index
Current index of the queue.
Larger value means newer, but not larger than maxQueueSize. When the index is equal to -1, the undo queue is empty. An index of 0 means that there is one event to undo.
Current index of the queue.
Larger value means newer, but not larger than maxQueueSize. When the index is equal to -1, the undo queue is empty. An index of 0 means that there is one event to undo.