Moved drag scrolling to DarkScrollBase.

DarkUI/Controls/DarkScrollBase.cs

@@ -27,10 +27,14 @@ namespace DarkUI.Controls
 
         private Point _offsetMousePosition;
 
+        private int _maxDragChange = 0;
+        private Timer _dragTimer;
+
         #endregion
 
         #region Property Region
 
+
         [Browsable(false)]
         [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
         public Rectangle Viewport
@@ -67,6 +71,23 @@ namespace DarkUI.Controls
             get { return _offsetMousePosition; }
         }
 
+        [Category("Behavior")]
+        [Description("Determines the maximum scroll change when dragging.")]
+        [DefaultValue(0)]
+        public int MaxDragChange
+        {
+            get { return _maxDragChange; }
+            set
+            {
+                _maxDragChange = value;
+                Invalidate();
+            }
+        }
+
+        [Browsable(false)]
+        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
+        public bool IsDragging { get; private set; }
+
         #endregion
 
         #region Constructor Region
@@ -87,97 +108,10 @@ namespace DarkUI.Controls
 
             _vScrollBar.MouseDown += delegate { Select(); };
             _hScrollBar.MouseDown += delegate { Select(); };
-        }
 
-        #endregion
+            _dragTimer = new Timer();
-
+            _dragTimer.Interval = 1;
-        #region Event Handler Region
+            _dragTimer.Tick += DragTimer_Tick;
-
-        protected override void OnCreateControl()
-        {
-            base.OnCreateControl();
-
-            UpdateScrollBars();
-        }
-
-        protected override void OnGotFocus(EventArgs e)
-        {
-            base.OnGotFocus(e);
-
-            Invalidate();
-        }
-
-        protected override void OnLostFocus(EventArgs e)
-        {
-            base.OnLostFocus(e);
-
-            Invalidate();
-        }
-
-        protected override void OnResize(EventArgs e)
-        {
-            base.OnResize(e);
-
-            UpdateScrollBars();
-        }
-
-        protected override void OnMouseMove(MouseEventArgs e)
-        {
-            base.OnMouseMove(e);
-
-            _offsetMousePosition = new Point(e.X + Viewport.Left, e.Y + Viewport.Top);
-        }
-
-        protected override void OnMouseDown(MouseEventArgs e)
-        {
-            base.OnMouseDown(e);
-
-            if (e.Button == MouseButtons.Right)
-                Select();
-        }
-
-        protected override void OnMouseWheel(MouseEventArgs e)
-        {
-            base.OnMouseWheel(e);
-
-            var horizontal = false;
-
-            if (_hScrollBar.Visible && ModifierKeys == Keys.Control)
-                horizontal = true;
-
-            if (_hScrollBar.Visible && !_vScrollBar.Visible)
-                horizontal = true;
-
-            if (!horizontal)
-            {
-                if (e.Delta > 0)
-                    _vScrollBar.ScrollByPhysical(3);
-                else if (e.Delta < 0)
-                    _vScrollBar.ScrollByPhysical(-3);
-            }
-            else
-            {
-                if (e.Delta > 0)
-                    _hScrollBar.ScrollByPhysical(3);
-                else if (e.Delta < 0)
-                    _hScrollBar.ScrollByPhysical(-3);
-            }
-        }
-
-        protected override void OnPreviewKeyDown(PreviewKeyDownEventArgs e)
-        {
-            base.OnPreviewKeyDown(e);
-
-            // Allows arrow keys to trigger OnKeyPress
-            switch (e.KeyCode)
-            {
-                case Keys.Up:
-                case Keys.Down:
-                case Keys.Left:
-                case Keys.Right:
-                    e.IsInputKey = true;
-                    break;
-            }
         }
 
         #endregion
@@ -287,6 +221,18 @@ namespace DarkUI.Controls
                 _hScrollBar.Value = value;
         }
 
+        protected virtual void StartDrag()
+        {
+            IsDragging = true;
+            _dragTimer.Start();
+        }
+
+        protected virtual void StopDrag()
+        {
+            IsDragging = false;
+            _dragTimer.Stop();
+        }
+
         public Point PointToView(Point point)
         {
             return new Point(point.X - Viewport.Left, point.Y - Viewport.Top);
@@ -298,5 +244,151 @@ namespace DarkUI.Controls
         }
 
