
 nCrunchTemp_*
 
+# CodeRush
+.cr/
+
 # Others
 sql/
 *.Cache

native/Avalonia.Native/inc/comimpl.h

@@ -8,8 +8,109 @@
 
 #include <cstring>
 
+/**
+ START_COM_CALL causes AddRef to be called at the beggining of a function.
+ When a function is exited, it causes ReleaseRef to be called.
+ This ensures that the object cannot be destroyed whilst the function is running.
+ For example: Window Show is called, which triggers an event, and user calls Close inside the event
+ causing the refcount to reach 0, and the object to be destroyed. Function then continues and this pointer
+ will now be invalid.
+ 
+ START_COM_CALL protects against this scenario.
+ */
+#define START_COM_CALL auto r = this->UnknownSelf()
+
 __IID_DEF(IUnknown, 0, 0, 0, C0, 00, 00, 00, 00, 00, 00, 46);
 
+template<class TInterface>
+class ComPtr
+{
+private:
+    TInterface* _obj;
+public:
+    ComPtr()
+    {
+        _obj = 0;
+    }
+    
+    ComPtr(TInterface* pObj)
+    {
+        _obj = 0;
+
+        if (pObj)
+        {
+            _obj = pObj;
+            _obj->AddRef();
+        }
+    }
+    
+    ComPtr(const ComPtr& ptr)
+    {
+        _obj = 0;
+        
+        if (ptr._obj)
+        {
+            _obj = ptr._obj;
+            _obj->AddRef();
+        }
+
+    }
+    
+    ComPtr& operator=(ComPtr other)
+    {
+        if(_obj != NULL)
+            _obj->Release();
+        _obj = other._obj;
+        if(_obj != NULL)
+            _obj->AddRef();
+        return *this;
+    }
+
+    ~ComPtr()
+    {
+        if (_obj)
+        {
+            _obj->Release();
+            _obj = 0;
+        }
+    }
+    
+    TInterface* getRaw()
+    {
+        return _obj;
+    }
+    
+    TInterface* getRetainedReference()
+    {
+        if(_obj == NULL)
+            return NULL;
+        _obj->AddRef();
+        return _obj;
+    }
+    
+    TInterface** getPPV()
+    {
+        return &_obj;
+    }
+    
+    operator TInterface*() const
+    {
+        return _obj;
+    }
+    TInterface& operator*() const
+    {
+        return *_obj;
+    }
+    TInterface** operator&()
+    {
+        return &_obj;
+    }
+    TInterface* operator->() const
+    {
+        return _obj;
+    }
+};
+
 class ComObject : public virtual IUnknown
 {
 private:
@@ -58,6 +159,12 @@ public:
         _refCount++;
         return S_OK;
     }
+    
+protected:
+   ComPtr<IUnknown> UnknownSelf()
+    {
+       return this;
+   }
 
 };
 
@@ -104,94 +211,5 @@ public:
     virtual ~ComSingleObject(){}
 };
 
-template<class TInterface>
-class ComPtr
-{
-private:
-    TInterface* _obj;
-public:
-    ComPtr()
-    {
-        _obj = 0;
-    }
-    
-    ComPtr(TInterface* pObj)
-    {
-        _obj = 0;
-
-        if (pObj)
-        {
-            _obj = pObj;
-            _obj->AddRef();
-        }
-    }
-    
-    ComPtr(const ComPtr& ptr)
-    {
-        _obj = 0;
-        
-        if (ptr._obj)
-        {
-            _obj = ptr._obj;
-            _obj->AddRef();
-        }
-
-    }
-    
-    ComPtr& operator=(ComPtr other)
-    {
-        if(_obj != NULL)
-            _obj->Release();
-        _obj = other._obj;
-        if(_obj != NULL)
-            _obj->AddRef();
-        return *this;
-    }
-
-    ~ComPtr()
-    {
-        if (_obj)
-        {
-            _obj->Release();
-            _obj = 0;
-        }
-    }
-    
-    TInterface* getRaw()
-    {
-        return _obj;
-    }
-    
-    TInterface* getRetainedReference()
-    {
-        if(_obj == NULL)
-            return NULL;
-        _obj->AddRef();
-        return _obj;
-    }
-    
-    TInterface** getPPV()
-    {
-        return &_obj;
-    }
-    
-    operator TInterface*() const
-    {
-        return _obj;
-    }
-    TInterface& operator*() const
-    {
-        return *_obj;
-    }
-    TInterface** operator&()
-    {
-        return &_obj;
-    }
-    TInterface* operator->() const
-    {
-        return _obj;
-    }
-};
-
 #endif // COMIMPL_H_INCLUDED
 #pragma clang diagnostic pop

native/Avalonia.Native/src/OSX/AvnString.mm

@@ -43,6 +43,8 @@ public:
     
     virtual HRESULT Pointer(void**retOut) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(retOut == nullptr)
@@ -58,14 +60,19 @@ public:
     
     virtual HRESULT Length(int*retOut) override
     {
-        if(retOut == nullptr)
+        START_COM_CALL;
+        
+        @autoreleasepool
         {
-            return E_POINTER;
+            if(retOut == nullptr)
+            {
+                return E_POINTER;
+            }
+            
+            *retOut = _length;
+            
+            return S_OK;
         }
-        
-        *retOut = _length;
-        
-        return S_OK;
     }
 };
 
@@ -109,10 +116,15 @@ public:
     
     virtual HRESULT Get(unsigned int index, IAvnString**ppv) override
     {
-        if(_list.size() <= index)
-            return E_INVALIDARG;
-        *ppv = _list[index].getRetainedReference();
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            if(_list.size() <= index)
+                return E_INVALIDARG;
+            *ppv = _list[index].getRetainedReference();
+            return S_OK;
+        }
     }
 };
 

native/Avalonia.Native/src/OSX/Screens.mm

@@ -8,6 +8,8 @@ class Screens : public ComSingleObject<IAvnScreens, &IID_IAvnScreens>
 public:
     virtual HRESULT GetScreenCount (int* ret) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             *ret = (int)[NSScreen screens].count;
@@ -18,6 +20,8 @@ public:
     
     virtual HRESULT GetScreen (int index, AvnScreen* ret) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(index < 0 || index >= [NSScreen screens].count)

native/Avalonia.Native/src/OSX/cgl.mm

@@ -69,6 +69,8 @@ public:
     
     virtual HRESULT LegacyMakeCurrent() override
     {
+        START_COM_CALL;
+        
         if(CGLSetCurrentContext(Context) != 0)
             return E_FAIL;
         return S_OK;
@@ -76,6 +78,8 @@ public:
     
     virtual HRESULT MakeCurrent(IUnknown** ppv) override
     {
+        START_COM_CALL;
+        
         CGLContextObj saved = CGLGetCurrentContext();
         CGLLockContext(Context);
         if(CGLSetCurrentContext(Context) != 0)
@@ -128,6 +132,8 @@ public:
     
     virtual HRESULT CreateContext(IAvnGlContext* share, IAvnGlContext**ppv) override
     {
+        START_COM_CALL;
+        
         CGLContextObj shareContext = nil;
         if(share != nil)
         {
@@ -144,6 +150,8 @@ public:
     
     virtual HRESULT WrapContext(void* native, IAvnGlContext**ppv) override
     {
+        START_COM_CALL;
+        
         if(native == nil)
             return E_INVALIDARG;
         *ppv = new AvnGlContext((CGLContextObj) native);

native/Avalonia.Native/src/OSX/clipboard.mm

@@ -25,6 +25,8 @@ public:
    
     virtual HRESULT GetText (char* type, IAvnString**ppv) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(ppv == nullptr)
@@ -42,6 +44,8 @@ public:
     
     virtual HRESULT GetStrings(char* type, IAvnStringArray**ppv) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             *ppv= nil;
@@ -69,56 +73,71 @@ public:
     
     virtual HRESULT SetText (char* type, char* utf8String) override
     {
-        Clear();
+        START_COM_CALL;
+        
         @autoreleasepool
         {
+            Clear();
+            
             auto string = [NSString stringWithUTF8String:(const char*)utf8String];
             auto typeString = [NSString stringWithUTF8String:(const char*)type];
             if(_item == nil)
                 [_pb setString: string forType: typeString];
             else
                 [_item setString: string forType:typeString];
-        }
         
-        return S_OK;
+            return S_OK;
+        }
     }
     
     virtual HRESULT SetBytes(char* type, void* bytes, int len) override
     {
-        auto typeString = [NSString stringWithUTF8String:(const char*)type];
-        auto data = [NSData dataWithBytes:bytes length:len];
-        if(_item == nil)
-            [_pb setData:data forType:typeString];
-        else
-            [_item setData:data forType:typeString];
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            auto typeString = [NSString stringWithUTF8String:(const char*)type];
+            auto data = [NSData dataWithBytes:bytes length:len];
+            if(_item == nil)
+                [_pb setData:data forType:typeString];
+            else
+                [_item setData:data forType:typeString];
+            return S_OK;
+        }
     }
        
     virtual HRESULT GetBytes(char* type, IAvnString**ppv) override
     {
-        *ppv = nil;
-        auto typeString = [NSString stringWithUTF8String:(const char*)type];
-        NSData*data;
-        @try
+        START_COM_CALL;
+        
+        @autoreleasepool
         {
-            if(_item)
-                data = [_item dataForType:typeString];
-            else
-                data = [_pb dataForType:typeString];
-            if(data == nil)
+            *ppv = nil;
+            auto typeString = [NSString stringWithUTF8String:(const char*)type];
+            NSData*data;
+            @try
+            {
+                if(_item)
+                    data = [_item dataForType:typeString];
+                else
+                    data = [_pb dataForType:typeString];
+                if(data == nil)
+                    return E_FAIL;
+            }
+            @catch(NSException* e)
+            {
                 return E_FAIL;
+            }
+            *ppv = CreateByteArray((void*)data.bytes, (int)data.length);
+            return S_OK;
         }
-        @catch(NSException* e)
-        {
-            return E_FAIL;
-        }
-        *ppv = CreateByteArray((void*)data.bytes, (int)data.length);
-        return S_OK;
     }
 
 
     virtual HRESULT Clear() override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(_item != nil)
@@ -128,15 +147,20 @@ public:
                 [_pb clearContents];
                 [_pb setString:@"" forType:NSPasteboardTypeString];
             }
-        }
         
-        return S_OK;
+            return S_OK;
+        }
     }
     
     virtual HRESULT ObtainFormats(IAvnStringArray** ppv) override
     {
-        *ppv = CreateAvnStringArray(_item == nil ? [_pb types] : [_item types]);
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            *ppv = CreateAvnStringArray(_item == nil ? [_pb types] : [_item types]);
+            return S_OK;
+        }
     }
 };
 

native/Avalonia.Native/src/OSX/controlhost.mm

@@ -16,11 +16,16 @@ public:
     
     virtual HRESULT CreateDefaultChild(void* parent, void** retOut) override
     {
-        NSView* view = [NSView new];
-        [view setWantsLayer: true];
+        START_COM_CALL;
         
-        *retOut = (__bridge_retained void*)view;
-        return S_OK;
+        @autoreleasepool
+        {
+            NSView* view = [NSView new];
+            [view setWantsLayer: true];
+            
+            *retOut = (__bridge_retained void*)view;
+            return S_OK;
+        }
     };
     
     virtual IAvnNativeControlHostTopLevelAttachment* CreateAttachment() override
@@ -69,32 +74,42 @@ public:
     
     virtual HRESULT InitializeWithChildHandle(void* child) override
     {
-        if(_child != nil)
-            return E_FAIL;
-        _child = (__bridge NSView*)child;
-        if(_child == nil)
-            return E_FAIL;
-        [_holder addSubview:_child];
-        [_child setHidden: false];
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            if(_child != nil)
+                return E_FAIL;
+            _child = (__bridge NSView*)child;
+            if(_child == nil)
+                return E_FAIL;
+            [_holder addSubview:_child];
+            [_child setHidden: false];
+            return S_OK;
+        }
     };
     
     virtual HRESULT AttachTo(IAvnNativeControlHost* host) override
     {
-        if(host == nil)
-        {
-            [_holder removeFromSuperview];
-            [_holder setHidden: true];
-        }
-        else
+        START_COM_CALL;
+        
+        @autoreleasepool
         {
-            AvnNativeControlHost* chost = dynamic_cast<AvnNativeControlHost*>(host);
-            if(chost == nil || chost->View == nil)
-                return E_FAIL;
-            [_holder setHidden:true];
-            [chost->View addSubview:_holder];
+            if(host == nil)
+            {
+                [_holder removeFromSuperview];
+                [_holder setHidden: true];
+            }
+            else
+            {
+                AvnNativeControlHost* chost = dynamic_cast<AvnNativeControlHost*>(host);
+                if(chost == nil || chost->View == nil)
+                    return E_FAIL;
+                [_holder setHidden:true];
+                [chost->View addSubview:_holder];
+            }
+            return S_OK;
         }
-        return S_OK;
     };
     
     virtual void ShowInBounds(float x, float y, float width, float height) override

native/Avalonia.Native/src/OSX/cursor.mm

@@ -53,36 +53,46 @@ public:
     
     virtual HRESULT GetCursor (AvnStandardCursorType cursorType, IAvnCursor** retOut) override
     {
-        *retOut = s_cursorMap[cursorType];
+        START_COM_CALL;
         
-        if(*retOut != nullptr)
+        @autoreleasepool
         {
-            (*retOut)->AddRef();
-        }
+            *retOut = s_cursorMap[cursorType];
             
-        return S_OK;
+            if(*retOut != nullptr)
+            {
+                (*retOut)->AddRef();
+            }
+                
+            return S_OK;
+        }
     }
     
     virtual HRESULT CreateCustomCursor (void* bitmapData, size_t length, AvnPixelSize hotPixel, IAvnCursor** retOut) override
     {
-        if(bitmapData == nullptr || retOut == nullptr)
+        START_COM_CALL;
+        
+        @autoreleasepool
         {
-            return E_POINTER;
+            if(bitmapData == nullptr || retOut == nullptr)
+            {
+                return E_POINTER;
+            }
+            
+            NSData *imageData = [NSData dataWithBytes:bitmapData length:length];
+            NSImage *image = [[NSImage alloc] initWithData:imageData];
+            
+            
+            NSPoint hotSpot;
+            hotSpot.x = hotPixel.Width;
+            hotSpot.y = hotPixel.Height;
+            
+            *retOut = new Cursor([[NSCursor new] initWithImage: image hotSpot: hotSpot]);
+            
+            (*retOut)->AddRef();
+            
+            return S_OK;
         }
-        
-        NSData *imageData = [NSData dataWithBytes:bitmapData length:length];
-        NSImage *image = [[NSImage alloc] initWithData:imageData];
-        
-        
-        NSPoint hotSpot;
-        hotSpot.x = hotPixel.Width;
-        hotSpot.y = hotPixel.Height;
-        
-        *retOut = new Cursor([[NSCursor new] initWithImage: image hotSpot: hotSpot]);
-        
-        (*retOut)->AddRef();
-        
-        return S_OK;
     }
 };
 

native/Avalonia.Native/src/OSX/main.mm

@@ -107,27 +107,42 @@ public:
     
     virtual HRESULT SetApplicationTitle(char* utf8String) override
     {
-        auto appTitle = [NSString stringWithUTF8String: utf8String];
+        START_COM_CALL;
         
-        [[NSProcessInfo processInfo] setProcessName:appTitle];
-        
-        
-        SetProcessName(appTitle);
-        
-        return S_OK;
+        @autoreleasepool
+        {
+            auto appTitle = [NSString stringWithUTF8String: utf8String];
+            
+            [[NSProcessInfo processInfo] setProcessName:appTitle];
+            
+            
+            SetProcessName(appTitle);
+            
+            return S_OK;
+        }
     }
     
     virtual HRESULT SetShowInDock(int show)  override
     {
-        AvnDesiredActivationPolicy = show
-            ? NSApplicationActivationPolicyRegular : NSApplicationActivationPolicyAccessory;
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            AvnDesiredActivationPolicy = show
+                ? NSApplicationActivationPolicyRegular : NSApplicationActivationPolicyAccessory;
+            return S_OK;
+        }
     }
     
     virtual HRESULT SetDisableDefaultApplicationMenuItems (bool enabled) override
     {
-        SetAutoGenerateDefaultAppMenuItems(!enabled);
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            SetAutoGenerateDefaultAppMenuItems(!enabled);
+            return S_OK;
+        }
     }
 };
 
@@ -165,6 +180,8 @@ public:
     FORWARD_IUNKNOWN()
     virtual HRESULT Initialize(IAvnGCHandleDeallocatorCallback* deallocator, IAvnApplicationEvents* events) override
     {
+        START_COM_CALL;
+        
         _deallocator = deallocator;
         @autoreleasepool{
             [[ThreadingInitializer new] do];
@@ -180,89 +197,154 @@ public:
     
     virtual HRESULT CreateWindow(IAvnWindowEvents* cb, IAvnGlContext* gl, IAvnWindow** ppv)  override
     {
-        if(cb == nullptr || ppv == nullptr)
-            return E_POINTER;
-        *ppv = CreateAvnWindow(cb, gl);
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            if(cb == nullptr || ppv == nullptr)
+                return E_POINTER;
+            *ppv = CreateAvnWindow(cb, gl);
+            return S_OK;
+        }
     };
     
     virtual HRESULT CreatePopup(IAvnWindowEvents* cb, IAvnGlContext* gl, IAvnPopup** ppv) override
     {
-        if(cb == nullptr || ppv == nullptr)
-            return E_POINTER;
+        START_COM_CALL;
         
-        *ppv = CreateAvnPopup(cb, gl);
-        return S_OK;
+        @autoreleasepool
+        {
+            if(cb == nullptr || ppv == nullptr)
+                return E_POINTER;
+            
+            *ppv = CreateAvnPopup(cb, gl);
+            return S_OK;
+        }
     }
     
     virtual HRESULT CreatePlatformThreadingInterface(IAvnPlatformThreadingInterface** ppv)  override
     {
-        *ppv = CreatePlatformThreading();
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            *ppv = CreatePlatformThreading();
+            return S_OK;
+        }
     }
     
     virtual HRESULT CreateSystemDialogs(IAvnSystemDialogs** ppv) override
     {
-        *ppv = ::CreateSystemDialogs();
-        return  S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            *ppv = ::CreateSystemDialogs();
+            return  S_OK;
+        }
     }
     
     virtual HRESULT CreateScreens (IAvnScreens** ppv) override
     {
-        *ppv = ::CreateScreens ();
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            *ppv = ::CreateScreens ();
+            return S_OK;
+        }
     }
 
     virtual HRESULT CreateClipboard(IAvnClipboard** ppv) override
     {
-        *ppv = ::CreateClipboard (nil, nil);
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            *ppv = ::CreateClipboard (nil, nil);
+            return S_OK;
+        }
     }
     
     virtual HRESULT CreateDndClipboard(IAvnClipboard** ppv) override
     {
-        *ppv = ::CreateClipboard (nil, [NSPasteboardItem new]);
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            *ppv = ::CreateClipboard (nil, [NSPasteboardItem new]);
+            return S_OK;
+        }
     }
 
     virtual HRESULT CreateCursorFactory(IAvnCursorFactory** ppv) override
     {
-        *ppv = ::CreateCursorFactory();
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            *ppv = ::CreateCursorFactory();
+            return S_OK;
+        }
     }
     
     virtual HRESULT ObtainGlDisplay(IAvnGlDisplay** ppv) override
     {
-        auto rv = ::GetGlDisplay();
-        if(rv == NULL)
-            return E_FAIL;
-        rv->AddRef();
-        *ppv = rv;
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            auto rv = ::GetGlDisplay();
+            if(rv == NULL)
+                return E_FAIL;
+            rv->AddRef();
+            *ppv = rv;
+            return S_OK;
+        }
     }
     
     virtual HRESULT CreateMenu (IAvnMenuEvents* cb, IAvnMenu** ppv) override
     {
-        *ppv = ::CreateAppMenu(cb);
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            *ppv = ::CreateAppMenu(cb);
+            return S_OK;
+        }
     }
     
     virtual HRESULT CreateMenuItem (IAvnMenuItem** ppv) override
     {
-        *ppv = ::CreateAppMenuItem();
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            *ppv = ::CreateAppMenuItem();
+            return S_OK;
+        }
     }
     
     virtual HRESULT CreateMenuItemSeparator (IAvnMenuItem** ppv) override
     {
-        *ppv = ::CreateAppMenuItemSeparator();
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            *ppv = ::CreateAppMenuItemSeparator();
+            return S_OK;
+        }
     }
     
     virtual HRESULT SetAppMenu (IAvnMenu* appMenu) override
     {
-        ::SetAppMenu(s_appTitle, appMenu);
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            ::SetAppMenu(s_appTitle, appMenu);
+            return S_OK;
+        }
     }
 };
 

native/Avalonia.Native/src/OSX/menu.mm

@@ -95,6 +95,8 @@ NSMenuItem* AvnAppMenuItem::GetNative()
 
 HRESULT AvnAppMenuItem::SetSubMenu (IAvnMenu* menu)
 {
+    START_COM_CALL;
+    
     @autoreleasepool
     {
         if(menu != nullptr)
@@ -114,6 +116,8 @@ HRESULT AvnAppMenuItem::SetSubMenu (IAvnMenu* menu)
 
 HRESULT AvnAppMenuItem::SetTitle (char* utf8String)
 {
+    START_COM_CALL;
+    
     @autoreleasepool
     {
         if (utf8String != nullptr)
@@ -128,6 +132,8 @@ HRESULT AvnAppMenuItem::SetTitle (char* utf8String)
 
 HRESULT AvnAppMenuItem::SetGesture (AvnKey key, AvnInputModifiers modifiers)
 {
+    START_COM_CALL;
+    
     @autoreleasepool
     {
         if(key != AvnKeyNone)
@@ -183,6 +189,8 @@ HRESULT AvnAppMenuItem::SetGesture (AvnKey key, AvnInputModifiers modifiers)
 
 HRESULT AvnAppMenuItem::SetAction (IAvnPredicateCallback* predicate, IAvnActionCallback* callback)
 {
+    START_COM_CALL;
+    
     @autoreleasepool
     {
         _predicate = predicate;
@@ -193,6 +201,8 @@ HRESULT AvnAppMenuItem::SetAction (IAvnPredicateCallback* predicate, IAvnActionC
 
 HRESULT AvnAppMenuItem::SetIsChecked (bool isChecked)
 {
+    START_COM_CALL;
+    
     @autoreleasepool
     {
         [_native setState:(isChecked && _isCheckable ? NSOnState : NSOffState)];
@@ -202,6 +212,8 @@ HRESULT AvnAppMenuItem::SetIsChecked (bool isChecked)
 
