Fix minimap updating the viewport without having the mouse captured (#169)

Author: miroiu

Nodify/Minimap/Minimap.cs

@@ -98,6 +98,11 @@ public event ZoomEventHandler Zoom
         /// </summary>
         protected internal Panel ItemsHost { get; private set; } = default!;
 
+        /// <summary>
+        /// Whether the user is currently dragging the minimap.
+        /// </summary>
+        protected bool IsDragging { get; private set; }
+
         static Minimap()
         {
             DefaultStyleKeyProperty.OverrideMetadata(typeof(Minimap), new FrameworkPropertyMetadata(typeof(Minimap)));
@@ -111,19 +116,31 @@ public override void OnApplyTemplate()
             ItemsHost = GetTemplateChild(ElementItemsHost) as Panel ?? throw new InvalidOperationException($"{ElementItemsHost} is missing or is not of type {nameof(Panel)}.");
         }
 
-        protected bool IsDragging { get; private set; }
+        protected override DependencyObject GetContainerForItemOverride()
+            => new MinimapItem();
+
+        protected override bool IsItemItsOwnContainerOverride(object item)
+            => item is MinimapItem;
+
+        protected override void OnLostMouseCapture(MouseEventArgs e)
+            => IsDragging = false;
 
         protected override void OnMouseDown(MouseButtonEventArgs e)
         {
             var gestures = EditorGestures.Mappings.Minimap;
             if (!IsReadOnly && gestures.DragViewport.Matches(this, e))
             {
-                this.CaptureMouseSafe();
                 IsDragging = true;
 
                 SetViewportLocation(e.GetPosition(ItemsHost));
 
                 e.Handled = true;
+
+                if (Mouse.Captured == null || IsMouseCaptured)
+                {
+                    Focus();
+                    CaptureMouse();
+                }
             }
         }
 
@@ -135,28 +152,13 @@ protected override void OnMouseMove(MouseEventArgs e)
             }
         }
 
-        private void SetViewportLocation(Point location)
-        {
-            var position = location - new Vector(ViewportSize.Width / 2, ViewportSize.Height / 2) + (Vector)Extent.Location;
-
-            if (MaxViewportOffset.Width != 0 || MaxViewportOffset.Height != 0)
-            {
-                double maxRight = ResizeToViewport ? ItemsExtent.Right : Math.Max(ItemsExtent.Right, ItemsExtent.Left + ViewportSize.Width);
-                double maxBottom = ResizeToViewport ? ItemsExtent.Bottom : Math.Max(ItemsExtent.Bottom, ItemsExtent.Top + ViewportSize.Height);
-
-                position.X = position.X.Clamp(ItemsExtent.Left - ViewportSize.Width / 2 - MaxViewportOffset.Width, maxRight - ViewportSize.Width / 2 + MaxViewportOffset.Width);
-                position.Y = position.Y.Clamp(ItemsExtent.Top - ViewportSize.Height / 2 - MaxViewportOffset.Height, maxBottom - ViewportSize.Height / 2 + MaxViewportOffset.Height);
-            }
-
-            ViewportLocation = position;
-        }
-
         protected override void OnMouseUp(MouseButtonEventArgs e)
         {
             var gestures = EditorGestures.Mappings.Minimap;
             if (IsDragging && gestures.DragViewport.Matches(this, e))
             {
                 IsDragging = false;
+                e.Handled = true;
             }
 
             if (IsMouseCaptured && e.RightButton == MouseButtonState.Released && e.LeftButton == MouseButtonState.Released && e.MiddleButton == MouseButtonState.Released)
@@ -169,6 +171,11 @@ protected override void OnMouseWheel(MouseWheelEventArgs e)
         {
             if (!IsReadOnly && !e.Handled && EditorGestures.Mappings.Minimap.ZoomModifierKey == Keyboard.Modifiers)
             {
+                if (!ResizeToViewport)
+                {
+                    SetViewportLocation(e.GetPosition(ItemsHost));
+                }
+
                 double zoom = Math.Pow(2.0, e.Delta / 3.0 / Mouse.MouseWheelDeltaForOneLine);
                 var location = ViewportLocation + (Vector)ViewportSize / 2;
 
@@ -183,10 +190,20 @@ protected override void OnMouseWheel(MouseWheelEventArgs e)
             }
         }
 
-        protected override DependencyObject GetContainerForItemOverride()
-            => new MinimapItem();
+        private void SetViewportLocation(Point location)
+        {
+            var position = location - new Vector(ViewportSize.Width / 2, ViewportSize.Height / 2) + (Vector)Extent.Location;
 
-        protected override bool IsItemItsOwnContainerOverride(object item)
-            => item is MinimapItem;
+            if (MaxViewportOffset.Width != 0 || MaxViewportOffset.Height != 0)
+            {
+                double maxRight = ResizeToViewport ? ItemsExtent.Right : Math.Max(ItemsExtent.Right, ItemsExtent.Left + ViewportSize.Width);
+                double maxBottom = ResizeToViewport ? ItemsExtent.Bottom : Math.Max(ItemsExtent.Bottom, ItemsExtent.Top + ViewportSize.Height);
+
+                position.X = position.X.Clamp(ItemsExtent.Left - ViewportSize.Width / 2 - MaxViewportOffset.Width, maxRight - ViewportSize.Width / 2 + MaxViewportOffset.Width);
+                position.Y = position.Y.Clamp(ItemsExtent.Top - ViewportSize.Height / 2 - MaxViewportOffset.Height, maxBottom - ViewportSize.Height / 2 + MaxViewportOffset.Height);
+            }
+
+            ViewportLocation = position;
+        }
     }
 }