Make FileChangeWatcher reload a file not only when there were external writes to the file, but also when the file was replaced by an external app. Fixes reloading the file when doing "svn revert".

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/3.0@3604 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Main/Base/Project/Src/Gui/WorkbenchSingleton.cs

@@ -311,6 +311,27 @@ namespace ICSharpCode.SharpDevelop.Gui
 		{
 			caller.BeginCall(method, new object[] { arg1, arg2, arg3 });
 		}
+		
+		/// <summary>
+		/// Calls a method on the GUI thread, but delays the call a bit.
+		/// </summary>
+		public static void CallLater(int delayMilliseconds, Action method)
+		{
+			if (delayMilliseconds <= 0)
+				throw new ArgumentOutOfRangeException("delayMilliseconds", delayMilliseconds, "Value must be positive");
+			if (method == null)
+				throw new ArgumentNullException("method");
+			SafeThreadAsyncCall(
+				delegate {
+					Timer t = new Timer();
+					t.Interval = delayMilliseconds;
+					t.Tick += delegate { 
+						t.Stop();
+						method();
+					};
+					t.Start();
+				});
+		}
 		#endregion
 		
 		static void OnWorkbenchCreated()

src/Main/Base/Project/Src/Services/File/FileChangeWatcher.cs

@@ -80,8 +80,8 @@ namespace ICSharpCode.SharpDevelop
 		
 		public bool Enabled {
 			get { return enabled; }
-			set { 
-				enabled = value; 
+			set {
+				enabled = value;
 				SetWatcher();
 			}
 		}
@@ -111,11 +111,12 @@ namespace ICSharpCode.SharpDevelop
 				if (watcher == null) {
 					watcher = new FileSystemWatcher();
 					watcher.SynchronizingObject = WorkbenchSingleton.MainForm;
-					watcher.Changed += new FileSystemEventHandler(this.OnFileChangedEvent);
+					watcher.Changed += OnFileChangedEvent;
+					watcher.Created += OnFileChangedEvent;
+					watcher.Renamed += OnFileChangedEvent;
 				}
 				watcher.Path = Path.GetDirectoryName(fileName);
 				watcher.Filter = Path.GetFileName(fileName);
-				watcher.NotifyFilter = NotifyFilters.LastWrite;
 				watcher.EnableRaisingEvents = true;
 			} catch (PlatformNotSupportedException) {
 				if (watcher != null) {
@@ -127,15 +128,18 @@ namespace ICSharpCode.SharpDevelop
 		
 		void OnFileChangedEvent(object sender, FileSystemEventArgs e)
 		{
-			if (e.ChangeType != WatcherChangeTypes.Deleted) {
-				if (file == null)
-					return;
-				LoggingService.Debug("File " + file.FileName + " was changed externally");
+			LoggingService.Debug("File " + file.FileName + " was changed externally: " + e.ChangeType);
+			if (file == null)
+				return;
+			if (!wasChangedExternally) {
 				wasChangedExternally = true;
 				if (WorkbenchSingleton.Workbench.IsActiveWindow) {
-					// delay showing message a bit, prevents showing two messages
-					// when the file changes twice in quick succession
-					WorkbenchSingleton.SafeThreadAsyncCall(MainForm_Activated, this, EventArgs.Empty);
+					// delay reloading message a bit, prevents showing two messages
+					// when the file changes twice in quick succession; and prevents
+					// trying to reload the file while it is still being written
+					WorkbenchSingleton.CallLater(
+						500,
+						delegate { MainForm_Activated(this, EventArgs.Empty); } );
 				}
 			}
 		}
@@ -149,6 +153,8 @@ namespace ICSharpCode.SharpDevelop
 					return;
 				
 				string fileName = file.FileName;
+				if (!File.Exists(fileName))
+					return;
 				
 				string message = StringParser.Parse("${res:ICSharpCode.SharpDevelop.DefaultEditor.Gui.Editor.TextEditorDisplayBinding.FileAlteredMessage}", new string[,] {{"File", Path.GetFullPath(fileName)}});
 				if ((AutoLoadExternalChangesOption && file.IsDirty == false)