UnitResult Undo()
{
if (globallyRepeatableUnits.Count < 1)
{
throw new InvalidOperationException("No unit to undo.");
}
IUndoableUnit undoableUnit = globallyUndoableUnits.Pop();
IInternalUnit repeatableUnit = globallyRepeatableUnits.Pop();
var eventArgs = new CancellableUndoServiceEventArgs(undoableUnit);
OnUndoing(eventArgs);
if (eventArgs.Cancel)
{
globallyUndoableUnits.AddLast(undoableUnit);
globallyRepeatableUnits.AddLast(repeatableUnit);
return(UnitResult.Cancelled);
}
globallyRedoableUnits.AddLast(undoableUnit);
UnitResult result = undoableUnit.Undo();
OnUndone(new UndoServiceEventArgs(undoableUnit));
return(result);
}
void IInternalUndoService.NotifyUnitRepeatableChanged(IInternalUnit unit)
{
/* Here we should notify listeners that a unit has changed its repeatable property.
* This will prompt repopulation of any Repeatable unit lists etc. */
}
