Merge pull request #3943 from AvaloniaUI/features/child-windows-api

Refactor Child Window API

native/Avalonia.Native/inc/avalonia-native.h

@@ -267,7 +267,8 @@ AVNCOM(IAvnPopup, 03) : virtual IAvnWindowBase
 
 AVNCOM(IAvnWindow, 04) : virtual IAvnWindowBase
 {
-    virtual HRESULT ShowDialog (IAvnWindow* parent) = 0;
+    virtual HRESULT SetEnabled (bool enable) = 0;
+    virtual HRESULT SetParent (IAvnWindow* parent) = 0;
     virtual HRESULT SetCanResize(bool value) = 0;
     virtual HRESULT SetDecorations(SystemDecorations value) = 0;
     virtual HRESULT SetTitle (void* utf8Title) = 0;
@@ -309,6 +310,8 @@ AVNCOM(IAvnWindowEvents, 06) : IAvnWindowBaseEvents
     virtual bool Closing () = 0;
     
     virtual void WindowStateChanged (AvnWindowState state) = 0;
+    
+    virtual void GotInputWhenDisabled () = 0;
 };
 
 AVNCOM(IAvnMacOptions, 07) : IUnknown

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

@@ -19,8 +19,7 @@ class WindowBaseImpl;
 -(void) pollModalSession: (NSModalSession _Nonnull) session;
 -(void) restoreParentWindow;
 -(bool) shouldTryToHandleEvents;
--(bool) isModal;
+-(void) setEnabled: (bool) enable;
--(void) setModal: (bool) isModal;
 -(void) showAppMenuOnly;
 -(void) showWindowMenuWithAppMenu;
 -(void) applyMenu:(NSMenu* _Nullable)menu;

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

@@ -497,12 +497,7 @@ private:
     virtual HRESULT Show () override
     {
         @autoreleasepool
-        {
+        {            
-            if([Window parentWindow] != nil)
-                [[Window parentWindow] removeChildWindow:Window];
-            
-            [Window setModal:FALSE];
-            
             WindowBaseImpl::Show();
             
             HideOrShowTrafficLights();
@@ -511,7 +506,16 @@ private:
         }
     }
     
-    virtual HRESULT ShowDialog (IAvnWindow* parent) override
+    virtual HRESULT SetEnabled (bool enable) override
+    {
+        @autoreleasepool
+        {
+            [Window setEnabled:enable];
+            return S_OK;
+        }
+    }
+    
+    virtual HRESULT SetParent (IAvnWindow* parent) override
     {
         @autoreleasepool
         {
@@ -522,12 +526,9 @@ private:
             if(cparent == nullptr)
                 return E_INVALIDARG;
             
-            [Window setModal:TRUE];
-            
             [cparent->Window addChildWindow:Window ordered:NSWindowAbove];
-            WindowBaseImpl::Show();
             
-            HideOrShowTrafficLights();
+            UpdateStyle();
             
             return S_OK;
         }
@@ -883,15 +884,15 @@ protected:
         switch (_decorations)
         {
             case SystemDecorationsNone:
-                s = s | NSWindowStyleMaskFullSizeContentView | NSWindowStyleMaskMiniaturizable;
+                s = s | NSWindowStyleMaskFullSizeContentView;
                 break;
 
             case SystemDecorationsBorderOnly:
-                s = s | NSWindowStyleMaskTitled | NSWindowStyleMaskFullSizeContentView | NSWindowStyleMaskMiniaturizable;
+                s = s | NSWindowStyleMaskTitled | NSWindowStyleMaskFullSizeContentView;
                 break;
 
             case SystemDecorationsFull:
-                s = s | NSWindowStyleMaskTitled | NSWindowStyleMaskClosable | NSWindowStyleMaskMiniaturizable | NSWindowStyleMaskBorderless;
+                s = s | NSWindowStyleMaskTitled | NSWindowStyleMaskClosable | NSWindowStyleMaskBorderless;
                 
                 if(_canResize)
                 {
@@ -900,6 +901,10 @@ protected:
                 break;
         }
 
