Mac: Fix some memory leaks

src/Eto.Mac/Drawing/FormattedTextHandler.cs

@@ -13,9 +13,13 @@ namespace Eto.iOS.Drawing
 {
 	public class EtoLayoutManager : NSLayoutManager
 	{
-		public Brush ForegroundBrush { get; set; } = new SolidBrush(SystemColors.ControlText);
-
-		internal GraphicsHandler CurrentGraphics { get; set; }
+		WeakReference WeakHandler { get; set; }
+
+		public FormattedTextHandler Handler
+		{ 
+			get => WeakHandler.Target as FormattedTextHandler;
+			set => WeakHandler = new WeakReference(value);
+		}
 
 		static IntPtr selShowCGGlyphs_Positions_Count_Font_Matrix_Attributes_InContext_Handle = Selector.GetHandle("showCGGlyphs:positions:count:font:matrix:attributes:inContext:");
 
@@ -29,13 +33,17 @@ public class EtoLayoutManager : NSLayoutManager
 		[Export("showCGGlyphs:positions:count:font:matrix:attributes:inContext:")]
 		protected void ShowGlyphs(IntPtr glyphs, IntPtr positions, nuint glyphCount, IntPtr font, CGAffineTransform textMatrix, IntPtr attributes, IntPtr graphicsContext)
 		{
-			if (ForegroundBrush is SolidBrush)
+			var h = Handler;
+			if (h == null)
+				return;
+			var foregroundBrush = h.ForegroundBrush;
+			if (foregroundBrush is SolidBrush)
 			{
 				// attributes can be null, Xamarin.Mac doesn't allow that when calling base. ugh.
 				Messaging.void_objc_msgSendSuper_IntPtr_IntPtr_nuint_IntPtr_CGAffineTransform_IntPtr_IntPtr(SuperHandle, selShowCGGlyphs_Positions_Count_Font_Matrix_Attributes_InContext_Handle, glyphs, positions, glyphCount, font, textMatrix, attributes, graphicsContext);
 				//base.ShowGlyphs(glyphs, positions, glyphCount, font, textMatrix, attributes, graphicsContext);
 			}
-			else if (glyphCount > 0)
+			else if (glyphCount > 0 && h.CurrentGraphics != null)
 			{
 				// draw manually so we can use a custom brush/fill.
 				var ctx = NSGraphicsContext.CurrentContext.GraphicsPort;
@@ -53,7 +61,7 @@ protected void ShowGlyphs(IntPtr glyphs, IntPtr positions, nuint glyphCount, Int
 				ctx.TextMatrix = m;
 				CTFontDrawGlyphs(font, glyphs, positions, glyphCount, ctx.Handle);
 
-				ForegroundBrush.Draw(CurrentGraphics, false, FillMode.Winding, false);
+				foregroundBrush.Draw(h.CurrentGraphics, false, FillMode.Winding, false);
 				ctx.RestoreState();
 			}
 		}
@@ -77,6 +85,9 @@ public class FormattedTextHandler : WidgetHandler<EtoLayoutManager, FormattedTex
 		FormattedTextWrapMode _wrap;
 		FormattedTextAlignment _alignment;
 		SizeF _maximumSize = SizeF.MaxValue;
+		Brush _foregroundBrush = new SolidBrush(SystemColors.ControlText);
+
+		internal GraphicsHandler CurrentGraphics { get; set; }
 
 		public FormattedTextAlignment Alignment
 		{
@@ -177,10 +188,10 @@ public Font Font
 
 		public Brush ForegroundBrush
 		{
-			get => Control.ForegroundBrush;
+			get => _foregroundBrush;
 			set
 			{
-				Control.ForegroundBrush = value;
+				_foregroundBrush = value;
 				Invalidate();
 			}
 		}
@@ -253,9 +264,9 @@ public FormattedTextHandler()
 		public void DrawText(GraphicsHandler graphics, PointF location)
 		{
 			EnsureString();
-			Control.CurrentGraphics = graphics;
-			var ctx = graphics.Control;
+			CurrentGraphics = graphics;
 			storage.DrawString(new CGRect(location.ToNS(), container.Size), NSStringDrawingOptions.UsesLineFragmentOrigin | NSStringDrawingOptions.TruncatesLastVisibleLine);
+			CurrentGraphics = null;
 			// Control.DrawGlyphs(new NSRange(0, (int)_text.Length), location.ToNS());
 		}
 	}

src/Eto.Mac/Drawing/GraphicsHandler.cs

@@ -111,6 +111,11 @@ public GraphicsHandler(NSView view, CGContext context, nfloat height)
 
 		protected override void Dispose(bool disposing)
 		{
+			if (disposing)
+			{
+				_formattedText?.Dispose();
+				_formattedText = null;
+			}
 			base.Dispose(disposing);
 		}
 

src/Eto.Mac/Forms/MacBase.cs

@@ -57,7 +57,6 @@ public void AddToNotificationCenter()
 			if (!isNotification && c != null)
 			{
 				NSNotificationCenter.DefaultCenter.AddObserver(this, selPerformAction, KeyPath, c);
-				c.DangerousRetain();
 				isNotification = true;
 			}
 		}
@@ -69,12 +68,10 @@ public void AddToControl()
 			{
 				//Console.WriteLine ("{0}: 3. Adding observer! {1}, {2}", ((IRef)this.Handler).WidgetID, this.GetType (), Control.GetHashCode ());
 				c.AddObserver(this, KeyPath, NSKeyValueObservingOptions.New, IntPtr.Zero);
-				c.DangerousRetain();
 				isControl = true;
 			}
 		}
 
