[A11y] Make the DockItemTitleTabs keyboard accessible

Implement tabbing through the dock items, showing their focus

2 files changed, 212 insertions, 30 deletions

diff --git a/main/src/core/MonoDevelop.Ide/MonoDevelop.Components.Docking/DockItemTitleTab.cs b/main/src/core/MonoDevelop.Ide/MonoDevelop.Components.Docking/DockItemTitleTab.cs
index 1e385e7637..9d94608c51 100644
--- a/main/src/core/MonoDevelop.Ide/MonoDevelop.Components.Docking/DockItemTitleTab.cs
+++ b/main/src/core/MonoDevelop.Ide/MonoDevelop.Components.Docking/DockItemTitleTab.cs
@@ -25,7 +25,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-using Gtk; 
+using Gtk;
 
 using System;
 using MonoDevelop.Ide.Gui;
@@ -38,8 +38,8 @@ using MonoDevelop.Ide.Fonts;
 
 namespace MonoDevelop.Components.Docking
 {
-	
-	class DockItemTitleTab: Gtk.EventBox
+
+	class DockItemTitleTab : Gtk.EventBox
 	{
 		static Xwt.Drawing.Image dockTabActiveBackImage = Xwt.Drawing.Image.FromResource ("padbar-active.9.png");
 		static Xwt.Drawing.Image dockTabBackImage = Xwt.Drawing.Image.FromResource ("padbar-inactive.9.png");
@@ -60,6 +60,7 @@ namespace MonoDevelop.Components.Docking
 		DockItem item;
 		bool allowPlaceholderDocking;
 		bool mouseOver;
+		Widget currentFocus = null; // Currently focused child
 
 		IDisposable subscribedLeaveEvent;
 
@@ -72,6 +73,8 @@ namespace MonoDevelop.Components.Docking
 		static readonly Xwt.WidgetSpacing TabPadding;
 		static readonly Xwt.WidgetSpacing TabActivePadding;
 
+		internal event EventHandler<EventArgs> TabPressed;
+
 		static DockItemTitleTab ()
 		{
 			pixClose = Xwt.Drawing.Image.FromResource ("pad-close-9.png");
@@ -95,7 +98,7 @@ namespace MonoDevelop.Components.Docking
 				tabActiveBackImage9 = dockTabActiveBackImage as Xwt.Drawing.NinePatchImage;
 			TabActivePadding = tabActiveBackImage9.Padding;
 		}
-		
+
 		public DockItemTitleTab (DockItem item, DockFrame frame)
 		{
 			var actionHandler = new ActionDelegate (this);
@@ -105,6 +108,7 @@ namespace MonoDevelop.Components.Docking
 			Accessible.SetRole (AtkCocoa.Roles.AXGroup, "pad header");
 			Accessible.SetSubRole ("XAPadHeader");
 
+			CanFocus = true;
 			this.item = item;
 			this.frame = frame;
 			this.VisibleWindow = false;
@@ -194,10 +198,10 @@ namespace MonoDevelop.Components.Docking
 				tabIcon = new ImageView ();

 				tabIcon.Accessible.SetShouldIgnore (true);

 				tabIcon.Show ();

-				box.PackStart (tabIcon, false, false, 3);

-				

-				labelWidget = new ExtendedLabel (label);

-				// Ignore the label because the title tab already contains its name

+				box.PackStart (tabIcon, false, false, 3);
+
+				labelWidget = new ExtendedLabel (label);
+				// Ignore the label because the title tab already contains its name
 				labelWidget.Accessible.SetShouldIgnore (true);

 				labelWidget.UseMarkup = true;

 				var alignLabel = new Alignment (0.0f, 0.5f, 1, 1);

@@ -210,8 +214,8 @@ namespace MonoDevelop.Components.Docking
 				btnDock = new ImageButton ();

 				btnDock.Image = pixAutoHide;

 				btnDock.TooltipText = GettextCatalog.GetString ("Auto Hide");