 HRESULT AvnAppMenuItem::SetToggleType(AvnMenuItemToggleType toggleType)
 {
+    START_COM_CALL;
+    
     @autoreleasepool
     {
         switch(toggleType)
@@ -231,6 +243,8 @@ HRESULT AvnAppMenuItem::SetToggleType(AvnMenuItemToggleType toggleType)
 
 HRESULT AvnAppMenuItem::SetIcon(void *data, size_t length)
 {
+    START_COM_CALL;
+    
     @autoreleasepool
     {
         if(data != nullptr)
@@ -317,6 +331,8 @@ void AvnAppMenu::RaiseClosed()
 
 HRESULT AvnAppMenu::InsertItem(int index, IAvnMenuItem *item)
 {
+    START_COM_CALL;
+    
     @autoreleasepool
     {
         if([_native hasGlobalMenuItem])
@@ -337,6 +353,8 @@ HRESULT AvnAppMenu::InsertItem(int index, IAvnMenuItem *item)
 
 HRESULT AvnAppMenu::RemoveItem (IAvnMenuItem* item)
 {
+    START_COM_CALL;
+    
     @autoreleasepool
     {
         auto avnMenuItem = dynamic_cast<AvnAppMenuItem*>(item);
@@ -352,6 +370,8 @@ HRESULT AvnAppMenu::RemoveItem (IAvnMenuItem* item)
 
 HRESULT AvnAppMenu::SetTitle (char* utf8String)
 {
+    START_COM_CALL;
+    
     @autoreleasepool
     {
         if (utf8String != nullptr)
@@ -365,6 +385,8 @@ HRESULT AvnAppMenu::SetTitle (char* utf8String)
 
 HRESULT AvnAppMenu::Clear()
 {
+    START_COM_CALL;
+    
     @autoreleasepool
     {
         [_native removeAllItems];

native/Avalonia.Native/src/OSX/platformthreading.mm

@@ -114,6 +114,8 @@ public:
     
     virtual HRESULT RunLoop(IAvnLoopCancellation* cancel) override
     {
+        START_COM_CALL;
+        
         auto can = dynamic_cast<LoopCancellation*>(cancel);
         if(can->Cancelled)
             return S_OK;

native/Avalonia.Native/src/OSX/rendertarget.mm

@@ -247,6 +247,8 @@ public:
     
     virtual HRESULT GetPixelSize(AvnPixelSize* ret)  override
     {
+        START_COM_CALL;
+        
         if(!_surface)
             return E_FAIL;
         *ret = _surface->size;
@@ -255,6 +257,8 @@ public:
     
     virtual HRESULT GetScaling(double* ret)  override
     {
+        START_COM_CALL;
+        
         if(!_surface)
             return E_FAIL;
         *ret = _surface->scale;
@@ -281,6 +285,8 @@ public:
     
     virtual HRESULT BeginDrawing(IAvnGlSurfaceRenderingSession** ret)  override
     {
+        START_COM_CALL;
+        
         ComPtr<IUnknown> releaseContext;
         @synchronized (_target->lock) {
             if(_target->surface == nil)

native/Avalonia.Native/src/OSX/window.mm

@@ -29,10 +29,12 @@ public:
     IAvnMenu* _mainMenu;
     
     bool _shown;
+    bool _inResize;
     
     WindowBaseImpl(IAvnWindowBaseEvents* events, IAvnGlContext* gl)
     {
         _shown = false;
+        _inResize = false;
         _mainMenu = nullptr;
         BaseEvents = events;
         _glContext = gl;
@@ -54,6 +56,8 @@ public:
     
     virtual HRESULT ObtainNSWindowHandle(void** ret) override
     {
+        START_COM_CALL;
+        
         if (ret == nullptr)
         {
             return E_POINTER;
@@ -66,6 +70,8 @@ public:
     
     virtual HRESULT ObtainNSWindowHandleRetained(void** ret) override
     {
+        START_COM_CALL;
+        
         if (ret == nullptr)
         {
             return E_POINTER;
@@ -78,6 +84,8 @@ public:
     
     virtual HRESULT ObtainNSViewHandle(void** ret) override
     {
+        START_COM_CALL;
+        
         if (ret == nullptr)
         {
             return E_POINTER;
@@ -90,6 +98,8 @@ public:
     
     virtual HRESULT ObtainNSViewHandleRetained(void** ret) override
     {
+        START_COM_CALL;
+        
         if (ret == nullptr)
         {
             return E_POINTER;
@@ -107,23 +117,27 @@ public:
     
     virtual HRESULT Show(bool activate) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             SetPosition(lastPositionSet);
             UpdateStyle();
             
             [Window setContentView: StandardContainer];
+            [Window setTitle:_lastTitle];
             
             if(ShouldTakeFocusOnShow() && activate)
             {
+                [Window orderFront: Window];
                 [Window makeKeyAndOrderFront:Window];
+                [Window makeFirstResponder:View];
                 [NSApp activateIgnoringOtherApps:YES];
             }
             else
             {
                 [Window orderFront: Window];
             }
-            [Window setTitle:_lastTitle];
             
             _shown = true;
             
@@ -138,6 +152,8 @@ public:
     
     virtual HRESULT Hide () override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(Window != nullptr)
@@ -152,6 +168,8 @@ public:
     
     virtual HRESULT Activate () override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(Window != nullptr)
@@ -166,6 +184,8 @@ public:
     
     virtual HRESULT SetTopMost (bool value) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             [Window setLevel: value ? NSFloatingWindowLevel : NSNormalWindowLevel];
@@ -176,11 +196,16 @@ public:
     
     virtual HRESULT Close() override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if (Window != nullptr)
             {
-                [Window close];
+                auto window = Window;
+                Window = nullptr;
+                
+                [window close];
             }
             
             return S_OK;
@@ -189,6 +214,8 @@ public:
     
     virtual HRESULT GetClientSize(AvnSize* ret) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(ret == nullptr)
@@ -202,8 +229,25 @@ public:
         }
     }
     
+    virtual HRESULT GetFrameSize(AvnSize* ret) override
+    {
+        @autoreleasepool
+        {
+            if(ret == nullptr)
+                return E_POINTER;
+            
+            auto frame = [Window frame];
+            ret->Width = frame.size.width;
+            ret->Height = frame.size.height;
+            
+            return S_OK;
+        }
+    }
+    
     virtual HRESULT GetScaling (double* ret) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(ret == nullptr)
@@ -222,6 +266,8 @@ public:
     
     virtual HRESULT SetMinMaxSize (AvnSize minSize, AvnSize maxSize) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             [Window setMinSize: ToNSSize(minSize)];
@@ -233,6 +279,15 @@ public:
     
     virtual HRESULT Resize(double x, double y) override
     {
+        if(_inResize)
+        {
+            return S_OK;
+        }
+        
+        _inResize = true;
+        
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             auto maxSize = [Window maxSize];
@@ -258,13 +313,19 @@ public:
                 y = maxSize.height;
             }
             
-            if(!_shown)
+            @try
             {
-                BaseEvents->Resized(AvnSize{x,y});
+                if(!_shown)
+                {
+                    BaseEvents->Resized(AvnSize{x,y});
+                }
+                
+                [Window setContentSize:NSSize{x, y}];
+            }
+            @finally
+            {
+                _inResize = false;
             }
-            
-            [StandardContainer setFrameSize:NSSize{x,y}];
-            [Window setContentSize:NSSize{x, y}];
             
             return S_OK;
         }
@@ -272,6 +333,8 @@ public:
     
     virtual HRESULT Invalidate (AvnRect rect) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             [View setNeedsDisplayInRect:[View frame]];
@@ -282,6 +345,8 @@ public:
     
     virtual HRESULT SetMainMenu(IAvnMenu* menu) override
     {
+        START_COM_CALL;
+        
         _mainMenu = menu;
         
         auto nativeMenu = dynamic_cast<AvnAppMenu*>(menu);
@@ -300,6 +365,8 @@ public:
     
     virtual HRESULT BeginMoveDrag () override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             auto lastEvent = [View lastMouseDownEvent];
@@ -317,11 +384,15 @@ public:
     
     virtual HRESULT BeginResizeDrag (AvnWindowEdge edge) override
     {
+        START_COM_CALL;
+        
         return S_OK;
     }
     
     virtual HRESULT GetPosition (AvnPoint* ret) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(ret == nullptr)
@@ -342,6 +413,8 @@ public:
     
     virtual HRESULT SetPosition (AvnPoint point) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             lastPositionSet = point;
@@ -353,6 +426,8 @@ public:
     
     virtual HRESULT PointToClient (AvnPoint point, AvnPoint* ret) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(ret == nullptr)
@@ -371,6 +446,8 @@ public:
     
     virtual HRESULT PointToScreen (AvnPoint point, AvnPoint* ret) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(ret == nullptr)
@@ -388,12 +465,16 @@ public:
     
     virtual HRESULT ThreadSafeSetSwRenderedFrame(AvnFramebuffer* fb, IUnknown* dispose) override
     {
+        START_COM_CALL;
+        
         [View setSwRenderedFrame: fb dispose: dispose];
         return S_OK;
     }
     
     virtual HRESULT SetCursor(IAvnCursor* cursor) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             Cursor* avnCursor = dynamic_cast<Cursor*>(cursor);
@@ -423,6 +504,8 @@ public:
     
     virtual HRESULT CreateGlRenderTarget(IAvnGlSurfaceRenderTarget** ppv) override
     {
+        START_COM_CALL;
+        
         if(View == NULL)
             return E_FAIL;
         *ppv = [renderTarget createSurfaceRenderTarget];
@@ -431,6 +514,8 @@ public:
     
     virtual HRESULT CreateNativeControlHost(IAvnNativeControlHost** retOut) override
     {
+        START_COM_CALL;
+        
         if(View == NULL)
             return E_FAIL;
         *retOut = ::CreateNativeControlHost(View);
@@ -439,6 +524,8 @@ public:
     
     virtual HRESULT SetBlurEnabled (bool enable) override
     {
+        START_COM_CALL;
+        
         [StandardContainer ShowBlur:enable];
         
         return S_OK;
@@ -448,6 +535,8 @@ public:
                                               IAvnClipboard* clipboard, IAvnDndResultCallback* cb,
                                               void* sourceHandle) override
     {
+        START_COM_CALL;
+        
         auto item = TryGetPasteboardItem(clipboard);
         [item setString:@"" forType:GetAvnCustomDataType()];
         if(item == nil)
@@ -549,6 +638,11 @@ private:
     
     void HideOrShowTrafficLights ()
     {
+        if (Window == nil)
+        {
+            return;
+        }
+        
         for (id subview in Window.contentView.superview.subviews) {
             if ([subview isKindOfClass:NSClassFromString(@"NSTitlebarContainerView")]) {
                 NSView *titlebarView = [subview subviews][0];
@@ -575,8 +669,10 @@ private:
     
     virtual HRESULT Show (bool activate) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
-        {            
+        {
             WindowBaseImpl::Show(activate);
             
             HideOrShowTrafficLights();
@@ -587,6 +683,8 @@ private:
     
     virtual HRESULT SetEnabled (bool enable) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             [Window setEnabled:enable];
@@ -596,6 +694,8 @@ private:
     
     virtual HRESULT SetParent (IAvnWindow* parent) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(parent == nullptr)
@@ -672,6 +772,7 @@ private:
                 }
                 
                 _lastWindowState = state;
+                _actualWindowState = state;
                 WindowEvents->WindowStateChanged(state);
             }
         }
@@ -707,6 +808,8 @@ private:
     
     virtual HRESULT SetCanResize(bool value) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             _canResize = value;
@@ -717,6 +820,8 @@ private:
     
     virtual HRESULT SetDecorations(SystemDecorations value) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             auto currentWindowState = _lastWindowState;
@@ -782,6 +887,8 @@ private:
     
     virtual HRESULT SetTitle (char* utf8title) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             _lastTitle = [NSString stringWithUTF8String:(const char*)utf8title];
@@ -793,6 +900,8 @@ private:
     
     virtual HRESULT SetTitleBarColor(AvnColor color) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             float a = (float)color.Alpha / 255.0f;
@@ -822,6 +931,8 @@ private:
     
     virtual HRESULT GetWindowState (AvnWindowState*ret) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if(ret == nullptr)
@@ -855,86 +966,111 @@ private:
     
     virtual HRESULT TakeFocusFromChildren () override
     {
-        if(Window == nil)
-            return S_OK;
-        if([Window isKeyWindow])
-            [Window makeFirstResponder: View];
+        START_COM_CALL;
         
-        return S_OK;
+        @autoreleasepool
+        {
+            if(Window == nil)
+                return S_OK;
+            if([Window isKeyWindow])
+                [Window makeFirstResponder: View];
+            
+            return S_OK;
+        }
     }
     
     virtual HRESULT SetExtendClientArea (bool enable) override
     {
-        _isClientAreaExtended = enable;
+        START_COM_CALL;
         
-        if(enable)
+        @autoreleasepool
         {
-            Window.titleVisibility = NSWindowTitleHidden;
-            
-            [Window setTitlebarAppearsTransparent:true];
-            
-            auto wantsTitleBar = (_extendClientHints & AvnSystemChrome) || (_extendClientHints & AvnPreferSystemChrome);
+            _isClientAreaExtended = enable;
             
-            if (wantsTitleBar)
-            {
-                [StandardContainer ShowTitleBar:true];
-            }
-            else
+            if(enable)
             {
-                [StandardContainer ShowTitleBar:false];
-            }
-            
-            if(_extendClientHints & AvnOSXThickTitleBar)
-            {
-                Window.toolbar = [NSToolbar new];
-                Window.toolbar.showsBaselineSeparator = false;
+                Window.titleVisibility = NSWindowTitleHidden;
+                
+                [Window setTitlebarAppearsTransparent:true];
+                
+                auto wantsTitleBar = (_extendClientHints & AvnSystemChrome) || (_extendClientHints & AvnPreferSystemChrome);
+                
+                if (wantsTitleBar)
+                {
+                    [StandardContainer ShowTitleBar:true];
+                }
+                else
+                {
+                    [StandardContainer ShowTitleBar:false];
+                }
+                
+                if(_extendClientHints & AvnOSXThickTitleBar)
+                {
+                    Window.toolbar = [NSToolbar new];
+                    Window.toolbar.showsBaselineSeparator = false;
+                }
+                else
+                {
+                    Window.toolbar = nullptr;
+                }
             }
             else
             {
+                Window.titleVisibility = NSWindowTitleVisible;
                 Window.toolbar = nullptr;
+                [Window setTitlebarAppearsTransparent:false];
+                View.layer.zPosition = 0;
             }
+            
+            [Window setIsExtended:enable];
+            
+            HideOrShowTrafficLights();
+            
+            UpdateStyle();
+            
+            return S_OK;
         }
-        else
-        {
-            Window.titleVisibility = NSWindowTitleVisible;
-            Window.toolbar = nullptr;
-            [Window setTitlebarAppearsTransparent:false];
-            View.layer.zPosition = 0;
-        }
-        
-        [Window setIsExtended:enable];
-        
-        HideOrShowTrafficLights();
-        
-        UpdateStyle();
-        
-        return S_OK;
     }
     
     virtual HRESULT SetExtendClientAreaHints (AvnExtendClientAreaChromeHints hints) override
     {
-        _extendClientHints = hints;
+        START_COM_CALL;
         
-        SetExtendClientArea(_isClientAreaExtended);
-        return S_OK;
+        @autoreleasepool
+        {
+            _extendClientHints = hints;
+            
+            SetExtendClientArea(_isClientAreaExtended);
+            return S_OK;
+        }
     }
     
     virtual HRESULT GetExtendTitleBarHeight (double*ret) override
     {
-        if(ret == nullptr)
+        START_COM_CALL;
+        
+        @autoreleasepool
         {
-            return E_POINTER;
+            if(ret == nullptr)
+            {
+                return E_POINTER;
+            }
+            
+            *ret = [Window getExtendedTitleBarHeight];
+            
+            return S_OK;
         }
-        
-        *ret = [Window getExtendedTitleBarHeight];
-        
-        return S_OK;
     }
     
     virtual HRESULT SetExtendTitleBarHeight (double value) override
     {
-        [StandardContainer SetTitleBarHeightHint:value];
-        return S_OK;
+        START_COM_CALL;
+        
+        @autoreleasepool
+        {
+            [StandardContainer SetTitleBarHeightHint:value];
+            return S_OK;
+        }
     }
     
     void EnterFullScreenMode ()
@@ -963,8 +1099,15 @@ private:
     
     virtual HRESULT SetWindowState (AvnWindowState state) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
+            if(Window == nullptr)
+            {
+                return  S_OK;
+            }
+            
             if(_actualWindowState == state)
             {
                 return S_OK;
@@ -1149,6 +1292,9 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     [_blurBehind setWantsLayer:true];
     _blurBehind.hidden = true;
     
+    [_blurBehind setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];
+    [_content setAutoresizingMask:NSViewWidthSizable | NSViewHeightSizable];
+    
     [self addSubview:_blurBehind];
     [self addSubview:_content];
     
@@ -1184,9 +1330,6 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     _settingSize = true;
     [super setFrameSize:newSize];
     
-    [_blurBehind setFrameSize:newSize];
-    [_content setFrameSize:newSize];
-    
     auto window = objc_cast<AvnWindow>([self window]);
     
     // TODO get actual titlebar size
@@ -1202,6 +1345,7 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     [_titleBarMaterial setFrame:tbar];
     tbar.size.height = height < 1 ? 0 : 1;
     [_titleBarUnderline setFrame:tbar];
+
     _settingSize = false;
 }
 
@@ -1911,7 +2055,7 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     {
         if(![self windowShouldClose:self]) return;
     }
-    
+
     [self close];
 }
 
@@ -2247,11 +2391,12 @@ protected:
     
     virtual HRESULT Resize(double x, double y) override
     {
+        START_COM_CALL;
+        
         @autoreleasepool
         {
             if (Window != nullptr)
             {
-                [StandardContainer setFrameSize:NSSize{x,y}];
                 [Window setContentSize:NSSize{x, y}];
             
                 [Window setFrameTopLeftPoint:ToNSPoint(ConvertPointY(lastPositionSet))];

samples/ControlCatalog/Pages/NumericUpDownPage.xaml

@@ -2,7 +2,8 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:sys="clr-namespace:System;assembly=netstandard"
              x:Class="ControlCatalog.Pages.NumericUpDownPage">
-  <StackPanel Orientation="Vertical" Spacing="4">
+  <StackPanel Orientation="Vertical" Spacing="4"
+              MaxWidth="800">
     <TextBlock Margin="2" Classes="h1">Numeric up-down control</TextBlock>
     <TextBlock Margin="2" Classes="h2" TextWrapping="Wrap">Numeric up-down control provides a TextBox with button spinners that allow incrementing and decrementing numeric values by using the spinner buttons, keyboard up/down arrows, or mouse wheel.</TextBlock>
 
@@ -68,24 +69,36 @@
         <NumericUpDown Grid.Row="3" Grid.Column="1" Value="{Binding #upDown.Value}" VerticalAlignment="Center"
                        Margin="2" HorizontalAlignment="Center"/>
 
+
       </Grid>
     </Grid>
 
-    <StackPanel Margin="2,10,2,2" Orientation="Horizontal" Spacing="10">
-      <TextBlock FontSize="14" FontWeight="Bold" VerticalAlignment="Center">Usage of NumericUpDown:</TextBlock>
-      <NumericUpDown Name="upDown" Minimum="0" Maximum="10" Increment="0.5"
-                     CultureInfo="en-US" VerticalAlignment="Center"
-                     Watermark="Enter text" FormatString="{Binding SelectedFormat.Value}"/>
+    <WrapPanel Margin="2,10,2,2">
+      <StackPanel Orientation="Vertical" Margin="10">
+        <Label Target="upDown" FontSize="14" FontWeight="Bold" VerticalAlignment="Center">Usage of decimal NumericUpDown:</Label>
+        <NumericUpDown Name="upDown" Minimum="0" Maximum="10" Increment="0.5"
+                       CultureInfo="en-US" VerticalAlignment="Center" Value="{Binding DecimalValue}"
+                       Watermark="Enter text" FormatString="{Binding SelectedFormat.Value}"/>
+      </StackPanel>
+
+      <StackPanel Orientation="Vertical" Margin="10">
+        <Label Target="DoubleUpDown" FontSize="14" FontWeight="Bold" VerticalAlignment="Center">Usage of double NumericUpDown:</Label>
+        <NumericUpDown Name="DoubleUpDown" Minimum="0" Maximum="10" Increment="0.5"
+                       CultureInfo="en-US" VerticalAlignment="Center" Value="{Binding DoubleValue}"
+                       Watermark="Enter text" FormatString="{Binding SelectedFormat.Value}"/>
+      </StackPanel>
       
-      <TextBlock FontSize="14" FontWeight="Bold" VerticalAlignment="Center">NumericUpDown with Validation Errors:</TextBlock>
-      <NumericUpDown Minimum="0" Maximum="10" Increment="0.5"
-                     CultureInfo="en-US" VerticalAlignment="Center"
-                     Watermark="Enter text" FormatString="{Binding SelectedFormat.Value}">
-        <DataValidationErrors.Error>
-          <sys:Exception /> 
-        </DataValidationErrors.Error>
-      </NumericUpDown>
-    </StackPanel>
+      <StackPanel Orientation="Vertical" Margin="10">
+        <Label Target="ValidationUpDown" FontSize="14" FontWeight="Bold" VerticalAlignment="Center">NumericUpDown with Validation Errors:</Label>
+        <NumericUpDown x:Name="ValidationUpDown" Minimum="0" Maximum="10" Increment="0.5"
+                       CultureInfo="en-US" VerticalAlignment="Center"
+                       Watermark="Enter text" FormatString="{Binding SelectedFormat.Value}">
+          <DataValidationErrors.Error>
+            <sys:Exception /> 
+          </DataValidationErrors.Error>
+        </NumericUpDown>
+      </StackPanel>
+    </WrapPanel>
 
   </StackPanel>
 </UserControl>

samples/ControlCatalog/Pages/NumericUpDownPage.xaml.cs

@@ -32,11 +32,26 @@ namespace ControlCatalog.Pages
         private FormatObject _selectedFormat;
         private IList<Location> _spinnerLocations;
 
+        private double _doubleValue;
+        private decimal _decimalValue;
+
         public NumbersPageViewModel()
         {
             SelectedFormat = Formats.FirstOrDefault();
         }
 
