Merge pull request #10895 from AvaloniaUI/linux-frame-position

X11 - Return frame position for Window.Position

src/Avalonia.X11/X11Window.Ime.cs

@@ -89,7 +89,7 @@ namespace Avalonia.X11
             }
         }
 
-        private void UpdateImePosition() => _imeControl?.UpdateWindowInfo(Position, RenderScaling);
+        private void UpdateImePosition() => _imeControl?.UpdateWindowInfo(_position ?? default, RenderScaling);
 
         private void HandleKeyEvent(ref XEvent ev)
         {

src/Avalonia.X11/X11Window.cs

@@ -124,7 +124,7 @@ namespace Avalonia.X11
             if (!_popup && Screen != null)
             {
                 var monitor = Screen.AllScreens.OrderBy(x => x.Scaling)
-                   .FirstOrDefault(m => m.Bounds.Contains(Position));
+                   .FirstOrDefault(m => m.Bounds.Contains(_position ?? default));
 
                 if (monitor != null)
                 {
@@ -326,23 +326,16 @@ namespace Avalonia.X11
         {
             get
             {
-                XGetWindowProperty(_x11.Display, _handle, _x11.Atoms._NET_FRAME_EXTENTS, IntPtr.Zero,
-                    new IntPtr(4), false, (IntPtr)Atom.AnyPropertyType, out var _,
-                    out var _, out var nitems, out var _, out var prop);
+                var extents = GetFrameExtents();
 
-                if (nitems.ToInt64() != 4)
+                if(extents == null)
                 {
-                    // Window hasn't been mapped by the WM yet, so can't get the extents.
                     return null;
                 }
 
-                var data = (IntPtr*)prop.ToPointer();
-                var extents = new Thickness(data[0].ToInt32(), data[2].ToInt32(), data[1].ToInt32(), data[3].ToInt32());
-                XFree(prop);
-                
                 return new Size(
-                    (_realSize.Width + extents.Left + extents.Right) / RenderScaling,
-                    (_realSize.Height + extents.Top + extents.Bottom) / RenderScaling);
+                    (_realSize.Width + extents.Value.Left + extents.Value.Right) / RenderScaling,
+                    (_realSize.Height + extents.Value.Top + extents.Value.Bottom) / RenderScaling);
             }
         }
 
@@ -556,6 +549,25 @@ namespace Avalonia.X11
             }
         }
 
+        private Thickness? GetFrameExtents()
+        {
+            XGetWindowProperty(_x11.Display, _handle, _x11.Atoms._NET_FRAME_EXTENTS, IntPtr.Zero,
+                new IntPtr(4), false, (IntPtr)Atom.AnyPropertyType, out var _,
+                out var _, out var nitems, out var _, out var prop);
+
+            if (nitems.ToInt64() != 4)
+            {
+                // Window hasn't been mapped by the WM yet, so can't get the extents.
+                return null;
+            }
+
+            var data = (IntPtr*)prop.ToPointer();
+            var extents = new Thickness(data[0].ToInt32(), data[2].ToInt32(), data[1].ToInt32(), data[3].ToInt32());
+            XFree(prop);
+
+            return extents;
+        }
+
         private bool UpdateScaling(bool skipResize = false)
         {
             double newScaling;
@@ -564,7 +576,7 @@ namespace Avalonia.X11
             else
             {
                 var monitor = _platform.X11Screens.Screens.OrderBy(x => x.Scaling)
-                    .FirstOrDefault(m => m.Bounds.Contains(Position));
+                    .FirstOrDefault(m => m.Bounds.Contains(_position ?? default));
                 newScaling = monitor?.Scaling ?? RenderScaling;
             }
 
@@ -916,11 +928,11 @@ namespace Avalonia.X11
 
         public void Hide() => XUnmapWindow(_x11.Display, _handle);
         
-        public Point PointToClient(PixelPoint point) => new Point((point.X - Position.X) / RenderScaling, (point.Y - Position.Y) / RenderScaling);
+        public Point PointToClient(PixelPoint point) => new Point((point.X - (_position ?? default).X) / RenderScaling, (point.Y - (_position ?? default).Y) / RenderScaling);
 
         public PixelPoint PointToScreen(Point point) => new PixelPoint(
-            (int)(point.X * RenderScaling + Position.X),
-            (int)(point.Y * RenderScaling + Position.Y));
+            (int)(point.X * RenderScaling + (_position ?? default).X),
+            (int)(point.Y * RenderScaling + (_position ?? default).Y));
         
         public void SetSystemDecorations(SystemDecorations enabled)
         {
@@ -984,20 +996,36 @@ namespace Avalonia.X11
         
         public PixelPoint Position
         {
-            get => _position ?? default;
+            get
+            {
+                if(_position == null)
+                {
+                    return default;
+                }
+
+                var extents = GetFrameExtents();
+
+                if(extents == null)
+                {
+                    extents = default(Thickness);
+                }
+
+                return new PixelPoint(_position.Value.X - (int)extents.Value.Left, _position.Value.Y - (int)extents.Value.Top);
+            }
             set
             {
-                if(!_usePositioningFlags)
+                if (!_usePositioningFlags)
                 {
                     _usePositioningFlags = true;
                     UpdateSizeHints(null);
                 }
-                
+
                 var changes = new XWindowChanges
                 {
-                    x = (int)value.X,
+                    x = value.X,
                     y = (int)value.Y
                 };
+
                 XConfigureWindow(_x11.Display, _handle, ChangeWindowFlags.CWX | ChangeWindowFlags.CWY,
                     ref changes);
                 XFlush(_x11.Display);
@@ -1006,7 +1034,6 @@ namespace Avalonia.X11
                     _position = value;
                     PositionChanged?.Invoke(value);
                 }
-
             }
         }