private IDisposable Start(string commandCaption, bool visible)
{
AssertNoCommand();
currentArea = this;
currentCommand = new Command(commandCaption, this, visible);
return currentCommand;
}
/// <summary>Commits current command and saves changes into history</summary>
public void Commit()
{
AssertCurrentCommand();
if (currentCommand.HasChanges)
{
currentCommand.Commit();
// remove all redo records
int count = history.Count - currentPosition - 1;
history.RemoveRange(currentPosition + 1, count);
// add command to history
if (currentCommand.Visible)
{
history.Add(currentCommand);
currentPosition++;
TruncateHistory();
}
else
{
// merge with previous command
if (currentPosition >= 0)
history[currentPosition].Merge(currentCommand);
}
currentCommand = null;
OnCommandDone(CommandDoneType.Commit);
}
else
currentCommand = null;
}
/// <summary>
/// Rollback current command. It does not saves any changes done in current command.
/// </summary>
public void Cancel()
{
AssertCurrentCommand();
currentCommand.Undo();
currentCommand = null;
}
/// <summary>
/// Clears all history. It does not affect current data but history only.
/// It is usefull after any data initialization if you want forbid user to undo this initialization.
/// </summary>
public void ClearHistory()
{
currentCommand = null;
currentPosition = -1;
history.Clear();
}
internal void Merge(Command mergedCommand)
{
if (merges == null)
merges = new Dictionary<IUndoRedoMember, object>();
foreach (IUndoRedoMember member in mergedCommand.changes.Keys)
merges[member] = mergedCommand[member];
}