Revert "WPF - Resize Hack for when browser switches from hidden to visible (#2779)"

This reverts commit a83c8b3.

Author: amaitland

CefSharp.Wpf/ChromiumWebBrowser.cs

@@ -138,29 +138,12 @@ public partial class ChromiumWebBrowser : Control, IRenderWebBrowser, IWpfWebBro
         /// </summary>
         private static bool DesignMode;
 
-        private bool resizeHackForIssue2779Enabled;
-        private CefSharp.Structs.Size? resizeHackForIssue2779Size;
-
         /// <summary>
         /// The value for disposal, if it's 1 (one) then this instance is either disposed
         /// or in the process of getting disposed
         /// </summary>
         private int disposeSignaled;
 
-        /// <summary>
-        /// Hack to work around issue https://github.com/cefsharp/CefSharp/issues/2779
-        /// Enabled by default
-        /// </summary>
-        public bool EnableResizeHackForIssue2779 { get; set; }
-
-        /// <summary>
-        /// Number of miliseconds to wait after resizing the browser when it first
-        /// becomes visible. After the delay the browser will revert to it's
-        /// original size.
-        /// Hack to work around issue https://github.com/cefsharp/CefSharp/issues/2779
-        /// </summary>
-        public int ResizeHackForIssue2279DelayInMs { get; set; }
-
         /// <summary>
         /// Gets a value indicating whether this instance is disposed.
         /// </summary>
@@ -510,9 +493,6 @@ public ChromiumWebBrowser(string initialAddress)
         [MethodImpl(MethodImplOptions.NoInlining)]
         private void NoInliningConstructor()
         {
-            EnableResizeHackForIssue2779 = true;
-            ResizeHackForIssue2279DelayInMs = 50;
-
             //Initialize CEF if it hasn't already been initialized
             if (!Cef.IsInitialized)
             {
@@ -779,18 +759,7 @@ Rect IRenderWebBrowser.GetViewRect()
         /// <returns>View Rectangle</returns>
         protected virtual Rect GetViewRect()
         {
-            //Take a local copy as the value is set on a different thread,
-            //Its possible the struct is set to null after our initial check.
-            var resizeRect = resizeHackForIssue2779Size;
-
-            if (resizeRect == null)
-            {
-                return viewRect;
-            }
-
-            var size = resizeRect.Value;
-
-            return new Rect(0, 0, size.Width, size.Height);
+            return viewRect;
         }
 
         bool IRenderWebBrowser.GetScreenPoint(int viewX, int viewY, out int screenX, out int screenY)
@@ -935,11 +904,6 @@ void IRenderWebBrowser.OnPaint(PaintElementType type, Rect dirtyRect, IntPtr buf
         /// <param name="height">height</param>
         protected virtual void OnPaint(bool isPopup, Rect dirtyRect, IntPtr buffer, int width, int height)
         {
-            if (resizeHackForIssue2779Enabled)
-            {
-                return;
-            }
-
             var paint = Paint;
             if (paint != null)
             {
@@ -1668,7 +1632,7 @@ private void PresentationSourceChangedHandler(object sender, SourceChangedEventA
             }
         }
 
-        private async void OnWindowStateChanged(object sender, EventArgs e)
+        private void OnWindowStateChanged(object sender, EventArgs e)
         {
             var window = (Window)sender;
 
@@ -1679,54 +1643,16 @@ private async void OnWindowStateChanged(object sender, EventArgs e)
                 {
                     if (previousWindowState == WindowState.Minimized && browser != null)
                     {
-                        await CefUiThreadRunAsync(async () =>
-                        {
-                            var host = browser?.GetHost();
-                            if (host != null && !host.IsDisposed)
-                            {
-                                try
-                                {
-                                    host.WasHidden(false);
-
-                                    await ResizeHackFor2779();
-                                }
-                                catch (ObjectDisposedException)
-                                {
-                                    // Because Dispose runs in another thread there's a race condition between
-                                    // that and this code running on the CEF UI thread, so the host could be disposed
-                                    // between the check and using it. We can either synchronize access using locking
-                                    // (potentially blocking the UI thread in Dispose) or catch the extremely rare
-                                    // exception, which is what we do here
-                                }
-                            }
-                        });
+                        browser.GetHost().WasHidden(false);
                     }
-
                     break;
                 }
                 case WindowState.Minimized:
                 {
-                    await CefUiThreadRunAsync(() =>
+                    if (browser != null)
                     {
-                        var host = browser?.GetHost();
-                        if (host != null && !host.IsDisposed)
-                        {
-                            if (EnableResizeHackForIssue2779)
-                            {
-                                resizeHackForIssue2779Enabled = true;
-                            }
-
-                            try
-                            {
-                                host.WasHidden(true);
-                            }
-                            catch (ObjectDisposedException)
-                            {
-                                // See comment in catch in OnWindowStateChanged
-                            }
-                        }
-                    });
-
+                        browser.GetHost().WasHidden(true);
+                    }
                     break;
                 }
             }
@@ -1869,24 +1795,6 @@ internal void UiThreadRunAsync(Action action, DispatcherPriority priority = Disp
             }
         }
 
