Package org.eclipse.graphiti.pattern

Interface ICustomUndoRedoPattern

All Known Subinterfaces:
ICustomAbortableUndoRedoPattern
public interface ICustomUndoRedoPattern
This interface can by used and implemented by customers within any pattern to signal the need for additional work that needs to be done before or after undo and redo. When a pattern implements this interface, and the framework performs an undo or a redo, the framework will call the contained methods.

Implementing this interface is especially helpful if customers want to implement undo/redo functionality for non-EMF changes, e.g. for non-EMF domain models. Note that any EMF-model change (including the changes done to the graphical representation (Graphiti PictogramElements and GraphicsAlgorithms will by handled automatically by the Graphiti framework no matter if this interface is implemented by a pattern or not. The pattern may use the context and feature objects (e.g. the contained properties set) passed to the contained methods while executing the pattern in order to collect any information needed for undo.

In case you want to cancel undo/redo operations in #preUndo(IContext)/#preRedo(IContext), you need to implement ICustomAbortableUndoRedoPattern which offers an ICustomAbortableUndoRedoPattern.isAbort() method that causes the cancellation of undo/redo operation in case true is returned.

Since:
0.12
See Also:

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    canRedo(IFeature feature, IContext context)
    Decides if the processed feature can be re-done.
    boolean
    canUndo(IFeature feature, IContext context)
    Decides if the changes done by a processed pattern functionality can be undone.
    void
    postRedo(IFeature feature, IContext context)
    This method will be called by the Graphiti framework after the EMF undo has finished.
    void
    postUndo(IFeature feature, IContext context)
    This method will be called by the Graphiti framework after the EMF undo is finished.
    void
    preRedo(IFeature feature, IContext context)
    This method will be called by the Graphiti framework before the EMF undo has triggered.
    void
    preUndo(IFeature feature, IContext context)
    This method will be called by the Graphiti framework before the EMF undo is triggered.

  • Method Details

    • canUndo

      boolean canUndo(IFeature feature, IContext context)
      Decides if the changes done by a processed pattern functionality can be undone. This method is called once by the Graphiti framework just before any undo work is started, e.g. before #preUndo(IContext).

      Note that as soon as any pattern reports false here, also all previous entries in the command stack are no longer reachable for undo.

      Parameters:
      feature - this is the instance of the IFeature object that was in use when executing the pattern functionality
      context - this is the instance of the IContext object that was in use when executing the feature.
      Returns:
      true if the feature can be undone, false if not

    • preUndo

      void preUndo(IFeature feature, IContext context)
      This method will be called by the Graphiti framework before the EMF undo is triggered. Customers may revert their non-EMF changes done by the pattern functionality here or in #postUndo(IContext).
      Parameters:
      feature - this is the instance of the IFeature object that was in use when executing the pattern functionality
      context - this is the instance of the IContext object that was in use when executing the feature

    • postUndo

      void postUndo(IFeature feature, IContext context)
      This method will be called by the Graphiti framework after the EMF undo is finished. Customers may revert their non-EMF changes done by the pattern functionality here or in #preUndo(IContext).
      Parameters:
      feature - this is the instance of the IFeature object that was in use when executing the pattern functionality
      context - this is the instance of the IContext object that was in use when executing the feature

    • canRedo

      boolean canRedo(IFeature feature, IContext context)
      Decides if the processed feature can be re-done. This method is called once by the Graphiti framework just before any redo work is started, e.g. before #preRedo(IContext).

      Note that as soon as any pattern reports false here, also all consecutive entries in the command stack are no longer reachable for redo.

      Parameters:
      feature - this is the instance of the IFeature object that was in use when executing the pattern functionality
      context - this is the instance of the IContext object that was in use when executing the feature
      Returns:
      true if the feature can be re-done, false if not

    • preRedo

      void preRedo(IFeature feature, IContext context)
      This method will be called by the Graphiti framework before the EMF undo has triggered. Customers may re-apply their non-EMF changes done by the pattern functionality here or in #postRedo(IContext). (Usually it might be sufficient to delegate to the execution method of the feature.)
      Parameters:
      feature - this is the instance of the IFeature object that was in use when executing the pattern functionality
      context - this is the instance of the IContext object that was in use when executing the feature

    • postRedo

      void postRedo(IFeature feature, IContext context)
      This method will be called by the Graphiti framework after the EMF undo has finished. Customers may re-apply their non-EMF changes done by the pattern functionality here or in #preRedo(IContext). (Usually it might be sufficient to delegate to the execution method of the feature.)
      Parameters:
      feature - this is the instance of the IFeature object that was in use when executing the pattern functionality
      context - this is the instance of the IContext object that was in use when executing the feature