-				btnDock.CanFocus = false;

-				//			btnDock.WidthRequest = btnDock.HeightRequest = 17;

+				btnDock.CanFocus = true;
+				//			btnDock.WidthRequest = btnDock.HeightRequest = 17;
 				btnDock.Clicked += OnClickDock;

 				btnDock.ButtonPressEvent += (o, args) => args.RetVal = true;

 				btnDock.WidthRequest = btnDock.SizeRequest ().Width;

@@ -220,8 +224,8 @@ namespace MonoDevelop.Components.Docking
 				btnClose = new ImageButton ();

 				btnClose.Image = pixClose;

 				btnClose.TooltipText = GettextCatalog.GetString ("Close");

-				btnClose.CanFocus = false;

-				//			btnClose.WidthRequest = btnClose.HeightRequest = 17;

+				btnClose.CanFocus = true;
+				//			btnClose.WidthRequest = btnClose.HeightRequest = 17;
 				btnClose.WidthRequest = btnDock.SizeRequest ().Width;

 				btnClose.Clicked += delegate {

 					item.Visible = false;

@@ -250,8 +254,7 @@ namespace MonoDevelop.Components.Docking
 				btnClose.Name = string.Format ("btnClose_{0}", labelNoSpaces ?? string.Empty);

 				realLabel = GettextCatalog.GetString ("Close {0}", label);

 				realHelp = GettextCatalog.GetString ("Close the {0} pad", label);

-			}

-			else {

+			} else {

 				labelWidget.Parent.Hide ();

 				realLabel = GettextCatalog.GetString ("Close pad");

 				realHelp = GettextCatalog.GetString ("Close the pad");

@@ -266,7 +269,7 @@ namespace MonoDevelop.Components.Docking
 				Accessible.SetTitle (label);
 				Accessible.SetLabel (label);
 			}
-			
+
 			// Get the required size before setting the ellipsize property, since ellipsized labels
 			// have a width request of 0
 			box.ShowAll ();
@@ -320,7 +323,7 @@ namespace MonoDevelop.Components.Docking
 		public int MinWidth {
 			get { return minWidth; }
 		}
-		
+
 		public bool Active {
 			get {
 				return active;
@@ -341,7 +344,7 @@ namespace MonoDevelop.Components.Docking
 				return page;
 			}
 		}
-		
+
 		public void UpdateBehavior ()
 		{
 			if (btnClose == null)
@@ -349,7 +352,7 @@ namespace MonoDevelop.Components.Docking
 
 			btnClose.Visible = (item.Behavior & DockItemBehavior.CantClose) == 0;
 			btnDock.Visible = (item.Behavior & DockItemBehavior.CantAutoHide) == 0;
-			
+
 			if (active || mouseOver) {
 				if (btnClose.Image == null)
 					btnClose.Image = pixClose;
@@ -371,6 +374,13 @@ namespace MonoDevelop.Components.Docking
 		bool tabPressed, tabActivated;
 		double pressX, pressY;
 
+		protected override void OnActivate ()
+		{
+			TabPressed?.Invoke (this, EventArgs.Empty);
+
+			base.OnActivate ();
+		}
+
 		protected override bool OnButtonPressEvent (Gdk.EventButton evnt)
 		{
 			if (evnt.TriggersContextMenu ()) {
@@ -381,6 +391,7 @@ namespace MonoDevelop.Components.Docking
 					tabPressed = true;
 					pressX = evnt.X;
 					pressY = evnt.Y;
+					TabPressed?.Invoke (this, EventArgs.Empty);
 				} else if (evnt.Type == Gdk.EventType.TwoButtonPress) {
 					tabActivated = true;
 				}
@@ -398,8 +409,7 @@ namespace MonoDevelop.Components.Docking
 					else
 						item.Status = DockItemStatus.AutoHide;
 				}
-			}
-			else if (!evnt.TriggersContextMenu () && evnt.Button == 1) {
+			} else if (!evnt.TriggersContextMenu () && evnt.Button == 1) {
 				frame.DockInPlaceholder (item);
 				frame.HidePlaceholder ();
 				if (GdkWindow != null)
@@ -411,15 +421,25 @@ namespace MonoDevelop.Components.Docking
 			return base.OnButtonReleaseEvent (evnt);
 		}
 