+        public double DoubleValue
+        {
+            get { return _doubleValue; }
+            set { this.RaiseAndSetIfChanged(ref _doubleValue, value); }
+        }
+
+        public decimal DecimalValue
+        {
+            get { return _decimalValue; }
+            set { this.RaiseAndSetIfChanged(ref _decimalValue, value); }
+        }
+
         public IList<FormatObject> Formats
         {
             get

samples/Sandbox/Program.cs

@@ -4,12 +4,12 @@ namespace Sandbox
 {
     public class Program
     {
-        static void Main(string[] args)
-        {
+        static void Main(string[] args) => BuildAvaloniaApp()
+            .StartWithClassicDesktopLifetime(args);
+
+        public static AppBuilder BuildAvaloniaApp() =>
             AppBuilder.Configure<App>()
                 .UsePlatformDetect()
-                .LogToTrace()
-                .StartWithClassicDesktopLifetime(args);
-        }
+                .LogToTrace();
     }
 }

src/Android/Avalonia.Android/Platform/SkiaPlatform/TopLevelImpl.cs

@@ -55,6 +55,8 @@ namespace Avalonia.Android.Platform.SkiaPlatform
 
         public virtual Size ClientSize => Size.ToSize(RenderScaling);
 
+        public Size? FrameSize => null;
+
         public IMouseDevice MouseDevice { get; } = new MouseDevice();
 
         public Action Closed { get; set; }

src/Avalonia.Animation/Animation.cs

@@ -3,10 +3,11 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Reactive.Disposables;
 using System.Reactive.Linq;
+using System.Threading;
 using System.Threading.Tasks;
+
 using Avalonia.Animation.Animators;
 using Avalonia.Animation.Easings;
-using Avalonia.Collections;
 using Avalonia.Data;
 using Avalonia.Metadata;
 
@@ -319,7 +320,7 @@ namespace Avalonia.Animation
             return (newAnimatorInstances, subscriptions);
         }
 
-        /// <inheritdocs/>
+        /// <inheritdoc/>
         public IDisposable Apply(Animatable control, IClock clock, IObservable<bool> match, Action onComplete)
         {
             var (animators, subscriptions) = InterpretKeyframes(control);
@@ -344,25 +345,40 @@ namespace Avalonia.Animation
 
                 if (onComplete != null)
                 {
-                    Task.WhenAll(completionTasks).ContinueWith(_ => onComplete());
+                    Task.WhenAll(completionTasks).ContinueWith(
+                        (_, state) => ((Action)state).Invoke(),
+                        onComplete);
                 }
             }
             return new CompositeDisposable(subscriptions);
         }
 
-        /// <inheritdocs/>
-        public Task RunAsync(Animatable control, IClock clock = null)
+        /// <inheritdoc/>
+        public Task RunAsync(Animatable control, IClock clock = null, CancellationToken cancellationToken = default)
         {
+            if (cancellationToken.IsCancellationRequested)
+            {
+                return Task.CompletedTask;
+            }
+
             var run = new TaskCompletionSource<object>();
 
             if (this.IterationCount == IterationCount.Infinite)
                 run.SetException(new InvalidOperationException("Looping animations must not use the Run method."));
 
-            IDisposable subscriptions = null;
+            IDisposable subscriptions = null, cancellation = null;
             subscriptions = this.Apply(control, clock, Observable.Return(true), () =>
             {
-                run.SetResult(null);
+                run.TrySetResult(null);
+                subscriptions?.Dispose();
+                cancellation?.Dispose();
+            });
+
+            cancellation = cancellationToken.Register(() =>
+            {
+                run.TrySetResult(null);
                 subscriptions?.Dispose();
+                cancellation?.Dispose();
             });
 
             return run.Task;

src/Avalonia.Animation/ApiCompatBaseline.txt

@@ -0,0 +1,6 @@
+Compat issues with assembly Avalonia.Animation:
+MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.Animation.RunAsync(Avalonia.Animation.Animatable, Avalonia.Animation.IClock)' does not exist in the implementation but it does exist in the contract.
+InterfacesShouldHaveSameMembers : Interface member 'public System.Threading.Tasks.Task Avalonia.Animation.IAnimation.RunAsync(Avalonia.Animation.Animatable, Avalonia.Animation.IClock)' is present in the contract but not in the implementation.
+MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.IAnimation.RunAsync(Avalonia.Animation.Animatable, Avalonia.Animation.IClock)' does not exist in the implementation but it does exist in the contract.
+InterfacesShouldHaveSameMembers : Interface member 'public System.Threading.Tasks.Task Avalonia.Animation.IAnimation.RunAsync(Avalonia.Animation.Animatable, Avalonia.Animation.IClock, System.Threading.CancellationToken)' is present in the implementation but not in the contract.
+Total Issues: 4

src/Avalonia.Animation/IAnimation.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Avalonia.Animation
@@ -16,6 +17,6 @@ namespace Avalonia.Animation
         /// <summary>
         /// Run the animation on the specified control.
         /// </summary>
-        Task RunAsync(Animatable control, IClock clock);
+        Task RunAsync(Animatable control, IClock clock, CancellationToken cancellationToken = default);
     }
 }

src/Avalonia.Base/Collections/AvaloniaList.cs

@@ -454,6 +454,28 @@ namespace Avalonia.Collections
             }
         }
 
+        /// <summary>
+        /// Ensures that the capacity of the list is at least <see cref="capacity"/>.
+        /// </summary>
+        /// <param name="capacity">The capacity.</param>
+        public void EnsureCapacity(int capacity)
+        {
+            // Adapted from List<T> implementation.
+            var currentCapacity = _inner.Capacity;
+
+            if (currentCapacity < capacity)
+            {
+                var newCapacity = currentCapacity == 0 ? 4 : currentCapacity * 2;
+
+                if (newCapacity < capacity)
+                {
+                    newCapacity = capacity;
+                }
+
+                _inner.Capacity = newCapacity;
+            }
+        }
+
         /// <summary>
         /// Removes an item from the collection.
         /// </summary>
@@ -633,24 +655,6 @@ namespace Avalonia.Collections
         /// <inheritdoc/>
         Delegate[] INotifyCollectionChangedDebug.GetCollectionChangedSubscribers() => _collectionChanged?.GetInvocationList();
 
-        private void EnsureCapacity(int capacity)
-        {
-            // Adapted from List<T> implementation.
-            var currentCapacity = _inner.Capacity;
-
-            if (currentCapacity < capacity)
-            {
-                var newCapacity = currentCapacity == 0 ? 4 : currentCapacity * 2;
-
-                if (newCapacity < capacity)
-                {
-                    newCapacity = capacity;
-                }
-
-                _inner.Capacity = newCapacity;
-            }
-        }
-
         /// <summary>
         /// Raises the <see cref="CollectionChanged"/> event with an add action.
         /// </summary>

src/Avalonia.Base/Utilities/MathUtilities.cs

@@ -224,6 +224,34 @@ namespace Avalonia.Utilities
             }
         }
 
+        /// <summary>
+        /// Clamps a value between a minimum and maximum value.
+        /// </summary>
+        /// <param name="val">The value.</param>
+        /// <param name="min">The minimum value.</param>
+        /// <param name="max">The maximum value.</param>
+        /// <returns>The clamped value.</returns>
+        public static decimal Clamp(decimal val, decimal min, decimal max)
+        {
+            if (min > max)
+            {
+                ThrowCannotBeGreaterThanException(min, max);
+            }
+
+            if (val < min)
+            {
+                return min;
+            }
+            else if (val > max)
+            {
+                return max;
+            }
+            else
+            {
+                return val;
+            }
+        }
+
         /// <summary>
         /// Clamps a value between a minimum and maximum value.
         /// </summary>
@@ -281,8 +309,8 @@ namespace Avalonia.Utilities
         {
             return angle * 2 * Math.PI;
         }
-        
-        private static void ThrowCannotBeGreaterThanException(double min, double max)
+
+        private static void ThrowCannotBeGreaterThanException<T>(T min, T max)
         {
             throw new ArgumentException($"{min} cannot be greater than {max}.");
         }

src/Avalonia.Controls.DataGrid/DataGrid.cs

@@ -75,7 +75,6 @@ namespace Avalonia.Controls
         private const double DATAGRID_defaultMinColumnWidth = 20;
         private const double DATAGRID_defaultMaxColumnWidth = double.PositiveInfinity;
 
-        private List<Exception> _validationErrors;
         private List<Exception> _bindingValidationErrors;
         private IDisposable _validationSubscription;
 
@@ -102,7 +101,6 @@ namespace Avalonia.Controls
         private bool _areHandlersSuspended;
         private bool _autoSizingColumns;
         private IndexToValueTable<bool> _collapsedSlotsTable;
-        private DataGridCellCoordinates _currentCellCoordinates;
         private Control _clickedElement;
 
         // used to store the current column during a Reset
@@ -141,7 +139,6 @@ namespace Avalonia.Controls
         private DataGridSelectedItemsCollection _selectedItems;
         private bool _temporarilyResetCurrentCell;
         private object _uneditedValue; // Represents the original current cell value at the time it enters editing mode.
-        private ICellEditBinding _currentCellEditBinding;
 
         // An approximation of the sum of the heights in pixels of the scrolling rows preceding
         // the first displayed scrolling row.  Since the scrolled off rows are discarded, the grid

src/Avalonia.Controls.DataGrid/DataGridRows.cs

@@ -425,7 +425,7 @@ namespace Avalonia.Controls
                 UpdateDisplayedRows(DisplayData.FirstScrollingSlot, CellsHeight);
             }
 
-            if (DisplayData.FirstScrollingSlot < slot && DisplayData.LastScrollingSlot > slot)
+            if (DisplayData.FirstScrollingSlot < slot && (DisplayData.LastScrollingSlot > slot || DisplayData.LastScrollingSlot == -1))
             {
                 // The row is already displayed in its entirety
                 return true;

src/Avalonia.Controls.DataGrid/Utils/ReflectionHelper.cs

@@ -340,10 +340,30 @@ namespace Avalonia.Controls.Utils
         internal static PropertyInfo GetPropertyOrIndexer(this Type type, string propertyPath, out object[] index)
         {
             index = null;
+            // Return the default value of GetProperty if the first character is not an indexer token.
             if (string.IsNullOrEmpty(propertyPath) || propertyPath[0] != LeftIndexerToken)
             {
-                // Return the default value of GetProperty if the first character is not an indexer token.
-                return type.GetProperty(propertyPath);
+                var property = type.GetProperty(propertyPath);
+                if (property != null)
+                {
+                    return property;
+                }
+
+                // GetProperty does not return inherited interface properties,
+                // so we need to enumerate them manually.
+                if (type.IsInterface)
+                {
+                    foreach (var typeInterface in type.GetInterfaces())
+                    {
+                        property = type.GetProperty(propertyPath);
+                        if (property != null)
+                        {
+                            return property;
+                        }
+                    }
+                }
+
+                return null;
             }
 
             if (propertyPath.Length < 2 || propertyPath[propertyPath.Length - 1] != RightIndexerToken)

src/Avalonia.Controls/ApiCompatBaseline.txt

@@ -4,12 +4,38 @@ InterfacesShouldHaveSameMembers : Interface member 'public System.Boolean Avalon
 InterfacesShouldHaveSameMembers : Interface member 'public void Avalonia.Controls.IMenuItem.StaysOpenOnClick.set(System.Boolean)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public void Avalonia.Controls.INativeMenuExporterEventsImplBridge.RaiseClosed()' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public void Avalonia.Controls.INativeMenuExporterEventsImplBridge.RaiseOpening()' is present in the implementation but not in the contract.
+MembersMustExist : Member 'public Avalonia.DirectProperty<Avalonia.Controls.NumericUpDown, System.Double> Avalonia.DirectProperty<Avalonia.Controls.NumericUpDown, System.Double> Avalonia.Controls.NumericUpDown.ValueProperty' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public Avalonia.StyledProperty<System.Double> Avalonia.StyledProperty<System.Double> Avalonia.Controls.NumericUpDown.IncrementProperty' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public Avalonia.StyledProperty<System.Double> Avalonia.StyledProperty<System.Double> Avalonia.Controls.NumericUpDown.MaximumProperty' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public Avalonia.StyledProperty<System.Double> Avalonia.StyledProperty<System.Double> Avalonia.Controls.NumericUpDown.MinimumProperty' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public System.Double Avalonia.Controls.NumericUpDown.Increment.get()' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public void Avalonia.Controls.NumericUpDown.Increment.set(System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public System.Double Avalonia.Controls.NumericUpDown.Maximum.get()' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public void Avalonia.Controls.NumericUpDown.Maximum.set(System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public System.Double Avalonia.Controls.NumericUpDown.Minimum.get()' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public void Avalonia.Controls.NumericUpDown.Minimum.set(System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'protected System.Double Avalonia.Controls.NumericUpDown.OnCoerceIncrement(System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'protected System.Double Avalonia.Controls.NumericUpDown.OnCoerceMaximum(System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'protected System.Double Avalonia.Controls.NumericUpDown.OnCoerceMinimum(System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'protected System.Double Avalonia.Controls.NumericUpDown.OnCoerceValue(System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'protected void Avalonia.Controls.NumericUpDown.OnIncrementChanged(System.Double, System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'protected void Avalonia.Controls.NumericUpDown.OnMaximumChanged(System.Double, System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'protected void Avalonia.Controls.NumericUpDown.OnMinimumChanged(System.Double, System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'protected void Avalonia.Controls.NumericUpDown.OnValueChanged(System.Double, System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'protected void Avalonia.Controls.NumericUpDown.RaiseValueChangedEvent(System.Double, System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public System.Double Avalonia.Controls.NumericUpDown.Value.get()' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public void Avalonia.Controls.NumericUpDown.Value.set(System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public void Avalonia.Controls.NumericUpDownValueChangedEventArgs..ctor(Avalonia.Interactivity.RoutedEvent, System.Double, System.Double)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public System.Double Avalonia.Controls.NumericUpDownValueChangedEventArgs.NewValue.get()' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public System.Double Avalonia.Controls.NumericUpDownValueChangedEventArgs.OldValue.get()' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'public Avalonia.StyledProperty<System.Boolean> Avalonia.StyledProperty<System.Boolean> Avalonia.Controls.ScrollViewer.AllowAutoHideProperty' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'public Avalonia.AvaloniaProperty<Avalonia.Media.Stretch> Avalonia.AvaloniaProperty<Avalonia.Media.Stretch> Avalonia.Controls.Viewbox.StretchProperty' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'public void Avalonia.Controls.Embedding.Offscreen.OffscreenTopLevelImplBase.SetCursor(Avalonia.Platform.IPlatformHandle)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'public Avalonia.AvaloniaProperty Avalonia.AvaloniaProperty Avalonia.Controls.Notifications.NotificationCard.CloseOnClickProperty' does not exist in the implementation but it does exist in the contract.
 EnumValuesMustMatch : Enum value 'Avalonia.Platform.ExtendClientAreaChromeHints Avalonia.Platform.ExtendClientAreaChromeHints.Default' is (System.Int32)2 in the implementation but (System.Int32)1 in the contract.
+InterfacesShouldHaveSameMembers : Interface member 'public System.Nullable<Avalonia.Size> Avalonia.Platform.ITopLevelImpl.FrameSize' is present in the implementation but not in the contract.
+InterfacesShouldHaveSameMembers : Interface member 'public System.Nullable<Avalonia.Size> Avalonia.Platform.ITopLevelImpl.FrameSize.get()' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public void Avalonia.Platform.ITopLevelImpl.SetCursor(Avalonia.Platform.ICursorImpl)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public void Avalonia.Platform.ITopLevelImpl.SetCursor(Avalonia.Platform.IPlatformHandle)' is present in the contract but not in the implementation.
 MembersMustExist : Member 'public void Avalonia.Platform.ITopLevelImpl.SetCursor(Avalonia.Platform.IPlatformHandle)' does not exist in the implementation but it does exist in the contract.
-Total Issues: 13
+Total Issues: 39

src/Avalonia.Controls/Application.cs

@@ -13,6 +13,7 @@ using Avalonia.Platform;
 using Avalonia.Rendering;
 using Avalonia.Styling;
 using Avalonia.Threading;
+#nullable enable
 
 namespace Avalonia
 {
@@ -35,27 +36,27 @@ namespace Avalonia
         /// <summary>
         /// The application-global data templates.
         /// </summary>
-        private DataTemplates _dataTemplates;
+        private DataTemplates? _dataTemplates;
 
         private readonly Lazy<IClipboard> _clipboard =
             new Lazy<IClipboard>(() => (IClipboard)AvaloniaLocator.Current.GetService(typeof(IClipboard)));
         private readonly Styler _styler = new Styler();
-        private Styles _styles;
-        private IResourceDictionary _resources;
+        private Styles? _styles;
+        private IResourceDictionary? _resources;
         private bool _notifyingResourcesChanged;
-        private Action<IReadOnlyList<IStyle>> _stylesAdded;
-        private Action<IReadOnlyList<IStyle>> _stylesRemoved;
+        private Action<IReadOnlyList<IStyle>>? _stylesAdded;
+        private Action<IReadOnlyList<IStyle>>? _stylesRemoved;
 
         /// <summary>
         /// Defines the <see cref="DataContext"/> property.
         /// </summary>
-        public static readonly StyledProperty<object> DataContextProperty =
+        public static readonly StyledProperty<object?> DataContextProperty =
             StyledElement.DataContextProperty.AddOwner<Application>();
 
         /// <inheritdoc/>
-        public event EventHandler<ResourcesChangedEventArgs> ResourcesChanged;
+        public event EventHandler<ResourcesChangedEventArgs>? ResourcesChanged;
 
-        public event EventHandler<UrlOpenedEventArgs> UrlsOpened; 
+        public event EventHandler<UrlOpenedEventArgs>? UrlsOpened; 
 
         /// <summary>
         /// Creates an instance of the <see cref="Application"/> class.
@@ -72,7 +73,7 @@ namespace Avalonia
         /// The data context property specifies the default object that will
         /// be used for data binding.
         /// </remarks>
-        public object DataContext
+        public object? DataContext
         {
             get { return GetValue(DataContextProperty); }
             set { SetValue(DataContextProperty, value); }
@@ -162,7 +163,7 @@ namespace Avalonia
         /// <summary>
         /// Gets the styling parent of the application, which is null.
         /// </summary>
-        IStyleHost IStyleHost.StylingParent => null;
+        IStyleHost? IStyleHost.StylingParent => null;
 
         /// <inheritdoc/>
         bool IStyleHost.IsStylesInitialized => _styles != null;
@@ -194,7 +195,7 @@ namespace Avalonia
         public virtual void Initialize() { }
 
         /// <inheritdoc/>
-        bool IResourceNode.TryGetResource(object key, out object value)
+        bool IResourceNode.TryGetResource(object key, out object? value)
         {
             value = null;
             return (_resources?.TryGetResource(key, out value) ?? false) ||
@@ -279,17 +280,17 @@ namespace Avalonia
             NotifyResourcesChanged(e);
         }
 
-        private string _name;
+        private string? _name;
         /// <summary>
         /// Defines Name property
         /// </summary>
-        public static readonly DirectProperty<Application, string> NameProperty =
-            AvaloniaProperty.RegisterDirect<Application, string>("Name", o => o.Name, (o, v) => o.Name = v);
+        public static readonly DirectProperty<Application, string?> NameProperty =
+            AvaloniaProperty.RegisterDirect<Application, string?>("Name", o => o.Name, (o, v) => o.Name = v);
 
         /// <summary>
         /// Application name to be used for various platform-specific purposes
         /// </summary>
-        public string Name
+        public string? Name
         {
             get => _name;
             set => SetAndRaise(NameProperty, ref _name, value);

src/Avalonia.Controls/ComboBox.cs

@@ -77,14 +77,6 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<VerticalAlignment> VerticalContentAlignmentProperty =
             ContentControl.VerticalContentAlignmentProperty.AddOwner<ComboBox>();
 
-        /// <summary>
-        /// Defines the <see cref="IsTextSearchEnabled"/> property.
-        /// </summary>
-        public static readonly StyledProperty<bool> IsTextSearchEnabledProperty =
-            AvaloniaProperty.Register<ComboBox, bool>(nameof(IsTextSearchEnabled), true);
-
-        private string _textSearchTerm = string.Empty;
-        private DispatcherTimer _textSearchTimer;
         private bool _isDropDownOpen;
         private Popup _popup;
         private object _selectionBoxItem;
@@ -173,15 +165,6 @@ namespace Avalonia.Controls
             set { SetValue(VerticalContentAlignmentProperty, value); }
         }
 
-        /// <summary>
-        /// Gets or sets a value that specifies whether a user can jump to a value by typing.
-        /// </summary>
-        public bool IsTextSearchEnabled
-        {
-            get { return GetValue(IsTextSearchEnabledProperty); }
-            set { SetValue(IsTextSearchEnabledProperty, value); }
-        }
-
         /// <inheritdoc/>
         protected override IItemContainerGenerator CreateItemContainerGenerator()
         {
@@ -205,7 +188,7 @@ namespace Avalonia.Controls
             if (e.Handled)
                 return;
 
-            if (e.Key == Key.F4 ||
+            if ((e.Key == Key.F4 && e.KeyModifiers.HasAllFlags(KeyModifiers.Alt) == false) ||
                 ((e.Key == Key.Down || e.Key == Key.Up) && e.KeyModifiers.HasAllFlags(KeyModifiers.Alt)))
             {
                 IsDropDownOpen = !IsDropDownOpen;
@@ -247,32 +230,6 @@ namespace Avalonia.Controls
             }
         }
 
-        /// <inheritdoc />
-        protected override void OnTextInput(TextInputEventArgs e)
-        {
-            if (!IsTextSearchEnabled || e.Handled)
-                return;
-
-            StopTextSearchTimer();
-
-            _textSearchTerm += e.Text;
-
-            bool match(ItemContainerInfo info) => 
-                info.ContainerControl is IContentControl control &&
-                control.Content?.ToString()?.StartsWith(_textSearchTerm, StringComparison.OrdinalIgnoreCase) == true;
-
-            var info = ItemContainerGenerator.Containers.FirstOrDefault(match);
-
-            if (info != null)
-            {
-                SelectedIndex = info.Index;
-            }
-
-            StartTextSearchTimer();
-
-            e.Handled = true;
-        }
-
         /// <inheritdoc/>
         protected override void OnPointerWheelChanged(PointerWheelEventArgs e)
         {
@@ -470,31 +427,5 @@ namespace Avalonia.Controls
 
