[GUI] Add native Vulkan host surface support and more (#337)

* [GUI] Add native Vulkan host surface support and more

* reuse

* [GUI] set width session menu

src/SharpEmu.HLE/Host/Posix/PosixHostInput.cs

@@ -69,11 +69,118 @@ public sealed class PosixHostInput : IHostInput
     {
         // GLFW only delivers key events to the focused window, so a
         // delivering keyboard implies focus.
-        return _source?.HasKeyboardFocus ?? false;
+        return _source?.HasKeyboardFocus ?? IsEmbeddedX11WindowFocused();
     }
 
     public bool IsKeyDown(int virtualKey)
     {
-        return _source?.IsKeyDown(virtualKey) ?? false;
+        var source = _source;
+        if (source is not null)
+        {
+            return source.IsKeyDown(virtualKey);
+        }
+
+        return IsEmbeddedX11WindowFocused() && IsEmbeddedX11KeyDown(virtualKey);
     }
+
+    private static bool IsEmbeddedX11WindowFocused()
+    {
+        if (!OperatingSystem.IsLinux())
+        {
+            return false;
+        }
+
+        var display = HostSessionControl.EmbeddedHostDisplay;
+        var window = HostSessionControl.EmbeddedHostWindow;
+        if (display == 0 || window == 0 || XGetInputFocus(display, out var focusedWindow, out _) == 0 || focusedWindow == 0)
+        {
+            return false;
+        }
+
+        return GetTopLevelWindow(display, focusedWindow) == GetTopLevelWindow(display, window);
+    }
+
+    private static bool IsEmbeddedX11KeyDown(int virtualKey)
+    {
+        var display = HostSessionControl.EmbeddedHostDisplay;
+        var keysym = ToX11Keysym(virtualKey);
+        if (display == 0 || keysym == 0)
+        {
+            return false;
+        }
+
+        var keycode = XKeysymToKeycode(display, keysym);
+        if (keycode == 0)
+        {
+            return false;
+        }
+
+        var keymap = new byte[32];
+        XQueryKeymap(display, keymap);
+        return (keymap[keycode >> 3] & (1 << (keycode & 7))) != 0;
+    }
+
+    private static nint GetTopLevelWindow(nint display, nint window)
+    {
+        var current = window;
+        for (var depth = 0; depth < 16; depth++)
+        {
+            if (XQueryTree(display, current, out var root, out var parent, out var children, out _) == 0)
+            {
+                return 0;
+            }
+
+            if (children != 0)
+            {
+                XFree(children);
+            }
+
+            if (parent == 0 || parent == root)
+            {
+                return current;
+            }
+
+            current = parent;
+        }
+
+        return 0;
+    }
+
+    private static nuint ToX11Keysym(int virtualKey)
+    {
+        return virtualKey switch
+        {
+            0x08 => 0xFF08, // Backspace
+            0x09 => 0xFF09, // Tab
+            0x0D => 0xFF0D, // Return
+            0x1B => 0xFF1B, // Escape
+            0x25 => 0xFF51, // Left
+            0x26 => 0xFF52, // Up
+            0x27 => 0xFF53, // Right
+            0x28 => 0xFF54, // Down
+            >= 0x41 and <= 0x5A => (nuint)virtualKey,
+            _ => 0,
+        };
+    }
+
+    [System.Runtime.InteropServices.DllImport("libX11.so.6")]
+    private static extern int XGetInputFocus(nint display, out nint focus, out int revertTo);
+
+    [System.Runtime.InteropServices.DllImport("libX11.so.6")]
+    private static extern int XQueryKeymap(nint display, [System.Runtime.InteropServices.Out] byte[] keysReturn);
+
+    [System.Runtime.InteropServices.DllImport("libX11.so.6")]
+    private static extern byte XKeysymToKeycode(nint display, nuint keysym);
+
+    [System.Runtime.InteropServices.DllImport("libX11.so.6")]
+    private static extern int XQueryTree(
+        nint display,
+        nint window,
+        out nint root,
+        out nint parent,
+        out nint children,
+        out uint childCount);
+
+    [System.Runtime.InteropServices.DllImport("libX11.so.6")]
+    private static extern int XFree(nint data);
 }