[AVN] Introduced ComObjectWeakPtr (#17041)

1 year ago · e2a07cc04d
4 changed files with 165 additions and 80 deletions
--- a/native/Avalonia.Native/inc/comimpl.h
+++ b/native/Avalonia.Native/inc/comimpl.h
@ -7,6 +7,7 @@
 #define COMIMPL_H_INCLUDED

 #include <cstring>
+#include <memory>

 /**
 START_COM_CALL causes AddRef to be called at the beginning of a function.
@ -100,6 +101,13 @@ public:
        return _obj;
    }
    
+    template<class TCast> ComPtr<TCast> dynamicCast()
+    {
+        if(_obj == nullptr)
+            return nullptr;
+        return dynamic_cast<TCast*>(_obj);
+    }
+    
    TInterface** getPPV()
    {
        return &_obj;
@ -130,10 +138,18 @@ public:
    }
 };

+class ComObjectWeakRefToken
+{
+public:
+    bool Alive = true;
+};
+
+
 class ComObject : public virtual IUnknown
 {
 private:
    unsigned int _refCount;
+    std::shared_ptr<ComObjectWeakRefToken> _weakRefs;
 public:
    
    virtual ULONG AddRef()
@ -157,10 +173,22 @@ public:
        _refCount = 1;
        
    }
+    
    virtual ~ComObject()
    {
+        if(_weakRefs)
+            _weakRefs->Alive = false;
    }
    
+    std::shared_ptr<ComObjectWeakRefToken> __GetWeakRefToken()
+    {
+        if(_weakRefs == nullptr)
+        {
+            _weakRefs = std::make_shared<ComObjectWeakRefToken>();
+        }
+        return _weakRefs;
+    }
+
    
    virtual ::HRESULT STDMETHODCALLTYPE QueryInterfaceImpl(REFIID riid, void **ppvObject) = 0;
    
@ -188,6 +216,41 @@ protected:
 };


+template<class TClass>
+class ComObjectWeakPtr
+{
+private:
+    std::shared_ptr<ComObjectWeakRefToken> _token;
+    TClass* _rawPtr;
+public:
+    ComPtr<TClass> tryGet()
+    {
+        if(_rawPtr == nullptr)
+            return nullptr;
+        if(_token->Alive)
+            return _rawPtr;
+        return nullptr;
+    }
+    
+    template<class TCast> ComPtr<TCast> tryGetWithCast()
+    {
+        return tryGet().template dynamicCast<TCast>();
+    }
+    
+    ComObjectWeakPtr(TClass* obj)
+    {
+        _rawPtr = obj;
+        if(obj)
+            _token = obj->__GetWeakRefToken();
+    }
+    
+    ComObjectWeakPtr()
+    {
+        _rawPtr = nullptr;
+        _token = nullptr;
+    }
+};
+
 #define FORWARD_IUNKNOWN() \
 virtual ULONG Release() override \
 { \
--- a/native/Avalonia.Native/src/OSX/AvnView.mm
+++ b/native/Avalonia.Native/src/OSX/AvnView.mm
@ -11,7 +11,7 @@

@implementation AvnView
 {
-    ComPtr<TopLevelImpl> _parent;
+    ComObjectWeakPtr<TopLevelImpl> _parent;
    NSTrackingArea* _area;
    bool _isLeftPressed, _isMiddlePressed, _isRightPressed, _isXButton1Pressed, _isXButton2Pressed;
    AvnInputModifiers _modifierState;
@ -132,7 +132,8 @@
        _area = nullptr;
    }

-    if (_parent == nullptr)
+    auto parent = _parent.tryGet();
+    if (parent == nullptr)
    {
        return;
    }
@ -144,7 +145,7 @@
    _area = [[NSTrackingArea alloc] initWithRect:rect options:options owner:self userInfo:nullptr];
    [self addTrackingArea:_area];

-    _parent->UpdateCursor();
+    parent->UpdateCursor();

    auto fsize = [self convertSizeToBacking: [self frame].size];

@ -156,26 +157,28 @@

        auto reason = [self inLiveResize] ? ResizeUser : _resizeReason;

-        _parent->TopLevelEvents->Resized(FromNSSize(newSize), reason);
+        parent->TopLevelEvents->Resized(FromNSSize(newSize), reason);
    }
 }

 - (void)updateLayer
 {
    AvnInsidePotentialDeadlock deadlock;
-    if (_parent == nullptr)
+    auto parent = _parent.tryGet();
+    if (parent == nullptr)
    {
        return;
    }

