WIP: Right To Left support

src/Eto.Mac/AppDelegate.cs

@@ -48,6 +48,11 @@ public override NSApplicationTerminateReply ApplicationShouldTerminate(NSApplica
 			}
 			return args.Cancel ? NSApplicationTerminateReply.Cancel : NSApplicationTerminateReply.Now;
 		}
+
+		public override void WillTerminate(NSNotification notification)
+		{
+			ApplicationHandler.ResetRtlPreference();
+		}
 	}
 }
 

src/Eto.Mac/Forms/ApplicationHandler.cs

@@ -115,7 +115,7 @@ static void restart_WillTerminate(object sender, EventArgs e)
 			var args = new string[]
 			{
 				"-c",
-				"open \"$1\"", 
+				"open \"$1\"",
 				string.Empty,
 				NSBundle.MainBundle.BundlePath
 			};
@@ -129,7 +129,7 @@ public void Invoke(Action action)
 			else
 				Control.InvokeOnMainThread(action);
 		}
-		
+
 		public void AsyncInvoke(Action action)
 		{
 			Control.BeginInvokeOnMainThread(action);
@@ -150,23 +150,23 @@ public void Restart()
 			Control.Delegate = oldDelegate;
 		}
 
-		static readonly IntPtr selNextEventMatchingMaskUntilDateInModeDequeue_Handle = Selector.GetHandle ("nextEventMatchingMask:untilDate:inMode:dequeue:");
-		static readonly IntPtr selSendEvent_Handle = Selector.GetHandle ("sendEvent:");
-		
+		static readonly IntPtr selNextEventMatchingMaskUntilDateInModeDequeue_Handle = Selector.GetHandle("nextEventMatchingMask:untilDate:inMode:dequeue:");
+		static readonly IntPtr selSendEvent_Handle = Selector.GetHandle("sendEvent:");
+
 		public void RunIteration()
 		{
 			MacView.InMouseTrackingLoop = false;
 			// drain the event queue only for a short period of time so it doesn't lock up
 			var date = NSDate.FromTimeIntervalSinceNow(0.001);
-			for (;;)
+			for (; ; )
 			{
 				// dequeue the event
 				var evt = Control.NextEvent(NSEventMask.AnyEvent, date, NSRunLoopMode.Default, true);
-				
+
 				// no event? cool, let's get out of here
 				if (evt == null)
 					break;
-				
+
 				// dispatch the event
 				Control.SendEvent(evt);
 			}
@@ -196,7 +196,7 @@ public void Run()
 
 
 				EtoBundle.Init();
-				
+
 				EtoFontManager.Install();
 
 				if (Control.Delegate == null)
@@ -227,7 +227,7 @@ public void Open(string url)
 
 #if Mac64
 		delegate void UncaughtExceptionHandlerDelegate(IntPtr nsexceptionPtr);
-		
+
 		[DllImport(Constants.FoundationLibrary)]
 		static extern void NSSetUncaughtExceptionHandler(UncaughtExceptionHandlerDelegate handler);
 
@@ -325,5 +325,44 @@ public void EnableFullScreen()
 		public Keys AlternateModifier => Keys.Alt;
 