             SelectedIndex = prev;
         }
-
-        private void StartTextSearchTimer()
-        {
-            _textSearchTimer = new DispatcherTimer { Interval = TimeSpan.FromSeconds(1) };
-            _textSearchTimer.Tick += TextSearchTimer_Tick;
-            _textSearchTimer.Start();
-        }
-
-        private void StopTextSearchTimer()
-        {
-            if (_textSearchTimer == null)
-            {
-                return;
-            }
-
-            _textSearchTimer.Stop();
-            _textSearchTimer.Tick -= TextSearchTimer_Tick;
-
-            _textSearchTimer = null;
-        }
-
-        private void TextSearchTimer_Tick(object sender, EventArgs e)
-        {
-            _textSearchTerm = string.Empty;
-            StopTextSearchTimer();
-        }
     }
 }

src/Avalonia.Controls/Embedding/Offscreen/OffscreenTopLevelImpl.cs

@@ -35,6 +35,8 @@ namespace Avalonia.Controls.Embedding.Offscreen
             }
         }
 
+        public Size? FrameSize => null;
+
         public double RenderScaling
         {
             get { return _scaling; }

src/Avalonia.Controls/Expander.cs

@@ -1,7 +1,11 @@
+using System.Threading;
+
 using Avalonia.Animation;
 using Avalonia.Controls.Metadata;
 using Avalonia.Controls.Primitives;
 
+#nullable enable
+
 namespace Avalonia.Controls
 {
     /// <summary>
@@ -36,8 +40,8 @@ namespace Avalonia.Controls
     [PseudoClasses(":expanded", ":up", ":down", ":left", ":right")]
     public class Expander : HeaderedContentControl
     {
-        public static readonly StyledProperty<IPageTransition> ContentTransitionProperty =
-            AvaloniaProperty.Register<Expander, IPageTransition>(nameof(ContentTransition));
+        public static readonly StyledProperty<IPageTransition?> ContentTransitionProperty =
+            AvaloniaProperty.Register<Expander, IPageTransition?>(nameof(ContentTransition));
 
         public static readonly StyledProperty<ExpandDirection> ExpandDirectionProperty =
             AvaloniaProperty.Register<Expander, ExpandDirection>(nameof(ExpandDirection), ExpandDirection.Down);
@@ -50,6 +54,7 @@ namespace Avalonia.Controls
                 defaultBindingMode: Data.BindingMode.TwoWay);
 
         private bool _isExpanded;
+        private CancellationTokenSource? _lastTransitionCts;
 
         static Expander()
         {
@@ -61,7 +66,7 @@ namespace Avalonia.Controls
             UpdatePseudoClasses(ExpandDirection);
         }
 
-        public IPageTransition ContentTransition
+        public IPageTransition? ContentTransition
         {
             get => GetValue(ContentTransitionProperty);
             set => SetValue(ContentTransitionProperty, value);
@@ -83,19 +88,23 @@ namespace Avalonia.Controls
             }
         }
 
-        protected virtual void OnIsExpandedChanged(AvaloniaPropertyChangedEventArgs e)
+        protected virtual async void OnIsExpandedChanged(AvaloniaPropertyChangedEventArgs e)
         {
             if (Content != null && ContentTransition != null && Presenter is Visual visualContent)
             {
                 bool forward = ExpandDirection == ExpandDirection.Left ||
                                 ExpandDirection == ExpandDirection.Up;
+
+                _lastTransitionCts?.Cancel();
+                _lastTransitionCts = new CancellationTokenSource();
+
                 if (IsExpanded)
                 {
-                    ContentTransition.Start(null, visualContent, forward);
+                    await ContentTransition.Start(null, visualContent, forward, _lastTransitionCts.Token);
                 }
                 else
                 {
-                    ContentTransition.Start(visualContent, null, !forward);
+                    await ContentTransition.Start(visualContent, null, forward, _lastTransitionCts.Token);
                 }
             }
         }

src/Avalonia.Controls/Grid.cs

@@ -978,6 +978,7 @@ namespace Avalonia.Controls
         /// width is not registered in columns.</param>
         /// <param name="forceInfinityV">Passed through to MeasureCell.
         /// When "true" cells' desired height is not registered in rows.</param>
+        /// <param name="hasDesiredSizeUChanged">return true when desired size has changed</param>
         private void MeasureCellsGroup(
             int cellsHead,
             Size referenceSize,

src/Avalonia.Controls/GridLength.cs

@@ -77,6 +77,12 @@ namespace Avalonia.Controls
         /// </summary>
         public static GridLength Auto => new GridLength(0, GridUnitType.Auto);
 
+        /// <summary>
+        /// Gets an instance of <see cref="GridLength"/> that indicates that a row or column should
+        /// fill its content.
+        /// </summary>
+        public static GridLength Star => new GridLength(1, GridUnitType.Star);
+
         /// <summary>
         /// Gets the unit of the <see cref="GridLength"/>.
         /// </summary>

src/Avalonia.Controls/ItemsControl.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Collections.Specialized;
+using System.Linq;
 using Avalonia.Collections;
 using Avalonia.Controls.Generators;
 using Avalonia.Controls.Metadata;

src/Avalonia.Controls/Menu.cs

@@ -17,7 +17,6 @@ namespace Avalonia.Controls
         private static readonly ITemplate<IPanel> DefaultPanel =
             new FuncTemplate<IPanel>(() => new StackPanel { Orientation = Orientation.Horizontal });
 
-        private LightDismissOverlayLayer? _overlay;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="Menu"/> class.

src/Avalonia.Controls/MenuItem.cs

@@ -36,7 +36,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="HotKey"/> property.
         /// </summary>
-        public static readonly StyledProperty<KeyGesture> HotKeyProperty =
+        public static readonly StyledProperty<KeyGesture?> HotKeyProperty =
             HotKeyManager.HotKeyProperty.AddOwner<MenuItem>();
 
         /// <summary>
@@ -108,7 +108,7 @@ namespace Avalonia.Controls
         private ICommand? _command;
         private bool _commandCanExecute = true;
         private Popup? _popup;
-        private KeyGesture _hotkey;
+        private KeyGesture? _hotkey;
         private bool _isEmbeddedInMenu;
 
         /// <summary>
@@ -214,7 +214,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets or sets an <see cref="KeyGesture"/> associated with this control
         /// </summary>
-        public KeyGesture HotKey
+        public KeyGesture? HotKey
         {
             get { return GetValue(HotKeyProperty); }
             set { SetValue(HotKeyProperty, value); }

src/Avalonia.Controls/NumericUpDown/NumericUpDown.cs

@@ -45,10 +45,18 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="CultureInfo"/> property.
         /// </summary>
+        [Obsolete]
         public static readonly DirectProperty<NumericUpDown, CultureInfo> CultureInfoProperty =
             AvaloniaProperty.RegisterDirect<NumericUpDown, CultureInfo>(nameof(CultureInfo), o => o.CultureInfo,
                 (o, v) => o.CultureInfo = v, CultureInfo.CurrentCulture);
 
+        /// <summary>
+        /// Defines the <see cref="NumberFormat"/> property.
+        /// </summary>
+        public static readonly DirectProperty<NumericUpDown, NumberFormatInfo> NumberFormatProperty =
+            AvaloniaProperty.RegisterDirect<NumericUpDown, NumberFormatInfo>(nameof(NumberFormat), o => o.NumberFormat,
+                (o, v) => o.NumberFormat = v, NumberFormatInfo.CurrentInfo);
+
         /// <summary>
         /// Defines the <see cref="FormatString"/> property.
         /// </summary>
@@ -58,8 +66,8 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="Increment"/> property.
         /// </summary>
-        public static readonly StyledProperty<double> IncrementProperty =
-            AvaloniaProperty.Register<NumericUpDown, double>(nameof(Increment), 1.0d, coerce: OnCoerceIncrement);
+        public static readonly StyledProperty<decimal> IncrementProperty =
+            AvaloniaProperty.Register<NumericUpDown, decimal>(nameof(Increment), 1.0m, coerce: OnCoerceIncrement);
 
         /// <summary>
         /// Defines the <see cref="IsReadOnly"/> property.
@@ -70,14 +78,14 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="Maximum"/> property.
         /// </summary>
-        public static readonly StyledProperty<double> MaximumProperty =
-            AvaloniaProperty.Register<NumericUpDown, double>(nameof(Maximum), double.MaxValue, coerce: OnCoerceMaximum);
+        public static readonly StyledProperty<decimal> MaximumProperty =
+            AvaloniaProperty.Register<NumericUpDown, decimal>(nameof(Maximum), decimal.MaxValue, coerce: OnCoerceMaximum);
 
         /// <summary>
         /// Defines the <see cref="Minimum"/> property.
         /// </summary>
-        public static readonly StyledProperty<double> MinimumProperty =
-            AvaloniaProperty.Register<NumericUpDown, double>(nameof(Minimum), double.MinValue, coerce: OnCoerceMinimum);
+        public static readonly StyledProperty<decimal> MinimumProperty =
+            AvaloniaProperty.Register<NumericUpDown, decimal>(nameof(Minimum), decimal.MinValue, coerce: OnCoerceMinimum);
 
         /// <summary>
         /// Defines the <see cref="ParsingNumberStyle"/> property.
@@ -96,8 +104,8 @@ namespace Avalonia.Controls
         /// <summary>
         /// Defines the <see cref="Value"/> property.
         /// </summary>
-        public static readonly DirectProperty<NumericUpDown, double> ValueProperty =
-            AvaloniaProperty.RegisterDirect<NumericUpDown, double>(nameof(Value), updown => updown.Value,
+        public static readonly DirectProperty<NumericUpDown, decimal> ValueProperty =
+            AvaloniaProperty.RegisterDirect<NumericUpDown, decimal>(nameof(Value), updown => updown.Value,
                 (updown, v) => updown.Value = v, defaultBindingMode: BindingMode.TwoWay, enableDataValidation: true);
 
         /// <summary>
@@ -106,7 +114,6 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<string> WatermarkProperty =
             AvaloniaProperty.Register<NumericUpDown, string>(nameof(Watermark));
 
-
         /// <summary>
         /// Defines the <see cref="HorizontalContentAlignment"/> property.
         /// </summary>
@@ -121,7 +128,7 @@ namespace Avalonia.Controls
 
         private IDisposable _textBoxTextChangedSubscription;
 
-        private double _value;
+        private decimal _value;
         private string _text;
         private bool _internalValueSet;
         private bool _clipValueToMinMax;
@@ -129,7 +136,8 @@ namespace Avalonia.Controls
         private bool _isTextChangedFromUI;
         private CultureInfo _cultureInfo;
         private NumberStyles _parsingNumberStyle = NumberStyles.Any;
-        
+        private NumberFormatInfo _numberFormat;
+
         /// <summary>
         /// Gets the Spinner template part.
         /// </summary>
@@ -179,10 +187,25 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets or sets the current CultureInfo.
         /// </summary>
+        [Obsolete("CultureInfo is obsolete, please use NumberFormat instead.")]
         public CultureInfo CultureInfo
         {
             get { return _cultureInfo; }
-            set { SetAndRaise(CultureInfoProperty, ref _cultureInfo, value); }
+            set
+            {
+                SetAndRaise(CultureInfoProperty, ref _cultureInfo, value);
+                //Set and Raise the NumberFormatProperty when CultureInfo is changed.
+                SetAndRaise(NumberFormatProperty, ref _numberFormat, value?.NumberFormat);
+            }
+        }
+
+        /// <summary>
+        /// Gets or sets the current NumberFormatInfo
+        /// </summary>
+        public NumberFormatInfo NumberFormat
+        {
+            get { return _numberFormat; }
+            set { SetAndRaise(NumberFormatProperty, ref _numberFormat, value); }
         }
 
         /// <summary>
@@ -197,7 +220,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets or sets the amount in which to increment the <see cref="Value"/>.
         /// </summary>
-        public double Increment
+        public decimal Increment
         {
             get { return GetValue(IncrementProperty); }
             set { SetValue(IncrementProperty, value); }
@@ -215,7 +238,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets or sets the maximum allowed value.
         /// </summary>
-        public double Maximum
+        public decimal Maximum
         {
             get { return GetValue(MaximumProperty); }
             set { SetValue(MaximumProperty, value); }
@@ -224,7 +247,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets or sets the minimum allowed value.
         /// </summary>
-        public double Minimum
+        public decimal Minimum
         {
             get { return GetValue(MinimumProperty); }
             set { SetValue(MinimumProperty, value); }
@@ -251,7 +274,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets or sets the value.
         /// </summary>
-        public double Value
+        public decimal Value
         {
             get { return _value; }
             set
@@ -270,7 +293,6 @@ namespace Avalonia.Controls
             set { SetValue(WatermarkProperty, value); }
         }
 
-
         /// <summary>
         /// Gets or sets the horizontal alignment of the content within the control.
         /// </summary>
@@ -311,6 +333,7 @@ namespace Avalonia.Controls
         static NumericUpDown()
         {
             CultureInfoProperty.Changed.Subscribe(OnCultureInfoChanged);
+            NumberFormatProperty.Changed.Subscribe(OnNumberFormatChanged);
             FormatStringProperty.Changed.Subscribe(FormatStringChanged);
             IncrementProperty.Changed.Subscribe(IncrementChanged);
             IsReadOnlyProperty.Changed.Subscribe(OnIsReadOnlyChanged);
@@ -397,6 +420,19 @@ namespace Avalonia.Controls
             }
         }
 
+        /// <summary>
+        /// Called when the <see cref="NumberFormat"/> property value changed.
+        /// </summary>
+        /// <param name="oldValue">The old value.</param>
+        /// <param name="newValue">The new value.</param>
+        protected virtual void OnNumberFormatChanged(NumberFormatInfo oldValue, NumberFormatInfo newValue)
+        {
+            if (IsInitialized)
+            {
+                SyncTextAndValueProperties(false, null);
+            }
+        }
+
         /// <summary>
         /// Called when the <see cref="FormatString"/> property value changed.
         /// </summary>
@@ -415,7 +451,7 @@ namespace Avalonia.Controls
         /// </summary>
         /// <param name="oldValue">The old value.</param>
         /// <param name="newValue">The new value.</param>
-        protected virtual void OnIncrementChanged(double oldValue, double newValue)
+        protected virtual void OnIncrementChanged(decimal oldValue, decimal newValue)
         {
             if (IsInitialized)
             {
@@ -438,7 +474,7 @@ namespace Avalonia.Controls
         /// </summary>
         /// <param name="oldValue">The old value.</param>
         /// <param name="newValue">The new value.</param>
-        protected virtual void OnMaximumChanged(double oldValue, double newValue)
+        protected virtual void OnMaximumChanged(decimal oldValue, decimal newValue)
         {
             if (IsInitialized)
             {
@@ -455,7 +491,7 @@ namespace Avalonia.Controls
         /// </summary>
         /// <param name="oldValue">The old value.</param>
         /// <param name="newValue">The new value.</param>
-        protected virtual void OnMinimumChanged(double oldValue, double newValue)
+        protected virtual void OnMinimumChanged(decimal oldValue, decimal newValue)
         {
             if (IsInitialized)
             {
@@ -485,7 +521,7 @@ namespace Avalonia.Controls
         /// </summary>
         /// <param name="oldValue">The old value.</param>
         /// <param name="newValue">The new value.</param>
-        protected virtual void OnValueChanged(double oldValue, double newValue)
+        protected virtual void OnValueChanged(decimal oldValue, decimal newValue)
         {
             if (!_internalValueSet && IsInitialized)
             {
@@ -501,7 +537,7 @@ namespace Avalonia.Controls
         /// Called when the <see cref="Increment"/> property has to be coerced.
         /// </summary>
         /// <param name="baseValue">The value.</param>
-        protected virtual double OnCoerceIncrement(double baseValue)
+        protected virtual decimal OnCoerceIncrement(decimal baseValue)
         {
             return baseValue;
         }
@@ -510,7 +546,7 @@ namespace Avalonia.Controls
         /// Called when the <see cref="Maximum"/> property has to be coerced.
         /// </summary>
         /// <param name="baseValue">The value.</param>
-        protected virtual double OnCoerceMaximum(double baseValue)
+        protected virtual decimal OnCoerceMaximum(decimal baseValue)
         {
             return Math.Max(baseValue, Minimum);
         }
@@ -519,7 +555,7 @@ namespace Avalonia.Controls
         /// Called when the <see cref="Minimum"/> property has to be coerced.
         /// </summary>
         /// <param name="baseValue">The value.</param>
-        protected virtual double OnCoerceMinimum(double baseValue)
+        protected virtual decimal OnCoerceMinimum(decimal baseValue)
         {
             return Math.Min(baseValue, Maximum);
         }
@@ -528,7 +564,7 @@ namespace Avalonia.Controls
         /// Called when the <see cref="Value"/> property has to be coerced.
         /// </summary>
         /// <param name="baseValue">The value.</param>
-        protected virtual double OnCoerceValue(double baseValue)
+        protected virtual decimal OnCoerceValue(decimal baseValue)
         {
             return baseValue;
         }
@@ -562,7 +598,7 @@ namespace Avalonia.Controls
         /// </summary>
         /// <param name="oldValue">The old value.</param>
         /// <param name="newValue">The new value.</param>
-        protected virtual void RaiseValueChangedEvent(double oldValue, double newValue)
+        protected virtual void RaiseValueChangedEvent(decimal oldValue, decimal newValue)
         {
             var e = new NumericUpDownValueChangedEventArgs(ValueChangedEvent, oldValue, newValue);
             RaiseEvent(e);
@@ -571,9 +607,9 @@ namespace Avalonia.Controls
         /// <summary>
         /// Converts the formatted text to a value.
         /// </summary>
-        private double ConvertTextToValue(string text)
+        private decimal ConvertTextToValue(string text)
         {
-            double result = 0;
+            decimal result = 0;
 
             if (string.IsNullOrEmpty(text))
             {
@@ -609,10 +645,10 @@ namespace Avalonia.Controls
             //Manage FormatString of type "{}{0:N2} °" (in xaml) or "{0:N2} °" in code-behind.
             if (FormatString.Contains("{0"))
             {
-                return string.Format(CultureInfo, FormatString, Value);
+                return string.Format(NumberFormat, FormatString, Value);
             }
 
-            return Value.ToString(FormatString, CultureInfo);
+            return Value.ToString(FormatString, NumberFormat);
         }
 
         /// <summary>
@@ -674,6 +710,20 @@ namespace Avalonia.Controls
             }
         }
 
+        /// <summary>
+        /// Called when the <see cref="NumberFormat"/> property value changed.
+        /// </summary>
+        /// <param name="e">The event args.</param>
+        private static void OnNumberFormatChanged(AvaloniaPropertyChangedEventArgs e)
+        {
+            if (e.Sender is NumericUpDown upDown)
+            {
+                var oldValue = (NumberFormatInfo)e.OldValue;
+                var newValue = (NumberFormatInfo)e.NewValue;
+                upDown.OnNumberFormatChanged(oldValue, newValue);
+            }
+        }
+
         /// <summary>
         /// Called when the <see cref="Increment"/> property value changed.
         /// </summary>
@@ -682,8 +732,8 @@ namespace Avalonia.Controls
         {
             if (e.Sender is NumericUpDown upDown)
             {
-                var oldValue = (double)e.OldValue;
-                var newValue = (double)e.NewValue;
+                var oldValue = (decimal)e.OldValue;
+                var newValue = (decimal)e.NewValue;
                 upDown.OnIncrementChanged(oldValue, newValue);
             }
         }
@@ -724,8 +774,8 @@ namespace Avalonia.Controls
         {
             if (e.Sender is NumericUpDown upDown)
             {
-                var oldValue = (double)e.OldValue;
-                var newValue = (double)e.NewValue;
+                var oldValue = (decimal)e.OldValue;
+                var newValue = (decimal)e.NewValue;
                 upDown.OnMaximumChanged(oldValue, newValue);
             }
         }
@@ -738,8 +788,8 @@ namespace Avalonia.Controls
         {
             if (e.Sender is NumericUpDown upDown)
             {
-                var oldValue = (double)e.OldValue;
-                var newValue = (double)e.NewValue;
+                var oldValue = (decimal)e.OldValue;
+                var newValue = (decimal)e.NewValue;
                 upDown.OnMinimumChanged(oldValue, newValue);
             }
         }
@@ -766,13 +816,13 @@ namespace Avalonia.Controls
         {
             if (e.Sender is NumericUpDown upDown)
             {
-                var oldValue = (double)e.OldValue;
-                var newValue = (double)e.NewValue;
+                var oldValue = (decimal)e.OldValue;
+                var newValue = (decimal)e.NewValue;
                 upDown.OnValueChanged(oldValue, newValue);
             }
         }
 
-        private void SetValueInternal(double value)
+        private void SetValueInternal(decimal value)
         {
             _internalValueSet = true;
             try
@@ -785,7 +835,7 @@ namespace Avalonia.Controls
             }
         }
 
-        private static double OnCoerceMaximum(IAvaloniaObject instance, double value)
+        private static decimal OnCoerceMaximum(IAvaloniaObject instance, decimal value)
         {
             if (instance is NumericUpDown upDown)
             {
@@ -795,7 +845,7 @@ namespace Avalonia.Controls
             return value;
         }
 
-        private static double OnCoerceMinimum(IAvaloniaObject instance, double value)
+        private static decimal OnCoerceMinimum(IAvaloniaObject instance, decimal value)
         {
             if (instance is NumericUpDown upDown)
             {
@@ -805,7 +855,7 @@ namespace Avalonia.Controls
             return value;
         }
 
-        private static double OnCoerceIncrement(IAvaloniaObject instance, double value)
+        private static decimal OnCoerceIncrement(IAvaloniaObject instance, decimal value)
         {
             if (instance is NumericUpDown upDown)
             {
@@ -977,23 +1027,23 @@ namespace Avalonia.Controls
             return parsedTextIsValid;
         }
 
-        private double ConvertTextToValueCore(string currentValueText, string text)
+        private decimal ConvertTextToValueCore(string currentValueText, string text)
         {
-            double result;
+            decimal result;
 
             if (IsPercent(FormatString))
             {
-                result = decimal.ToDouble(ParsePercent(text, CultureInfo));
+                result = ParsePercent(text, NumberFormat);
             }
             else
             {
                 // Problem while converting new text
-                if (!double.TryParse(text, ParsingNumberStyle, CultureInfo, out var outputValue))
+                if (!decimal.TryParse(text, ParsingNumberStyle, NumberFormat, out var outputValue))
                 {
                     var shouldThrow = true;
 