+        if([Window parentWindow] == nullptr)
+        {
+            s |= NSWindowStyleMaskMiniaturizable;
+        }
         return s;
     }
 };
@@ -1081,15 +1086,28 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
 - (bool) ignoreUserInput
 {
     auto parentWindow = objc_cast<AvnWindow>([self window]);
+    
     if(parentWindow == nil || ![parentWindow shouldTryToHandleEvents])
+    {
+        auto window = dynamic_cast<WindowImpl*>(_parent.getRaw());
+        
+        if(window != nullptr)
+        {
+            window->WindowEvents->GotInputWhenDisabled();
+        }
+        
         return TRUE;
+    }
+    
     return FALSE;
 }
 
 - (void)mouseEvent:(NSEvent *)event withType:(AvnRawMouseEventType) type
 {
     if([self ignoreUserInput])
+    {
         return;
+    }
     
     [self becomeFirstResponder];
     auto localPoint = [self convertPoint:[event locationInWindow] toView:self];
@@ -1234,7 +1252,10 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
 - (void) keyboardEvent: (NSEvent *) event withType: (AvnRawKeyEventType)type
 {
     if([self ignoreUserInput])
+    {
         return;
+    }
+    
     auto key = s_KeyMap[[event keyCode]];
     
     auto timestamp = [event timestamp] * 1000;
@@ -1416,7 +1437,7 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     ComPtr<WindowBaseImpl> _parent;
     bool _canBecomeKeyAndMain;
     bool _closed;
-    bool _isModal;
+    bool _isEnabled;
     AvnMenu* _menu;
     double _lastScaling;
 }
@@ -1538,6 +1559,7 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
     _parent = parent;
     [self setDelegate:self];
     _closed = false;
+    _isEnabled = true;
     
     _lastScaling = [self backingScaleFactor];
     [self setOpaque:NO];
@@ -1604,28 +1626,12 @@ NSArray* AllLoopModes = [NSArray arrayWithObjects: NSDefaultRunLoopMode, NSEvent
 
 -(bool)shouldTryToHandleEvents
 {
-    for(NSWindow* uch in [self childWindows])
+    return _isEnabled;
-    {
-        auto ch = objc_cast<AvnWindow>(uch);
-        if(ch == nil)
-            continue;
-        
-        if(![ch isModal])
-            continue;
-        
-        return FALSE;
-    }
-    return TRUE;
-}
-
--(bool) isModal
-{
-    return _isModal;
 }
 
--(void) setModal: (bool) isModal
+-(void) setEnabled:(bool)enable
 {
-    _isModal = isModal;
+    _isEnabled = enable;
 }
 
 -(void)makeKeyWindow

src/Avalonia.Controls/Platform/IWindowImpl.cs

@@ -26,9 +26,21 @@ namespace Avalonia.Platform
         void SetTitle(string title);
 
         /// <summary>
-        /// Shows the window as a dialog.
+        /// Sets the parent of the window.
         /// </summary>
-        void ShowDialog(IWindowImpl parent);
+        /// <param name="parent">The parent <see cref="IWindowImpl"/>.</param>
+        void SetParent(IWindowImpl parent);
+        
+        /// <summary>
+        /// Disables the window for example when a modal dialog is open.
+        /// </summary>
+        /// <param name="enable">true if the window is enabled, or false if it is disabled.</param>
+        void SetEnabled(bool enable);
+
+        /// <summary>
+        /// Called when a disabled window received input. Can be used to activate child windows.
+        /// </summary>
+        Action GotInputWhenDisabled { get; set; }        
 
