Can now resize dock regions

DarkUI/DarkUI.csproj

@@ -108,6 +108,7 @@
     </Compile>
     <Compile Include="Docking\Items\DarkDockSplitter.cs" />
     <Compile Include="Extensions\BitmapExtensions.cs" />
+    <Compile Include="Extensions\IEnumerableExtensions.cs" />
     <Compile Include="Forms\DarkDialog.cs">
       <SubType>Form</SubType>
     </Compile>

DarkUI/Docking/DarkDockRegion.cs

@@ -86,7 +86,6 @@ namespace DarkUI
             var newGroup = new DarkDockGroup(DockPanel, this);
             _groups.Add(newGroup);
             Controls.Add(newGroup);
-            newGroup.BringToFront();
 
             PositionGroups();
 
@@ -121,10 +120,21 @@ namespace DarkUI
             }
 
             if (_groups.Count == 1)
+            {
                 _groups[0].Dock = DockStyle.Fill;
+            }
             else if (_groups.Count > 1)
+            {
                 foreach (var group in _groups)
-                    group.Dock = dockStyle;
+                {
+                    group.SendToBack();
+
+                    if (_groups.IsLast(group))
+                        group.Dock = dockStyle;
+                    else
+                        group.Dock = DockStyle.Fill;
+                }
+            }
         }
 
         private void BuildProperties()

DarkUI/Docking/Items/DarkDockSplitter.cs

@@ -44,6 +44,25 @@ namespace DarkUI
 
         #region Method Region
 
+        public void Move(Point difference)
+        {
+            switch (_splitterType)
+            {
+                case DarkSplitterType.Left:
+                    _control.Width += difference.X;
+                    break;
+                case DarkSplitterType.Right:
+                    _control.Width -= difference.X;
+                    break;
+                case DarkSplitterType.Top:
+                    _control.Height += difference.Y;
+                    break;
+                case DarkSplitterType.Bottom:
+                    _control.Height -= difference.Y;
+                    break;
+            }
+        }
+
         public void UpdateBounds()
         {
             switch (_splitterType)

DarkUI/Extensions/BitmapExtensions.cs

@@ -2,9 +2,9 @@
 
 namespace DarkUI
 {
-    public static class BitmapExtensions
+    internal static class BitmapExtensions
     {
-        public static Bitmap SetColor(this Bitmap bitmap, Color color)
+        internal static Bitmap SetColor(this Bitmap bitmap, Color color)
         {
             var newBitmap = new Bitmap(bitmap.Width, bitmap.Height);
             for (int i = 0; i < bitmap.Width; i++)
@@ -19,7 +19,7 @@ namespace DarkUI
             return newBitmap;
         }
 
-        public static Bitmap ChangeColor(this Bitmap bitmap, Color oldColor, Color newColor)
+        internal static Bitmap ChangeColor(this Bitmap bitmap, Color oldColor, Color newColor)
         {
             var newBitmap = new Bitmap(bitmap.Width, bitmap.Height);
             for (int i = 0; i < bitmap.Width; i++)

DarkUI/Extensions/IEnumerableExtensions.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace DarkUI
+{
+    internal static class IEnumerableExtensions
+    {
+        internal static bool IsLast<T>(this IEnumerable<T> items, T item)
+        {
+            var last = items.LastOrDefault();
+            if (last == null)
+                return false;
+            return item.Equals(last); // OR Object.ReferenceEquals(last, item)
+        }
+
+        internal static bool IsFirst<T>(this IEnumerable<T> items, T item)
+        {
+            var first = items.FirstOrDefault();
+            if (first == null)
+                return false;
+            return item.Equals(first);
+        }
+
+        internal static bool IsFirstOrLast<T>(this IEnumerable<T> items, T item)
+        {
+            return items.IsFirst(item) || items.IsLast(item);
+        }
+    }
+}

DarkUI/Win32/DarkDockResizeFilter.cs

@@ -1,4 +1,5 @@
-using System.Drawing;
+using System;
+using System.Drawing;
 using System.Windows.Forms;
 
 namespace DarkUI
@@ -10,6 +11,7 @@ namespace DarkUI
         private DarkDockPanel _dockPanel;
 
         private bool _isDragging;
+        private Point _initialContact;
         private DarkDockSplitter _activeSplitter;
 
