private void UndoModification(Modification modification, ref Point cursorPosition)
{
int lineCountToRemove = modification.NewLinesCount;
if (modification.StartLine + lineCountToRemove > textBufferLineList.Count)
lineCountToRemove = textBufferLineList.Count - modification.StartLine;
List<string> linesToRemove = textBufferLineList.GetRange(modification.StartLine, lineCountToRemove);
if (modification.ActionType == Modification.Action.Insert)
{
AddInsertionToRedoGroup(modification.StartLine,
modification.OriginalContents.Count, linesToRemove, cursorPosition);
}
else if (modification.ActionType == Modification.Action.Remove)
{
AddRemoveToRedoGroup(modification.StartLine,
modification.OriginalContents.Count, linesToRemove, cursorPosition);
}
cursorPosition = modification.CursorPosition;
textBufferLineList.RemoveRange(modification.StartLine, lineCountToRemove);
textBufferLineList.InsertRange(modification.StartLine, modification.OriginalContents);
}
internal void Add(Modification modification)
{
this.modifications.Add(modification);
}
private void RedoModification(Modification modification, ref Point cursorPosition)
{
// If modification is to be done on the line beyond the last, then we are essentially
// dealing with a non-existence line. In such cases, the "original line contents" (the
// thing we would like to backup on the undo group) will be an empty line.
//
bool modificationBeyondFinalLine = (textBufferLineList.Count == modification.StartLine);
List<string> originalContents = null;
if (false != modificationBeyondFinalLine)
{
originalContents = new List<string>();
originalContents.Add(string.Empty);
}
else
{
// Before we redo the changes, there will be the "original contents" that we
// would want to backup in the undo group. Store them somewhere safe and then
// remove the lines from the line list.
//
originalContents = textBufferLineList.GetRange(modification.StartLine, modification.NewLinesCount);
}
if (modification.ActionType == Modification.Action.Insert)
{
RecordInsertionInternal(modification.StartLine,
modification.OriginalContents.Count, originalContents, cursorPosition);
}
else if (modification.ActionType == Modification.Action.Remove)
{
RecordRemovalInternal(modification.StartLine,
modification.OriginalContents.Count, originalContents, cursorPosition);
}
if (false == modificationBeyondFinalLine)
textBufferLineList.RemoveRange(modification.StartLine, modification.NewLinesCount);
textBufferLineList.InsertRange(modification.StartLine, modification.OriginalContents);
cursorPosition = modification.CursorPosition;
}