Fix Window Positioning with Multiple Montiors

Co-authored-by: onesounds <[email protected]>

Author: Jack251970

Flow.Launcher.Infrastructure/UserSettings/Settings.cs

@@ -293,6 +293,10 @@ public SearchPrecisionScore QuerySearchPrecision
 
         public double WindowLeft { get; set; }
         public double WindowTop { get; set; }
+        public double PreviousScreenWidth { get; set; }
+        public double PreviousScreenHeight { get; set; }
+        public double PreviousDpiX { get; set; }
+        public double PreviousDpiY { get; set; }
 
         /// <summary>
         /// Custom left position on selected monitor

Flow.Launcher/MainWindow.xaml.cs

@@ -711,8 +711,26 @@ void InitializePositionInner()
             {
                 if (_settings.SearchWindowScreen == SearchWindowScreens.RememberLastLaunchLocation)
                 {
-                    Top = _settings.WindowTop;
+                    var previousScreenWidth = _settings.PreviousScreenWidth;
+                    var previousScreenHeight = _settings.PreviousScreenHeight;
+                    GetDpi(out var previousDpiX, out var previousDpiY);
+
+                    _settings.PreviousScreenWidth = SystemParameters.VirtualScreenWidth;
+                    _settings.PreviousScreenHeight = SystemParameters.VirtualScreenHeight;
+                    GetDpi(out var currentDpiX, out var currentDpiY);
+
+                    if (previousScreenWidth != 0 && previousScreenHeight != 0 &&
+                        previousDpiX != 0 && previousDpiY != 0 &&
+                        (previousScreenWidth != SystemParameters.VirtualScreenWidth ||
+                         previousScreenHeight != SystemParameters.VirtualScreenHeight ||
+                         previousDpiX != currentDpiX || previousDpiY != currentDpiY))
+                    {
+                        AdjustPositionForResolutionChange();
+                        return;
+                    }
+
                     Left = _settings.WindowLeft;
+                    Top = _settings.WindowTop;
                 }
                 else
                 {
@@ -725,27 +743,73 @@ void InitializePositionInner()
                             break;
                         case SearchWindowAligns.CenterTop:
                             Left = HorizonCenter(screen);
-                            Top = 10;
+                            Top = VerticalTop(screen);
                             break;
                         case SearchWindowAligns.LeftTop:
                             Left = HorizonLeft(screen);
-                            Top = 10;
+                            Top = VerticalTop(screen);
                             break;
                         case SearchWindowAligns.RightTop:
                             Left = HorizonRight(screen);
-                            Top = 10;
+                            Top = VerticalTop(screen);
                             break;
                         case SearchWindowAligns.Custom:
-                            Left = Win32Helper.TransformPixelsToDIP(this,
-                                screen.WorkingArea.X + _settings.CustomWindowLeft, 0).X;
-                            Top = Win32Helper.TransformPixelsToDIP(this, 0,
-                                screen.WorkingArea.Y + _settings.CustomWindowTop).Y;
+                            var customLeft = Win32Helper.TransformPixelsToDIP(this,
+                                screen.WorkingArea.X + _settings.CustomWindowLeft, 0);
+                            var customTop = Win32Helper.TransformPixelsToDIP(this, 0,
+                                screen.WorkingArea.Y + _settings.CustomWindowTop);
+                            Left = customLeft.X;
+                            Top = customTop.Y;
                             break;
                     }
                 }
             }
         }
 
+        private void AdjustPositionForResolutionChange()
+        {
+            var screenWidth = SystemParameters.VirtualScreenWidth;
+            var screenHeight = SystemParameters.VirtualScreenHeight;
+            GetDpi(out var currentDpiX, out var currentDpiY);
+
+            var previousLeft = _settings.WindowLeft;
+            var previousTop = _settings.WindowTop;
+            GetDpi(out var previousDpiX, out var previousDpiY);
+
+            var widthRatio = screenWidth / _settings.PreviousScreenWidth;
+            var heightRatio = screenHeight / _settings.PreviousScreenHeight;
+            var dpiXRatio = currentDpiX / previousDpiX;
+            var dpiYRatio = currentDpiY / previousDpiY;
+
+            var newLeft = previousLeft * widthRatio * dpiXRatio;
+            var newTop = previousTop * heightRatio * dpiYRatio;
+
+            var screenLeft = SystemParameters.VirtualScreenLeft;
+            var screenTop = SystemParameters.VirtualScreenTop;
+
+            var maxX = screenLeft + screenWidth - ActualWidth;
+            var maxY = screenTop + screenHeight - ActualHeight;
+
+            Left = Math.Max(screenLeft, Math.Min(newLeft, maxX));
+            Top = Math.Max(screenTop, Math.Min(newTop, maxY));
+        }
+
+        private void GetDpi(out double dpiX, out double dpiY)
+        {
+            var source = PresentationSource.FromVisual(this);
+            if (source != null && source.CompositionTarget != null)
+            {
+                var matrix = source.CompositionTarget.TransformToDevice;
+                dpiX = 96 * matrix.M11;
+                dpiY = 96 * matrix.M22;
+            }
+            else
+            {
+                dpiX = 96;
+                dpiY = 96;
+            }
+        }
+
         private Screen SelectedScreen()
         {
             Screen screen;
@@ -806,6 +870,13 @@ private double HorizonLeft(Screen screen)
             return left;
         }
 
+        public double VerticalTop(Screen screen)
+        {
+            var dip1 = Win32Helper.TransformPixelsToDIP(this, 0, screen.WorkingArea.Y);
+            var top = dip1.Y + 10;
+            return top;
+        }
+
         #endregion
 
         #region Window Animation

Flow.Launcher/SettingWindow.xaml.cs

@@ -137,18 +137,40 @@ public void UpdatePositionAndState()
 
         if (previousTop == null || previousLeft == null || !IsPositionValid(previousTop.Value, previousLeft.Value))
         {
-            Top = WindowTop();
-            Left = WindowLeft();
+            SetWindowPosition(WindowTop(), WindowLeft());
         }
         else
         {
-            Top = previousTop.Value;
-            Left = previousLeft.Value;
+            var left = _settings.SettingWindowLeft.Value;
+            var top = _settings.SettingWindowTop.Value;
+            AdjustWindowPosition(ref top, ref left);
+            SetWindowPosition(top, left);
         }
 
         WindowState = _settings.SettingWindowState;
     }
 
+    private void SetWindowPosition(double top, double left)
+    {
+        // Ensure window does not exceed screen boundaries
+        top = Math.Max(top, SystemParameters.VirtualScreenTop);
+        left = Math.Max(left, SystemParameters.VirtualScreenLeft);
+        top = Math.Min(top, SystemParameters.VirtualScreenHeight - ActualHeight);
+        left = Math.Min(left, SystemParameters.VirtualScreenWidth - ActualWidth);
+
+        Top = top;
+        Left = left;
+    }
+
+    private void AdjustWindowPosition(ref double top, ref double left)
+    {
+        // Adjust window position if it exceeds screen boundaries
+        top = Math.Max(top, SystemParameters.VirtualScreenTop);
+        left = Math.Max(left, SystemParameters.VirtualScreenLeft);
+        top = Math.Min(top, SystemParameters.VirtualScreenHeight - ActualHeight);
+        left = Math.Min(left, SystemParameters.VirtualScreenWidth - ActualWidth);
+    }
+
     private static bool IsPositionValid(double top, double left)
     {
         foreach (var screen in Screen.AllScreens)