Fixed SD2-1652: "Cannot save with current encoding" not implemented in AvalonEdit.AddIn

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@5630 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

data/resources/StringResources.resx

@@ -890,6 +890,15 @@ SharpDevelop can collect this information and upload it automatically.</value>
   <data name="AddIns.XamlBinding.Options.UseExtensionCompletion" xml:space="preserve">
     <value>Use markup extension completion</value>
   </data>
+  <data name="AvalonEdit.FileEncoding.EncodingCausesDataLoss" xml:space="preserve">
+    <value>The file cannot be saved with the current encoding ${encoding} without losing data.</value>
+  </data>
+  <data name="AvalonEdit.FileEncoding.EncodingCausesDataLoss.Continue" xml:space="preserve">
+    <value>Continue</value>
+  </data>
+  <data name="AvalonEdit.FileEncoding.EncodingCausesDataLoss.UseUTF8" xml:space="preserve">
+    <value>Save as UTF-8</value>
+  </data>
   <data name="BackendBindings.ExecutionManager.CantExecuteDLLError" xml:space="preserve">
     <value>Project is configured as dll and no execution command is specified.
 You can specifiy an execution command in the project options.</value>

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/AvalonEditViewContent.cs

@@ -77,8 +77,36 @@ namespace ICSharpCode.AvalonEdit.AddIn
 		{
 			if (file != PrimaryFile)
 				return;
+			
+			if (codeEditor.CanSaveWithCurrentEncoding()) {
+				codeEditor.Save(stream);
+			} else {
+				int r = MessageService.ShowCustomDialog(
+					"${res:Dialog.Options.IDEOptions.TextEditor.General.FontGroupBox.FileEncodingGroupBox}",
+					StringParser.Parse("${res:AvalonEdit.FileEncoding.EncodingCausesDataLoss}",
+					                   new StringTagPair("encoding", codeEditor.Encoding.EncodingName)),
+					0, -1,
+					"${res:AvalonEdit.FileEncoding.EncodingCausesDataLoss.UseUTF8}",
+					"${res:AvalonEdit.FileEncoding.EncodingCausesDataLoss.Continue}");
+				if (r == 1) {
+					// continue saving with data loss
+					MemoryStream ms = new MemoryStream();
+					codeEditor.Save(ms);
+					ms.Position = 0;
+					ms.WriteTo(stream);
+					ms.Position = 0;
+					// Read back the version we just saved to show the data loss to the user (he'll be able to press Undo).
+					using (StreamReader reader = new StreamReader(ms, codeEditor.Encoding, false)) {
+						codeEditor.Document.Text = reader.ReadToEnd();
+					}
+					return;
+				} else {
+					// unfortunately we don't support cancel within IViewContent.Save, so we'll use the safe choice of UTF-8 instead
+					codeEditor.Encoding = System.Text.Encoding.UTF8;
 					codeEditor.Save(stream);
 				}
+			}
+		}
 		
 		bool isLoading;
 		

src/AddIns/DisplayBindings/AvalonEdit.AddIn/Src/CodeEditor.cs

@@ -250,6 +250,24 @@ namespace ICSharpCode.AvalonEdit.AddIn
 		/// </summary>
 		public bool UseFixedEncoding { get; set; }
 		
+		public Encoding Encoding {
+			get { return primaryTextEditor.Encoding; }
+			set { primaryTextEditor.Encoding = value; }
+		}
+		
+		/// <summary>
+		/// Gets if the document can be saved with the current encoding without losing data.
+		/// </summary>
+		public bool CanSaveWithCurrentEncoding()
+		{
+			Encoding encoding = this.Encoding;
+			if (encoding == null || Utils.FileReader.IsUnicode(encoding))
+				return true;
+			// not a unicode codepage
+			string text = document.Text;
+			return encoding.GetString(encoding.GetBytes(text)) == text;
+		}
+		
 		// always use primary text editor for loading/saving
 		// (the file encoding is stored only there)
 		public void Load(Stream stream)