 		public bool IsActive => NSApplication.SharedApplication.Active;
+
+		public LayoutDirection DefaultLayoutDirection
+		{
+			get => NSApplication.SharedApplication.UserInterfaceLayoutDirection switch
+			{
+				NSApplicationLayoutDirection.LeftToRight => LayoutDirection.LeftToRight,
+				NSApplicationLayoutDirection.RightToLeft => LayoutDirection.RightToLeft,
+				_ => LayoutDirection.LeftToRight
+			};
+			set
+			{
+				var rtl = value == LayoutDirection.RightToLeft;
+				// NSUserDefaults.StandardUserDefaults.RegisterDefaults(NSDictionary.FromObjectsAndKeys(
+				// 	new NSObject[] { NSNumber.FromBoolean(rtl), NSNumber.FromBoolean(rtl) },
+				// 	new NSObject[] { new NSString("NSForceRightToLeftWritingDirection"), new NSString("AppleTextDirection") }
+				// ));
+				// Environment.SetEnvironmentVariable("NSForceRightToLeftWritingDirection", "YES");
+				// Environment.SetEnvironmentVariable("AppleTextDirection", "YES");
+				// Control.WillTerminate -= ResetRtlPreference;
+				if (rtl)
+				{
+					NSUserDefaults.StandardUserDefaults.SetValueForKey(NSNumber.FromBoolean(rtl), new NSString("NSForceRightToLeftWritingDirection"));
+					NSUserDefaults.StandardUserDefaults.SetValueForKey(NSNumber.FromBoolean(rtl), new NSString("AppleTextDirection"));
+				}
+				else
+				{
+					NSUserDefaults.StandardUserDefaults.RemoveObject(new NSString("NSForceRightToLeftWritingDirection"));
+					NSUserDefaults.StandardUserDefaults.RemoveObject(new NSString("AppleTextDirection"));
+				}
+				NSUserDefaults.StandardUserDefaults.Synchronize();
+			}
+		}
+
+		internal static void ResetRtlPreference()
+		{
+			// don't actually save these
+			NSUserDefaults.StandardUserDefaults.RemoveObject(new NSString("NSForceRightToLeftWritingDirection"));
+			NSUserDefaults.StandardUserDefaults.RemoveObject(new NSString("AppleTextDirection"));
+		}
 	}
 }

src/Eto.Mac/Forms/Cells/ImageTextCellHandler.cs

@@ -227,7 +227,7 @@ public override NSView GetViewForItem(NSTableView tableView, NSTableColumn table
 
 			var cell = view.TextCell;
 			cell.VerticalAlignment = VerticalAlignment;
-			cell.Alignment = TextAlignment.ToNS();
+			cell.Alignment = TextAlignment.ToNS(view.UserInterfaceLayoutDirection);
 
 			view.Tag = row;
 			view.Item = obj;

src/Eto.Mac/Forms/Cells/TextBoxCellHandler.cs

@@ -100,12 +100,13 @@ public CellView()
 				{
 					Wraps = false,
 					Scrollable = true,
-					UsesSingleLineMode = false // true prevents proper vertical alignment 
+					UsesSingleLineMode = false, // true prevents proper vertical alignment 
 				};
 				Selectable = false;
 				DrawsBackground = false;
 				Bezeled = false;
 				Bordered = false;
+				Alignment = NSTextAlignment.Right;
 				AutoresizingMask = NSViewResizingMask.HeightSizable | NSViewResizingMask.WidthSizable;
 			}
 			public CellView(IntPtr handle) : base(handle) { }

src/Eto.Mac/Forms/Controls/MacImageTextView.cs

@@ -33,7 +33,8 @@ void SetSizes(CGSize bounds)
                 var scaledHeight = Math.Min(imageSize.Height, bounds.Height);
                 var scaledWidth = imageSize.Width * scaledHeight / imageSize.Height;
                 _imageSize = new CGSize(scaledWidth, scaledHeight);
-                TextField.Frame = new CGRect(scaledWidth + ImagePadding, 0, bounds.Width - scaledWidth - ImagePadding, bounds.Height);
+				var isrtl = UserInterfaceLayoutDirection == NSUserInterfaceLayoutDirection.RightToLeft;
+				TextField.Frame = new CGRect(isrtl ? 0 : scaledWidth + ImagePadding, 0, bounds.Width - scaledWidth - ImagePadding, bounds.Height);
             }
         }
 
@@ -91,6 +92,9 @@ public override void DrawRect(CGRect dirtyRect)
 
                 var imageRect = new CGRect(0, bounds.Y, _imageSize.Width, _imageSize.Height);
                 imageRect.Y += (bounds.Height - _imageSize.Height) / 2;
+				var isrtl = UserInterfaceLayoutDirection == NSUserInterfaceLayoutDirection.RightToLeft;
+				if (isrtl)
+					imageRect.X += bounds.Width - _imageSize.Width;
 
                 const float alpha = 1; //Enabled ? 1 : (nfloat)0.5;
 

src/Eto.Mac/Forms/Controls/SplitterHandler.cs

@@ -229,6 +229,12 @@ void ResizeSubviews(CGSize oldSize2)
 				panel1Rect.Width = panel1Rect.X = panel2Rect.Width = panel2Rect.X = 0;
 			if (newFrame.Height <= 0)
 				panel1Rect.Height = panel1Rect.Y = panel2Rect.Height = panel2Rect.Y = 0;
+
+			if (splitView.IsVertical && splitView.UserInterfaceLayoutDirection == NSUserInterfaceLayoutDirection.RightToLeft)
+			{
+				panel1Rect.X = panel2Rect.Width + dividerThickness;
+				panel2Rect.X = 0;
+			}
 
