public void RecordStateBefore(Canvas canvas)
{
CanvasState canvasState = new CanvasState(canvas);
UndoStack.Push(new BufferState());
UndoStack.Peek().Before = canvasState;
RedoStack.Clear();
}
public void RecordStateAfter(Canvas canvas)
{
CanvasState canvasState = new CanvasState(canvas);
UndoStack.Peek().After = canvasState;
}