-    _parent->TopLevelEvents->RunRenderPriorityJobs();
+    parent->TopLevelEvents->RunRenderPriorityJobs();

-    if (_parent == nullptr)
+    parent = _parent.tryGet();
+    if (parent == nullptr)
    {
        return;
    }

-    _parent->TopLevelEvents->Paint();
+    parent->TopLevelEvents->Paint();
 }

 - (void)drawRect:(NSRect)dirtyRect
@ -196,9 +199,10 @@
    _lastPixelSize.Height = (int)fsize.height;
    [self updateRenderTarget];

-    if(_parent != nullptr)
+    auto parent = _parent.tryGet();
+    if(parent != nullptr)
    {
-        _parent->TopLevelEvents->ScalingChanged([[self window] backingScaleFactor]);
+        parent->TopLevelEvents->ScalingChanged([[self window] backingScaleFactor]);
    }

    [super viewDidChangeBackingProperties];
@ -206,7 +210,8 @@

 - (bool) ignoreUserInput:(bool)trigerInputWhenDisabled
 {
-    if(_parent == nullptr)
+    auto parent = _parent.tryGet();
+    if(parent == nullptr)
    {
        return TRUE;
    }
@ -221,7 +226,7 @@
    {
        if(trigerInputWhenDisabled)
        {
-            WindowImpl* windowImpl = dynamic_cast<WindowImpl*>(_parent.getRaw());
+            auto windowImpl = _parent.tryGetWithCast<WindowImpl>();
            
            if(windowImpl == nullptr){
                return FALSE;
@ -298,10 +303,10 @@
            )
            )
    {
-        WindowBaseImpl* windowBase = dynamic_cast<WindowBaseImpl*>(_parent.getRaw());
+        auto windowBase = _parent.tryGetWithCast<WindowBaseImpl>();
        
        if(windowBase != nullptr){
-            WindowBaseImpl* parent = windowBase->Parent;
+            auto parent = windowBase->Parent;
            
            if(parent != nullptr){
                auto parentWindow = parent->Window;
@ -313,10 +318,10 @@
        }
    }
       
-
-    if(_parent != nullptr)
+    auto parent = _parent.tryGet();
+    if(parent != nullptr)
    {
-        _parent->TopLevelEvents->RawMouseEvent(type, timestamp, modifiers, point, delta);
+        parent->TopLevelEvents->RawMouseEvent(type, timestamp, modifiers, point, delta);
    }

    [super mouseMoved:event];
@ -324,7 +329,9 @@

 - (BOOL) resignFirstResponder
 {
-    _parent->TopLevelEvents->LostFocus();
+    auto parent = _parent.tryGet();
+    if(parent)
+        parent->TopLevelEvents->LostFocus();
    return YES;
 }

@ -463,7 +470,8 @@

 - (void) keyboardEvent: (NSEvent *) event withType: (AvnRawKeyEventType)type
 {
-    if([self ignoreUserInput: false] || _parent == nullptr)
+    auto parent = _parent.tryGet();
+    if([self ignoreUserInput: false] || parent == nullptr)
    {
        return;
    }
@ -477,7 +485,7 @@
    auto timestamp = static_cast<uint64_t>([event timestamp] * 1000);
    auto modifiers = [self getModifiers:[event modifierFlags]];

-    _parent->TopLevelEvents->RawKeyEvent(type, timestamp, modifiers, key, physicalKey, keySymbolUtf8);
+    parent->TopLevelEvents->RawKeyEvent(type, timestamp, modifiers, key, physicalKey, keySymbolUtf8);
 }

 - (void)setModifiers:(NSEventModifierFlags)modifierFlags
@ -551,12 +559,14 @@
 }

 - (bool) handleKeyDown: (NSTimeInterval) timestamp withKey:(AvnKey)key withPhysicalKey:(AvnPhysicalKey)physicalKey withModifiers:(AvnInputModifiers)modifiers withKeySymbol:(NSString*)keySymbol {
-    return _parent->TopLevelEvents->RawKeyEvent(KeyDown, timestamp, modifiers, key, physicalKey, [keySymbol UTF8String]);
+    auto parent = _parent.tryGet();
+    return parent->TopLevelEvents->RawKeyEvent(KeyDown, timestamp, modifiers, key, physicalKey, [keySymbol UTF8String]);
 }

 - (void)keyDown:(NSEvent *)event
 {
-    if([self ignoreUserInput: false] || _parent == nullptr)
+    auto parent = _parent.tryGet();
+    if([self ignoreUserInput: false] || parent == nullptr)
    {
        return;
    }
@ -573,7 +583,7 @@
    auto modifiers = [self getModifiers:[event modifierFlags]];
    