-		static readonly IntPtr selRelease_Handle = Selector.GetHandle("release");
 		static readonly IntPtr selRemoveObserverForKeyPath_Handle = Selector.GetHandle("removeObserver:forKeyPath:");
 
 		public void Remove()
@@ -83,15 +80,13 @@ public void Remove()
 			if (isNotification)
 			{
 				NSNotificationCenter.DefaultCenter.RemoveObserver(this);
-				Messaging.void_objc_msgSend(ControlHandle, selRelease_Handle);
 
 				isNotification = false;
 			}
 			if (isControl)
 			{
 				//Console.WriteLine ("{0}: 4. Removing observer! {1}, {2}", ((IRef)this.Handler).WidgetID, Handler.GetType (), Control.GetHashCode ());
 				Messaging.void_objc_msgSend_IntPtr_IntPtr(ControlHandle, selRemoveObserverForKeyPath_Handle, Handle, KeyPath.Handle);
-				Messaging.void_objc_msgSend(ControlHandle, selRelease_Handle);
 				isControl = false;
 			}
 		}

src/Eto.Mac/Forms/MacWindow.cs

@@ -1071,15 +1071,21 @@ protected override void Initialize()
 		{
 			base.Initialize();
 
-			// need to send Got/LostFocus to child when window Got/LostFocus is called
-			HandleEvent(Window.LostFocusEvent);
-			HandleEvent(Window.GotFocusEvent);
+			if (!Widget.IsAttached)
+			{
+				// need to send Got/LostFocus to child when window Got/LostFocus is called
+				HandleEvent(Window.LostFocusEvent);
+				HandleEvent(Window.GotFocusEvent);
+			}
 		}
 
 		public override void OnLoad(EventArgs e)
 		{
-			PerformAutoSize();
-			PositionWindow();
+			if (!Widget.IsAttached)
+			{
+				PerformAutoSize();
+				PositionWindow();
+			}
 			base.OnLoad(e);
 		}
 
@@ -1097,14 +1103,17 @@ protected override void FireOnShown()
 		public override void OnLoadComplete(EventArgs e)
 		{
 			base.OnLoadComplete(e);
-			if (initialState != null)
+			if (!Widget.IsAttached)
 			{
-				WindowState = initialState.Value;
-				initialState = null;
-				Callback.OnSizeChanged(Widget, EventArgs.Empty);
+				if (initialState != null)
+				{
+					WindowState = initialState.Value;
+					initialState = null;
+					Callback.OnSizeChanged(Widget, EventArgs.Empty);
+				}
+				else if (!setInitialSize)
+					Callback.OnSizeChanged(Widget, EventArgs.Empty);
 			}
-			else if (!setInitialSize)
-				Callback.OnSizeChanged(Widget, EventArgs.Empty);
 		}
 
 		protected virtual void PositionWindow()

src/Eto.Mac/Forms/NativeFormHandler.cs

@@ -36,6 +36,39 @@ protected override void ConfigureWindow()
 		{
 		}
 
+		internal static Window CreateWrapper(NSWindowController windowController, NSWindow nswindow)
+		{
+			var handle = windowController?.Handle ?? nswindow.Handle;
+
+			s_cachedWindows ??= new Dictionary<NativeHandle, WeakReference>();
+
+			if (s_cachedWindows.TryGetValue(handle, out var windowReference) && windowReference.Target is Window window)
+				return window;
+
+			var handler = windowController != null ? new NativeFormHandler(windowController) : new NativeFormHandler(nswindow);
+ 			window = new Form(handler);
+			s_cachedWindows.Add(handle, new WeakReference(window));
+			List<NativeHandle> toRemove = null;
+			foreach (var entry in s_cachedWindows)
+			{
+				if (!entry.Value.IsAlive)
+				{
+					toRemove ??= new List<NativeHandle>();
+					toRemove.Add(entry.Key);
+				}
+			}
+			if (toRemove != null)
+			{
+				foreach	(var entry in toRemove)
+				{
+					s_cachedWindows.Remove(entry);
+				}
+			}
+			return window;
+		}
+
+		static Dictionary<NativeHandle, WeakReference> s_cachedWindows;
+
 		public override Size Size
 		{
 			get => Control.Frame.Size.ToEtoSize();

src/Eto.Mac/MacHelpers.cs

@@ -94,7 +94,7 @@ public static Window ToEtoWindow(this NSWindow window)
 			if (window is IMacControl macControl && macControl.WeakHandler?.Target is IMacWindow macWindow)
 				return macWindow.Widget;
 
-			return new Form(new NativeFormHandler(window));
+			return NativeFormHandler.CreateWrapper(null, window);
 		}
 
 		/// <summary>
@@ -106,7 +106,7 @@ public static Window ToEtoWindow(this NSWindowController windowController)
 		{
 			if (windowController == null)
 				return null;
-			return new Form(new NativeFormHandler(windowController));
+			return NativeFormHandler.CreateWrapper(windowController, null);
 		}
 
 		/// <summary>