Update Clipboard.ContainsText using a separate thread.

Fix/workaround for SD2-1466 - SharpDevelop freezes when debugged application sets clipboard text.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/3.0@3605 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Libraries/ICSharpCode.TextEditor/Project/Src/Gui/TextAreaClipboardHandler.cs

@@ -32,14 +32,33 @@ namespace ICSharpCode.TextEditor
 			}
 		}
 		
+		public delegate bool ClipboardContainsTextDelegate();
+		
+		/// <summary>
+		/// Is called when CachedClipboardContainsText should be updated.
+		/// If this property is null (the default value), the text editor uses
+		/// System.Windows.Forms.Clipboard.ContainsText.
+		/// </summary>
+		/// <remarks>
+		/// This property is useful if you want to prevent the default Clipboard.ContainsText
+		/// behaviour that waits for the clipboard to be available - the clipboard might
+		/// never become available if it is owned by a process that is paused by the debugger.
+		/// </remarks>
+		public static ClipboardContainsTextDelegate GetClipboardContainsText;
+		
 		public bool EnablePaste {
 			get {
 				if (!textArea.EnableCutOrPaste)
 					return false;
-				try {
-					return Clipboard.ContainsText();
-				} catch (ExternalException) {
-					return false;
+				ClipboardContainsTextDelegate d = GetClipboardContainsText;
+				if (d != null) {
+					return d();
+				} else {
+					try {
+						return Clipboard.ContainsText();
+					} catch (ExternalException) {
+						return false;
+					}
 				}
 			}
 		}

src/Main/Base/Project/ICSharpCode.SharpDevelop.csproj

@@ -473,6 +473,7 @@
     <Compile Include="Src\TextEditor\Bookmarks\Bookmark.cs" />
     <Compile Include="Src\TextEditor\Bookmarks\BookmarkEventHandler.cs" />
     <Compile Include="Src\TextEditor\Bookmarks\BookmarkManager.cs" />
+    <Compile Include="Src\TextEditor\ClipboardHandling.cs" />
     <Compile Include="Src\TextEditor\Codons\AddInTreeSyntaxModeProvider.cs" />
     <Compile Include="Src\TextEditor\Codons\EditActionDoozer.cs" />
     <Compile Include="Src\TextEditor\Codons\SyntaxModeDoozer.cs" />

src/Main/Base/Project/Src/Commands/EditCommands.cs

@@ -5,6 +5,7 @@
 //     <version>$Revision$</version>
 // </file>
 
+using ICSharpCode.SharpDevelop.DefaultEditor;
 using System;
 using System.Windows.Forms;
 using ICSharpCode.Core;
@@ -122,7 +123,7 @@ namespace ICSharpCode.SharpDevelop.Commands
 				get { return comboBox.SelectionLength > 0; }
 			}
 			public bool EnablePaste {
-				get { return ClipboardWrapper.ContainsText; }
+				get { return ClipboardHandling.GetClipboardContainsText(); }
 			}
 			public bool EnableDelete {
 				get { return true; }

src/Main/Base/Project/Src/TextEditor/ClipboardHandling.cs

@@ -0,0 +1,67 @@
+// <file>
+//     <copyright see="prj:///doc/copyright.txt"/>
+//     <license see="prj:///doc/license.txt"/>
+//     <author name="Daniel Grunwald"/>
+//     <version>$Revision$</version>
+// </file>
+
+using ICSharpCode.Core.WinForms;
+using System;
+using System.Threading;
+using ICSharpCode.SharpDevelop.Gui;
+
+namespace ICSharpCode.SharpDevelop.DefaultEditor
+{
+	/// <summary>
+	/// This class fixes SD2-1466: SharpDevelop freezes when debugged application sets clipboard text.
+	/// The problem is that Clipboard.ContainsText may wait for the application owning the clipboard,
+	/// which in turn may currently wait for SharpDevelop (through the debugger)
+	/// </summary>
+	static class ClipboardHandling
+	{
+		public static void Initialize()
+		{
+			ICSharpCode.TextEditor.TextAreaClipboardHandler.GetClipboardContainsText = GetClipboardContainsText;
+			WorkbenchSingleton.MainForm.Activated += WorkbenchSingleton_MainForm_Activated;
+		}
+
+		static void WorkbenchSingleton_MainForm_Activated(object sender, EventArgs e)
+		{
+			UpdateClipboardContainsText();
+		}
+		
+		static bool clipboardContainsText;
+		
+		public static bool GetClipboardContainsText()
+		{
+			WorkbenchSingleton.DebugAssertMainThread();
+			if (WorkbenchSingleton.Workbench.IsActiveWindow) {
+				UpdateClipboardContainsText();
+			}
+			return clipboardContainsText;
+		}
+		
+		static Thread updateThread;
+		
+		static void UpdateClipboardContainsText()
+		{
+			if (updateThread != null)
+				return;
+			Thread t = new Thread(new ThreadStart(DoUpdate));
+			t.SetApartmentState(ApartmentState.STA);
+			t.IsBackground = true;
+			updateThread = t;
+			t.Start();
+			t.Join(50); // wait a few ms in case the clipboard can be accessed without problems
+		}
+		
+		static void DoUpdate()
+		{
+			try {
+				clipboardContainsText = ClipboardWrapper.ContainsText;
+			} finally {
+				updateThread = null;
+			}
+		}
+	}
+}

src/Main/Base/Project/Src/TextEditor/Gui/Editor/TextEditorDisplayBinding.cs

@@ -33,6 +33,7 @@ namespace ICSharpCode.SharpDevelop.DefaultEditor.Gui.Editor
 			HighlightingManager.Manager.AddSyntaxModeFileProvider(new ICSharpCode.SharpDevelop.DefaultEditor.Codons.AddInTreeSyntaxModeProvider());
 			HighlightingManager.Manager.AddSyntaxModeFileProvider(new FileSyntaxModeProvider(Path.Combine(PropertyService.DataDirectory, "modes")));
 			HighlightingManager.Manager.AddSyntaxModeFileProvider(new FileSyntaxModeProvider(modeDir));
+			ClipboardHandling.Initialize();
 		}
 		
 		/// <summary>