         /// <summary>
         /// Enables or disables system window decorations (title bar, buttons, etc)

src/Avalonia.Controls/Window.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
 using System.Reactive.Linq;
@@ -68,6 +69,8 @@ namespace Avalonia.Controls
     /// </summary>
     public class Window : WindowBase, IStyleable, IFocusScope, ILayoutRoot
     {
+        private List<Window> _children = new List<Window>();
+
         /// <summary>
         /// Defines the <see cref="SizeToContent"/> property.
         /// </summary>
@@ -131,7 +134,7 @@ namespace Avalonia.Controls
         /// </summary>
         public static readonly RoutedEvent WindowClosedEvent =
             RoutedEvent.Register<Window, RoutedEventArgs>("WindowClosed", RoutingStrategies.Direct);
-        
+
         /// <summary>
         /// Routed event that can be used for global tracking of opening windows
         /// </summary>
@@ -183,6 +186,7 @@ namespace Avalonia.Controls
             : base(impl)
         {
             impl.Closing = HandleClosing;
+            impl.GotInputWhenDisabled = OnGotInputWhenDisabled;
             impl.WindowStateChanged = HandleWindowStateChanged;
             _maxPlatformClientSize = PlatformImpl?.MaxClientSize ?? default(Size);
             this.GetObservable(ClientSizeProperty).Skip(1).Subscribe(x => PlatformImpl?.Resize(x));
@@ -302,7 +306,7 @@ namespace Avalonia.Controls
                 PlatformImpl?.Move(value);
             }
         }
-        
+
         /// <summary>
         /// Starts moving a window with left button being held. Should be called from left mouse button press event handler
         /// </summary>
@@ -323,7 +327,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Fired before a window is closed.
         /// </summary>
-        public event EventHandler<CancelEventArgs> Closing;      
+        public event EventHandler<CancelEventArgs> Closing;
 
         /// <summary>
         /// Closes the window.
@@ -365,19 +369,59 @@ namespace Avalonia.Controls
             {
                 if (close)
                 {
-                    PlatformImpl?.Dispose();
+                    CloseInternal();
                 }
             }
         }
 
+        private void CloseInternal()
+        {
+            foreach (var child in _children.ToList())
+            {
+                // if we HandleClosing() before then there will be no children.
+                child.CloseInternal();
+            }
+
+            if (Owner is Window owner)
+            {
+                owner.RemoveChild(this);
+            }
+
+            Owner = null;
+
+            PlatformImpl?.Dispose();
+        }
+
         /// <summary>
         /// Handles a closing notification from <see cref="IWindowImpl.Closing"/>.
         /// </summary>
         protected virtual bool HandleClosing()
         {
-            var args = new CancelEventArgs();
+            bool canClose = true;
-            OnClosing(args);
+
-            return args.Cancel;
+            foreach (var child in _children.ToList())
+            {
+                if (!child.HandleClosing())
+                {
+                    child.CloseInternal();
+                }
+                else
+                {
+                    canClose = false;
+                }
+            }
+
+            if (canClose)
+            {
+                var args = new CancelEventArgs();
+                OnClosing(args);
+
+                return args.Cancel;
+            }
+            else
+            {
+                return !canClose;
+            }
         }
 
         protected virtual void HandleWindowStateChanged(WindowState state)
@@ -407,6 +451,14 @@ namespace Avalonia.Controls
             using (BeginAutoSizing())
             {
                 Renderer?.Stop();
+
+                if (Owner is Window owner)
+                {
+                    owner.RemoveChild(this);
+                }
+
+                Owner = null;
+
                 PlatformImpl?.Hide();
             }
 
@@ -519,7 +571,10 @@ namespace Avalonia.Controls
 
             using (BeginAutoSizing())
             {
-                PlatformImpl?.ShowDialog(owner.PlatformImpl);
+                PlatformImpl.SetParent(owner.PlatformImpl);
+                Owner = owner;
+                owner.AddChild(this);
+                PlatformImpl?.Show();
 
                 Renderer?.Start();
 
@@ -541,6 +596,37 @@ namespace Avalonia.Controls
             return result.Task;
         }
 