+		protected override bool OnFocusInEvent (Gdk.EventFocus evnt)
+		{
+			mouseOver = true;
+			UpdateBehavior ();
+			return base.OnFocusInEvent (evnt);
+		}
+
+		protected override bool OnFocusOutEvent (Gdk.EventFocus evnt)
+		{
+			if (currentFocus == null) {
+				mouseOver = false;
+				UpdateBehavior ();
+			}
+			return base.OnFocusOutEvent (evnt);
+		}
+
 		void HandlePress (object sender, EventArgs args)
 		{
-			// FIXME: How to support double click?
-			frame.DockInPlaceholder (item);
-			frame.HidePlaceholder ();
-			if (GdkWindow != null)
-				GdkWindow.Cursor = null;
-			frame.Toplevel.KeyPressEvent -= HeaderKeyPress;
-			frame.Toplevel.KeyReleaseEvent -= HeaderKeyRelease;
+			TabPressed?.Invoke (this, EventArgs.Empty);
 		}
 
 		void HandleShowMenu (object sender, EventArgs args)
@@ -455,6 +475,163 @@ namespace MonoDevelop.Components.Docking
 			UpdateBehavior ();
 		}
 
+		enum FocusWidget
+		{
+			None,
+			Widget,
+			DockButton,
+			CloseButton
+		};
+
+		bool FocusCurrentWidget (DirectionType direction)
+		{
+			if (currentFocus == null) {
+				return false;
+			}
+
+			return currentFocus.ChildFocus (direction);
+		}
+
+		bool MoveFocusToWidget (FocusWidget widget, DirectionType direction)
+		{
+			switch (widget) {
+			case FocusWidget.Widget:
+				GrabFocus ();
+				currentFocus = null;
+				return true;
+
+			case FocusWidget.DockButton:
+				currentFocus = btnDock;
+				return btnDock.ChildFocus (direction);
+
+			case FocusWidget.CloseButton:
+				currentFocus = btnClose;
+				return btnClose.ChildFocus (direction);
+
+			case FocusWidget.None:
+				break;
+			}
+
+			return false;
+		}
+
+		FocusWidget GetNextWidgetToFocus (FocusWidget widget, DirectionType direction) {
+			FocusWidget nextSite;
+
+			switch (widget) {
+			case FocusWidget.CloseButton:
+				switch (direction) {
+				case DirectionType.TabForward:
+				case DirectionType.Right:
+				case DirectionType.Down:
+					return FocusWidget.None;
+
+				case DirectionType.TabBackward:
+				case DirectionType.Left:
+				case DirectionType.Up:
+					if (btnDock.Image != null) {
+						nextSite = FocusWidget.DockButton;
+					} else {
+						nextSite = FocusWidget.Widget;
+					}
+					return nextSite;
+				}
+
+				break;
+
+			case FocusWidget.DockButton:
+				switch (direction) {
+				case DirectionType.TabForward:
+				case DirectionType.Right:
+				case DirectionType.Down:
+					return btnClose.Image == null ? FocusWidget.None : FocusWidget.CloseButton;
+
+				case DirectionType.TabBackward:
+				case DirectionType.Left:
+				case DirectionType.Up:
+					return FocusWidget.Widget;
+				}
+
+				break;
+
+			case FocusWidget.Widget:
+				switch (direction) {
+				case DirectionType.TabForward:
+				case DirectionType.Right:
+				case DirectionType.Down:
+					if (btnDock.Image != null) {
+						nextSite = FocusWidget.DockButton;
+					} else if (btnClose.Image != null) {
+						nextSite = FocusWidget.CloseButton;
+					} else {
+						nextSite = FocusWidget.None;
+					}
+					return nextSite;
+