                     // Check if CurrentValueText is also failing => it also contains special characters. ex : 90°
-                    if (!double.TryParse(currentValueText, ParsingNumberStyle, CultureInfo, out var _))
+                    if (!decimal.TryParse(currentValueText, ParsingNumberStyle, NumberFormat, out var _))
                     {
                         // extract non-digit characters
                         var currentValueTextSpecialCharacters = currentValueText.Where(c => !char.IsDigit(c));
@@ -1006,7 +1056,7 @@ namespace Avalonia.Controls
                                 text = text.Replace(character.ToString(), string.Empty);
                             }
                             // if without the special characters, parsing is good, do not throw
-                            if (double.TryParse(text, ParsingNumberStyle, CultureInfo, out outputValue))
+                            if (decimal.TryParse(text, ParsingNumberStyle, NumberFormat, out outputValue))
                             {
                                 shouldThrow = false;
                             }
@@ -1023,7 +1073,7 @@ namespace Avalonia.Controls
             return result;
         }
 
-        private void ValidateMinMax(double value)
+        private void ValidateMinMax(decimal value)
         {
             if (value < Minimum)
             {

src/Avalonia.Controls/NumericUpDown/NumericUpDownValueChangedEventArgs.cs

@@ -4,13 +4,13 @@ namespace Avalonia.Controls
 {
     public class NumericUpDownValueChangedEventArgs : RoutedEventArgs
     {
-        public NumericUpDownValueChangedEventArgs(RoutedEvent routedEvent, double oldValue,  double newValue) : base(routedEvent)
+        public NumericUpDownValueChangedEventArgs(RoutedEvent routedEvent, decimal oldValue, decimal newValue) : base(routedEvent)
         {
             OldValue = oldValue;
             NewValue = newValue;
         }
 
-        public double OldValue { get; }
-        public double NewValue { get; }
+        public decimal OldValue { get; }
+        public decimal NewValue { get; }
     }
 }

src/Avalonia.Controls/Platform/ITopLevelImpl.cs

@@ -22,6 +22,11 @@ namespace Avalonia.Platform
         /// </summary>
         Size ClientSize { get; }
 
+        /// <summary>
+        /// Gets the total size of the toplevel, excluding shadows.
+        /// </summary>
+        Size? FrameSize { get; }
+
         /// <summary>
         /// Gets the scaling factor for the toplevel. This is used for rendering.
         /// </summary>

src/Avalonia.Controls/Presenters/CarouselPresenter.cs

@@ -186,7 +186,7 @@ namespace Avalonia.Controls.Presenters
 
                 if (PageTransition != null && (from != null || to != null))
                 {
-                    await PageTransition.Start((Visual)from, (Visual)to, fromIndex < toIndex);
+                    await PageTransition.Start((Visual)from, (Visual)to, fromIndex < toIndex, default);
                 }
                 else if (to != null)
                 {

src/Avalonia.Controls/Presenters/ScrollContentPresenter.cs

@@ -511,8 +511,8 @@ namespace Avalonia.Controls.Presenters
             else if (scrollable.IsLogicalScrollEnabled)
             {
                 Viewport = scrollable.Viewport;
-                Extent = scrollable.Extent;
                 Offset = scrollable.Offset;
+                Extent = scrollable.Extent;
             }
         }
 

src/Avalonia.Controls/Primitives/AdornerLayer.cs

@@ -1,19 +1,33 @@
 using System;
 using System.Collections.Specialized;
-using System.Linq;
-using System.Resources;
 using Avalonia.Media;
 using Avalonia.Rendering;
-using Avalonia.Utilities;
 using Avalonia.VisualTree;
 
+#nullable enable
+
 namespace Avalonia.Controls.Primitives
 {
-    // TODO: Need to track position of adorned elements and move the adorner if they move.
+    /// <summary>
+    /// Represents a surface for showing adorners.
+    /// Adorners are always on top of the adorned element and are positioned to stay relative to the adorned element.
+    /// </summary>
+    /// <remarks>
+    /// TODO: Need to track position of adorned elements and move the adorner if they move.
+    /// </remarks>
     public class AdornerLayer : Canvas, ICustomSimpleHitTest
     {
-        public static readonly AttachedProperty<Visual> AdornedElementProperty =
-            AvaloniaProperty.RegisterAttached<AdornerLayer, Visual, Visual>("AdornedElement");
+        /// <summary>
+        /// Allows for getting and setting of the adorned element.
+        /// </summary>
+        public static readonly AttachedProperty<Visual?> AdornedElementProperty =
+            AvaloniaProperty.RegisterAttached<AdornerLayer, Visual, Visual?>("AdornedElement");
+
+        /// <summary>
+        /// Allows for controlling clipping of the adorner.
+        /// </summary>
+        public static readonly AttachedProperty<bool> IsClipEnabledProperty =
+            AvaloniaProperty.RegisterAttached<AdornerLayer, Visual, bool>("IsClipEnabled", true);
 
         private static readonly AttachedProperty<AdornedElementInfo> s_adornedElementInfoProperty =
             AvaloniaProperty.RegisterAttached<AdornerLayer, Visual, AdornedElementInfo>("AdornedElementInfo");
@@ -28,7 +42,7 @@ namespace Avalonia.Controls.Primitives
             Children.CollectionChanged += ChildrenCollectionChanged;
         }
 
-        public static Visual GetAdornedElement(Visual adorner)
+        public static Visual? GetAdornedElement(Visual adorner)
         {
             return adorner.GetValue(AdornedElementProperty);
         }
@@ -38,12 +52,19 @@ namespace Avalonia.Controls.Primitives
             adorner.SetValue(AdornedElementProperty, adorned);
         }
 
-        public static AdornerLayer GetAdornerLayer(IVisual visual)
+        public static AdornerLayer? GetAdornerLayer(IVisual visual)
+        {
+            return visual.FindAncestorOfType<VisualLayerManager>()?.AdornerLayer;
+        }
+
+        public static bool GetIsClipEnabled(Visual adorner)
         {
-            return visual.GetVisualAncestors()
-                .OfType<VisualLayerManager>()
-                .FirstOrDefault()
-                ?.AdornerLayer;
+            return adorner.GetValue(IsClipEnabledProperty);
+        }
+
+        public static void SetIsClipEnabled(Visual adorner, bool isClipEnabled)
+        {
+            adorner.SetValue(IsClipEnabledProperty, isClipEnabled);
         }
 
         protected override Size MeasureOverride(Size availableSize)
@@ -70,12 +91,13 @@ namespace Avalonia.Controls.Primitives
             foreach (var child in Children)
             {
                 var info = child.GetValue(s_adornedElementInfoProperty);
+                var isClipEnabled = child.GetValue(IsClipEnabledProperty);
 
                 if (info != null && info.Bounds.HasValue)
                 {
                     child.RenderTransform = new MatrixTransform(info.Bounds.Value.Transform);
                     child.RenderTransformOrigin = new RelativePoint(new Point(0,0), RelativeUnit.Absolute);
-                    UpdateClip(child, info.Bounds.Value);
+                    UpdateClip(child, info.Bounds.Value, isClipEnabled);
                     child.Arrange(info.Bounds.Value.Bounds);
                 }
                 else
@@ -87,16 +109,23 @@ namespace Avalonia.Controls.Primitives
             return finalSize;
         }
 
-        private static void AdornedElementChanged(AvaloniaPropertyChangedEventArgs e)
+        private static void AdornedElementChanged(AvaloniaPropertyChangedEventArgs<Visual?> e)
         {
             var adorner = (Visual)e.Sender;
-            var adorned = (Visual)e.NewValue;
+            var adorned = e.NewValue.GetValueOrDefault();
             var layer = adorner.GetVisualParent<AdornerLayer>();
             layer?.UpdateAdornedElement(adorner, adorned);
         }
 
-        private void UpdateClip(IControl control, TransformedBounds bounds)
+        private void UpdateClip(IControl control, TransformedBounds bounds, bool isEnabled)
         {
+            if (!isEnabled)
+            {
+                control.Clip = null;
+
+                return;
+            }
+
             if (!(control.Clip is RectangleGeometry clip))
             {
                 clip = new RectangleGeometry();
@@ -129,13 +158,13 @@ namespace Avalonia.Controls.Primitives
             InvalidateArrange();
         }
 
-        private void UpdateAdornedElement(Visual adorner, Visual adorned)
+        private void UpdateAdornedElement(Visual adorner, Visual? adorned)
         {
             var info = adorner.GetValue(s_adornedElementInfoProperty);
 
             if (info != null)
             {
-                info.Subscription.Dispose();
+                info.Subscription!.Dispose();
 
                 if (adorned == null)
                 {
@@ -163,7 +192,7 @@ namespace Avalonia.Controls.Primitives
 
         private class AdornedElementInfo
         {
-            public IDisposable Subscription { get; set; }
+            public IDisposable? Subscription { get; set; }
 
             public TransformedBounds? Bounds { get; set; }
         }

src/Avalonia.Controls/Primitives/SelectingItemsControl.cs

@@ -10,6 +10,7 @@ using Avalonia.Data;
 using Avalonia.Input;
 using Avalonia.Input.Platform;
 using Avalonia.Interactivity;
+using Avalonia.Threading;
 using Avalonia.VisualTree;
 
 #nullable enable
@@ -91,6 +92,12 @@ namespace Avalonia.Controls.Primitives
             AvaloniaProperty.Register<SelectingItemsControl, SelectionMode>(
                 nameof(SelectionMode));
 
+        /// <summary>
+        /// Defines the <see cref="IsTextSearchEnabled"/> property.
+        /// </summary>
+        public static readonly StyledProperty<bool> IsTextSearchEnabledProperty =
+            AvaloniaProperty.Register<ItemsControl, bool>(nameof(IsTextSearchEnabled), true);
+
         /// <summary>
         /// Event that should be raised by items that implement <see cref="ISelectable"/> to
         /// notify the parent <see cref="SelectingItemsControl"/> that their selection state
@@ -110,6 +117,8 @@ namespace Avalonia.Controls.Primitives
                 RoutingStrategies.Bubble);
 
         private static readonly IList Empty = Array.Empty<object>();
+        private string _textSearchTerm = string.Empty;
+        private DispatcherTimer? _textSearchTimer;
         private ISelectionModel? _selection;
         private int _oldSelectedIndex;
         private object? _oldSelectedItem;
@@ -305,6 +314,15 @@ namespace Avalonia.Controls.Primitives
             }
         }
 
+        /// <summary>
+        /// Gets or sets a value that specifies whether a user can jump to a value by typing.
+        /// </summary>
+        public bool IsTextSearchEnabled
+        {
+            get { return GetValue(IsTextSearchEnabledProperty); }
+            set { SetValue(IsTextSearchEnabledProperty, value); }
+        }
+
         /// <summary>
         /// Gets or sets the selection mode.
         /// </summary>
@@ -490,6 +508,36 @@ namespace Avalonia.Controls.Primitives
             }
         }
 
+        protected override void OnTextInput(TextInputEventArgs e)
+        {
+            if (!e.Handled)
+            {
+                if (!IsTextSearchEnabled)
+                    return;
+
+                StopTextSearchTimer();
+
+                _textSearchTerm += e.Text;
+
+                bool match(ItemContainerInfo info) =>
+                    info.ContainerControl is IContentControl control &&
+                    control.Content?.ToString()?.StartsWith(_textSearchTerm, StringComparison.OrdinalIgnoreCase) == true;
+
+                var info = ItemContainerGenerator.Containers.FirstOrDefault(match);
+
+                if (info != null)
+                {
+                    SelectedIndex = info.Index;
+                }
+
+                StartTextSearchTimer();
+
+                e.Handled = true;
+            }
+
+            base.OnTextInput(e);
+        }
+
         protected override void OnKeyDown(KeyEventArgs e)
         {
             base.OnKeyDown(e);
@@ -962,6 +1010,32 @@ namespace Avalonia.Controls.Primitives
             }
         }
 
+        private void StartTextSearchTimer()
+        {
+            _textSearchTimer = new DispatcherTimer { Interval = TimeSpan.FromSeconds(1) };
+            _textSearchTimer.Tick += TextSearchTimer_Tick;
+            _textSearchTimer.Start();
+        }
+
+        private void StopTextSearchTimer()
+        {
+            if (_textSearchTimer == null)
+            {
+                return;
+            }
+
+            _textSearchTimer.Tick -= TextSearchTimer_Tick;
+            _textSearchTimer.Stop();
+
+            _textSearchTimer = null;
+        }
+
+        private void TextSearchTimer_Tick(object sender, EventArgs e)
+        {
+            _textSearchTerm = string.Empty;
+            StopTextSearchTimer();
+        }
+
         // When in a BeginInit..EndInit block, or when the DataContext is updating, we need to
         // defer changes to the selection model because we have no idea in which order properties
         // will be set. Consider:

src/Avalonia.Controls/Primitives/Thumb.cs

@@ -56,6 +56,26 @@ namespace Avalonia.Controls.Primitives
         {
         }
 
+        protected override void OnPointerCaptureLost(PointerCaptureLostEventArgs e)
+        {
+            if (_lastPoint.HasValue)
+            {
+                var ev = new VectorEventArgs
+                {
+                    RoutedEvent = DragCompletedEvent,
+                    Vector = _lastPoint.Value,
+                };
+
+                _lastPoint = null;
+
+                RaiseEvent(ev);
+            }
+
+            PseudoClasses.Remove(":pressed");
+
+            base.OnPointerCaptureLost(e);
+        }
+
         protected override void OnPointerMoved(PointerEventArgs e)
         {
             if (_lastPoint.HasValue)

src/Avalonia.Controls/Repeater/ViewportManager.cs

@@ -27,7 +27,6 @@ namespace Avalonia.Controls
         private IScrollAnchorProvider _scroller;
         private IControl _makeAnchorElement;
         private bool _isAnchorOutsideRealizedRange;
-        private Task _cacheBuildAction;
         private Rect _visibleWindow;
         private Rect _layoutExtent;
         // This is the expected shift by the layout.

src/Avalonia.Controls/Repeater/VirtualizationInfo.cs

@@ -27,7 +27,6 @@ namespace Avalonia.Controls
     internal class VirtualizationInfo
     {
         private int _pinCounter;
-        private object _data;
 
         public Rect ArrangeBounds { get; set; }
         public bool AutoRecycleCandidate { get; set; }

src/Avalonia.Controls/RowDefinitions.cs

@@ -1,5 +1,4 @@
 using System.Linq;
-using Avalonia.Collections;
 
 namespace Avalonia.Controls
 {
@@ -25,6 +24,11 @@ namespace Avalonia.Controls
             AddRange(GridLength.ParseLengths(s).Select(x => new RowDefinition(x)));
         }
 
+        public override string ToString()
+        {
+            return string.Join(",", this.Select(x => x.Height));
+        }
+
         /// <summary>
         /// Parses a string representation of row definitions collection.
         /// </summary>
@@ -32,4 +36,4 @@ namespace Avalonia.Controls
         /// <returns>The <see cref="RowDefinitions"/>.</returns>
         public static RowDefinitions Parse(string s) => new RowDefinitions(s);
     }
-}
+}

src/Avalonia.Controls/Shapes/Arc.cs

@@ -0,0 +1,103 @@
+using System;
+using Avalonia.Media;
+
+namespace Avalonia.Controls.Shapes
+{
+    public class Arc : Shape
+    {
+        /// <summary>
+        /// Defines the <see cref="StartAngle"/> property.
+        /// </summary>
+        public static readonly StyledProperty<double> StartAngleProperty =
+            AvaloniaProperty.Register<Arc, double>(nameof(StartAngle), 0.0);
+
+        /// <summary>
+        /// Defines the <see cref="SweepAngle"/> property.
+        /// </summary>
+        public static readonly StyledProperty<double> SweepAngleProperty =
+            AvaloniaProperty.Register<Arc, double>(nameof(SweepAngle), 0.0);
+
+        static Arc()
+        {
+            StrokeThicknessProperty.OverrideDefaultValue<Arc>(1);
+            AffectsGeometry<Arc>(BoundsProperty, StrokeThicknessProperty, StartAngleProperty, SweepAngleProperty);
+        }
+
+        /// <summary>
+        /// Gets or sets the angle at which the arc starts, in degrees.
+        /// </summary>
+        public double StartAngle
+        {
+            get => GetValue(StartAngleProperty);
+            set => SetValue(StartAngleProperty, value);
+        }
+
+        /// <summary>
+        /// Gets or sets the angle, in degrees, added to the <see cref="StartAngle"/> defining where the arc ends.
+        /// A positive value is clockwise, negative is counter-clockwise.
+        /// </summary>
+        public double SweepAngle
+        {
+            get => GetValue(SweepAngleProperty);
+            set => SetValue(SweepAngleProperty, value);
+        }
+
+        protected override Geometry CreateDefiningGeometry()
+        {
+            var angle1 = DegreesToRad(StartAngle);
+            var angle2 = angle1 + DegreesToRad(SweepAngle);
+
+            var startAngle = Math.Min(angle1, angle2);
+            var sweepAngle = Math.Max(angle1, angle2);
+
+            var normStart = RadToNormRad(startAngle);
+            var normEnd = RadToNormRad(sweepAngle);
+
+            var rect = new Rect(Bounds.Size);
+
+            if ((normStart == normEnd) && (startAngle != sweepAngle)) // Complete ring.
+            {
+                return new EllipseGeometry(rect.Deflate(StrokeThickness / 2));
+            }
+            else if (SweepAngle == 0)
+            {
+                return new StreamGeometry();
+            }
+            else // Partial arc.
+            {
+                var deflatedRect = rect.Deflate(StrokeThickness / 2);
+
+                var centerX = rect.Center.X;
+                var centerY = rect.Center.Y;
+
+                var radiusX = deflatedRect.Width / 2;
+                var radiusY = deflatedRect.Height / 2;
+
+                var angleGap = RadToNormRad(sweepAngle - startAngle);
+
+                var startPoint = GetRingPoint(radiusX, radiusY, centerX, centerY, startAngle);
+                var endPoint = GetRingPoint(radiusX, radiusY, centerX, centerY, sweepAngle);
+
+                var arcGeometry = new StreamGeometry();
+
+                using (var ctx = arcGeometry.Open())
+                {
+                    ctx.BeginFigure(startPoint, false);
+                    ctx.ArcTo(endPoint, new Size(radiusX, radiusY), angleGap, angleGap >= Math.PI,
+                        SweepDirection.Clockwise);
+                    ctx.EndFigure(false);
+                }
+
+                return arcGeometry;
+            }
+        }
+
+        static double DegreesToRad(double inAngle) =>
+            inAngle * Math.PI / 180;
+
+        static double RadToNormRad(double inAngle) => ((inAngle % (Math.PI * 2)) + (Math.PI * 2)) % (Math.PI * 2);
+
+        static Point GetRingPoint(double radiusX, double radiusY, double centerX, double centerY, double angle) =>
+            new Point((radiusX * Math.Cos(angle)) + centerX, (radiusY * Math.Sin(angle)) + centerY);
+    }
+}

src/Avalonia.Controls/SplitView.cs

@@ -133,7 +133,7 @@ namespace Avalonia.Controls
             AvaloniaProperty.Register<SplitView, object?>(nameof(Pane));
 
         /// <summary>
-        /// Defines the <see cref="HeaderTemplate"/> property.
+        /// Defines the <see cref="PaneTemplate"/> property.
         /// </summary>
         public static readonly StyledProperty<IDataTemplate?> PaneTemplateProperty =
             AvaloniaProperty.Register<HeaderedContentControl, IDataTemplate?>(nameof(PaneTemplate));

src/Avalonia.Controls/TextBox.cs

@@ -145,7 +145,7 @@ namespace Avalonia.Controls
                 (o, v) => o.UndoLimit = v,
                 unsetValue: -1);
 
-        struct UndoRedoState : IEquatable<UndoRedoState>
+        readonly struct UndoRedoState : IEquatable<UndoRedoState>
         {
             public string Text { get; }
             public int CaretPosition { get; }
@@ -1290,7 +1290,7 @@ namespace Avalonia.Controls
 
         private void UpdatePseudoclasses()
         {
-            PseudoClasses.Set(":empty", string.IsNullOrWhiteSpace(Text));
+            PseudoClasses.Set(":empty", string.IsNullOrEmpty(Text));
         }
 
         private bool IsPasswordBox => PasswordChar != default(char);

src/Avalonia.Controls/TopLevel.cs

@@ -42,6 +42,12 @@ namespace Avalonia.Controls
         public static readonly DirectProperty<TopLevel, Size> ClientSizeProperty =
             AvaloniaProperty.RegisterDirect<TopLevel, Size>(nameof(ClientSize), o => o.ClientSize);
 
+        /// <summary>
+        /// Defines the <see cref="FrameSize"/> property.
+        /// </summary>
+        public static readonly DirectProperty<TopLevel, Size?> FrameSizeProperty =
+            AvaloniaProperty.RegisterDirect<TopLevel, Size?>(nameof(FrameSize), o => o.FrameSize);
+
         /// <summary>
         /// Defines the <see cref="IInputRoot.PointerOverElement"/> property.
         /// </summary>
@@ -74,6 +80,7 @@ namespace Avalonia.Controls
         private readonly IPlatformRenderInterface _renderInterface;
         private readonly IGlobalStyles _globalStyles;
         private Size _clientSize;
+        private Size? _frameSize;
         private WindowTransparencyLevel _actualTransparencyLevel;
         private ILayoutManager _layoutManager;
         private Border _transparencyFallbackBorder;
@@ -161,6 +168,7 @@ namespace Avalonia.Controls
             styler?.ApplyStyles(this);
 
             ClientSize = impl.ClientSize;
+            FrameSize = impl.FrameSize;
             
             this.GetObservable(PointerOverElementProperty)
                 .Select(
@@ -197,6 +205,15 @@ namespace Avalonia.Controls
             protected set { SetAndRaise(ClientSizeProperty, ref _clientSize, value); }
         }
 
+        /// <summary>
+        /// Gets or sets the total size of the window.
+        /// </summary>
+        public Size? FrameSize
+        {
+            get { return _frameSize; }
+            protected set { SetAndRaise(FrameSizeProperty, ref _frameSize, value); }
+        }
+
         /// <summary>
         /// Gets or sets the <see cref="WindowTransparencyLevel"/> that the TopLevel should use when possible.
         /// </summary>
@@ -366,6 +383,7 @@ namespace Avalonia.Controls
         protected virtual void HandleResized(Size clientSize)
         {
             ClientSize = clientSize;
+            FrameSize = PlatformImpl.FrameSize;
             Width = clientSize.Width;
             Height = clientSize.Height;
             LayoutManager.ExecuteLayoutPass();

src/Avalonia.Controls/TreeView.cs

@@ -166,11 +166,9 @@ namespace Avalonia.Controls
         {
             item.IsExpanded = true;
 
