fix(Core): define GetScreen for Windows

Fixes region capture on Windows

Author: BrycensRanch

SnapX.Avalonia/Views/RegionSelectorWindow.axaml.cs

@@ -36,24 +36,50 @@ public RegionSelectorWindow(RegionSelectorViewModel vm)
     {
         DataContext = vm;
         InitializeComponent();
+
         _selectionRect = this.FindControl<Rectangle>("SelectionRect");
         _infoBox = this.FindControl<TextBox>("InfoBox");
         _canvas = this.FindControl<Canvas>("Canvas");
 
-        // var workingArea = Screens.All
-        //     .Select(screen => screen.Bounds)
-        //     .Aggregate((acc, next) => acc.Union(next));
-        var (x, y, width, height) = Methods.GetActiveScreen().GetAwaiter().GetResult();
-        DebugHelper.WriteLine($"VirtualScreen details: X is {x} Y is {y} Width is {width}  Height is {height}");
-        Position = new PixelPoint(x, y);
-        // Width = width;
-        // height = width;
-        _canvas.Width = width;
-        _canvas.Height = height;
-        var viewBox = _canvas.Parent as Viewbox;
-        viewBox.Width = width;
-        viewBox.Height = height;
+        // Set initial state to invisible/minimized to prevent flicker
+        // until the async position logic finishes.
+        Opacity = 0;
+    }
+    protected override async void OnOpened(EventArgs e)
+    {
+        base.OnOpened(e);
+
+        await SetupWindowBoundsAsync();
+
+        Opacity = 1;
+    }
+    private async Task SetupWindowBoundsAsync()
+    {
+        var bounds = await Task.Run(async() =>
+        {
+            var (x, y, width, height) = await Methods.GetActiveScreen();
+            DebugHelper.WriteLine($"VirtualScreen details: X is {x} Y is {y} Width is {width}  Height is {height}");
+
+            return new PixelRect(x, y, width, height);
+        });
+
+        Dispatcher.UIThread.Post(() =>
+        {
+            Position = new PixelPoint(bounds.X, bounds.Y);
+            Width = bounds.Width;
+            Height = bounds.Height;
+
+            _canvas.Width = bounds.Width;
+            _canvas.Height = bounds.Height;
+
+            if (_canvas.Parent is Viewbox viewBox)
+            {
+                viewBox.Width = bounds.Width;
+                viewBox.Height = bounds.Height;
+            }
 
+            DebugHelper.WriteLine($"Selector Ready: {bounds.Width}x{bounds.Height} at {bounds.X},{bounds.Y}");
+        });
     }
     public RegionSelectorWindow() : this(new RegionSelectorViewModel()) { }
     private void OnPointerPressed(object? Sender, PointerPressedEventArgs E)

SnapX.Core/NativeMethods.txt

@@ -20,6 +20,20 @@ GetCursorPos
 SetCursorPos
 SetForegroundWindow
 GetForegroundWindow
+MonitorFromPoint
+GetMonitorInfo
+MONITORINFOEXW
+MONITORINFOF_PRIMARY
+EnumDisplayMonitors
+EnumDisplaySettings
+DEVMODEW
+ENUM_DISPLAY_SETTINGS_MODE
+GetDpiForMonitor
+MONITOR_DPI_TYPE
+CreateDC
+GetDeviceCaps
+DeleteDC
+GET_DEVICE_CAPS_INDEX
 OpenClipboard
 CloseClipboard
 EmptyClipboard

SnapX.Core/SharpCapture/Windows/WindowsCapture.cs

@@ -12,6 +12,7 @@
 using Windows.Win32;
 using Windows.Win32.Foundation;
 using Windows.Win32.UI.WindowsAndMessaging;
+using SnapX.Core.Utils.Native;
 using WinRT;
 
 
@@ -179,6 +180,8 @@ private static IDirect3DDevice CreateDirect3DDeviceFromVorticeDevice(ID3D11Devic
 
         return device;
     }
+    public override async Task<Rectangle> GetScreen(Point pos) => Methods.NativeAPI.GetScreen(pos)?.Bounds ?? Rectangle.Empty;
+
     private static ID3D11Texture2D Texture2DFromSurface(IDirect3DSurface surface, ID3D11Device device, IntPtr captureHwnd)
     {
         DebugHelper.WriteLine("=== IDirect3DSurface ===");