    //InputMethod is active
-    if(_parent->InputMethod->IsActive()){
+    if(parent->InputMethod->IsActive()){
        auto hasInputModifier = modifiers != AvnInputModifiersNone;
        
        //Handle keyDown first if an input modifier is present
@ -605,7 +615,7 @@
            if(keySymbol != nullptr && key != AvnKeyEnter){
                auto timestamp = static_cast<uint64_t>([event timestamp] * 1000);
                
-                _parent->TopLevelEvents->RawTextInputEvent(timestamp, [keySymbol UTF8String]);
+                parent->TopLevelEvents->RawTextInputEvent(timestamp, [keySymbol UTF8String]);
            }
        }
    }
@ -681,16 +691,18 @@
    }
    
    _markedRange = NSMakeRange(_selectedRange.location, [markedText length]);
-        
-    if(_parent->InputMethod->IsActive()){
-        _parent->InputMethod->Client->SetPreeditText((char*)[markedText UTF8String]);
+    auto parent = _parent.tryGet();
+
+    if(parent->InputMethod->IsActive()){
+        parent->InputMethod->Client->SetPreeditText((char*)[markedText UTF8String]);
    }
 }

 - (void)unmarkText
 {
-    if(_parent->InputMethod->IsActive()){
-        _parent->InputMethod->Client->SetPreeditText(nullptr);
+    auto parent = _parent.tryGet();
+    if(parent->InputMethod->IsActive()){
+        parent->InputMethod->Client->SetPreeditText(nullptr);
    }
    
    _markedRange = NSMakeRange(_selectedRange.location, 0);
@ -718,7 +730,8 @@

 - (void)insertText:(id)string replacementRange:(NSRange)replacementRange
 {
-    if(_parent == nullptr){
+    auto parent = _parent.tryGet();
+    if(parent == nullptr){
        return;
    }
    
@ -737,7 +750,7 @@
        
    uint64_t timestamp = static_cast<uint64_t>([NSDate timeIntervalSinceReferenceDate] * 1000);
        
-    _parent->TopLevelEvents->RawTextInputEvent(timestamp, [text UTF8String]);
+    parent->TopLevelEvents->RawTextInputEvent(timestamp, [text UTF8String]);
 }

 - (NSUInteger)characterIndexForPoint:(NSPoint)point
@ -747,7 +760,8 @@

 - (NSRect)firstRectForCharacterRange:(NSRange)range actualRange:(NSRangePointer)actualRange
 {
-    if(!_parent->InputMethod->IsActive()){
+    auto parent = _parent.tryGet();
+    if(!parent->InputMethod->IsActive()){
        return NSZeroRect;
    }
    
@ -763,7 +777,8 @@
    NSDragOperation nsop = [info draggingSourceOperationMask];

    auto effects = ConvertDragDropEffects(nsop);
-    int reffects = (int)_parent->TopLevelEvents
+    auto parent = _parent.tryGet();
+    int reffects = (int)parent->TopLevelEvents
            ->DragEvent(type, point, modifiers, effects,
                    CreateClipboard([info draggingPasteboard], nil),
                    GetAvnDataObjectHandleFromDraggingInfo(info));
--- a/native/Avalonia.Native/src/OSX/AvnWindow.mm
+++ b/native/Avalonia.Native/src/OSX/AvnWindow.mm
@ -29,7 +29,7 @@

@implementation CLASS_NAME
 {
-    ComPtr<WindowBaseImpl> _parent;
+    ComObjectWeakPtr<WindowBaseImpl> _parent;
    bool _closed;
    bool _isEnabled;
    bool _canBecomeKeyWindow;
@ -42,7 +42,8 @@

 -(AvnView* _Nullable) view
 {
-    return _parent->View;
+    auto parent = _parent.tryGet();
+    return parent ? parent->View : nullptr;
 }

 -(void) setIsExtended:(bool)value;
@ -52,7 +53,8 @@

 -(bool) isDialog
 {
-    return _parent->IsModal();
+    auto parent = _parent.tryGet();
+    return parent ? parent->IsModal() : false;
 }