-            var panel = item.Presenter.Panel;
-
-            if (panel != null)
+            if (item.Presenter?.Panel != null)
             {
-                foreach (var child in panel.Children)
+                foreach (var child in item.Presenter.Panel.Children)
                 {
                     if (child is TreeViewItem treeViewItem)
                     {

src/Avalonia.Controls/Window.cs

@@ -592,6 +592,14 @@ namespace Avalonia.Controls
                     owner.RemoveChild(this);
                 }
 
+                if (_children.Count > 0)
+                {
+                    foreach (var child in _children.ToArray())
+                    {
+                        child.child.Hide();
+                    }
+                }
+
                 Owner = null;
 
                 PlatformImpl?.Hide();
@@ -635,6 +643,22 @@ namespace Avalonia.Controls
                 throw new InvalidOperationException("Cannot re-show a closed window.");
             }
 
+            if (parent != null)
+            {
+                if (parent.PlatformImpl == null)
+                {
+                    throw new InvalidOperationException("Cannot show a window with a closed parent.");
+                }
+                else if (parent == this)
+                {
+                    throw new InvalidOperationException("A Window cannot be its own parent.");
+                }
+                else if (!parent.IsVisible)
+                {
+                    throw new InvalidOperationException("Cannot show window with non-visible parent.");
+                }
+            }
+
             if (IsVisible)
             {
                 return;
@@ -708,11 +732,22 @@ namespace Avalonia.Controls
             {
                 throw new ArgumentNullException(nameof(owner));
             }
-
-            if (IsVisible)
+            else if (owner.PlatformImpl == null)
+            {
+                throw new InvalidOperationException("Cannot show a window with a closed owner.");
+            }
+            else if (owner == this)
+            {
+                throw new InvalidOperationException("A Window cannot be its own owner.");
+            }
+            else if (IsVisible)
             {
                 throw new InvalidOperationException("The window is already being shown.");
             }
+            else if (!owner.IsVisible)
+            {
+                throw new InvalidOperationException("Cannot show window with non-visible parent.");
+            }
 
             RaiseEvent(new RoutedEventArgs(WindowOpenedEvent));
 

src/Avalonia.Controls/WindowBase.cs

@@ -222,6 +222,7 @@ namespace Avalonia.Controls
         protected override void HandleResized(Size clientSize)
         {
             ClientSize = clientSize;
+            FrameSize = PlatformImpl.FrameSize;
             LayoutManager.ExecuteLayoutPass();
             Renderer?.Resized(clientSize);
         }

src/Avalonia.DesignerSupport/Remote/Stubs.cs

@@ -21,6 +21,7 @@ namespace Avalonia.DesignerSupport.Remote
         public IPlatformHandle Handle { get; }
         public Size MaxAutoSizeHint { get; }
         public Size ClientSize { get; }
+        public Size? FrameSize => null;
         public double RenderScaling { get; } = 1.0;
         public double DesktopScaling => 1.0;
         public IEnumerable<object> Surfaces { get; }

src/Avalonia.Headless/HeadlessWindowImpl.cs

@@ -41,6 +41,7 @@ namespace Avalonia.Headless
         }
 
         public Size ClientSize { get; set; }
+        public Size? FrameSize => null;
         public double RenderScaling { get; } = 1;
         public double DesktopScaling => RenderScaling;
         public IEnumerable<object> Surfaces { get; }

src/Avalonia.Layout/ElementManager.cs

@@ -325,7 +325,10 @@ namespace Avalonia.Layout
                         break;
 
                     case NotifyCollectionChangedAction.Move:
-                        throw new NotImplementedException();
+                        int size = args.OldItems != null ? args.OldItems.Count : 1;
+                        OnItemsRemoved(args.OldStartingIndex, size);
+                        OnItemsAdded(args.NewStartingIndex, size);
+                        break;
                 }
             }
         }

src/Avalonia.Native/WindowImplBase.cs

@@ -104,6 +104,20 @@ namespace Avalonia.Native
             }
         }
 
+        public Size? FrameSize
+        {
+            get
+            {
+                if (_native != null)
+                {
+                    var s = _native.FrameSize;
+                    return new Size(s.Width, s.Height);
+                }
+
+                return default;
+            }
+        }
+
         public IEnumerable<object> Surfaces => new[] {
             (_gpu ? _glSurface : (object)null),
             this 

src/Avalonia.Native/avn.idl

@@ -435,6 +435,7 @@ interface IAvnWindowBase : IUnknown
      HRESULT Close();
      HRESULT Activate();
      HRESULT GetClientSize(AvnSize*ret);
+     HRESULT GetFrameSize(AvnSize*ret);
      HRESULT GetScaling(double*ret);
      HRESULT SetMinMaxSize(AvnSize minSize, AvnSize maxSize);
      HRESULT Resize(double width, double height);

src/Avalonia.ReactiveUI/TransitioningContentControl.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Threading;
+
 using Avalonia.Animation;
 using Avalonia.Controls;
 using Avalonia.Styling;
@@ -22,7 +24,9 @@ namespace Avalonia.ReactiveUI
         /// </summary>
         public static readonly StyledProperty<object?> DefaultContentProperty =
             AvaloniaProperty.Register<TransitioningContentControl, object?>(nameof(DefaultContent));
-        
+
+        private CancellationTokenSource? _lastTransitionCts;
+
         /// <summary>
         /// Gets or sets the animation played when content appears and disappears.
         /// </summary>
@@ -62,11 +66,14 @@ namespace Avalonia.ReactiveUI
         /// <param name="content">New content to set.</param>
         private async void UpdateContentWithTransition(object? content)
         {
+            _lastTransitionCts?.Cancel();
+            _lastTransitionCts = new CancellationTokenSource();
+
             if (PageTransition != null)
-                await PageTransition.Start(this, null, true);
+                await PageTransition.Start(this, null, true, _lastTransitionCts.Token);
             base.Content = content;
             if (PageTransition != null)
-                await PageTransition.Start(null, this, true);
+                await PageTransition.Start(null, this, true, _lastTransitionCts.Token);
         }
     }
 }

src/Avalonia.Themes.Fluent/Controls/ComboBox.xaml

@@ -112,9 +112,7 @@
                 <Panel Height="12"
                        Width="12" />
                 <Path x:Name="DropDownGlyph"
-                      Stretch="Uniform"
-                      VerticalAlignment="Center"
-                      Data="M1939 486L2029 576L1024 1581L19 576L109 486L1024 1401L1939 486Z" />
+                      VerticalAlignment="Center" />
               </Panel>
             </Viewbox>
             <Popup Name="PART_Popup"
@@ -160,6 +158,8 @@
 
   <Style Selector="ComboBox /template/ Path#DropDownGlyph">
     <Setter Property="Fill" Value="{DynamicResource ComboBoxDropDownGlyphForeground}" />
+    <Setter Property="Data" Value="M1939 486L2029 576L1024 1581L19 576L109 486L1024 1401L1939 486Z" />
+    <Setter Property="Stretch" Value="Uniform" />
   </Style>
 
   <!--  PointerOver State  -->

src/Avalonia.Visuals/Animation/CompositePageTransition.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Linq;
+using System.Threading;
 using System.Threading.Tasks;
 using Avalonia.Metadata;
 
@@ -35,25 +36,11 @@ namespace Avalonia.Animation
         [Content]
         public List<IPageTransition> PageTransitions { get; set; } = new List<IPageTransition>();
 
-        /// <summary>
-        /// Starts the animation.
-        /// </summary>
-        /// <param name="from">
-        /// The control that is being transitioned away from. May be null.
-        /// </param>
-        /// <param name="to">
-        /// The control that is being transitioned to. May be null.
-        /// </param>
-        /// <param name="forward">
-        /// Defines the direction of the transition.
-        /// </param>
-        /// <returns>
-        /// A <see cref="Task"/> that tracks the progress of the animation.
-        /// </returns>
-        public Task Start(Visual from, Visual to, bool forward)
+        /// <inheritdoc />
+        public Task Start(Visual from, Visual to, bool forward, CancellationToken cancellationToken)
         {
             var transitionTasks = PageTransitions
-                .Select(transition => transition.Start(from, to, forward))
+                .Select(transition => transition.Start(from, to, forward, cancellationToken))
                 .ToList();
             return Task.WhenAll(transitionTasks);
         }

src/Avalonia.Visuals/Animation/CrossFade.cs

@@ -1,5 +1,7 @@
 using System;
 using System.Collections.Generic;
+using System.Reactive.Disposables;
+using System.Threading;
 using System.Threading.Tasks;
 using Avalonia.Animation.Easings;
 using Avalonia.Styling;
@@ -97,49 +99,39 @@ namespace Avalonia.Animation
             set => _fadeOutAnimation.Easing = value;
         }
 
-        /// <summary>
-        /// Starts the animation.
-        /// </summary>
-        /// <param name="from">
-        /// The control that is being transitioned away from. May be null.
-        /// </param>
-        /// <param name="to">
-        /// The control that is being transitioned to. May be null.
-        /// </param>
-        /// <returns>
-        /// A <see cref="Task"/> that tracks the progress of the animation.
-        /// </returns>
-        public async Task Start(Visual from, Visual to)
+        /// <inheritdoc cref="Start(Visual, Visual, CancellationToken)" />
+        public async Task Start(Visual from, Visual to, CancellationToken cancellationToken)
         {
-            var tasks = new List<Task>();
-
-            if (to != null)
-            {
-                to.Opacity = 0;
-            }
-
-            if (from != null)
+            if (cancellationToken.IsCancellationRequested)
             {
-                tasks.Add(_fadeOutAnimation.RunAsync(from));
+                return;
             }
 
-            if (to != null)
+            var tasks = new List<Task>();
+            using (var disposables = new CompositeDisposable())
             {
-                to.IsVisible = true;
-                tasks.Add(_fadeInAnimation.RunAsync(to));
+                if (to != null)
+                {
+                    disposables.Add(to.SetValue(Visual.OpacityProperty, 0, Data.BindingPriority.Animation));
+                }
 
-            }
+                if (from != null)
+                {
+                    tasks.Add(_fadeOutAnimation.RunAsync(from, null, cancellationToken));
+                }
 
-            await Task.WhenAll(tasks);
+                if (to != null)
+                {
+                    to.IsVisible = true;
+                    tasks.Add(_fadeInAnimation.RunAsync(to, null, cancellationToken));
+                }
 
-            if (from != null)
-            {
-                from.IsVisible = false;
-            }
+                await Task.WhenAll(tasks);
 
-            if (to != null)
-            {
-                to.Opacity = 1;
+                if (from != null && !cancellationToken.IsCancellationRequested)
+                {
+                    from.IsVisible = false;
+                }
             }
         }
 
@@ -155,12 +147,13 @@ namespace Avalonia.Animation
         /// <param name="forward">
         /// Unused for cross-fades.
         /// </param>
+        /// <param name="cancellationToken">allowed cancel transition</param>
         /// <returns>
         /// A <see cref="Task"/> that tracks the progress of the animation.
         /// </returns>
-        Task IPageTransition.Start(Visual from, Visual to, bool forward)
+        Task IPageTransition.Start(Visual from, Visual to, bool forward, CancellationToken cancellationToken)
         {
-            return Start(from, to);
+            return Start(from, to, cancellationToken);
         }
     }
 }

src/Avalonia.Visuals/Animation/IPageTransition.cs

@@ -1,3 +1,4 @@
+using System.Threading;
 using System.Threading.Tasks;
 
 namespace Avalonia.Animation
@@ -19,9 +20,12 @@ namespace Avalonia.Animation
         /// <param name="forward">
         /// If the animation is bidirectional, controls the direction of the animation.
         /// </param>
+        /// <param name="cancellationToken">
+        /// Animation cancellation.
+        /// </param>
         /// <returns>
         /// A <see cref="Task"/> that tracks the progress of the animation.
         /// </returns>
-        Task Start(Visual from, Visual to, bool forward);
+        Task Start(Visual from, Visual to, bool forward, CancellationToken cancellationToken);
     }
 }

src/Avalonia.Visuals/Animation/PageSlide.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Threading;
 using System.Threading.Tasks;
 using Avalonia.Animation.Easings;
 using Avalonia.Media;
@@ -60,23 +61,14 @@ namespace Avalonia.Animation
         /// </summary>
         public Easing SlideOutEasing { get; set; } = new LinearEasing();
 
-        /// <summary>
-        /// Starts the animation.
-        /// </summary>
-        /// <param name="from">
-        /// The control that is being transitioned away from. May be null.
-        /// </param>
-        /// <param name="to">
-        /// The control that is being transitioned to. May be null.
-        /// </param>
-        /// <param name="forward">
-        /// If true, the new page is slid in from the right, or if false from the left.
-        /// </param>
-        /// <returns>
-        /// A <see cref="Task"/> that tracks the progress of the animation.
-        /// </returns>
-        public async Task Start(Visual from, Visual to, bool forward)
+        /// <inheritdoc />
+        public async Task Start(Visual from, Visual to, bool forward, CancellationToken cancellationToken)
         {
+            if (cancellationToken.IsCancellationRequested)
+            {
+                return;
+            }
+
             var tasks = new List<Task>();
             var parent = GetVisualParent(from, to);
             var distance = Orientation == SlideAxis.Horizontal ? parent.Bounds.Width : parent.Bounds.Height;
@@ -109,7 +101,7 @@ namespace Avalonia.Animation
                     },
                     Duration = Duration
                 };
-                tasks.Add(animation.RunAsync(from));
+                tasks.Add(animation.RunAsync(from, null, cancellationToken));
             }
 
             if (to != null)
@@ -140,12 +132,12 @@ namespace Avalonia.Animation
                     },
                     Duration = Duration
                 };
-                tasks.Add(animation.RunAsync(to));
+                tasks.Add(animation.RunAsync(to, null, cancellationToken));
             }
 
             await Task.WhenAll(tasks);
 
-            if (from != null)
+            if (from != null && !cancellationToken.IsCancellationRequested)
             {
                 from.IsVisible = false;
             }

src/Avalonia.Visuals/ApiCompatBaseline.txt

@@ -1,4 +1,11 @@
 Compat issues with assembly Avalonia.Visuals:
+MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.CompositePageTransition.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.CrossFade.Start(Avalonia.Visual, Avalonia.Visual)' does not exist in the implementation but it does exist in the contract.
+InterfacesShouldHaveSameMembers : Interface member 'public System.Threading.Tasks.Task Avalonia.Animation.IPageTransition.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean)' is present in the contract but not in the implementation.
+MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.IPageTransition.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean)' does not exist in the implementation but it does exist in the contract.
+InterfacesShouldHaveSameMembers : Interface member 'public System.Threading.Tasks.Task Avalonia.Animation.IPageTransition.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean, System.Threading.CancellationToken)' is present in the implementation but not in the contract.
+MembersMustExist : Member 'public System.Threading.Tasks.Task Avalonia.Animation.PageSlide.Start(Avalonia.Visual, Avalonia.Visual, System.Boolean)' does not exist in the implementation but it does exist in the contract.
+TypeCannotChangeClassification : Type 'Avalonia.Media.Immutable.ImmutableSolidColorBrush' is a 'class' in the implementation but is a 'struct' in the contract.
 MembersMustExist : Member 'public void Avalonia.Media.TextFormatting.DrawableTextRun.Draw(Avalonia.Media.DrawingContext)' does not exist in the implementation but it does exist in the contract.
 CannotAddAbstractMembers : Member 'public void Avalonia.Media.TextFormatting.DrawableTextRun.Draw(Avalonia.Media.DrawingContext, Avalonia.Point)' is abstract in the implementation but is missing in the contract.
 CannotSealType : Type 'Avalonia.Media.TextFormatting.GenericTextParagraphProperties' is actually (has the sealed modifier) sealed in the implementation but not sealed in the contract.
@@ -63,9 +70,8 @@ InterfacesShouldHaveSameMembers : Interface member 'public System.Boolean Avalon
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IGlyphRunImpl Avalonia.Platform.IPlatformRenderInterface.CreateGlyphRun(Avalonia.Media.GlyphRun)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IGlyphRunImpl Avalonia.Platform.IPlatformRenderInterface.CreateGlyphRun(Avalonia.Media.GlyphRun, System.Double)' is present in the contract but not in the implementation.
 MembersMustExist : Member 'public Avalonia.Platform.IGlyphRunImpl Avalonia.Platform.IPlatformRenderInterface.CreateGlyphRun(Avalonia.Media.GlyphRun, System.Double)' does not exist in the implementation but it does exist in the contract.
-Total Issues: 64
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IWriteableBitmapImpl Avalonia.Platform.IPlatformRenderInterface.LoadWriteableBitmap(System.IO.Stream)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IWriteableBitmapImpl Avalonia.Platform.IPlatformRenderInterface.LoadWriteableBitmap(System.String)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IWriteableBitmapImpl Avalonia.Platform.IPlatformRenderInterface.LoadWriteableBitmapToHeight(System.IO.Stream, System.Int32, Avalonia.Visuals.Media.Imaging.BitmapInterpolationMode)' is present in the implementation but not in the contract.
 InterfacesShouldHaveSameMembers : Interface member 'public Avalonia.Platform.IWriteableBitmapImpl Avalonia.Platform.IPlatformRenderInterface.LoadWriteableBitmapToWidth(System.IO.Stream, System.Int32, Avalonia.Visuals.Media.Imaging.BitmapInterpolationMode)' is present in the implementation but not in the contract.
-Total Issues: 11
+Total Issues: 75

src/Avalonia.Visuals/Media/BoxShadow.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Globalization;
+using System.Text;
 using Avalonia.Animation.Animators;
 using Avalonia.Utilities;
 
@@ -75,6 +76,46 @@ namespace Avalonia.Media
                 return rv;
             }
         }
+
+        public override string ToString()
+        {
+            var sb = new StringBuilder();
+
+            if (IsEmpty)
+            {
+                return "none";
+            }
+
+            if (IsInset)
+            {
+                sb.Append("inset");
+            }
+
+            if (OffsetX != 0.0)
+            {
+                sb.AppendFormat(" {0}", OffsetX.ToString());
+            }
+
+            if (OffsetY != 0.0)
+            {
+                sb.AppendFormat(" {0}", OffsetY.ToString());
+            }
+            
+            if (Blur != 0.0)
+            {
+                sb.AppendFormat(" {0}", Blur.ToString());
+            }
+
+            if (Spread != 0.0)
+            {
+                sb.AppendFormat(" {0}", Spread.ToString());
+            }
+
+            sb.AppendFormat(" {0}", Color.ToString());
+
+            return sb.ToString();
+        }
+
         public static unsafe BoxShadow Parse(string s)
         {
             if(s == null)

src/Avalonia.Visuals/Media/BoxShadows.cs

@@ -1,6 +1,6 @@
 using System;
-using System.Collections.Generic;
 using System.ComponentModel;
+using System.Text;
 using Avalonia.Animation.Animators;
 
 namespace Avalonia.Media
@@ -43,6 +43,24 @@ namespace Avalonia.Media
             }
         }
 
+        public override string ToString()
+        {
+            var sb = new StringBuilder();
+
+            if (Count == 0)
+            {
+                return "none";
+            }
+
+            foreach (var boxShadow in this)
+            {
+                sb.AppendFormat("{0} ", boxShadow.ToString());
+            }
+
+            return sb.ToString();
+
+        }
+
         [EditorBrowsable(EditorBrowsableState.Never)]
         public struct BoxShadowsEnumerator
         {

src/Avalonia.Visuals/Media/Brush.cs

@@ -2,6 +2,7 @@ using System;
 using System.ComponentModel;
 using Avalonia.Animation;
 using Avalonia.Animation.Animators;
+using Avalonia.Media.Immutable;
 
 namespace Avalonia.Media
 {
@@ -47,7 +48,7 @@ namespace Avalonia.Media
 
             if (s[0] == '#')
             {
-                return new SolidColorBrush(Color.Parse(s));
+                return new ImmutableSolidColorBrush(Color.Parse(s));
             }
 
             var brush = KnownColors.GetKnownBrush(s);

src/Avalonia.Visuals/Media/Immutable/ImmutableSolidColorBrush.cs

@@ -5,7 +5,7 @@ namespace Avalonia.Media.Immutable
     /// <summary>
     /// Fills an area with a solid color.
     /// </summary>
-    public readonly struct ImmutableSolidColorBrush : ISolidColorBrush, IEquatable<ImmutableSolidColorBrush>
+    public class ImmutableSolidColorBrush : ISolidColorBrush, IEquatable<ImmutableSolidColorBrush>
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="ImmutableSolidColorBrush"/> class.
@@ -48,8 +48,9 @@ namespace Avalonia.Media.Immutable
 
         public bool Equals(ImmutableSolidColorBrush other)
         {
-            // ReSharper disable once CompareOfFloatsByEqualityOperator
-            return Color == other.Color && Opacity == other.Opacity;
+            if (ReferenceEquals(null, other)) return false;
+            if (ReferenceEquals(this, other)) return true;
+            return Color.Equals(other.Color) && Opacity.Equals(other.Opacity);
         }
 
         public override bool Equals(object obj)
@@ -67,12 +68,12 @@ namespace Avalonia.Media.Immutable
 
         public static bool operator ==(ImmutableSolidColorBrush left, ImmutableSolidColorBrush right)
         {
-            return left.Equals(right);
+            return Equals(left, right);
         }
 
         public static bool operator !=(ImmutableSolidColorBrush left, ImmutableSolidColorBrush right)
         {
-            return !left.Equals(right);
+            return !Equals(left, right);
         }
 