         #endregion
@@ -33,16 +35,13 @@ namespace DarkUI
                   m.Msg == (int)WM.RBUTTONDOWN || m.Msg == (int)WM.RBUTTONUP || m.Msg == (int)WM.RBUTTONDBLCLK))
                 return false;
 
-            // Exit out early if we're simply releasing a drag over the area
+            // Exit out early if we're simply releasing a non-splitter drag over the area
             if (m.Msg == (int)WM.LBUTTONUP && !_isDragging)
                 return false;
 
             // Force cursor if already dragging.
-            ForceDraggingCursor();
-
-            // Stop all events from going through if we're dragging a splitter.
             if (_isDragging)
-                return true;
+                Cursor.Current = _activeSplitter.ResizeCursor;
 
             // Return out early if we're dragging something that's not a splitter.
             if (m.Msg == (int)WM.MOUSEMOVE && !_isDragging && _dockPanel.MouseButtonState != MouseButtons.None)
@@ -65,17 +64,26 @@ namespace DarkUI
             // Start drag.
             if (m.Msg == (int)WM.LBUTTONDOWN)
             {
+                foreach (var splitter in _dockPanel.Splitters)
+                {
+                    if (splitter.Bounds.Contains(_dockPanel.PointToClient(Cursor.Position)))
+                    {
+                        StartDrag(splitter);
+                        return true;
+                    }
+                }
             }
 
             // Stop drag.
             if (m.Msg == (int)WM.LBUTTONUP)
             {
+                if (_isDragging)
+                {
+                    StopDrag();
+                    return true;
+                }
             }
 
-            // Stop events passing through if we just started to drag something
-            if (_isDragging)
-            return true;
-
             // Stop events passing through if we're hovering over a splitter
             foreach (var splitter in _dockPanel.Splitters)
             {
@@ -83,6 +91,10 @@ namespace DarkUI
                     return true;
             }
 
+            // Stop all events from going through if we're dragging a splitter.
+            if (_isDragging)
+                return true;
+
             return false;
         }
 
@@ -90,19 +102,25 @@ namespace DarkUI
 
         #region Method Region
 
-        private void ForceDraggingCursor()
+        private void StartDrag(DarkDockSplitter splitter)
         {
-            if (_isDragging)
-            {
-                SetCursor(_activeSplitter.ResizeCursor);
-                return;
-            }
+            Console.WriteLine("Start drag");
+
+            _activeSplitter = splitter;
+            Cursor.Current = _activeSplitter.ResizeCursor;
+
+            _initialContact = Cursor.Position;
+            _isDragging = true;
         }
 
-        private void ResetCursor()
+        private void StopDrag()
         {
-            Cursor.Current = Cursors.Default;
-            CheckCursor();
+            Console.WriteLine("Stop drag");
+
+            var difference = new Point(_initialContact.X - Cursor.Position.X, _initialContact.Y - Cursor.Position.Y);
+            _activeSplitter.Move(difference);
+
+            _isDragging = false;
         }
 
         private void CheckCursor()
@@ -114,15 +132,16 @@ namespace DarkUI
             {
                 if (splitter.Bounds.Contains(_dockPanel.PointToClient(Cursor.Position)))
                 {
-                    SetCursor(splitter.ResizeCursor);
+                    Cursor.Current = splitter.ResizeCursor;
                     return;
                 }
             }
         }
 
-        private void SetCursor(Cursor cursor)
+        private void ResetCursor()
         {
-            Cursor.Current = cursor;
+            Cursor.Current = Cursors.Default;
+            CheckCursor();
         }
 
         #endregion

Example/Forms/MainForm.cs

@@ -43,6 +43,11 @@ namespace Example
             DockPanel.AddContent(_dockLayers);
             DockPanel.AddContent(_dockHistory);
 
+            // Add 3 dummy documents to the main document area of the dock panel
+            DockPanel.AddContent(new DockDocument { DockText = "Document 1" });
+            DockPanel.AddContent(new DockDocument { DockText = "Document 2" });
+            DockPanel.AddContent(new DockDocument { DockText = "Document 3" });
+
             // Show the tool windows as visible in the 'Window' menu
             mnuProject.Checked = true;
             mnuProperties.Checked = true;