Improve window drag behavior when transitioning from maximized state

Author: onesounds

Flow.Launcher/MainWindow.xaml.cs

@@ -465,7 +465,52 @@ private void OnPreviewMouseMove(object sender, MouseEventArgs e)
 
         private void OnMouseDown(object sender, MouseButtonEventArgs e)
         {
-            if (e.ChangedButton == MouseButton.Left) DragMove();
+            if (e.ChangedButton == MouseButton.Left)
+            {
+                try
+                {
+                    if (WindowState == WindowState.Maximized)
+                    {
+                        // 최대화된 창의 크기 기준으로 비율 계산
+                        double maxWidth = this.ActualWidth;
+                        double maxHeight = this.ActualHeight;
+                        var mousePos = e.GetPosition(this);
+                        double xRatio = mousePos.X / maxWidth;
+                        double yRatio = mousePos.Y / maxHeight;
+
+                        // 현재 모니터 정보
+                        var screen = Screen.FromHandle(new WindowInteropHelper(this).Handle);
+                        var workingArea = screen.WorkingArea;
+                        var screenLeftTop = Win32Helper.TransformPixelsToDIP(this, workingArea.X, workingArea.Y);
+
+                        // Normal로 전환
+                        WindowState = WindowState.Normal;
+
+                        Dispatcher.BeginInvoke(new Action(() =>
+                        {
+                            double normalWidth = Width;
+                            double normalHeight = Height;
+
+                            // 최대화된 창 크기와 Normal 창 크기 차이만큼 비율 적용
+                            Left = screenLeftTop.X + (maxWidth - normalWidth) * xRatio;
+                            Top = screenLeftTop.Y + (maxHeight - normalHeight) * yRatio;
+
+                            if (Mouse.LeftButton == MouseButtonState.Pressed)
+                            {
+                                DragMove();
+                            }
+                        }), DispatcherPriority.ApplicationIdle);
+                    }
+                    else
+                    {
+                        DragMove();
+                    }
+                }
+                catch (InvalidOperationException)
+                {
+                    // 무시
+                }
+            }
         }
 
         #endregion