Restoring a previous object state is performed by reading the record from the undo filer and applying modification methods of the object for parameters being rolled back. Before restoring the previous object state during an undo operation, recording of the current object state is performed for the assumed redo operation. This is done automatically using the same mechanisms that are used for undo recording.
If the object does not use partial undo, the state of the object
is restored automatically. You must take care of restoring the object state
only when using partial undo by overriding the implementation of the
applyPartialUndo() method.
If the object uses automatic undo, the state of the object is restored
by calling its
dwgInFields() method.
Implementing Undo and Redo Operations
Implementing Save and Load Functions
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