 			splitView.Subviews[0].Frame = panel1Rect;
 			splitView.Subviews[1].Frame = panel2Rect;

src/Eto.Mac/Forms/MacView.cs

@@ -750,6 +750,11 @@ public virtual void InvalidateMeasure()
 			Widget.VisualParent.GetMacControl()?.InvalidateMeasure();
 		}
 
+		protected override void Initialize()
+		{
+			base.Initialize();
+		}
+
 		protected virtual SizeF GetNaturalSize(SizeF availableSize)
 		{
 			var naturalSize = NaturalSize;
@@ -1729,6 +1734,22 @@ public virtual void OnViewDidMoveToWindow()
 
 		public bool IsMouseCaptured => MacView.CapturedControl == this;
 
+		public LayoutDirection LayoutDirection
+		{
+			get => EventControl.UserInterfaceLayoutDirection switch
+			{
+				NSUserInterfaceLayoutDirection.LeftToRight => LayoutDirection.LeftToRight,
+				NSUserInterfaceLayoutDirection.RightToLeft => LayoutDirection.RightToLeft,
+				_ => LayoutDirection.LeftToRight
+			};
+			set => EventControl.UserInterfaceLayoutDirection = value switch
+			{
+				LayoutDirection.LeftToRight => NSUserInterfaceLayoutDirection.LeftToRight,
+				LayoutDirection.RightToLeft => NSUserInterfaceLayoutDirection.RightToLeft,
+				_ => NSUserInterfaceLayoutDirection.LeftToRight,
+			};
+		}
+
 		public bool CaptureMouse()
 		{
 			if (!Widget.Loaded || !Widget.Visible)

src/Eto.Mac/Forms/TableLayoutHandler.cs

@@ -276,6 +276,7 @@ void PerformLayout()
 #endif
 
 			float starty = Padding.Top;
+			var isrtl = Control.UserInterfaceLayoutDirection == NSUserInterfaceLayoutDirection.RightToLeft;
 			for (int y = 0; y < final_heights.Length; y++)
 			{
 				float startx = Padding.Left;
@@ -290,6 +291,9 @@ void PerformLayout()
 						frame.Width = final_widths[x];
 						frame.Height = final_heights[y];
 						frame.X = (nfloat)Math.Round(Math.Max(0, startx));
+						if (isrtl)
+							frame.X = controlSize.Width - frame.X - frame.Width;
+
 						frame.Y = (nfloat)Math.Round(flipped ? starty : controlSize.Height - starty - frame.Height);
 						if (frame != oldframe)
 							macView.SetAlignmentFrame(frame);

src/Eto.Mac/MacConversions.cs

@@ -463,19 +463,25 @@ public static TextAlignment ToEto(this NSTextAlignment align)
 			}
 		}
 
-		public static NSTextAlignment ToNS(this TextAlignment align)
+		public static NSTextAlignment ToNS(this TextAlignment align, NSUserInterfaceLayoutDirection? direction = null)
 		{
-			switch (align)
-			{
-				case TextAlignment.Left:
-					return NSTextAlignment.Left;
-				case TextAlignment.Center:
-					return NSTextAlignment.Center;
-				case TextAlignment.Right:
-					return NSTextAlignment.Right;
-				default:
-					throw new NotSupportedException();
-			}
+			var dir = direction ?? (NSUserInterfaceLayoutDirection)NSApplication.SharedApplication.UserInterfaceLayoutDirection;
+			if (dir == NSUserInterfaceLayoutDirection.RightToLeft)
+				return align switch
+				{
+					TextAlignment.Left => NSTextAlignment.Right,
+					TextAlignment.Right => NSTextAlignment.Left,
+					TextAlignment.Center => NSTextAlignment.Center,
+					_ => throw new NotSupportedException()
+				};
+			else
+				return align switch
+				{
+					TextAlignment.Left => NSTextAlignment.Left,
+					TextAlignment.Right => NSTextAlignment.Right,
+					TextAlignment.Center => NSTextAlignment.Center,
+					_ => throw new NotSupportedException()
+				};
 		}
 
