Initial commit of existing code.

* All renderdoc code up to this point was written by me, history is available by request

WinFormsUI/Docking/DockWindowCollection.cs

@@ -0,0 +1,38 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.ObjectModel;
+
+namespace WeifenLuo.WinFormsUI.Docking
+{
+    public class DockWindowCollection : ReadOnlyCollection<DockWindow>
+    {
+        internal DockWindowCollection(DockPanel dockPanel)
+            : base(new List<DockWindow>())
+        {
+            Items.Add(new DockWindow(dockPanel, DockState.Document));
+            Items.Add(new DockWindow(dockPanel, DockState.DockLeft));
+            Items.Add(new DockWindow(dockPanel, DockState.DockRight));
+            Items.Add(new DockWindow(dockPanel, DockState.DockTop));
+            Items.Add(new DockWindow(dockPanel, DockState.DockBottom));
+        }
+
+        public DockWindow this [DockState dockState]
+        {
+            get
+            {
+                if (dockState == DockState.Document)
+                    return Items[0];
+                else if (dockState == DockState.DockLeft || dockState == DockState.DockLeftAutoHide)
+                    return Items[1];
+                else if (dockState == DockState.DockRight || dockState == DockState.DockRightAutoHide)
+                    return Items[2];
+                else if (dockState == DockState.DockTop || dockState == DockState.DockTopAutoHide)
+                    return Items[3];
+                else if (dockState == DockState.DockBottom || dockState == DockState.DockBottomAutoHide)
+                    return Items[4];
+
+                throw (new ArgumentOutOfRangeException());
+            }
+        }
+    }
+}