Windows Fullscreen Fixes (#87)

This PR fixes two bugs introduced in #80 :
- Exiting fullscreen could exit the Ryujinx window  (https://github.com/Ryubing/Issues/issues/415)
- Toggling fullscreen on would move the window to the primary monitor

And two other bugs related to input view :
- Exiting fullscreen when window was previously in a non maximized state now conserves the window coordinates and size properly (https://github.com/Ryubing/Issues/issues/425)
- Opening the ryujinx app no makes the app grow slightly larger vertically on each launch (+31px on my 1080p monitor) (https://github.com/Ryubing/Issues/issues/425)

Reviewed-on: https://git.ryujinx.app/projects/Ryubing/pulls/87

src/Ryujinx/UI/Helpers/Win32NativeInterop.cs

@@ -63,6 +63,18 @@ namespace Ryujinx.Ava.UI.Helpers
             }
         }
 
+        [StructLayout(LayoutKind.Sequential)]
+        public struct NativeRect
+        {
+            public int Left;
+            public int Top;
+            public int Right;
+            public int Bottom;
+
+            public int Width => Right - Left;
+            public int Height => Bottom - Top;
+        }
+
         public static nint CreateEmptyCursor()
         {
             return CreateCursor(nint.Zero, 0, 0, 1, 1, [0xFF], [0x00]);
@@ -119,6 +131,10 @@ namespace Ryujinx.Ava.UI.Helpers
         [LibraryImport("user32.dll", SetLastError = true)]
         public static partial nint SetWindowLongPtrW(nint hWnd, int nIndex, nint value);
 
+        [LibraryImport("user32.dll", SetLastError = true)]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        public static partial bool GetWindowRect(nint hWnd, out NativeRect lpRect);
+
         [LibraryImport("user32.dll", SetLastError = true)]
         [return: MarshalAs(UnmanagedType.Bool)]
         public static partial bool SetWindowPos(

src/Ryujinx/UI/ViewModels/MainWindowViewModel.cs

@@ -2060,6 +2060,12 @@ namespace Ryujinx.Ava.UI.ViewModels
         }
 
         private nint _savedWindowStyle;
+        private WindowState _savedWindowState;
+        private PixelPoint _savedWindowPosition;
+        private double _savedWindowWidth;
+        private double _savedWindowHeight;
+        private Win32NativeInterop.NativeRect _savedWindowRect;
+        private bool _savedWindowRectValid;
 
         [SupportedOSPlatform("windows")]
         private void MakeWindowFullscreen()
@@ -2067,19 +2073,36 @@ namespace Ryujinx.Ava.UI.ViewModels
             nint hwnd = Window.TryGetPlatformHandle()?.Handle ?? nint.Zero;
             if (hwnd == nint.Zero) return;
 
+            PixelPoint windowCenter = new(
+                Window.Position.X + (int)(Window.Bounds.Width / 2),
+                Window.Position.Y + (int)(Window.Bounds.Height / 2));
+
+            Avalonia.Platform.Screen? screen =
+                Window.Screens.ScreenFromVisual(Window) ??
+                Window.Screens.ScreenFromPoint(windowCenter) ??
+                Window.Screens.Primary;
+
+            if (screen == null)
+            {
+                return; // Can't determine screen size, don't attempt fullscreen
+            }
+
             // Save current style and placement
             _savedWindowStyle = Win32NativeInterop.GetWindowLongPtrW(hwnd, Win32NativeInterop.GWL_STYLE);
+            _savedWindowState = WindowState;
+            _savedWindowPosition = Window.Position;
+            _savedWindowWidth = Window.Width;
+            _savedWindowHeight = Window.Height;
+            _savedWindowRectValid = Win32NativeInterop.GetWindowRect(hwnd, out _savedWindowRect);
 
             // Remove window chrome: WS_OVERLAPPEDWINDOW -> WS_POPUP | WS_VISIBLE
             Win32NativeInterop.SetWindowLongPtrW(hwnd, Win32NativeInterop.GWL_STYLE,
                 unchecked((nint)(Win32NativeInterop.WS_POPUP | Win32NativeInterop.WS_VISIBLE)));
 
-            // TODO: why is this nullable
+            int w = screen.Bounds.Width;
-            Avalonia.Platform.Screen? screen = Window.Screens.ScreenFromVisual(Window);
+            int h = screen.Bounds.Height;
-            int w = screen?.Bounds.Width ?? 0;
-            int h = screen?.Bounds.Height ?? 0;
 
-            Win32NativeInterop.SetWindowPos(hwnd, nint.Zero, 0, 0, w, h,
+            Win32NativeInterop.SetWindowPos(hwnd, nint.Zero, screen.Bounds.X, screen.Bounds.Y, w, h,
                 Win32NativeInterop.SWP_NOZORDER | Win32NativeInterop.SWP_NOACTIVATE | Win32NativeInterop.SWP_FRAMECHANGED);
 