 -(double) getExtendedTitleBarHeight
@ -194,7 +196,7 @@

 - (BOOL)windowShouldClose:(NSWindow *_Nonnull)sender
 {
-    auto window = dynamic_cast<WindowImpl*>(_parent.getRaw());
+    auto window = _parent.tryGet().dynamicCast<WindowImpl>();

    if(window != nullptr)
    {
@ -212,20 +214,17 @@
 - (void)windowWillClose:(NSNotification *_Nonnull)notification
 {
    _closed = true;
-    if(_parent)
+    auto window = _parent.tryGetWithCast<WindowImpl>();
+    if(window)
    {
-        ComPtr<WindowBaseImpl> parent = _parent;
-        _parent = NULL;
-        
-            auto window = dynamic_cast<WindowImpl*>(parent.getRaw());
        
        if(window != nullptr)
        {
            window->SetParent(nullptr);
        }
        
-        parent->BaseEvents->Closed();
-        [parent->View onClosed];
+        window->BaseEvents->Closed();
+        [window->View onClosed];
    }
 }

@ -247,7 +246,7 @@
    if(_canBecomeKeyWindow && !_closed)
    {
        // If the window has a child window being shown as a dialog then don't allow it to become the key window.
-        auto parent = dynamic_cast<WindowImpl*>(_parent.getRaw());
+        auto parent = _parent.tryGet().dynamicCast<WindowImpl>();
        
        if(parent != nullptr)
        {
@ -286,9 +285,10 @@
 {
    [self showWindowMenuWithAppMenu];

-    if(_parent != nullptr)
+    auto parent = _parent.tryGet();
+    if(parent != nullptr)
    {
-        _parent->BaseEvents->Activated();
+        parent->BaseEvents->Activated();
    }

    [super becomeKeyWindow];
@ -296,19 +296,21 @@

 - (void)windowDidBecomeKey:(NSNotification *_Nonnull)notification
 {
-    if (_parent == nullptr)
+    auto parent = _parent.tryGet();
+    if (parent == nullptr)
        return;

-    if (_parent->View != nullptr)
-        [_parent->View setModifiers:NSEvent.modifierFlags];
+    if (parent->View != nullptr)
+        [parent->View setModifiers:NSEvent.modifierFlags];

-    _parent->BringToFront();
+    parent->BringToFront();
    
    dispatch_async(dispatch_get_main_queue(), ^{
        @try {
            [self invalidateShadow];
-            if (self->_parent != nullptr)
-                self->_parent->BringToFront();
+            auto parent = self->_parent.tryGet();
+            if (parent != nullptr)
+                parent->BringToFront();
        }
        @finally{
        }
@ -317,7 +319,7 @@

 - (void)windowDidMiniaturize:(NSNotification *_Nonnull)notification
 {
-    auto parent = dynamic_cast<IWindowStateChanged*>(_parent.operator->());
+    auto parent = _parent.tryGetWithCast<IWindowStateChanged>();

    if(parent != nullptr)
    {
@ -327,7 +329,7 @@

 - (void)windowDidDeminiaturize:(NSNotification *_Nonnull)notification
 {
-    auto parent = dynamic_cast<IWindowStateChanged*>(_parent.operator->());
+    auto parent = _parent.tryGetWithCast<IWindowStateChanged>();

    if(parent != nullptr)
    {
@ -337,7 +339,7 @@

 - (void)windowDidResize:(NSNotification *_Nonnull)notification
 {
-    auto parent = dynamic_cast<IWindowStateChanged*>(_parent.operator->());
+    auto parent = _parent.tryGetWithCast<IWindowStateChanged>();

    if(parent != nullptr)
    {
@ -347,7 +349,7 @@

 - (void)windowWillExitFullScreen:(NSNotification *_Nonnull)notification
 {
-    auto parent = dynamic_cast<IWindowStateChanged*>(_parent.operator->());
+    auto parent = _parent.tryGetWithCast<IWindowStateChanged>();

    if(parent != nullptr)
    {
@ -357,7 +359,7 @@

 - (void)windowDidExitFullScreen:(NSNotification *_Nonnull)notification
 {
-    auto parent = dynamic_cast<IWindowStateChanged*>(_parent.operator->());
+    auto parent = _parent.tryGetWithCast<IWindowStateChanged>();

    if(parent != nullptr)
    {
@ -381,7 +383,7 @@
 - (void)windowWillEnterFullScreen:(NSNotification *_Nonnull)notification
 {
    _isTransitioningToFullScreen = true;
-    auto parent = dynamic_cast<IWindowStateChanged*>(_parent.operator->());
+    auto parent = _parent.tryGetWithCast<IWindowStateChanged>();

    if(parent != nullptr)
    {
@ -392,7 +394,7 @@
 - (void)windowDidEnterFullScreen:(NSNotification *_Nonnull)notification
 {
    _isTransitioningToFullScreen = false;
-    auto parent = dynamic_cast<IWindowStateChanged*>(_parent.operator->());
+    auto parent = _parent.tryGetWithCast<IWindowStateChanged>();

    if(parent != nullptr)
    {
@ -403,13 +405,15 @@

 - (BOOL)windowShouldZoom:(NSWindow *_Nonnull)window toFrame:(NSRect)newFrame
 {
-    return _parent->CanZoom();
+    auto parent = _parent.tryGet();
+    return parent ? parent->CanZoom() : false;
 }