         /// <summary>

src/Avalonia.Visuals/Rendering/SceneGraph/BitmapBlendModeNode.cs

@@ -19,7 +19,7 @@ namespace Avalonia.Rendering.SceneGraph
         }
 
         /// <summary>
-        /// Initializes a new instance of the <see cref="BitmapBlendNode"/> class that represents an
+        /// Initializes a new instance of the <see cref="BitmapBlendModeNode"/> class that represents an
         /// <see cref="BitmapBlendingMode"/> pop.
         /// </summary>
         public BitmapBlendModeNode()
@@ -40,7 +40,7 @@ namespace Avalonia.Rendering.SceneGraph
         /// <summary>
         /// Determines if this draw operation equals another.
         /// </summary>
-        /// <param name="opacity">The opacity of the other draw operation.</param>
+        /// <param name="blendingMode">the <see cref="BitmapBlendModeNode"/> how to compare</param>
         /// <returns>True if the draw operations are the same, otherwise false.</returns>
         /// <remarks>
         /// The properties of the other draw operation are passed in as arguments to prevent

src/Avalonia.X11/TransparencyHelper.cs

@@ -10,7 +10,6 @@ namespace Avalonia.X11
         private readonly X11Globals _globals;
         private WindowTransparencyLevel _currentLevel;
         private WindowTransparencyLevel _requestedLevel;
-        private bool _isCompositing;
         private bool _blurAtomsAreSet;
         
         public Action<WindowTransparencyLevel> TransparencyLevelChanged { get; set; }

src/Avalonia.X11/X11Window.cs

@@ -30,7 +30,6 @@ namespace Avalonia.X11
         ITopLevelImplWithTextInputMethod
     {
         private readonly AvaloniaX11Platform _platform;
-        private readonly IWindowImpl _popupParent;
         private readonly bool _popup;
         private readonly X11Info _x11;
         private XConfigureEvent? _configure;
@@ -297,6 +296,30 @@ namespace Avalonia.X11
 
         public Size ClientSize => new Size(_realSize.Width / RenderScaling, _realSize.Height / RenderScaling);
 
+        public Size? FrameSize
+        {
+            get
+            {
+                XGetWindowProperty(_x11.Display, _handle, _x11.Atoms._NET_FRAME_EXTENTS, IntPtr.Zero,
+                    new IntPtr(4), false, (IntPtr)Atom.AnyPropertyType, out var _,
+                    out var _, out var nitems, out var _, out var prop);
+
+                if (nitems.ToInt64() != 4)
+                {
+                    // Window hasn't been mapped by the WM yet, so can't get the extents.
+                    return null;
+                }
+
+                var data = (IntPtr*)prop.ToPointer();
+                var extents = new Thickness(data[0].ToInt32(), data[2].ToInt32(), data[1].ToInt32(), data[3].ToInt32());
+                XFree(prop);
+                
+                return new Size(
+                    (_realSize.Width + extents.Left + extents.Right) / RenderScaling,
+                    (_realSize.Height + extents.Top + extents.Bottom) / RenderScaling);
+            }
+        }
+
         public double RenderScaling
         {
             get
@@ -589,6 +612,13 @@ namespace Avalonia.X11
 
         private void OnPropertyChange(IntPtr atom, bool hasValue)
         {
+            if (atom == _x11.Atoms._NET_FRAME_EXTENTS)
+            {
+                // Occurs once the window has been mapped, which is the earliest the extents
+                // can be retrieved, so invoke event to force update of TopLevel.FrameSize.
+                Resized.Invoke(ClientSize);
+            }
+
             if (atom == _x11.Atoms._NET_WM_STATE)
             {
                 WindowState state = WindowState.Normal;

src/Linux/Avalonia.LinuxFramebuffer/FramebufferToplevelImpl.cs

@@ -15,7 +15,6 @@ namespace Avalonia.LinuxFramebuffer
         private readonly IOutputBackend _outputBackend;
         private readonly IInputBackend _inputBackend;
 
-        private bool _renderQueued;
         public IInputRoot InputRoot { get; private set; }
 
         public FramebufferToplevelImpl(IOutputBackend outputBackend, IInputBackend inputBackend)
@@ -62,6 +61,7 @@ namespace Avalonia.LinuxFramebuffer
         }
 
         public Size ClientSize => ScaledSize;
+        public Size? FrameSize => null;
         public IMouseDevice MouseDevice => new MouseDevice();
         public IPopupImpl CreatePopup() => null;
 

src/Linux/Avalonia.LinuxFramebuffer/Input/EvDev/EvDevTouchScreen.cs

@@ -7,7 +7,6 @@ namespace Avalonia.LinuxFramebuffer.Input.EvDev
     internal class EvDevSingleTouchScreen : EvDevDeviceHandler
     {
         private readonly IScreenInfoProvider _screenInfo;
-        private readonly int _width, _height;
         private readonly Matrix _calibration;
         private input_absinfo _axisX;
         private input_absinfo _axisY;

src/Linux/Avalonia.LinuxFramebuffer/LinuxFramebufferPlatform.cs

@@ -132,7 +132,10 @@ public static class LinuxFramebufferPlatformExtensions
 {
     public static int StartLinuxFbDev<T>(this T builder, string[] args, string fbdev = null, double scaling = 1)
         where T : AppBuilderBase<T>, new() =>
-        StartLinuxDirect(builder, args, new FbdevOutput(fbdev) {Scaling = scaling});
+        StartLinuxDirect(builder, args, new FbdevOutput(fileName: fbdev, format: null) { Scaling = scaling });
+    public static int StartLinuxFbDev<T>(this T builder, string[] args, string fbdev, PixelFormat? format, double scaling)
+        where T : AppBuilderBase<T>, new() =>
+        StartLinuxDirect(builder, args, new FbdevOutput(fileName: fbdev, format: format) { Scaling = scaling });
 
     public static int StartLinuxDrm<T>(this T builder, string[] args, string card = null, double scaling = 1)
         where T : AppBuilderBase<T>, new() => StartLinuxDirect(builder, args, new DrmOutput(card) {Scaling = scaling});

src/Linux/Avalonia.LinuxFramebuffer/LockedFramebuffer.cs

@@ -41,6 +41,6 @@ namespace Avalonia.LinuxFramebuffer
         public PixelSize Size => new PixelSize((int)_varInfo.xres, (int) _varInfo.yres);
         public int RowBytes => (int) _fixedInfo.line_length;
         public Vector Dpi { get; }
-        public PixelFormat Format => _varInfo.blue.offset == 16 ? PixelFormat.Rgba8888 : PixelFormat.Bgra8888;
+        public PixelFormat Format => _varInfo.bits_per_pixel == 16 ? PixelFormat.Rgb565 : _varInfo.blue.offset == 16 ? PixelFormat.Rgba8888 : PixelFormat.Bgra8888;
     }
 }

src/Linux/Avalonia.LinuxFramebuffer/Output/DrmOutput.cs

@@ -16,7 +16,6 @@ namespace Avalonia.LinuxFramebuffer.Output
     public unsafe class DrmOutput : IGlOutputBackend, IGlPlatformSurface
     {
         private DrmCard _card;
-        private readonly EglGlPlatformSurface _eglPlatformSurface;
         public PixelSize PixelSize => _mode.Resolution;
         public double Scaling { get; set; }
         public IGlContext PrimaryContext => _deferredContext;

src/Linux/Avalonia.LinuxFramebuffer/Output/FbdevOutput.cs

@@ -16,16 +16,33 @@ namespace Avalonia.LinuxFramebuffer
         private IntPtr _mappedAddress;
         public double Scaling { get; set; }
 
-        public FbdevOutput(string fileName = null)
+        /// <summary>
+        /// Create a Linux frame buffer device output
+        /// </summary>
+        /// <param name="fileName">The frame buffer device name.
+        /// Defaults to the value in environment variable FRAMEBUFFER or /dev/fb0 when FRAMEBUFFER is not set</param>
+        public FbdevOutput(string fileName = null) : this(fileName, null)
         {
-            fileName = fileName ?? Environment.GetEnvironmentVariable("FRAMEBUFFER") ?? "/dev/fb0";
+        }
+
+        /// <summary>
+        /// Create a Linux frame buffer device output
+        /// </summary>
+        /// <param name="fileName">The frame buffer device name.
+        /// Defaults to the value in environment variable FRAMEBUFFER or /dev/fb0 when FRAMEBUFFER is not set</param>
+        /// <param name="format">The required pixel format for the frame buffer.
+        /// A null value will leave the frame buffer in the current pixel format.
+        /// Otherwise sets the frame buffer to the required format</param>
+        public FbdevOutput(string fileName, PixelFormat? format)
+        {
+            fileName ??= Environment.GetEnvironmentVariable("FRAMEBUFFER") ?? "/dev/fb0";
             _fd = NativeUnsafeMethods.open(fileName, 2, 0);
             if (_fd <= 0)
                 throw new Exception("Error: " + Marshal.GetLastWin32Error());
 
             try
             {
-                Init();
+                Init(format);
             }
             catch
             {
@@ -34,25 +51,28 @@ namespace Avalonia.LinuxFramebuffer
             }
         }
 
-        void Init()
+        void Init(PixelFormat? format)
         {
             fixed (void* pnfo = &_varInfo)
             {
                 if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOGET_VSCREENINFO, pnfo))
                     throw new Exception("FBIOGET_VSCREENINFO error: " + Marshal.GetLastWin32Error());
 
-                SetBpp();
+                if (format.HasValue)
+                {
+                    SetBpp(format.Value);
 
-                if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOPUT_VSCREENINFO, pnfo))
-                    _varInfo.transp = new fb_bitfield();
+                    if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOPUT_VSCREENINFO, pnfo))
+                        _varInfo.transp = new fb_bitfield();
 
-                NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOPUT_VSCREENINFO, pnfo);
+                    NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOPUT_VSCREENINFO, pnfo);
 
-                if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOGET_VSCREENINFO, pnfo))
-                    throw new Exception("FBIOGET_VSCREENINFO error: " + Marshal.GetLastWin32Error());
+                    if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOGET_VSCREENINFO, pnfo))
+                        throw new Exception("FBIOGET_VSCREENINFO error: " + Marshal.GetLastWin32Error());
 
-                if (_varInfo.bits_per_pixel != 32)
-                    throw new Exception("Unable to set 32-bit display mode");
+                    if (_varInfo.bits_per_pixel != 32)
+                        throw new Exception("Unable to set 32-bit display mode");
+                }
             }
             fixed(void*pnfo = &_fixedInfo)
                 if (-1 == NativeUnsafeMethods.ioctl(_fd, FbIoCtl.FBIOGET_FSCREENINFO, pnfo))
@@ -70,17 +90,43 @@ namespace Avalonia.LinuxFramebuffer
             }
         }
 
-        void SetBpp()
+        void SetBpp(PixelFormat format)
         {
-            _varInfo.bits_per_pixel = 32;
-            _varInfo.grayscale = 0;
-            _varInfo.red = _varInfo.blue = _varInfo.green = _varInfo.transp = new fb_bitfield
+            switch (format)
             {
-                length = 8
-            };
-            _varInfo.green.offset = 8;
-            _varInfo.blue.offset = 16;
-            _varInfo.transp.offset = 24;
+            case PixelFormat.Rgba8888:
+                _varInfo.bits_per_pixel = 32;
+                _varInfo.grayscale = 0;
+                _varInfo.red = _varInfo.blue = _varInfo.green = _varInfo.transp = new fb_bitfield
+                {
+                    length = 8
+                };
+                _varInfo.green.offset = 8;
+                _varInfo.blue.offset = 16;
+                _varInfo.transp.offset = 24;
+                 break;
+            case PixelFormat.Bgra8888:
+                _varInfo.bits_per_pixel = 32;
+                _varInfo.grayscale = 0;
+                _varInfo.red = _varInfo.blue = _varInfo.green = _varInfo.transp = new fb_bitfield
+                {
+                    length = 8
+                };
+                _varInfo.green.offset = 8;
+                _varInfo.red.offset = 16;
+                _varInfo.transp.offset = 24;
+                 break;
+            case PixelFormat.Rgb565:
+                _varInfo.bits_per_pixel = 16;
+                _varInfo.grayscale = 0;
+                _varInfo.red = _varInfo.blue = _varInfo.green = _varInfo.transp = new fb_bitfield();
+                _varInfo.red.length = 5;
+                _varInfo.green.offset = 5;
+                _varInfo.green.length = 6;
+                _varInfo.blue.offset = 11;
+                _varInfo.blue.length = 5;
+                 break;
+            }
         }
 
         public string Id { get; private set; }

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlLanguageParseIntrinsics.cs

@@ -207,6 +207,20 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
                 return true;
             }
 
+            if (types.IBrush.IsAssignableFrom(type))
+            {
+                if (Color.TryParse(text, out Color color))
+                {
+                    var brushTypeRef = new XamlAstClrTypeReference(node, types.ImmutableSolidColorBrush, false);
+
+                    result = new XamlAstNewClrObjectNode(node, brushTypeRef,
+                        types.ImmutableSolidColorBrushConstructorColor,
+                        new List<IXamlAstValueNode> { new XamlConstantNode(node, types.UInt, color.ToUint32()) });
+
+                    return true;
+                }
+            }
+
             result = null;
             return false;
         }

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlBindingPathParser.cs

@@ -9,7 +9,6 @@ using XamlX.Ast;
 using XamlX.Transform;
 using XamlX.Transform.Transformers;
 using XamlX.TypeSystem;
-
 using XamlParseException = XamlX.XamlParseException;
 
 namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
@@ -21,6 +20,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
             if (node is XamlAstObjectNode binding && binding.Type.GetClrType().Equals(context.GetAvaloniaTypes().CompiledBindingExtension))
             {
                 var convertedNode = ConvertLongFormPropertiesToBindingExpressionNode(context, binding);
+                var foundPath = false;
 
                 if (binding.Arguments.Count > 0 && binding.Arguments[0] is XamlAstTextNode bindingPathText)
                 {
@@ -32,9 +32,18 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                         nodes.Insert(nodes.TakeWhile(x => x is BindingExpressionGrammar.ITransformNode).Count(), convertedNode);
                     }
 
-                    binding.Arguments[0] = new ParsedBindingPathNode(bindingPathText, context.GetAvaloniaTypes().CompiledBindingPath, nodes);
+                    if (nodes.Count == 1 && nodes[0] is BindingExpressionGrammar.EmptyExpressionNode)
+                    {
+                        binding.Arguments.RemoveAt(0);
+                    }
+                    else
+                    {
+                        binding.Arguments[0] = new ParsedBindingPathNode(bindingPathText, context.GetAvaloniaTypes().CompiledBindingPath, nodes);
+                        foundPath = true;
+                    }
                 }
-                else
+                
+                if (!foundPath)
                 {
                     var bindingPathAssignment = binding.Children.OfType<XamlAstXamlPropertyValueNode>()
                         .FirstOrDefault(v => v.Property.GetClrProperty().Name == "Path");
@@ -44,12 +53,19 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                         var reader = new CharacterReader(pathValue.Text.AsSpan());
                         var (nodes, _) = BindingExpressionGrammar.Parse(ref reader);
 
-                        if (convertedNode != null)
+                        if (nodes.Count == 1 && nodes[0] is BindingExpressionGrammar.EmptyExpressionNode)
                         {
-                            nodes.Insert(nodes.TakeWhile(x => x is BindingExpressionGrammar.ITransformNode).Count(), convertedNode);
+                            bindingPathAssignment.Values.RemoveAt(0);
                         }
+                        else
+                        {
+                            if (convertedNode != null)
+                            {
+                                nodes.Insert(nodes.TakeWhile(x => x is BindingExpressionGrammar.ITransformNode).Count(), convertedNode);
+                            }
 
-                        bindingPathAssignment.Values[0] = new ParsedBindingPathNode(pathValue, context.GetAvaloniaTypes().CompiledBindingPath, nodes);
+                            bindingPathAssignment.Values[0] = new ParsedBindingPathNode(pathValue, context.GetAvaloniaTypes().CompiledBindingPath, nodes);
+                        }
                     }
                 }
             }

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs

@@ -80,7 +80,10 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
         public IXamlType ColumnDefinitions { get; }
         public IXamlType Classes { get; }
         public IXamlMethod ClassesBindMethod { get; }
-        public IXamlProperty StyledElementClassesProperty { get; set; }
+        public IXamlProperty StyledElementClassesProperty { get; }
+        public IXamlType IBrush { get; }
+        public IXamlType ImmutableSolidColorBrush { get; }
+        public IXamlConstructor ImmutableSolidColorBrushConstructorColor { get; }
 
         public AvaloniaXamlIlWellKnownTypes(TransformerConfiguration cfg)
         {
@@ -178,6 +181,10 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                 .FindMethod( "BindClass", IDisposable, false, IStyledElement,
                 cfg.WellKnownTypes.String,
                 IBinding, cfg.WellKnownTypes.Object);
+
+            IBrush = cfg.TypeSystem.GetType("Avalonia.Media.IBrush");
+            ImmutableSolidColorBrush = cfg.TypeSystem.GetType("Avalonia.Media.Immutable.ImmutableSolidColorBrush");
+            ImmutableSolidColorBrushConstructorColor = ImmutableSolidColorBrush.GetConstructor(new List<IXamlType> { UInt });
         }
     }
 

src/Skia/Avalonia.Skia/DrawingContextImpl.cs

@@ -591,7 +591,7 @@ namespace Avalonia.Skia
         /// Configure paint wrapper for using gradient brush.
         /// </summary>
         /// <param name="paintWrapper">Paint wrapper.</param>
-        /// <param name="targetSize">Target size.</param>
+        /// <param name="targetRect">Target bound rect.</param>
         /// <param name="gradientBrush">Gradient brush.</param>
         private void ConfigureGradientBrush(ref PaintWrapper paintWrapper, Rect targetRect, IGradientBrush gradientBrush)
         {

src/Skia/Avalonia.Skia/Gpu/ISkiaGpu.cs

@@ -16,11 +16,12 @@ namespace Avalonia.Skia
         /// <param name="surfaces">Surfaces.</param>
         /// <returns>Created render target or <see langword="null"/> if it fails.</returns>
         ISkiaGpuRenderTarget TryCreateRenderTarget(IEnumerable<object> surfaces);
-        
+
         /// <summary>
         /// Creates an offscreen render target surface
         /// </summary>
         /// <param name="size">size in pixels</param>
+        /// <param name="session">current Skia render session</param>
         ISkiaSurface TryCreateSurface(PixelSize size, ISkiaGpuRenderSession session);
     }
     

src/Windows/Avalonia.Win32.Interop/Wpf/WpfTopLevelImpl.cs

@@ -100,6 +100,7 @@ namespace Avalonia.Win32.Interop.Wpf
         }
 
         Size ITopLevelImpl.ClientSize => _finalSize;
+        Size? ITopLevelImpl.FrameSize => null;
         IMouseDevice ITopLevelImpl.MouseDevice => _mouse;
 
         double ITopLevelImpl.RenderScaling => PresentationSource.FromVisual(this)?.CompositionTarget?.TransformToDevice.M11 ?? 1;

src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs

@@ -745,6 +745,26 @@ namespace Avalonia.Win32.Interop
             WM_DISPATCH_WORK_ITEM = WM_USER,
         }
 
+        public enum DwmWindowAttribute : uint
+        {
+            DWMWA_NCRENDERING_ENABLED = 1,
+            DWMWA_NCRENDERING_POLICY,
+            DWMWA_TRANSITIONS_FORCEDISABLED,
+            DWMWA_ALLOW_NCPAINT,
+            DWMWA_CAPTION_BUTTON_BOUNDS,
+            DWMWA_NONCLIENT_RTL_LAYOUT,
+            DWMWA_FORCE_ICONIC_REPRESENTATION,
+            DWMWA_FLIP3D_POLICY,
+            DWMWA_EXTENDED_FRAME_BOUNDS,
+            DWMWA_HAS_ICONIC_BITMAP,
+            DWMWA_DISALLOW_PEEK,
+            DWMWA_EXCLUDED_FROM_PEEK,
+            DWMWA_CLOAK,
+            DWMWA_CLOAKED,
+            DWMWA_FREEZE_REPRESENTATION,
+            DWMWA_LAST
+        };
+
         public enum MapVirtualKeyMapTypes : uint
         {
             MAPVK_VK_TO_VSC = 0x00,
@@ -1388,6 +1408,9 @@ namespace Avalonia.Win32.Interop
         [DllImport("dwmapi.dll")]
         public static extern int DwmExtendFrameIntoClientArea(IntPtr hwnd, ref MARGINS margins);
 
