From 5b7822936a7300be1525489a21129d8d97d1ac14 Mon Sep 17 00:00:00 2001
From: Daniel Grunwald <daniel@danielgrunwald.de>
Date: Sat, 25 Feb 2006 16:02:27 +0000
Subject: [PATCH] Applied patch by John Simons: Closing an open file tab
 returns focus to the previously focused tab.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@1181 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61
---
 .../WinFormsUI/Docking/DockPane.cs            | 81 +++++++++++++++----
 .../WinFormsUI/Docking/Interfaces.cs          |  4 +-
 .../Workbench/Layouts/SdiWorkspaceLayout.cs   | 14 ++--
 3 files changed, 72 insertions(+), 27 deletions(-)

diff --git a/src/Libraries/DockPanel_Src/WinFormsUI/Docking/DockPane.cs b/src/Libraries/DockPanel_Src/WinFormsUI/Docking/DockPane.cs
index 7eb9492860..368efe5672 100644
--- a/src/Libraries/DockPanel_Src/WinFormsUI/Docking/DockPane.cs
+++ b/src/Libraries/DockPanel_Src/WinFormsUI/Docking/DockPane.cs
@@ -9,6 +9,7 @@
 // *****************************************************************************
 
 using System;
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Drawing;
 using System.Drawing.Drawing2D;
@@ -174,6 +175,31 @@ namespace WeifenLuo.WinFormsUI
 			base.Dispose(disposing);
 		}
 
+		private class VisitedTabsCollection
+		{
+			List<IDockContent> list = new List<IDockContent>();
+			public int Count {
+				get {
+					return list.Count;
+				}
+			}
+			public void PushOrMoveToEnd(IDockContent content)
+			{
+				for (int i = 0; i < list.Count; i++) {
+					if (list[i] == content || list[i].IsDisposed) {
+						list.RemoveAt(i--);
+					}
+				}
+				list.Add(content);
+			}
+			public IDockContent Pop()
+			{
+				IDockContent content = list[list.Count - 1];
+				list.RemoveAt(list.Count - 1);
+				return content;
+			}
+		}
+		private VisitedTabsCollection m_visitedTabs = new VisitedTabsCollection();
 		private IDockContent m_activeContent = null;
 		/// <include file='CodeDoc\DockPane.xml' path='//CodeDoc/Class[@name="DockPane"]/Property[@name="ActiveContent"]/*'/>
 		public virtual IDockContent ActiveContent
@@ -202,6 +228,11 @@ namespace WeifenLuo.WinFormsUI
 
 				m_activeContent = value;
 
+				if (m_activeContent != null && m_activeContent.DockHandler.DockState == DockState.Document)
+				{
+					m_visitedTabs.PushOrMoveToEnd(m_activeContent);
+				}
+				
 				if (DockPanel.DocumentStyle == DocumentStyles.DockingMdi && DockState == DockState.Document)
 				{
 					if (m_activeContent != null)
@@ -736,27 +767,43 @@ namespace WeifenLuo.WinFormsUI
 				return;
 
 			IDockContent prevVisible = null;
-			for (int i=Contents.IndexOf(ActiveContent)-1; i>=0; i--)
-				if (Contents[i].DockHandler.DockState == DockState)
-				{
-					prevVisible = Contents[i];
-					break;
-				}
-
-			IDockContent nextVisible = null;
-			for (int i=Contents.IndexOf(ActiveContent)+1; i<Contents.Count; i++)
-				if (Contents[i].DockHandler.DockState == DockState)
+			
+			if (ActiveContent.DockHandler.DockState == DockState.Unknown)
+			{
+				while(m_visitedTabs.Count > 0)
 				{
-					nextVisible = Contents[i];
-					break;
+					prevVisible = m_visitedTabs.Pop();
+					
+					if (prevVisible != null && !prevVisible.IsDisposed && prevVisible != ActiveContent)
+						break;
 				}
+			}
 
-			if (prevVisible != null)
+			if (prevVisible != null) {
 				ActiveContent = prevVisible;
-			else if (nextVisible != null)
-				ActiveContent = nextVisible;
-			else
-				ActiveContent = null;
+			} else {
+				for (int i=Contents.IndexOf(ActiveContent)-1; i>=0; i--)
+					if (Contents[i].DockHandler.DockState == DockState)
+					{
+						prevVisible = Contents[i];
+						break;
+					}
+				
+				IDockContent nextVisible = null;
+				for (int i=Contents.IndexOf(ActiveContent)+1; i<Contents.Count; i++)
+					if (Contents[i].DockHandler.DockState == DockState)
+					{
+						nextVisible = Contents[i];
+						break;
+					}
+			
+	 			if (prevVisible != null)
+	 				ActiveContent = prevVisible;
+				else if (nextVisible != null)
+					ActiveContent = nextVisible;
+	 			else
+	 				ActiveContent = null;
+			}
 		}
 
 		private static readonly object DockStateChangedEvent = new object();
diff --git a/src/Libraries/DockPanel_Src/WinFormsUI/Docking/Interfaces.cs b/src/Libraries/DockPanel_Src/WinFormsUI/Docking/Interfaces.cs
index dfeab502fd..000cc153ba 100644
--- a/src/Libraries/DockPanel_Src/WinFormsUI/Docking/Interfaces.cs
+++ b/src/Libraries/DockPanel_Src/WinFormsUI/Docking/Interfaces.cs
@@ -14,10 +14,12 @@ using System.Drawing;
 namespace WeifenLuo.WinFormsUI
 {
 	/// <include file='CodeDoc\Interfaces.xml' path='//CodeDoc/Interface[@name="IDockContent"]/InterfaceDef/*'/>
-	public interface IDockContent
+	public interface IDockContent : IDisposable
 	{
 		/// <include file='CodeDoc\Interfaces.xml' path='//CodeDoc/Interface[@name="IDockListContainer"]/Property[@name="DockHandler"]/*'/>
 		DockContentHandler DockHandler	{	get;	}
+		
+		bool IsDisposed { get; }
 	}
 
 	/// <include file='CodeDoc\Interfaces.xml' path='//CodeDoc/Interface[@name="IDockListContainer"]/InterfaceDef/*'/>
diff --git a/src/Main/Base/Project/Src/Gui/Workbench/Layouts/SdiWorkspaceLayout.cs b/src/Main/Base/Project/Src/Gui/Workbench/Layouts/SdiWorkspaceLayout.cs
index 03608f0036..af520e1e91 100644
--- a/src/Main/Base/Project/Src/Gui/Workbench/Layouts/SdiWorkspaceLayout.cs
+++ b/src/Main/Base/Project/Src/Gui/Workbench/Layouts/SdiWorkspaceLayout.cs
@@ -57,19 +57,15 @@ namespace ICSharpCode.SharpDevelop.Gui
 				} else {
 					activeContent = dockPanel.ActiveContent ?? lastActiveContent;
 				}
+				if (activeContent != null && activeContent.IsDisposed)
+					activeContent = null;
+				
 				lastActiveContent = activeContent;
 				
-				if (activeContent is IWorkbenchWindow) {
-					if ((activeContent as IWorkbenchWindow).IsDisposed)
-						return null;
+				if (activeContent is IWorkbenchWindow)
 					return ((IWorkbenchWindow)activeContent).ActiveViewContent;
-				}
-				
-				if (activeContent is PadContentWrapper) {
-					if ((activeContent as PadContentWrapper).IsDisposed)
-						return null;
+				if (activeContent is PadContentWrapper)
 					return ((PadContentWrapper)activeContent).PadContent;
-				}
 				
 				return activeContent;
 			}