This sample demonstrates viewing, deleting, limiting diagram history and groups diagram actions and stores it as a single entry in the history manager.
Diagram history are being handle all the diagram history. Using stackLimit property of the history manager
we limit the no. of entries can be stored on the diagram history. Also, we can get the list of entries in the undo
list and redo list using undoStack and redoStack. Also diagram history manager have the
option to group the action as the single entry by the help of the startGroupAction and endGroupAction public
Api. Also, we can add the custom entries to the diagram history. method can be used to print the diagrams.