 -(void)windowDidResignKey:(NSNotification* _Nonnull)notification
 {
-    if(_parent)
-        _parent->BaseEvents->Deactivated();
+    auto parent = _parent.tryGet();
+    if(parent)
+        parent->BaseEvents->Deactivated();

    [self showAppMenuOnly];
    
@ -420,25 +424,25 @@
 {
    AvnPoint position;

-    if(_parent != nullptr)
+    auto parent = _parent.tryGet();
+    if(parent != nullptr)
    {
-        auto cparent = dynamic_cast<WindowImpl*>(_parent.getRaw());
-
-        if(cparent != nullptr)
+        auto window = parent.dynamicCast<WindowImpl>();
+        if(window != nullptr)
        {
-            if(!cparent->IsShown())
+            if(!window->IsShown())
            {
                return;
            }

-            if(cparent->WindowState() == Maximized)
+            if(window->WindowState() == Maximized)
            {
-                cparent->SetWindowState(Normal);
+                window->SetWindowState(Normal);
            }
        }

-        _parent->GetPosition(&position);
-        _parent->BaseEvents->PositionChanged(position);
+        parent->GetPosition(&position);
+        parent->BaseEvents->PositionChanged(position);
    }
 }

@ -452,14 +456,15 @@
 {
    [super sendEvent:event];

+    auto parent = _parent.tryGetWithCast<WindowImpl>();
    /// This is to detect non-client clicks. This can only be done on Windows... not popups, hence the dynamic_cast.
-    if(_parent != nullptr && dynamic_cast<WindowImpl*>(_parent.getRaw()) != nullptr)
+    if(parent)
    {
        switch(event.type)
        {
            case NSEventTypeLeftMouseDown:
            {
-                AvnView* view = _parent->View;
+                AvnView* view = parent->View;
                NSPoint windowPoint = [event locationInWindow];
                NSPoint viewPoint = [view convertPoint:windowPoint fromView:nil];

@ -469,19 +474,19 @@
                    auto point = [self translateLocalPoint:avnPoint];
                    AvnVector delta = { 0, 0 };

-                    _parent->BaseEvents->RawMouseEvent(NonClientLeftButtonDown, static_cast<uint64>([event timestamp] * 1000), AvnInputModifiersNone, point, delta);
+                    parent->BaseEvents->RawMouseEvent(NonClientLeftButtonDown, static_cast<uint64>([event timestamp] * 1000), AvnInputModifiersNone, point, delta);
                }
                
                if(!_isTransitioningToFullScreen)
                {
-                    _parent->BringToFront();
+                    parent->BringToFront();
                }
            }
            break;

            case NSEventTypeMouseEntered:
            {
-                _parent->UpdateCursor();
+                parent->UpdateCursor();
            }
                break;

@ -516,9 +521,10 @@

 - (IAvnAutomationPeer* _Nonnull) automationPeer
 {
+    auto parent = _parent.tryGet();
    if (_automationPeer == nullptr)
    {
-        _automationPeer = _parent->BaseEvents->GetAutomationPeer();
+        _automationPeer = parent->BaseEvents->GetAutomationPeer();
        _automationNode = new AvnAutomationNode(self);
        _automationPeer->SetNode(_automationNode);
    }
@ -528,7 +534,8 @@

 - (void)raiseChildrenChanged
 {
-    [_parent->View raiseAccessibilityChildrenChanged];
+    auto parent = _parent.tryGet();
+    [parent->View raiseAccessibilityChildrenChanged];
 }

 - (void)raiseFocusChanged
--- a/native/Avalonia.Native/src/OSX/IWindowStateChanged.h
+++ b/native/Avalonia.Native/src/OSX/IWindowStateChanged.h
@ -6,7 +6,7 @@
 #ifndef AVALONIA_NATIVE_OSX_IWINDOWSTATECHANGED_H
 #define AVALONIA_NATIVE_OSX_IWINDOWSTATECHANGED_H

-struct IWindowStateChanged
+struct IWindowStateChanged: public IUnknown
 {
    virtual void WindowStateChanged () = 0;
    virtual void StartStateTransition () = 0;