[X11] Implemented cursor support

src/Avalonia.X11/Stubs.cs

@@ -9,14 +9,6 @@ using Avalonia.Platform;
 
 namespace Avalonia.X11
 {
-    class CursorFactoryStub : IStandardCursorFactory
-    {
-        public IPlatformHandle GetCursor(StandardCursorType cursorType)
-        {
-            return new PlatformHandle(IntPtr.Zero, "FAKE");
-        }
-    }
-
     class ClipboardStub : IClipboard
     {
         private string _text;

src/Avalonia.X11/X11Atoms.cs

@@ -176,9 +176,6 @@ namespace Avalonia.X11 {
 		public readonly IntPtr OEMTEXT;
 		public readonly IntPtr UNICODETEXT;
 		public readonly IntPtr TARGETS;
-		public readonly IntPtr PostAtom;
-		public readonly IntPtr HoverState;
-		public readonly IntPtr AsyncAtom;
 
 
 		public X11Atoms (IntPtr display) {
@@ -249,10 +246,7 @@ namespace Avalonia.X11 {
 				"PRIMARY",
 				"COMPOUND_TEXT",
 				"UTF8_STRING",
-				"TARGETS",
+				"TARGETS"};
-				"_SWF_AsyncAtom",
-				"_SWF_PostMessageAtom",
-				"_SWF_HoverAtom" };
 
 			IntPtr[] atoms = new IntPtr [atom_names.Length];;
 
@@ -324,9 +318,6 @@ namespace Avalonia.X11 {
 			OEMTEXT = atoms [off++];
 			UNICODETEXT = atoms [off++];
 			TARGETS = atoms [off++];
-			AsyncAtom = atoms [off++];
-			PostAtom = atoms [off++];
-			HoverState = atoms [off++];
 
 			DIB = XA_PIXMAP;
 

src/Avalonia.X11/X11CursorFactory.cs

@@ -0,0 +1,57 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Avalonia.Input;
+using Avalonia.Platform;
+
+namespace Avalonia.X11
+{
+    class X11CursorFactory : IStandardCursorFactory
+    {
+        private readonly IntPtr _display;
+        private Dictionary<CursorFontShape, IntPtr> _cursors;
+
+        private static readonly Dictionary<StandardCursorType, CursorFontShape> s_mapping =
+            new Dictionary<StandardCursorType, CursorFontShape>
+            {
+                {StandardCursorType.Arrow, CursorFontShape.XC_arrow},
+                {StandardCursorType.Cross, CursorFontShape.XC_cross},
+                {StandardCursorType.Hand, CursorFontShape.XC_hand1},
+                {StandardCursorType.Help, CursorFontShape.XC_question_arrow},
+                {StandardCursorType.Ibeam, CursorFontShape.XC_xterm},
+                {StandardCursorType.No, CursorFontShape.XC_X_cursor},
+                {StandardCursorType.Wait, CursorFontShape.XC_watch},
+                {StandardCursorType.AppStarting, CursorFontShape.XC_watch},
+                {StandardCursorType.BottomSize, CursorFontShape.XC_bottom_side},
+                {StandardCursorType.DragCopy, CursorFontShape.XC_center_ptr},
+                {StandardCursorType.DragLink, CursorFontShape.XC_fleur},
+                {StandardCursorType.DragMove, CursorFontShape.XC_diamond_cross},
+                {StandardCursorType.LeftSide, CursorFontShape.XC_left_side},
+                {StandardCursorType.RightSide, CursorFontShape.XC_right_side},
+                {StandardCursorType.SizeAll, CursorFontShape.XC_sizing},
+                {StandardCursorType.TopSide, CursorFontShape.XC_top_side},
+                {StandardCursorType.UpArrow, CursorFontShape.XC_sb_up_arrow},
+                {StandardCursorType.BottomLeftCorner, CursorFontShape.XC_bottom_left_corner},
+                {StandardCursorType.BottomRightCorner, CursorFontShape.XC_bottom_right_corner},
+                {StandardCursorType.SizeNorthSouth, CursorFontShape.XC_sb_v_double_arrow},
+                {StandardCursorType.SizeWestEast, CursorFontShape.XC_sb_h_double_arrow},
+                {StandardCursorType.TopLeftCorner, CursorFontShape.XC_top_left_corner},
+                {StandardCursorType.TopRightCorner, CursorFontShape.XC_top_right_corner},
+            };
+
+        public X11CursorFactory(IntPtr display)
+        {
+            _display = display;
+            _cursors = Enum.GetValues(typeof(CursorFontShape)).Cast<CursorFontShape>()
+                .ToDictionary(id => id, id => XLib.XCreateFontCursor(_display, id));
+        }
+        
+        public IPlatformHandle GetCursor(StandardCursorType cursorType)
+        {
+            var handle = s_mapping.TryGetValue(cursorType, out var shape)
+                ? _cursors[shape]
+                : _cursors[CursorFontShape.XC_arrow];
+            return new PlatformHandle(handle, "XCURSOR");
+        }
+    }
+}

src/Avalonia.X11/X11Info.cs

@@ -14,6 +14,7 @@ namespace Avalonia.X11
         public IntPtr BlackPixel { get; }
         public IntPtr RootWindow { get; }
         public IntPtr DefaultRootWindow { get; }
+        public IntPtr DefaultCursor { get; }
         public X11Atoms Atoms { get; }
 
         public IntPtr LastActivityTimestamp { get; set; }
@@ -25,6 +26,7 @@ namespace Avalonia.X11
             DefaultScreen = XDefaultScreen(display);
             BlackPixel = XBlackPixel(display, DefaultScreen);
             RootWindow = XRootWindow(display, DefaultScreen);
+            DefaultCursor = XCreateFontCursor(display, CursorFontShape.XC_arrow);
             DefaultRootWindow = XDefaultRootWindow(display);
             Atoms = new X11Atoms(display);
         }

src/Avalonia.X11/X11Platform.cs

@@ -36,7 +36,7 @@ namespace Avalonia.X11
                 .Bind<IRenderLoop>().ToConstant(new RenderLoop())
                 .Bind<PlatformHotkeyConfiguration>().ToConstant(new PlatformHotkeyConfiguration(InputModifiers.Control))
                 .Bind<IKeyboardDevice>().ToFunc(() => KeyboardDevice)
-                .Bind<IStandardCursorFactory>().ToConstant(new CursorFactoryStub())
+                .Bind<IStandardCursorFactory>().ToConstant(new X11CursorFactory(Display))
                 .Bind<IClipboard>().ToSingleton<ClipboardStub>()
                 .Bind<IPlatformSettings>().ToConstant(new PlatformSettingsStub())
                 .Bind<ISystemDialogImpl>().ToConstant(new SystemDialogsStub())

src/Avalonia.X11/X11Window.cs

@@ -482,6 +482,14 @@ namespace Avalonia.X11
 
         public void SetCursor(IPlatformHandle cursor)
         {
+            if (cursor == null)
+                XDefineCursor(_x11.Display, _handle, _x11.DefaultCursor);
+            else
+            {
+                if (cursor.HandleDescriptor != "XCURSOR")
+                    throw new ArgumentException("Expected XCURSOR handle type");
+                XDefineCursor(_x11.Display, _handle, cursor.Handle);
+            }
         }
 
         public IPlatformHandle Handle { get; }