-        protected async Task CefUiThreadRunAsync(Action action)
-        {
-            if (!IsDisposed && InternalIsBrowserInitialized())
-            {
-                if (Cef.CurrentlyOnThread(CefThreadIds.TID_UI))
-                {
-                    action();
-                }
-                else
-                {
-                    await Cef.UIThreadTaskFactory.StartNew(delegate
-                    {
-                        action();
-                    });
-                }
-            }
-        }
-
         /// <summary>
         /// Runs the specific Action on the Dispatcher in an sync fashion
         /// </summary>
@@ -1909,97 +1817,52 @@ private void UiThreadRunSync(Action action, DispatcherPriority priority = Dispat
         /// </summary>
         /// <param name="sender">The sender.</param>
         /// <param name="e">The <see cref="SizeChangedEventArgs"/> instance containing the event data.</param>
-        private async void OnActualSizeChanged(object sender, SizeChangedEventArgs e)
+        private void OnActualSizeChanged(object sender, SizeChangedEventArgs e)
         {
             // Initialize RenderClientAdapter when WPF has calculated the actual size of current content.
             CreateOffscreenBrowser(e.NewSize);
 
-            if (InternalIsBrowserInitialized())
-            {
-                await CefUiThreadRunAsync(() =>
-                {
-                    SetViewRect(e);
-
-                    var host = browser?.GetHost();
-                    if (host != null && !host.IsDisposed)
-                    {
-                        try
-                        {
-                            host.WasResized();
-                        }
-                        catch (ObjectDisposedException)
-                        {
-                            // See comment in catch in OnWindowStateChanged
-                        }
-                    }
-                });
-            }
-            else
-            {
-                //If the browser hasn't been created yet then directly update the viewRect
-                SetViewRect(e);
-            }
-        }
-
-        private void SetViewRect(SizeChangedEventArgs e)
-        {
             //NOTE: Previous we used Math.Ceiling to round the sizing up, we
             //now set UseLayoutRounding = true; on the control so the sizes are
             //already rounded to a whole number for us.
             viewRect = new Rect(0, 0, (int)e.NewSize.Width, (int)e.NewSize.Height);
+
+            if (browser != null)
+            {
+                browser.GetHost().WasResized();
+            }
         }
 
         /// <summary>
         /// Handles the <see cref="E:IsVisibleChanged" /> event.
         /// </summary>
         /// <param name="sender">The sender.</param>
         /// <param name="args">The <see cref="DependencyPropertyChangedEventArgs"/> instance containing the event data.</param>
-        private async void OnIsVisibleChanged(object sender, DependencyPropertyChangedEventArgs args)
+        private void OnIsVisibleChanged(object sender, DependencyPropertyChangedEventArgs args)
         {
             var isVisible = (bool)args.NewValue;
 
             if (browser != null)
             {
-                await CefUiThreadRunAsync(async () =>
-                {
-                    var host = browser?.GetHost();
-                    if (host != null && !host.IsDisposed)
-                    {
-                        try
-                        {
-                            host.WasHidden(!isVisible);
+                var host = browser.GetHost();
+                host.WasHidden(!isVisible);
 
-                            if (isVisible)
-                            {
-                                await ResizeHackFor2779();
-                            }
-                            else if (EnableResizeHackForIssue2779)
-                            {
-                                resizeHackForIssue2779Enabled = true;
-                            }
-                        }
-                        catch (ObjectDisposedException)
-                        {
-                            // See comment in catch in OnWindowStateChanged
-                        }
-                    }
-                });
-
-                if (browser != null)
+                if (isVisible)
                 {
                     //Fix for #1778 - When browser becomes visible we update the zoom level
                     //browsers of the same origin will share the same zoomlevel and
                     //we need to track the update, so our ZoomLevelProperty works
                     //properly
-                    var zoomLevel = await browser.GetHost().GetZoomLevelAsync();
-
-                    UiThreadRunAsync(() =>
+                    host.GetZoomLevelAsync().ContinueWith(t =>
                     {
                         if (!IsDisposed)
                         {
-                            SetCurrentValue(ZoomLevelProperty, zoomLevel);
+                            SetCurrentValue(ZoomLevelProperty, t.Result);
                         }
-                    });
+                    },
+                    CancellationToken.None,
+                    TaskContinuationOptions.OnlyOnRanToCompletion,
+                    TaskScheduler.FromCurrentSynchronizationContext());
                 }
             }
         }
@@ -2631,30 +2494,5 @@ public IBrowser GetBrowser()
 
             return browser;
         }
-
-        private async Task ResizeHackFor2779()
-        {
-            if (EnableResizeHackForIssue2779)
-            {
-                var host = browser?.GetHost();
-                if (host != null && !host.IsDisposed)
-                {
-                    resizeHackForIssue2779Size = new Structs.Size(viewRect.Width + 1, viewRect.Height + 1);
-                    host.WasResized();
-
-                    await Task.Delay(ResizeHackForIssue2279DelayInMs);
-
-                    if (!host.IsDisposed)
-                    {
-                        resizeHackForIssue2779Size = null;
-                        host.WasResized();
-
-                        resizeHackForIssue2779Enabled = false;
-
-                        host.Invalidate(PaintElementType.View);
-                    }
-                }
-            }
-        }
     }
 }