         #endregion
+
+        #region Event Handler Region
+
+        protected override void OnCreateControl()
+        {
+            base.OnCreateControl();
+
+            UpdateScrollBars();
+        }
+
+        protected override void OnGotFocus(EventArgs e)
+        {
+            base.OnGotFocus(e);
+
+            Invalidate();
+        }
+
+        protected override void OnLostFocus(EventArgs e)
+        {
+            base.OnLostFocus(e);
+
+            Invalidate();
+        }
+
+        protected override void OnResize(EventArgs e)
+        {
+            base.OnResize(e);
+
+            UpdateScrollBars();
+        }
+
+        protected override void OnMouseMove(MouseEventArgs e)
+        {
+            base.OnMouseMove(e);
+
+            _offsetMousePosition = new Point(e.X + Viewport.Left, e.Y + Viewport.Top);
+        }
+
+        protected override void OnMouseDown(MouseEventArgs e)
+        {
+            base.OnMouseDown(e);
+
+            if (e.Button == MouseButtons.Right)
+                Select();
+        }
+
+        protected override void OnMouseWheel(MouseEventArgs e)
+        {
+            base.OnMouseWheel(e);
+
+            var horizontal = false;
+
+            if (_hScrollBar.Visible && ModifierKeys == Keys.Control)
+                horizontal = true;
+
+            if (_hScrollBar.Visible && !_vScrollBar.Visible)
+                horizontal = true;
+
+            if (!horizontal)
+            {
+                if (e.Delta > 0)
+                    _vScrollBar.ScrollByPhysical(3);
+                else if (e.Delta < 0)
+                    _vScrollBar.ScrollByPhysical(-3);
+            }
+            else
+            {
+                if (e.Delta > 0)
+                    _hScrollBar.ScrollByPhysical(3);
+                else if (e.Delta < 0)
+                    _hScrollBar.ScrollByPhysical(-3);
+            }
+        }
+
+        protected override void OnPreviewKeyDown(PreviewKeyDownEventArgs e)
+        {
+            base.OnPreviewKeyDown(e);
+
+            // Allows arrow keys to trigger OnKeyPress
+            switch (e.KeyCode)
+            {
+                case Keys.Up:
+                case Keys.Down:
+                case Keys.Left:
+                case Keys.Right:
+                    e.IsInputKey = true;
+                    break;
+            }
+        }
+
+        private void DragTimer_Tick(object sender, EventArgs e)
+        {
+            var pos = PointToClient(MousePosition);
+
+            if (_vScrollBar.Visible)
+            {
+                // Scroll up
+                if (pos.Y < ClientRectangle.Top)
+                {
+                    var difference = (pos.Y - ClientRectangle.Top) * -1;
+
+                    if (MaxDragChange > 0 && difference > MaxDragChange)
+                        difference = MaxDragChange;
+
+                    _vScrollBar.Value = _vScrollBar.Value - difference;
+                }
+
+                // Scroll down
+                if (pos.Y > ClientRectangle.Bottom)
+                {
+                    var difference = pos.Y - ClientRectangle.Bottom;
+
+                    if (MaxDragChange > 0 && difference > MaxDragChange)
+                        difference = MaxDragChange;
+
+                    _vScrollBar.Value = _vScrollBar.Value + difference;
+                }
+            }
+
+            if (_hScrollBar.Visible)
+            {
+                // Scroll left
+                if (pos.X < ClientRectangle.Left)
+                {
+                    var difference = (pos.X - ClientRectangle.Left) * -1;
+
+                    if (MaxDragChange > 0 && difference > MaxDragChange)
+                        difference = MaxDragChange;
+
+                    _hScrollBar.Value = _hScrollBar.Value - difference;
+                }
+
+                // Scroll right
+                if (pos.X > ClientRectangle.Right)
+                {
+                    var difference = pos.X - ClientRectangle.Right;
+
+                    if (MaxDragChange > 0 && difference > MaxDragChange)
+                        difference = MaxDragChange;
+
+                    _hScrollBar.Value = _hScrollBar.Value + difference;
+                }
+            }
+        }
+
+        #endregion
     }
 }

DarkUI/Controls/DarkTreeView.cs

@@ -47,12 +47,10 @@ namespace DarkUI.Controls
         private Bitmap _nodeOpenHover;
         private Bitmap _nodeOpenHoverSelected;
 