+				case DirectionType.TabBackward:
+				case DirectionType.Left:
+				case DirectionType.Up:
+					return FocusWidget.None;
+				}
+
+				break;
+			case FocusWidget.None:
+				switch (direction) {
+				case DirectionType.TabForward:
+				case DirectionType.Right:
+				case DirectionType.Down:
+					return FocusWidget.Widget;
+
+				case DirectionType.TabBackward:
+				case DirectionType.Left:
+				case DirectionType.Up:
+					if (btnClose.Image != null) {
+						nextSite = FocusWidget.CloseButton;
+					} else if (btnDock.Image != null) {
+						nextSite = FocusWidget.DockButton;
+					} else {
+						nextSite = FocusWidget.Widget;
+					}
+					return nextSite;
+				}
+
+				break;
+			}
+
+			return FocusWidget.None;
+		}
+
+		protected override bool OnFocused (DirectionType direction)
+		{
+			if (!FocusCurrentWidget (direction)) {
+				FocusWidget focus = FocusWidget.None;
+
+				if (currentFocus == btnClose) {
+					focus = FocusWidget.CloseButton;
+				} else if (currentFocus == btnDock) {
+					focus = FocusWidget.DockButton;
+				} else if (IsFocus) {
+					focus = FocusWidget.Widget;
+				}
+
+				while ((focus = GetNextWidgetToFocus (focus, direction)) != FocusWidget.None) {
+					if (MoveFocusToWidget (focus, direction)) {
+						return true;
+					}
+				}
+
+				// Clean up the icons because OnFocusOutEvent has already been called
+				// so we need the icons to hide again
+				mouseOver = false;
+				UpdateBehavior ();
+
+				currentFocus = null;
+				return false;
+			}
+
+			return true;
+		}
+
 		[GLib.ConnectBeforeAttribute]
 		void HeaderKeyPress (object ob, Gtk.KeyPressEventArgs a)
 		{
@@ -527,6 +704,12 @@ namespace MonoDevelop.Components.Docking
 				DrawAsBrowser (evnt);
 			else
 				DrawNormal (evnt);
+
+			if (HasFocus) {
+				var alloc = labelWidget.Allocation;
+				Gtk.Style.PaintFocus (Style, GdkWindow, State, alloc, this, "label",
+				                      alloc.X, alloc.Y, alloc.Width, alloc.Height);
+			}
 			return base.OnExposeEvent (evnt);
 		}
 
diff --git a/main/src/core/MonoDevelop.Ide/MonoDevelop.Components.Docking/TabStrip.cs b/main/src/core/MonoDevelop.Ide/MonoDevelop.Components.Docking/TabStrip.cs
index 82dc1dd48e..c9e986f21a 100644
--- a/main/src/core/MonoDevelop.Ide/MonoDevelop.Components.Docking/TabStrip.cs
+++ b/main/src/core/MonoDevelop.Ide/MonoDevelop.Components.Docking/TabStrip.cs
@@ -94,7 +94,7 @@ namespace MonoDevelop.Components.Docking
 				tab.Page.Hide ();
 			}
 			
-			tab.ButtonPressEvent += OnTabPress;
+			tab.TabPressed += OnTabPress;
 			UpdateAccessibilityTabs ();
 		}
 
@@ -198,13 +198,12 @@ namespace MonoDevelop.Components.Docking
 				box.Remove (w);
 		}
 		
-		void OnTabPress (object s, Gtk.ButtonPressEventArgs args)
+		void OnTabPress (object s, EventArgs args)
 		{
 			CurrentTab = Array.IndexOf (box.Children, s);
 			DockItemTitleTab t = (DockItemTitleTab) s;
 			DockItem.SetFocus (t.Page);
 			QueueDraw ();
-			args.RetVal = true;
 		}
 
 		protected override void OnSizeAllocated (Gdk.Rectangle allocation)