 		public static Font ToEto(this NSFont font)

src/Eto/Forms/Application.cs

@@ -539,6 +539,19 @@
 	/// </summary>
 	/// <seealso cref="IsActiveChanged"/>
 	public bool IsActive => Handler.IsActive;
+
+
+	/// <summary>
+	/// Gets or sets the default layout direction for the user interface of the application.
+	/// </summary>
+	/// <remarks>
+	/// 
+	/// </remarks>
+	public LayoutDirection DefaultLayoutDirection
+	{
+		get => Handler.DefaultLayoutDirection;
+		set => Handler.DefaultLayoutDirection = value;
+	}
 
 	/// <summary>
 	/// Advanced. Runs an iteration of the main UI loop when you are blocking the UI thread with logic.
@@ -767,5 +780,6 @@
 		/// Gets a value indicating that the application is currently the active application
 		/// </summary>
 		bool IsActive { get; }
+		LayoutDirection DefaultLayoutDirection { get; set; }
 	}
 }

src/Eto/Forms/Controls/Control.cs

@@ -1,5 +1,20 @@
 namespace Eto.Forms;
 
+/// <summary>
+/// Specifies the layout direction of the user interface.
+/// </summary>
+public enum LayoutDirection
+{
+	/// <summary>
+	/// Indicates the user interface should be laid out from left to right
+	/// </summary>
+	LeftToRight,
+	/// <summary>
+	/// Indicates the user interface should be laid out from right to left
+	/// </summary>
+	RightToLeft
+}
+
 /// <summary>
 /// Base for all visual UI elements
 /// </summary>
@@ -885,6 +900,18 @@
 	/// Releases the mouse capture after a call to <see cref="CaptureMouse"/>.
 	/// </summary>
 	public void ReleaseMouseCapture() => Handler.ReleaseMouseCapture();
+
+	/// <summary>
+	/// Gets or sets the layout direction for this control explicitly.
+	/// </summary>
+	/// <remarks>
+	/// The default layout direction of a control is based on the <see cref="Application.LayoutDirection"/>.
+	/// </remarks>
+	public LayoutDirection LayoutDirection
+	{
+		get => Handler.LayoutDirection;
+		set => Handler.LayoutDirection = value;
+	}
 
 	/// <summary>
 	/// Gets or sets the width of the control size.
@@ -2030,6 +2057,7 @@
 		/// or it can be captured explicitly via <see cref="CaptureMouse"/>.
 		/// </remarks>
 		bool IsMouseCaptured { get; }
+		LayoutDirection LayoutDirection { get; set; }
 
 		/// <summary>
 		/// Captures all mouse events to this control.

src/Eto/Forms/Controls/ThemedControlHandler.cs

@@ -468,6 +468,14 @@ public override void AttachEvent(string id)
 
 	/// <inheritdoc />
 	public bool IsMouseCaptured => Control.IsMouseCaptured;
+
+	/// <inheritdoc />
+	public LayoutDirection LayoutDirection
+	{
+		get => Control.LayoutDirection;
+		set => Control.LayoutDirection = value;
+	}
+
 	/// <inheritdoc />
 	public bool CaptureMouse() => Control.CaptureMouse();
 	/// <inheritdoc />

test/Eto.Test.Gtk/Startup.cs

@@ -11,6 +11,7 @@ static void Main(string[] args)
 			platform.Add<INativeHostControls>(() => new NativeHostControls());
 
 			var app = new TestApplication(platform);
+			global::Gtk.Widget.DefaultDirection = global::Gtk.TextDirection.Rtl;
 			app.TestAssemblies.Add(typeof(Startup).Assembly);
 			app.Run();
 		}

test/Eto.Test.Mac/Info.plist

@@ -5,7 +5,7 @@
 	<key>CFBundleIconFile</key>
 	<string>TestIcon.icns</string>
 	<key>CFBundleIdentifier</key>
-	<string>com.yourcompany.Eto.Test.Mac</string>
+	<string>ca.picoe.Eto.Test.Mac</string>
 	<key>CFBundleName</key>
 	<string>Eto.Test.Mac</string>
 	<key>CFBundleVersion</key>