+        private void UpdateEnabled()
+        {
+            PlatformImpl.SetEnabled(_children.Count == 0);
+        }
+
+        private void AddChild(Window window)
+        {
+            _children.Add(window);
+            UpdateEnabled();
+        }
+
+        private void RemoveChild(Window window)
+        {
+            _children.Remove(window);
+            UpdateEnabled();
+        }
+
+        private void OnGotInputWhenDisabled()
+        {
+            var firstChild = _children.FirstOrDefault();
+
+            if (firstChild != null)
+            {
+                firstChild.OnGotInputWhenDisabled();
+            }
+            else
+            {
+                Activate();
+            }
+        }
+
         private void SetWindowStartupLocation(IWindowBaseImpl owner = null)
         {
             var scaling = owner?.Scaling ?? PlatformImpl?.Scaling ?? 1;
@@ -631,6 +717,13 @@ namespace Avalonia.Controls
             RaiseEvent(new RoutedEventArgs(WindowClosedEvent));
 
             base.HandleClosed();
+
+            if (Owner is Window owner)
+            {
+                owner.RemoveChild(this);
+            }
+
+            Owner = null;
         }
 
         /// <inheritdoc/>

src/Avalonia.Controls/WindowBase.cs

@@ -109,7 +109,7 @@ namespace Avalonia.Controls
         public WindowBase Owner
         {
             get { return _owner; }
-            set { SetAndRaise(OwnerProperty, ref _owner, value); }
+            protected set { SetAndRaise(OwnerProperty, ref _owner, value); }
         }
 
         /// <summary>

src/Avalonia.DesignerSupport/Remote/PreviewerWindowImpl.cs

@@ -83,6 +83,7 @@ namespace Avalonia.DesignerSupport.Remote
         }
 
         public IScreenImpl Screen { get; } = new ScreenStub();
+        public Action GotInputWhenDisabled { get; set; }
 
         public void Activate()
         {
@@ -115,5 +116,13 @@ namespace Avalonia.DesignerSupport.Remote
         public void SetTopmost(bool value)
         {
         }
+
+        public void SetParent(IWindowImpl parent)
+        {
+        }
+
+        public void SetEnabled(bool enable)
+        {
+        }
     }
 }

src/Avalonia.DesignerSupport/Remote/Stubs.cs

@@ -130,7 +130,17 @@ namespace Avalonia.DesignerSupport.Remote
         {
         }
 
+        public void SetParent(IWindowImpl parent)
+        {
+        }
+
+        public void SetEnabled(bool enable)
+        {
+        }
+
         public IPopupPositioner PopupPositioner { get; }
+
+        public Action GotInputWhenDisabled { get; set; }
     }
 
     class ClipboardStub : IClipboard

src/Avalonia.Native/PopupImpl.cs

@@ -43,6 +43,11 @@ namespace Avalonia.Native
                 _parent = parent;
             }
 
+            public void GotInputWhenDisabled()
+            {
+                // NOP on Popup
+            }
+
             bool IAvnWindowEvents.Closing()
             {
                 return true;

src/Avalonia.Native/WindowImpl.cs

@@ -40,7 +40,7 @@ namespace Avalonia.Native
 
             bool IAvnWindowEvents.Closing()
             {
-                if(_parent.Closing != null)
+                if (_parent.Closing != null)
                 {
                     return _parent.Closing();
                 }
@@ -52,15 +52,15 @@ namespace Avalonia.Native
             {
                 _parent.WindowStateChanged?.Invoke((WindowState)state);
             }
+
+            void IAvnWindowEvents.GotInputWhenDisabled()
+            {
+                _parent.GotInputWhenDisabled?.Invoke();
+            }
         }
 
         public IAvnWindow Native => _native;
 
-        public void ShowDialog(IWindowImpl window)
-        {
-            _native.ShowDialog(((WindowImpl)window).Native);
-        }
-
         public void CanResize(bool value)
         {
             _native.CanResize = value;
@@ -71,7 +71,7 @@ namespace Avalonia.Native
             _native.Decorations = (Interop.SystemDecorations)enabled;
         }
 
