x11 - prevent window from receiving input when disabled

src/Avalonia.X11/X11Window.cs

@@ -24,6 +24,7 @@ using Avalonia.X11.Glx;
 using Avalonia.X11.NativeDialogs;
 using static Avalonia.X11.XLib;
 using Avalonia.Input.Platform;
+using System.Runtime.InteropServices;
 // ReSharper disable IdentifierTypo
 // ReSharper disable StringLiteralTypo
 
@@ -772,7 +773,7 @@ namespace Avalonia.X11
 
         private void MouseEvent(RawPointerEventType type, ref XEvent ev, XModifierMask mods)
         {
-            if (_inputRoot is null)
+            if (_inputRoot is null || _disabled)
                 return;
             var mev = new RawPointerEventArgs(
                 _mouse, (ulong)ev.ButtonEvent.time.ToInt64(), _inputRoot,
@@ -1201,6 +1202,27 @@ namespace Avalonia.X11
         public void SetEnabled(bool enable)
         {
             _disabled = !enable;
+
+            var wmHintsPtr = XGetWMHints(_x11.Display, _handle);
+
+            XWMHints hints = default;
+
+            if (wmHintsPtr != IntPtr.Zero)
+            {
+                hints = Marshal.PtrToStructure<XWMHints>(wmHintsPtr);
+            }
+
+            var flags = hints.flags.ToInt64();
+            flags |= (long)XWMHintsFlags.InputHint;
+            hints.flags = (IntPtr)flags;
+            hints.input = enable ? 1 : 0;
+
+            XSetWMHints(_x11.Display, _handle, ref hints);
+
+            if (wmHintsPtr != IntPtr.Zero)
+            {
+                XFree(wmHintsPtr);
+            }
         }
 
         public void SetExtendClientAreaToDecorationsHint(bool extendIntoClientAreaHint)
@@ -1290,6 +1312,8 @@ namespace Avalonia.X11
 
         public bool NeedsManagedDecorations => false;
 
+        public bool IsEnabled => !_disabled;
+
         public class SurfacePlatformHandle : IPlatformNativeSurfaceHandle
         {
             private readonly X11Window _owner;

src/Avalonia.X11/XI2Manager.cs

@@ -217,6 +217,8 @@ namespace Avalonia.X11
 
         private void OnDeviceEvent(IXI2Client client, ParsedDeviceEvent ev)
         {
+            if (!client.IsEnabled)
+                return;
             if (ev.Type == XiEventType.XI_TouchBegin 
                 || ev.Type == XiEventType.XI_TouchUpdate 
                 || ev.Type == XiEventType.XI_TouchEnd)
@@ -370,6 +372,7 @@ namespace Avalonia.X11
 
     internal interface IXI2Client
     {
+        bool IsEnabled { get; }
         IInputRoot InputRoot { get; }
         void ScheduleXI2Input(RawInputEventArgs args);
         IMouseDevice MouseDevice { get; }

src/Avalonia.X11/XLib.cs

@@ -375,6 +375,9 @@ namespace Avalonia.X11
         [DllImport(libX11)]
         public static extern void XSetWMHints(IntPtr display, IntPtr window, ref XWMHints wmhints);
 
+        [DllImport(libX11)]
+        public static extern IntPtr XGetWMHints(IntPtr display, IntPtr window);
+
         [DllImport(libX11)]
         public static extern int XGetIconSizes(IntPtr display, IntPtr window, out IntPtr size_list, out int count);