SnapX.Core/Utils/Native/WindowsAPI.cs

@@ -10,7 +10,9 @@
 using SnapX.Core.Utils.Extensions;
 using Windows.Win32;
 using Windows.Win32.Foundation;
+using Windows.Win32.Graphics.Gdi;
 using Windows.Win32.System.Memory;
+using Windows.Win32.UI.HiDpi;
 using Windows.Win32.UI.Shell;
 using Windows.Win32.UI.WindowsAndMessaging;
 
@@ -241,6 +243,77 @@ public static Rectangle GetWindowRect(IntPtr hwnd)
         return new Rectangle(rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top);
     }
 
+    public override Screen? GetScreen(Point pos)
+    {
+        var pt = new System.Drawing.Point(pos.X, pos.Y);
+
+        // 2. Get the HMONITOR handle.
+        // MONITOR_DEFAULTTONEAREST ensures that even if the point is off-screen,
+        // it returns the closest monitor rather than null.
+        var hMonitor = PInvoke.MonitorFromPoint(pt, MONITOR_FROM_FLAGS.MONITOR_DEFAULTTONEAREST);
+
+        if (hMonitor == IntPtr.Zero)
+        {
+            return null;
+        }
+
+        unsafe
+        {
+            var info = new MONITORINFOEXW();
+            info.monitorInfo.cbSize = (uint)Marshal.SizeOf<MONITORINFOEXW>();
+
+            if (!PInvoke.GetMonitorInfo(hMonitor, (MONITORINFO*)&info)) return null;
+            var deviceName = info.szDevice.ToString();
+            var devMode = new DEVMODEW { dmSize = (ushort)sizeof(DEVMODEW) };
+            uint refreshRate = 0;
+            var orientation = ScreenOrientation.Landscape;
+            if (PInvoke.EnumDisplaySettings(deviceName, ENUM_DISPLAY_SETTINGS_MODE.ENUM_CURRENT_SETTINGS, ref devMode))
+            {
+                refreshRate = devMode.dmDisplayFrequency;
+                orientation = devMode.Anonymous1.Anonymous2.dmDisplayOrientation switch
+                {
+                    DEVMODE_DISPLAY_ORIENTATION.DMDO_90 => ScreenOrientation.Portrait,
+                    DEVMODE_DISPLAY_ORIENTATION.DMDO_270 => ScreenOrientation.Portrait,
+                    _ => ScreenOrientation.Landscape
+                };
+            }
+            PInvoke.GetDpiForMonitor(hMonitor, MONITOR_DPI_TYPE.MDT_EFFECTIVE_DPI, out var dpiX, out var _);
+            var scaleFactor = dpiX / 96.0;
+            var hdc = PInvoke.CreateDCW(null, deviceName, null, null);
+            double diagonalInches = 0;
+            if (!hdc.IsNull)
+            {
+                var widthMm = PInvoke.GetDeviceCaps(hdc, GET_DEVICE_CAPS_INDEX.HORZSIZE);
+                var heightMm = PInvoke.GetDeviceCaps(hdc, GET_DEVICE_CAPS_INDEX.VERTSIZE);
+
+                var widthInches = widthMm / 25.4;
+                var heightInches = heightMm / 25.4;
+                diagonalInches = Math.Sqrt(Math.Pow(widthInches, 2) + Math.Pow(heightInches, 2));
+
+                PInvoke.DeleteDC(hdc);
+            }
+            return new Screen
+            {
+                Id = deviceName,
+                // Index = index, unknown
+                Name = deviceName,
+                Bounds = new Rectangle(
+                    info.monitorInfo.rcMonitor.left,
+                    info.monitorInfo.rcMonitor.top,
+                    info.monitorInfo.rcMonitor.right - info.monitorInfo.rcMonitor.left,
+                    info.monitorInfo.rcMonitor.bottom - info.monitorInfo.rcMonitor.top
+                ),
+                RefreshRate = refreshRate,
+                Orientation = orientation,
+                DPI = dpiX,
+                ScaleFactor = scaleFactor,
+                DiagonalSizeInches = Math.Round(diagonalInches, 1),
+                IsPrimary = (info.monitorInfo.dwFlags & PInvoke.MONITORINFOF_PRIMARY) != 0,
+                SessionType = SessionType.Windows
+            };
+        }
+    }
+
     // Beginning of IntegrationHelper class being integrated into WindowsAPI class
 
     private static readonly string ApplicationPath = $"\"{AppDomain.CurrentDomain.BaseDirectory}\"";