-        public void SetTitleBarColor (Avalonia.Media.Color color)
+        public void SetTitleBarColor(Avalonia.Media.Color color)
         {
             _native.SetTitleBarColor(new AvnColor { Alpha = color.A, Red = color.R, Green = color.G, Blue = color.B });
         }
@@ -116,5 +116,17 @@ namespace Avalonia.Native
 
         public override IPopupImpl CreatePopup() =>
             _opts.OverlayPopups ? null : new PopupImpl(_factory, _opts, _glFeature, this);
+
+        public Action GotInputWhenDisabled { get; set; }
+
+        public void SetParent(IWindowImpl parent)
+        {
+            _native.SetParent(((WindowImpl)parent).Native);
+        }
+
+        public void SetEnabled(bool enable)
+        {
+            _native.SetEnabled(enable);
+        }
     }
 }

src/Avalonia.X11/X11Window.cs

@@ -41,9 +41,9 @@ namespace Avalonia.X11
         private IntPtr _renderHandle;
         private bool _mapped;
         private bool _wasMappedAtLeastOnce = false;
-        private HashSet<X11Window> _transientChildren = new HashSet<X11Window>();
-        private X11Window _transientParent;
         private double? _scalingOverride;
+        private bool _disabled;
+
         public object SyncRoot { get; } = new object();
 
         class InputEventContainer
@@ -746,7 +746,6 @@ namespace Avalonia.X11
 
         void Cleanup()
         {
-            SetTransientParent(null, false);
             if (_xic != IntPtr.Zero)
             {
                 XDestroyIC(_xic);
@@ -773,38 +772,24 @@ namespace Avalonia.X11
 
         bool ActivateTransientChildIfNeeded()
         {
-            if (_transientChildren.Count == 0)
+            if (_disabled)
-                return false;
+            {
-            var child = _transientChildren.First();
+                GotInputWhenDisabled?.Invoke();
-            if (!child.ActivateTransientChildIfNeeded())
+                return true;
-                child.Activate();
+            }
-            return true;
+
-        }
+            return false;
-        
-        void SetTransientParent(X11Window window, bool informServer = true)
-        {
-            _transientParent?._transientChildren.Remove(this);
-            _transientParent = window;
-            _transientParent?._transientChildren.Add(this);
-            if (informServer)
-                SetTransientForHint(_transientParent?._handle);
         }
 
-        void SetTransientForHint(IntPtr? parent)
+        public void SetParent(IWindowImpl parent)
         {
-            if (parent == null || parent == IntPtr.Zero)
+            if (parent == null || parent.Handle == null || parent.Handle.Handle == IntPtr.Zero)
                 XDeleteProperty(_x11.Display, _handle, _x11.Atoms.XA_WM_TRANSIENT_FOR);
             else
-                XSetTransientForHint(_x11.Display, _handle, parent.Value);
+                XSetTransientForHint(_x11.Display, _handle, parent.Handle.Handle);
         }
 
         public void Show()
-        {
-            SetTransientParent(null);
-            ShowCore();
-        }
-        
-        void ShowCore()
         {
             _wasMappedAtLeastOnce = true;
             XMapWindow(_x11.Display, _handle);
@@ -813,7 +798,6 @@ namespace Avalonia.X11
 
         public void Hide() => XUnmapWindow(_x11.Display, _handle);
         
-        
         public Point PointToClient(PixelPoint point) => new Point((point.X - Position.X) / Scaling, (point.Y - Position.Y) / Scaling);
 
         public PixelPoint PointToScreen(Point point) => new PixelPoint(
@@ -1034,13 +1018,14 @@ namespace Avalonia.X11
         {
             ChangeWMAtoms(value, _x11.Atoms._NET_WM_STATE_ABOVE);
         }
-
+        
-        public void ShowDialog(IWindowImpl parent)
+        public void SetEnabled(bool enable)
         {
-            SetTransientParent((X11Window)parent);
+            _disabled = !enable;
-            ShowCore();
         }
 
+        public Action GotInputWhenDisabled { get; set; }
+
         public void SetIcon(IWindowIconImpl icon)
         {
             if (icon != null)

src/Windows/Avalonia.Win32/WindowImpl.WndProc.cs

@@ -77,12 +77,6 @@ namespace Avalonia.Win32
                     s_instances.Remove(this);
                     Closed?.Invoke();
 
