历史记录
This docker allows you to quickly shift between undo states, and even go back in time far more quickly than rapidly reusing the Ctrl + Z shortcut.
合并撤销
Click on the settings icon at the bottom of the Undo History docker. It will show you a dialog box to enable cumulative undo. You can change these parameters:
合并起始时间
The amount of seconds required to consider a group of strokes to be worth one undo step.
分组间隔时间
According to this parameter – groups are made. Every stroke is put into the same group until two consecutive strokes have a time gap of more than T seconds. Then a new group is started.
Split strokes.
A user may want to keep the ability of Undoing/Redoing his/her last N strokes. Once N is crossed – the earlier strokes are merged into the group’s first stroke.