             WindowState = WindowState.FullScreen;
@@ -2094,10 +2117,34 @@ namespace Ryujinx.Ava.UI.ViewModels
             // Restore original window style
             Win32NativeInterop.SetWindowLongPtrW(hwnd, Win32NativeInterop.GWL_STYLE, _savedWindowStyle);
 
-            Win32NativeInterop.SetWindowPos(hwnd, nint.Zero, 0, 0, 0, 0,
+            if (_savedWindowState is WindowState.Maximized)
-                Win32NativeInterop.SWP_NOZORDER | Win32NativeInterop.SWP_NOACTIVATE |
+            {
-                Win32NativeInterop.SWP_FRAMECHANGED | Win32NativeInterop.SWP_NOMOVE | Win32NativeInterop.SWP_NOSIZE);
+                Win32NativeInterop.SetWindowPos(hwnd, nint.Zero, 0, 0, 0, 0,
+                    Win32NativeInterop.SWP_NOZORDER | Win32NativeInterop.SWP_NOACTIVATE |
+                    Win32NativeInterop.SWP_FRAMECHANGED | Win32NativeInterop.SWP_NOMOVE | Win32NativeInterop.SWP_NOSIZE);
+            }
+            else if (_savedWindowRectValid)
+            {
+                Dispatcher.UIThread.Post(() => RestoreSavedWindowRect(hwnd), DispatcherPriority.Background);
+            }
+            else
+            {
+                Win32NativeInterop.SetWindowPos(hwnd, nint.Zero, 0, 0, 0, 0,
+                    Win32NativeInterop.SWP_NOZORDER | Win32NativeInterop.SWP_NOACTIVATE |
+                    Win32NativeInterop.SWP_FRAMECHANGED | Win32NativeInterop.SWP_NOMOVE | Win32NativeInterop.SWP_NOSIZE);
+            }
+        }
 
+        [SupportedOSPlatform("windows")]
+        private void RestoreSavedWindowRect(nint hwnd)
+        {
+            Window.Position = _savedWindowPosition;
+            Window.Width = _savedWindowWidth;
+            Window.Height = _savedWindowHeight;
+
+            Win32NativeInterop.SetWindowPos(hwnd, nint.Zero, _savedWindowRect.Left, _savedWindowRect.Top,
+                _savedWindowRect.Width, _savedWindowRect.Height,
+                Win32NativeInterop.SWP_NOZORDER | Win32NativeInterop.SWP_NOACTIVATE | Win32NativeInterop.SWP_FRAMECHANGED);
         }
 
         public static void SaveConfig()

src/Ryujinx/UI/Windows/MainWindow.axaml.cs

@@ -48,6 +48,8 @@ namespace Ryujinx.Ava.UI.Windows
 
         private bool _isLoading;
         private bool _applicationsLoadedOnce;
+        private double _windowStartupWidthDelta;
+        private double _windowStartupHeightDelta;
 
         private UserChannelPersistence _userChannelPersistence;
         private static bool _deferLoad;
@@ -477,8 +479,8 @@ namespace Ryujinx.Ava.UI.Windows
             {
                 // Since scaling is being applied to the loaded settings from disk (see SetWindowSizePosition() above), scaling should be removed from width/height before saving out to disk
                 // as well - otherwise anyone not using a 1.0 scale factor their window will increase in size with every subsequent launch of the program when scaling is applied (Nov. 14, 2024)
-                ConfigurationState.Instance.UI.WindowStartup.WindowSizeHeight.Value = (int)(Height / Program.WindowScaleFactor);
+                ConfigurationState.Instance.UI.WindowStartup.WindowSizeHeight.Value = (int)((Height - _windowStartupHeightDelta) / Program.WindowScaleFactor);
-                ConfigurationState.Instance.UI.WindowStartup.WindowSizeWidth.Value = (int)(Width / Program.WindowScaleFactor);
+                ConfigurationState.Instance.UI.WindowStartup.WindowSizeWidth.Value = (int)((Width - _windowStartupWidthDelta) / Program.WindowScaleFactor);
 
                 ConfigurationState.Instance.UI.WindowStartup.WindowPositionX.Value = Position.X;
                 ConfigurationState.Instance.UI.WindowStartup.WindowPositionY.Value = Position.Y;
@@ -493,6 +495,9 @@ namespace Ryujinx.Ava.UI.Windows
 
             Initialize();
 
+            _windowStartupWidthDelta = Math.Max(0, Width - ViewModel.WindowWidth);
+            _windowStartupHeightDelta = Math.Max(0, Height - ViewModel.WindowHeight);
+
             PlatformSettings!.ColorValuesChanged += OnPlatformColorValuesChanged;
 
             ViewModel.Initialize(