-                    if (_parent != null)
-                    {
-                        _parent._disabledBy.Remove(this);
-                        _parent.UpdateEnabled();
-                    }
-
                     _mouseDevice.Dispose();
                     _touchDevice?.Dispose();
                     //Free other resources

src/Windows/Avalonia.Win32/WindowImpl.cs

@@ -45,7 +45,6 @@ namespace Avalonia.Win32
 #endif
 
         private const WindowStyles WindowStateMask = (WindowStyles.WS_MAXIMIZE | WindowStyles.WS_MINIMIZE);
-        private readonly List<WindowImpl> _disabledBy;
         private readonly TouchDevice _touchDevice;
         private readonly MouseDevice _mouseDevice;
         private readonly ManagedDeferredRendererLock _rendererLock;
@@ -70,7 +69,6 @@ namespace Avalonia.Win32
 
         public WindowImpl()
         {
-            _disabledBy = new List<WindowImpl>();
             _touchDevice = new TouchDevice();
             _mouseDevice = new WindowsMouseDevice();
 
@@ -342,31 +340,25 @@ namespace Avalonia.Win32
 
         public void Hide()
         {
-            if (_parent != null)
-            {
-                _parent._disabledBy.Remove(this);
-                _parent.UpdateEnabled();
-                _parent = null;
-            }
-
             UnmanagedMethods.ShowWindow(_hwnd, ShowWindowCommand.Hide);
         }
 
         public virtual void Show()
         {
-            SetWindowLongPtr(_hwnd, (int)WindowLongParam.GWL_HWNDPARENT, IntPtr.Zero);
+            SetWindowLongPtr(_hwnd, (int)WindowLongParam.GWL_HWNDPARENT, _parent != null ? _parent._hwnd : IntPtr.Zero);
             ShowWindow(_showWindowState);
         }
 
-        public void ShowDialog(IWindowImpl parent)
+        public Action GotInputWhenDisabled { get; set; }
+
+        public void SetParent(IWindowImpl parent)
         {
             _parent = (WindowImpl)parent;
-            _parent._disabledBy.Add(this);
+            SetWindowLongPtr(_hwnd, (int)WindowLongParam.GWL_HWNDPARENT, _parent._hwnd);
-            _parent.UpdateEnabled();
-            SetWindowLongPtr(_hwnd, (int)WindowLongParam.GWL_HWNDPARENT, ((WindowImpl)parent)._hwnd);
-            ShowWindow(_showWindowState);
         }
 
+        public void SetEnabled(bool enable) => EnableWindow(_hwnd, enable);
+
         public void BeginMoveDrag(PointerPressedEventArgs e)
         {
             _mouseDevice.Capture(null);
@@ -666,7 +658,7 @@ namespace Avalonia.Win32
             }
         }        
 
-        private WindowStyles GetWindowStateStyles ()
+        private WindowStyles GetWindowStateStyles()
         {
             return GetStyle() & WindowStateMask;
         }
@@ -721,11 +713,6 @@ namespace Avalonia.Win32
             }
         }
 
-        private void UpdateEnabled()
-        {
-            EnableWindow(_hwnd, _disabledBy.Count == 0);
-        }
-
         private void UpdateWindowProperties(WindowProperties newProperties, bool forceChanges = false)
         {
             var oldProperties = _windowProperties;

tests/Avalonia.Controls.UnitTests/WindowTests.cs

@@ -322,10 +322,9 @@ namespace Avalonia.Controls.UnitTests
                 {
                     var window = new Window();
                     window.WindowStartupLocation = WindowStartupLocation.CenterOwner;
-                    window.Position = new PixelPoint(60, 40);
+                    window.Position = new PixelPoint(60, 40);                    
-                    window.Owner = parentWindow;
 
-                    window.Show();
+                    window.ShowDialog(parentWindow);
 
                     var expectedPosition = new PixelPoint(
                         (int)(parentWindow.Position.X + parentWindow.ClientSize.Width / 2 - window.ClientSize.Width / 2),