-        private bool _isDragging;
         private DarkTreeNode _provisionalNode;
         private DarkTreeNode _dropNode;
         private bool _provisionalDragging;
         private List<DarkTreeNode> _dragNodes;
-        private Timer _dragTimer;
         private Point _dragPos;
 
         #endregion
@@ -103,6 +101,7 @@ namespace DarkUI.Controls
             set
             {
                 _itemHeight = value;
+                MaxDragChange = _itemHeight;
                 UpdateNodes();
             }
         }
@@ -153,9 +152,7 @@ namespace DarkUI.Controls
             _selectedNodes = new ObservableCollection<DarkTreeNode>();
             _selectedNodes.CollectionChanged += SelectedNodes_CollectionChanged;
 
-            _dragTimer = new Timer();
+            MaxDragChange = _itemHeight;
-            _dragTimer.Interval = 1;
-            _dragTimer.Tick += DragTimer_Tick;
 
             LoadIcons();
         }
@@ -284,7 +281,7 @@ namespace DarkUI.Controls
                 }
             }
 
-            if (_isDragging)
+            if (IsDragging)
             {
                 if (_dropNode != null)
                 {
@@ -299,7 +296,7 @@ namespace DarkUI.Controls
 
             CheckHover();
 
-            if (_isDragging)
+            if (IsDragging)
             {
                 HandleDrag();
             }
@@ -327,7 +324,7 @@ namespace DarkUI.Controls
 
         protected override void OnMouseUp(MouseEventArgs e)
         {
-            if (_isDragging)
+            if (IsDragging)
             {
                 HandleDrop();
             }
@@ -374,7 +371,7 @@ namespace DarkUI.Controls
         {
             base.OnKeyDown(e);
 
-            if (_isDragging)
+            if (IsDragging)
                 return;
 
             if (Nodes.Count == 0)
@@ -469,7 +466,7 @@ namespace DarkUI.Controls
 
         private void DragTimer_Tick(object sender, EventArgs e)
         {
-            if (!_isDragging)
+            if (!IsDragging)
             {
                 StopDrag();
                 return;
@@ -566,7 +563,7 @@ namespace DarkUI.Controls
 
         private void UpdateNodes()
         {
-            if (_isDragging)
+            if (IsDragging)
                 return;
 
             if (Nodes.Count == 0)
@@ -680,7 +677,7 @@ namespace DarkUI.Controls
         {
             if (!ClientRectangle.Contains(PointToClient(MousePosition)))
             {
-                if (_isDragging)
+                if (IsDragging)
                 {
                     if (_dropNode != null)
                     {
@@ -708,7 +705,7 @@ namespace DarkUI.Controls
 
         private void CheckNodeHover(DarkTreeNode node, Point location)
         {
-            if (_isDragging)
+            if (IsDragging)
             {
                 var rect = GetNodeFullRowArea(node);
                 if (rect.Contains(OffsetMousePosition))
@@ -1019,7 +1016,7 @@ namespace DarkUI.Controls
 
         #region Drag & Drop Region
 
-        private void StartDrag()
+        protected override void StartDrag()
         {
             if (!AllowMoveNodes)
             {
@@ -1043,11 +1040,10 @@ namespace DarkUI.Controls
             }
 
             _provisionalDragging = false;
-            _isDragging = true;
-
-            _dragTimer.Start();
 
             Cursor = Cursors.SizeAll;
+
+            base.StartDrag();
         }
 
         private void HandleDrag()
@@ -1127,17 +1123,16 @@ namespace DarkUI.Controls
             UpdateNodes();
         }
 
-        private void StopDrag()
+        protected override void StopDrag()
         {
-            _isDragging = false;
             _dragNodes = null;
             _dropNode = null;
 
-            _dragTimer.Stop();
-
             Cursor = Cursors.Default;
 
             Invalidate();
+
+            base.StopDrag();
         }
 
         protected virtual bool ForceDropToParent(DarkTreeNode node)
@@ -1214,7 +1209,7 @@ namespace DarkUI.Controls
             if (SelectedNodes.Count > 0 && SelectedNodes.Contains(node))
                 bgColor = Focused ? Colors.BlueSelection : Colors.GreySelection;
 
-            if (_isDragging && _dropNode == node)
+            if (IsDragging && _dropNode == node)
                 bgColor = Focused ? Colors.BlueSelection : Colors.GreySelection;
 
             using (var b = new SolidBrush(bgColor))