+        [DllImport("dwmapi.dll")]
+        public static extern int DwmGetWindowAttribute(IntPtr hwnd, int dwAttribute, out RECT pvAttribute, int cbAttribute);
+
         [DllImport("dwmapi.dll")]
         public static extern int DwmIsCompositionEnabled(out bool enabled);
 

src/Windows/Avalonia.Win32/WinRT/Composition/WinUICompositorConnection.cs

@@ -17,7 +17,6 @@ namespace Avalonia.Win32.WinRT.Composition
     class WinUICompositorConnection : IRenderTimer
     {
         private readonly EglContext _syncContext;
-        private IntPtr _queue;
         private ICompositor _compositor;
         private ICompositor2 _compositor2;
         private ICompositor5 _compositor5;

src/Windows/Avalonia.Win32/WindowImpl.cs

@@ -213,6 +213,21 @@ namespace Avalonia.Win32
             }
         }
 
+        public Size? FrameSize
+        {
+            get
+            {
+                if (DwmIsCompositionEnabled(out var compositionEnabled) != 0 || !compositionEnabled)
+                {
+                    GetWindowRect(_hwnd, out var rcWindow);
+                    return new Size(rcWindow.Width, rcWindow.Height) / RenderScaling;
+                }
+
+                DwmGetWindowAttribute(_hwnd, (int)DwmWindowAttribute.DWMWA_EXTENDED_FRAME_BOUNDS, out var rect, Marshal.SizeOf(typeof(RECT)));
+                return new Size(rect.Width, rect.Height) / RenderScaling;
+            }
+        }
+
         public IScreenImpl Screen { get; }
 
         public IPlatformHandle Handle { get; private set; }

src/iOS/Avalonia.iOS/AvaloniaView.cs

@@ -91,6 +91,7 @@ namespace Avalonia.iOS
             }
 
             public Size ClientSize => new Size(_view.Bounds.Width, _view.Bounds.Height);
+            public Size? FrameSize => null;
             public double RenderScaling => _view.ContentScaleFactor;
             public IEnumerable<object> Surfaces { get; set; }
             public Action<RawInputEventArgs> Input { get; set; }

tests/Avalonia.Animation.UnitTests/AnimationIterationTests.cs

@@ -9,6 +9,8 @@ using Avalonia.UnitTests;
 using Avalonia.Data;
 using Xunit;
 using Avalonia.Animation.Easings;
+using System.Threading;
+using System.Reactive.Linq;
 
 namespace Avalonia.Animation.UnitTests
 {
@@ -176,5 +178,271 @@ namespace Avalonia.Animation.UnitTests
             clock.Step(TimeSpan.FromSeconds(0.100d));
             Assert.Equal(border.Width, 300d);
         }
+
+        [Fact(Skip = "See #6111")]
+        public void Dispose_Subscription_Should_Stop_Animation()
+        {
+            var keyframe1 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 200d),
+                },
+                Cue = new Cue(1d)
+            };
+
+            var keyframe2 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 100d),
+                },
+                Cue = new Cue(0d)
+            };
+
+            var animation = new Animation()
+            {
+                Duration = TimeSpan.FromSeconds(10),
+                Delay = TimeSpan.FromSeconds(0),
+                DelayBetweenIterations = TimeSpan.FromSeconds(0),
+                IterationCount = new IterationCount(1),
+                Children =
+                {
+                    keyframe2,
+                    keyframe1
+                }
+            };
+
+            var border = new Border()
+            {
+                Height = 100d,
+                Width = 50d
+            };
+            var propertyChangedCount = 0;
+            var animationCompletedCount = 0;
+            border.PropertyChanged += (sender, e) =>
+            {
+                if (e.Property == Control.WidthProperty)
+                {
+                    propertyChangedCount++;
+                }
+            };
+
+            var clock = new TestClock();
+            var disposable = animation.Apply(border, clock, Observable.Return(true), () => animationCompletedCount++);
+
+            Assert.Equal(0, propertyChangedCount);
+
+            clock.Step(TimeSpan.FromSeconds(0));
+            Assert.Equal(0, animationCompletedCount);
+            Assert.Equal(1, propertyChangedCount);
+
+            disposable.Dispose();
+
+            // Clock ticks should be ignored after Dispose
+            clock.Step(TimeSpan.FromSeconds(5));
+            clock.Step(TimeSpan.FromSeconds(6));
+            clock.Step(TimeSpan.FromSeconds(7));
+
+            // On animation disposing (cancellation) on completed is not invoked (is it expected?)
+            Assert.Equal(0, animationCompletedCount);
+            // Initial property changed before cancellation + animation value removal.
+            Assert.Equal(2, propertyChangedCount);
+        }
+
+        [Fact]
+        public void Do_Not_Run_Cancelled_Animation()
+        {
+            var keyframe1 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 200d),
+                },
+                Cue = new Cue(1d)
+            };
+
+            var keyframe2 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 100d),
+                },
+                Cue = new Cue(0d)
+            };
+
+            var animation = new Animation()
+            {
+                Duration = TimeSpan.FromSeconds(10),
+                Delay = TimeSpan.FromSeconds(0),
+                DelayBetweenIterations = TimeSpan.FromSeconds(0),
+                IterationCount = new IterationCount(1),
+                Children =
+                {
+                    keyframe2,
+                    keyframe1
+                }
+            };
+
+            var border = new Border()
+            {
+                Height = 100d,
+                Width = 100d
+            };
+            var propertyChangedCount = 0;
+            border.PropertyChanged += (sender, e) =>
+            {
+                if (e.Property == Control.WidthProperty)
+                {
+                    propertyChangedCount++;
+                }
+            };
+
+            var clock = new TestClock();
+            var cancellationTokenSource = new CancellationTokenSource();
+            cancellationTokenSource.Cancel();
+            var animationRun = animation.RunAsync(border, clock, cancellationTokenSource.Token);
+
+            clock.Step(TimeSpan.FromSeconds(10));
+            Assert.Equal(0, propertyChangedCount);
+            Assert.True(animationRun.IsCompleted);
+        }
+
+        [Fact(Skip = "See #6111")]
+        public void Cancellation_Should_Stop_Animation()
+        {
+            var keyframe1 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 200d),
+                },
+                Cue = new Cue(1d)
+            };
+
+            var keyframe2 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 100d),
+                },
+                Cue = new Cue(0d)
+            };
+
+            var animation = new Animation()
+            {
+                Duration = TimeSpan.FromSeconds(10),
+                Delay = TimeSpan.FromSeconds(0),
+                DelayBetweenIterations = TimeSpan.FromSeconds(0),
+                IterationCount = new IterationCount(1),
+                Children =
+                {
+                    keyframe2,
+                    keyframe1
+                }
+            };
+
+            var border = new Border()
+            {
+                Height = 100d,
+                Width = 50d
+            };
+            var propertyChangedCount = 0;
+            border.PropertyChanged += (sender, e) =>
+            {
+                if (e.Property == Control.WidthProperty)
+                {
+                    propertyChangedCount++;
+                }
+            };
+
+            var clock = new TestClock();
+            var cancellationTokenSource = new CancellationTokenSource();
+            var animationRun = animation.RunAsync(border, clock, cancellationTokenSource.Token);
+
+            Assert.Equal(0, propertyChangedCount);
+
+            clock.Step(TimeSpan.FromSeconds(0));
+            Assert.False(animationRun.IsCompleted);
+            Assert.Equal(1, propertyChangedCount);
+
+            cancellationTokenSource.Cancel();
+            clock.Step(TimeSpan.FromSeconds(1));
+            clock.Step(TimeSpan.FromSeconds(2));
+            clock.Step(TimeSpan.FromSeconds(3));
+            //Assert.Equal(2, propertyChangedCount);
+
+            animationRun.Wait();
+
+            clock.Step(TimeSpan.FromSeconds(6));
+            Assert.True(animationRun.IsCompleted);
+            Assert.Equal(2, propertyChangedCount);
+        }
+
+        [Fact]
+        public void Cancellation_Of_Completed_Animation_Does_Not_Fail()
+        {
+            var keyframe1 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 200d),
+                },
+                Cue = new Cue(1d)
+            };
+
+            var keyframe2 = new KeyFrame()
+            {
+                Setters =
+                {
+                    new Setter(Border.WidthProperty, 100d),
+                },
+                Cue = new Cue(0d)
+            };
+
+            var animation = new Animation()
+            {
+                Duration = TimeSpan.FromSeconds(10),
+                Delay = TimeSpan.FromSeconds(0),
+                DelayBetweenIterations = TimeSpan.FromSeconds(0),
+                IterationCount = new IterationCount(1),
+                Children =
+                {
+                    keyframe2,
+                    keyframe1
+                }
+            };
+
+            var border = new Border()
+            {
+                Height = 100d,
+                Width = 50d
+            };
+            var propertyChangedCount = 0;
+            border.PropertyChanged += (sender, e) =>
+            {
+                if (e.Property == Control.WidthProperty)
+                {
+                    propertyChangedCount++;
+                }
+            };
+
+            var clock = new TestClock();
+            var cancellationTokenSource = new CancellationTokenSource();
+            var animationRun = animation.RunAsync(border, clock, cancellationTokenSource.Token);
+
+            Assert.Equal(0, propertyChangedCount);
+
+            clock.Step(TimeSpan.FromSeconds(0));
+            Assert.False(animationRun.IsCompleted);
+            Assert.Equal(1, propertyChangedCount);
+
+            clock.Step(TimeSpan.FromSeconds(10));
+            Assert.True(animationRun.IsCompleted);
+            Assert.Equal(2, propertyChangedCount);
+
+            cancellationTokenSource.Cancel();
+            animationRun.Wait();
+        }
     }
 }

tests/Avalonia.Controls.UnitTests/ComboBoxTests.cs

@@ -201,6 +201,65 @@ namespace Avalonia.Controls.UnitTests
                 
             }
             
-        } 
+        }
+
+        [Fact]
+        public void Close_Window_On_Alt_F4_When_ComboBox_Is_Focus()
+        {
+            var inputManagerMock = new Moq.Mock<IInputManager>();
+            var services = TestServices.StyledWindow.With(inputManager: inputManagerMock.Object);
+
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var window = new Window();
+
+                window.KeyDown += (s, e) =>
+                 {
+                     if (e.Handled == false 
+                     && e.KeyModifiers.HasAllFlags(KeyModifiers.Alt) == true 
+                     && e.Key == Key.F4 )
+                     {
+                         e.Handled = true;
+                         window.Close();
+                     }
+                 };
+
+                var count = 0;
+
+                var target = new ComboBox
+                {
+                    Items = new[] { new Canvas() },
+                    SelectedIndex = 0,
+                    Template = GetTemplate(),
+                };
+
+                window.Content = target;
+
+
+                window.Closing +=
+                    (sender, e) =>
+                    {
+                        count++;
+                    };
+
+                window.Show();
+
+                target.Focus();
+
+                _helper.Down(target);
+                _helper.Up(target);
+                Assert.True(target.IsDropDownOpen);
+
+                target.RaiseEvent(new KeyEventArgs
+                {
+                    RoutedEvent = InputElement.KeyDownEvent,
+                    KeyModifiers = KeyModifiers.Alt,
+                    Key = Key.F4
+                });
+
+
+                Assert.Equal(1, count);
+            }
+        }
     }
 }

tests/Avalonia.Controls.UnitTests/TreeViewTests.cs

@@ -1066,7 +1066,7 @@ namespace Avalonia.Controls.UnitTests
         [Fact]
         public void Auto_Expanding_In_Style_Should_Not_Break_Range_Selection()
         {
-            /// Issue #2980.
+            // Issue #2980.
             using (Application())
             {
                 var target = new DerivedTreeView

tests/Avalonia.Controls.UnitTests/WindowTests.cs

@@ -279,10 +279,11 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var parent = Mock.Of<Window>();
+                var parent = new Window();
                 var renderer = new Mock<IRenderer>();
                 var target = new Window(CreateImpl(renderer));
 
+                parent.Show();
                 target.ShowDialog<object>(parent);
 
                 renderer.Verify(x => x.Start(), Times.Once);
@@ -294,10 +295,11 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var parent = Mock.Of<Window>();
+                var parent = new Window();
                 var target = new Window();
                 var raised = false;
 
+                parent.Show();
                 target.Opened += (s, e) => raised = true;
 
                 target.ShowDialog<object>(parent);
@@ -326,14 +328,15 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var parent = new Mock<Window>();
+                var parent = new Window();
                 var windowImpl = new Mock<IWindowImpl>();
                 windowImpl.SetupProperty(x => x.Closed);
                 windowImpl.Setup(x => x.DesktopScaling).Returns(1);
                 windowImpl.Setup(x => x.RenderScaling).Returns(1);
 
+                parent.Show();
                 var target = new Window(windowImpl.Object);
-                var task = target.ShowDialog<bool>(parent.Object);
+                var task = target.ShowDialog<bool>(parent);
 
                 windowImpl.Object.Closed();
 
@@ -366,14 +369,16 @@ namespace Avalonia.Controls.UnitTests
         {
             using (UnitTestApplication.Start(TestServices.StyledWindow))
             {
-                var parent = new Mock<Window>();
+                var parent = new Window();
                 var windowImpl = new Mock<IWindowImpl>();
                 windowImpl.SetupProperty(x => x.Closed);
                 windowImpl.Setup(x => x.DesktopScaling).Returns(1);
                 windowImpl.Setup(x => x.RenderScaling).Returns(1);
 
+                parent.Show();
+
                 var target = new Window(windowImpl.Object);
-                var task = target.ShowDialog<bool>(parent.Object);
+                var task = target.ShowDialog<bool>(parent);
 
                 windowImpl.Object.Closed();
                 await task;
@@ -381,12 +386,128 @@ namespace Avalonia.Controls.UnitTests
                 var openedRaised = false;
                 target.Opened += (s, e) => openedRaised = true;
 
-                var ex = await Assert.ThrowsAsync<InvalidOperationException>(() => target.ShowDialog<bool>(parent.Object));
+                var ex = await Assert.ThrowsAsync<InvalidOperationException>(() => target.ShowDialog<bool>(parent));
                 Assert.Equal("Cannot re-show a closed window.", ex.Message);
                 Assert.False(openedRaised);
             }
         }
 
+        [Fact]
+        public void Calling_Show_With_Closed_Parent_Window_Should_Throw()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var parent = new Window();
+                var target = new Window();
+
+                parent.Close();
+
+                var ex = Assert.Throws<InvalidOperationException>(() => target.Show(parent));
+                Assert.Equal("Cannot show a window with a closed parent.", ex.Message);
+            }
+        }
+
+        [Fact]
+        public async Task Calling_ShowDialog_With_Closed_Parent_Window_Should_Throw()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var parent = new Window();
+                var target = new Window();
+
+                parent.Close();
+
+                var ex = await Assert.ThrowsAsync<InvalidOperationException>(() => target.ShowDialog(parent));
+                Assert.Equal("Cannot show a window with a closed owner.", ex.Message);
+            }
+        }
+
+        [Fact]
+        public void Calling_Show_With_Invisible_Parent_Window_Should_Throw()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var parent = new Window();
+                var target = new Window();
+
+                var ex = Assert.Throws<InvalidOperationException>(() => target.Show(parent));
+                Assert.Equal("Cannot show window with non-visible parent.", ex.Message);
+            }
+        }
+
+        [Fact]
+        public async Task Calling_ShowDialog_With_Invisible_Parent_Window_Should_Throw()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var parent = new Window();
+                var target = new Window();
+
+                var ex = await Assert.ThrowsAsync<InvalidOperationException>(() => target.ShowDialog(parent));
+                Assert.Equal("Cannot show window with non-visible parent.", ex.Message);
+            }
+        }
+
+        [Fact]
+        public void Calling_Show_With_Self_As_Parent_Window_Should_Throw()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var target = new Window();
+
+                var ex = Assert.Throws<InvalidOperationException>(() => target.Show(target));
+                Assert.Equal("A Window cannot be its own parent.", ex.Message);
+            }
+        }
+
+        [Fact]
+        public async Task Calling_ShowDialog_With_Self_As_Parent_Window_Should_Throw()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var target = new Window();
+
+                var ex = await Assert.ThrowsAsync<InvalidOperationException>(() => target.ShowDialog(target));
+                Assert.Equal("A Window cannot be its own owner.", ex.Message);
+            }
+        }
+
+        [Fact]
+        public void Hiding_Parent_Window_Should_Close_Children()
+        {
+            using (UnitTestApplication.Start(TestServices.MockWindowingPlatform))
+            {
+                var parent = new Window();
+                var child = new Window();
+
+                parent.Show();
+                child.Show(parent);
+
+                parent.Hide();
+
+                Assert.False(parent.IsVisible);
+                Assert.False(child.IsVisible);
+            }
+        }
+
+        [Fact]
+        public void Hiding_Parent_Window_Should_Close_Dialog_Children()
+        {
+            using (UnitTestApplication.Start(TestServices.MockWindowingPlatform))
+            {
+                var parent = new Window();
+                var child = new Window();
+
+                parent.Show();
+                child.ShowDialog(parent);
+
+                parent.Hide();
+
+                Assert.False(parent.IsVisible);
+                Assert.False(child.IsVisible);
+            }
+        }
+
         [Fact]
         public void Window_Should_Be_Centered_When_WindowStartupLocation_Is_CenterScreen()
         {
@@ -686,6 +807,7 @@ namespace Avalonia.Controls.UnitTests
             protected override void Show(Window window)
             {
                 var owner = new Window();
+                owner.Show();
                 window.ShowDialog(owner);
             }
         }

tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/CompiledBindingExtensionTests.cs

@@ -938,6 +938,110 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             }
         }
 
+        [Fact]
+        public void SupportsEmptyPath()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
+        xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests'
+        x:DataType='local:TestDataContext'>
+    <TextBlock Text='{CompiledBinding}' Name='textBlock' />
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var textBlock = window.FindControl<TextBlock>("textBlock");
+
+                var dataContext = new TestDataContext
+                {
+                    StringProperty = "foobar"
+                };
+
+                window.DataContext = dataContext;
+
+                Assert.Equal(typeof(TestDataContext).FullName, textBlock.Text);
+            }
+        }
+
+        [Fact]
+        public void SupportsEmptyPathWithStringFormat()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
+        xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests'
+        x:DataType='local:TestDataContext'>
+    <TextBlock Text='{CompiledBinding StringFormat=bar-\{0\}}' Name='textBlock' />
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var textBlock = window.FindControl<TextBlock>("textBlock");
+
+                var dataContext = new TestDataContext
+                {
+                    StringProperty = "foobar"
+                };
+
+                window.DataContext = dataContext;
+
+                Assert.Equal("bar-" + typeof(TestDataContext).FullName, textBlock.Text);
+            }
+        }
+
+        [Fact]
+        public void SupportsDotPath()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
+        xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests'
+        x:DataType='local:TestDataContext'>
+    <TextBlock Text='{CompiledBinding .}' Name='textBlock' />
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var textBlock = window.FindControl<TextBlock>("textBlock");
+
+                var dataContext = new TestDataContext
+                {
+                    StringProperty = "foobar"
+                };
+
+                window.DataContext = dataContext;
+
+                Assert.Equal(typeof(TestDataContext).FullName, textBlock.Text);
+            }
+        }
+
+        [Fact]
+        public void SupportsExplicitDotPathWithStringFormat()
+        {
+            using (UnitTestApplication.Start(TestServices.StyledWindow))
+            {
+                var xaml = @"
+<Window xmlns='https://github.com/avaloniaui'
+        xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'
+        xmlns:local='clr-namespace:Avalonia.Markup.Xaml.UnitTests.MarkupExtensions;assembly=Avalonia.Markup.Xaml.UnitTests'
+        x:DataType='local:TestDataContext'>
+    <TextBlock Text='{CompiledBinding Path=., StringFormat=bar-\{0\}}' Name='textBlock' />
+</Window>";
+                var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
+                var textBlock = window.FindControl<TextBlock>("textBlock");
+
+                var dataContext = new TestDataContext
+                {
+                    StringProperty = "foobar"
+                };
+
+                window.DataContext = dataContext;
+
+                Assert.Equal("bar-" + typeof(TestDataContext).FullName, textBlock.Text);
+            }
+        }
+
         void Throws(string type, Action cb)
         {
             try

tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/DynamicResourceExtensionTests.cs

@@ -33,7 +33,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
             DelayedBinding.ApplyBindings(border);
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 
@@ -80,7 +80,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
             DelayedBinding.ApplyBindings(border);
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 
@@ -108,7 +108,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
             DelayedBinding.ApplyBindings(border);
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 
@@ -140,7 +140,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
             DelayedBinding.ApplyBindings(border);
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 
@@ -212,7 +212,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var button = window.FindControl<Button>("button");
-                var brush = (SolidColorBrush)button.Background;
+                var brush = (ISolidColorBrush)button.Background;
 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
@@ -241,7 +241,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var button = window.FindControl<Button>("button");
-                var brush = (SolidColorBrush)button.Background;
+                var brush = (ISolidColorBrush)button.Background;
 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
@@ -275,7 +275,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var border = window.FindControl<Border>("border");
-                var brush = (SolidColorBrush)border.Background;
+                var brush = (ISolidColorBrush)border.Background;
 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
@@ -317,7 +317,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
                 window.Show();
 
                 var border = (Border)button.GetVisualChildren().Single();
-                var brush = (SolidColorBrush)border.Background;
+                var brush = (ISolidColorBrush)border.Background;
 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
@@ -648,7 +648,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
                 DelayedBinding.ApplyBindings(border);
 
-                var brush = (SolidColorBrush)border.Background;
+                var brush = (ISolidColorBrush)border.Background;
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
 
                 window.Content = null;
@@ -657,7 +657,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
                 window.Content = border;
 
-                brush = (SolidColorBrush)border.Background;
+                brush = (ISolidColorBrush)border.Background;
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
         }

tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/ResourceIncludeTests.cs

@@ -39,7 +39,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
                     var userControl = (UserControl)AvaloniaRuntimeXamlLoader.Load(xaml);
                     var border = userControl.FindControl<Border>("border");
 
-                    var brush = (SolidColorBrush)border.Background;
+                    var brush = (ISolidColorBrush)border.Background;
                     Assert.Equal(0xff506070, brush.Color.ToUint32());
                 }
             }

tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/StaticResourceExtensionTests.cs

@@ -29,7 +29,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             var userControl = (UserControl)AvaloniaRuntimeXamlLoader.Load(xaml);
             var border = userControl.FindControl<Border>("border");
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 
@@ -72,7 +72,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             var userControl = (UserControl)AvaloniaRuntimeXamlLoader.Load(xaml);
             var border = userControl.FindControl<Border>("border");
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 
@@ -119,7 +119,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             var userControl = (UserControl)AvaloniaRuntimeXamlLoader.Load(xaml);
             var border = userControl.FindControl<Border>("border");
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 
@@ -149,7 +149,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             var userControl = (UserControl)AvaloniaRuntimeXamlLoader.Load(xaml);
             var border = userControl.FindControl<Border>("border");
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 
@@ -200,7 +200,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var button = window.FindControl<Button>("button");
-                var brush = (SolidColorBrush)button.Background;
+                var brush = (ISolidColorBrush)button.Background;
 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
@@ -229,7 +229,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var button = window.FindControl<Button>("button");
-                var brush = (SolidColorBrush)button.Background;
+                var brush = (ISolidColorBrush)button.Background;
 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
@@ -263,7 +263,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
 
                 var window = (Window)AvaloniaRuntimeXamlLoader.Load(xaml);
                 var border = window.FindControl<Border>("border");
-                var brush = (SolidColorBrush)border.Background;
+                var brush = (ISolidColorBrush)border.Background;
 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
@@ -344,7 +344,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
                 window.Show();
 
                 var border = (Border)button.GetVisualChildren().Single();
-                var brush = (SolidColorBrush)border.Background;
+                var brush = (ISolidColorBrush)border.Background;
                 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }
@@ -484,12 +484,12 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             var userControl = (UserControl)AvaloniaRuntimeXamlLoader.Load(xaml);
             var border = userControl.FindControl<Border>("border");
 
-            var brush = (SolidColorBrush)border.Background;
+            var brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
 
             userControl.Content = null;
 
-            brush = (SolidColorBrush)border.Background;
+            brush = (ISolidColorBrush)border.Background;
             Assert.Equal(0xff506070, brush.Color.ToUint32());
         }
 

tests/Avalonia.Markup.Xaml.UnitTests/Xaml/BasicTests.cs

@@ -512,7 +512,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
             style.TryGetResource("Brush", out var brush);
 
             Assert.NotNull(brush);
-            Assert.IsType<SolidColorBrush>(brush);
+            Assert.IsAssignableFrom<ISolidColorBrush>(brush);
             Assert.Equal(Colors.White, ((ISolidColorBrush)brush).Color);
 
             style.TryGetResource("Double", out var d);

tests/Avalonia.Markup.Xaml.UnitTests/Xaml/StyleTests.cs

@@ -101,7 +101,7 @@ namespace Avalonia.Markup.Xaml.UnitTests.Xaml
     </UserControl.Styles>
 </UserControl>";
                 var userControl = (UserControl)AvaloniaRuntimeXamlLoader.Load(xaml);
-                var brush = (SolidColorBrush)((Style)userControl.Styles[0]).Resources["brush"];
+                var brush = (ISolidColorBrush)((Style)userControl.Styles[0]).Resources["brush"];
 
                 Assert.Equal(0xff506070, brush.Color.ToUint32());
             }