| Package | com.yworks.support |
| Interface | public interface IMementoSupport |
| Implementors | NodeMementoMementoSupport |
MementoUndoUnit
to create IUndoUnit implementations.
This interface uses the memento design pattern to implement undoability.
| Method | Defined By | ||
|---|---|---|---|
applyState(subject:Object, state:Object):void
Reapplies a previously queried state memento object to a given subject. | IMementoSupport | ||
getState(subject:Object):Object
Retrieves the state of a given subject as a memento. | IMementoSupport | ||
stateEquals(state1:Object, state2:Object):Boolean
Utility method that can determine whether two state memento objects are equal. | IMementoSupport | ||
| applyState | () | method |
public function applyState(subject:Object, state:Object):voidReapplies a previously queried state memento object to a given subject.
The state object has been created using the getState method.
Parameters
subject:Object — The subject to modify the state.
| |
state:Object — The state memento object as returned by GetState
|
| getState | () | method |
public function getState(subject:Object):ObjectRetrieves the state of a given subject as a memento.
The state memento returned can later be reapplied to the subject using the applyState method.
Parameters
subject:Object — The subject to read the state from.
|
Object — An instance that describes the current state of subject.
|
| stateEquals | () | method |
public function stateEquals(state1:Object, state2:Object):BooleanUtility method that can determine whether two state memento objects are equal.
Conservative implementations my simply return false. If this method yields
true the state is considered not to have changed and no undo unit will be created.
Parameters
state1:Object — The first state as obtained from GetState
| |
state2:Object — The second state as obtained from GetState
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Boolean — If the states equal and thus there is no need to apply state1
to an instance whose state is already state2
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