Add middle click and drag to scroll (implements dsharlet#209)

mikeoliphant · Dec 3, 2023 · f7d81c9 · f7d81c9
1 parent 2dafc08
commit f7d81c9
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Showing 2 changed files with 43 additions and 9 deletions.
diff --git a/LiveSPICE/Controls/SchematicControl.xaml.cs b/LiveSPICE/Controls/SchematicControl.xaml.cs
@@ -250,28 +250,35 @@ protected override void OnKeyUp(KeyEventArgs e)
         // Mouse events.
         protected override void OnMouseDown(MouseButtonEventArgs e)
         {
-            Focus();
-            Keyboard.Focus(this);
-            Circuit.Coord at = SnapToGrid(e.GetPosition(root));
             if (e.ChangedButton == MouseButton.Left)
             {
+                Focus();
+                Keyboard.Focus(this);
                 CaptureMouse();
                 if (Tool != null)
                 {
+                    Circuit.Coord at = SnapToGrid(e.GetPosition(root));
                     if (e.ClickCount == 2)
                         Tool.MouseDoubleClick(at);
                     else
                         Tool.MouseDown(at);
                 }
+                e.Handled = true;
             }
-            else
+            else if (e.ChangedButton == MouseButton.Middle)
+            {
+                Focus();
+                Keyboard.Focus(this);
+                CaptureMouse();
+                e.Handled = true;
+            }
+            else if (e.ChangedButton == MouseButton.Right)
             {
                 ReleaseMouseCapture();
                 if (Tool != null)
                     Tool.Cancel();
+                e.Handled = true;
             }
-
-            e.Handled = true;
         }
         protected override void OnMouseUp(MouseButtonEventArgs e)
         {
@@ -281,6 +288,12 @@ protected override void OnMouseUp(MouseButtonEventArgs e)
                 if (Tool != null)
                     Tool.MouseUp(at);
                 ReleaseMouseCapture();
+                e.Handled = true;
+            }
+            else if (e.ChangedButton == MouseButton.Middle)
+            {
+                ReleaseMouseCapture();
+                e.Handled = true;
             }
             else if (e.ChangedButton == MouseButton.Right && e.ClickCount == 1)
             {
@@ -290,22 +303,21 @@ protected override void OnMouseUp(MouseButtonEventArgs e)
                     if (ContextMenu != null)
                         ContextMenu.IsOpen = true;
                 }
+                e.Handled = true;
             }
-            e.Handled = true;
         }
         private Circuit.Coord? mouse = null;
         protected override void OnMouseMove(MouseEventArgs e)
         {
             Point x = e.GetPosition(root);
-            if (IsMouseCaptured)
+            if (IsMouseCaptured && e.LeftButton == MouseButtonState.Pressed)
                 BringIntoView(new Rect(x - AutoScrollBorder, x + AutoScrollBorder));
             Circuit.Coord at = SnapToGrid(x);
             if (!mouse.HasValue || mouse.Value != at)
             {
                 mouse = at;
                 if (Tool != null)
                     Tool.MouseMove(at);
-                e.Handled = true;
             }
         }
 

diff --git a/LiveSPICE/Controls/SchematicViewer.xaml.cs b/LiveSPICE/Controls/SchematicViewer.xaml.cs
@@ -80,6 +80,7 @@ public SchematicViewer()
             };
             scroll.PreviewMouseMove += (o, e) => mouse = e.GetPosition(this);
             scroll.MouseLeave += (o, e) => mouse = null;
+            scroll.MouseMove += scroll_MouseMove;
 
             SizeChanged += SchematicViewer_SizeChanged;
 
@@ -137,5 +138,26 @@ public void FocusCenter()
             }
             FocusRect(a, b, true);
         }
+
+        Point? mouse_scroll = null;
+        private void scroll_MouseMove(object o, System.Windows.Input.MouseEventArgs e)
+        {
+            if (IsMouseCaptureWithin && e.MiddleButton == MouseButtonState.Pressed)
+            {
+                Point x = e.GetPosition(this);
+                if (mouse_scroll.HasValue)
+                {
+                    Vector dx = x - mouse_scroll.Value;
+                    scroll.ScrollToHorizontalOffset(scroll.HorizontalOffset + dx.X * Zoom);
+                    scroll.ScrollToVerticalOffset(scroll.VerticalOffset + dx.Y * Zoom);
+                }
+                mouse_scroll = x;
+                e.Handled = true;
+            } 
+            else
+            {
+                mouse_scroll = null;
+            }
+        }
     }
 }