chargerlib.undo

Interface Undoable

public interface Undoable

Represents an object's capability to have its changes undone/redone. Changes represent transitions between states, which are then able to be restored or re-done. No edit actions per se should be performed by the implementation -- restoreState should exactly re-construct the state it represents.

Since:

Charger 3.8.3

See Also:

UndoStateManager

Method Summary

Modifier and Type	Method and Description
UndoableState	currentState() Creates a new instance of the current state of the target object.
void	restoreState(UndoableState state) Restores the object's current state from the given state.
void	setupMenus() Perform whatever setup is necessary if the undo/redo status may have changed.

Method Detail

currentState

UndoableState currentState()

Creates a new instance of the current state of the target object. Note that this method must create a complete copy (either through new, clone() or some other method. If only a reference is saved, then all saved states will really point to the same (current) state and there will appear to be no effect. It is up to the user to ensure that nothing in this method causes the undo manager to become enabled; obviously strange occurrences will result.

restoreState

void restoreState(UndoableState state)

Restores the object's current state from the given state. It is up to the user to ensure that nothing in this method causes the undo manager to become enabled; obviously strange occurrences will result.

setupMenus

void setupMenus()

Perform whatever setup is necessary if the undo/redo status may have changed. Subclasses override to do whatever menu (or other) setup is needed to make undo/redo available