Class UndoChangeRequest


  • public class UndoChangeRequest
    extends ChangeRequest
    A change request to undo. When executed, this change request will identify the undo stack associated with the specified context, and it will execute the top undo action on that stack, if there is one.

    Since:
    Ptolemy II 3.1
    Version:
    $Id$
    Author:
    Edward A. Lee and Neil Smyth
    Pt.AcceptedRating:
    Green (hyzheng)
    Pt.ProposedRating:
    Green (eal)
    • Constructor Detail

      • UndoChangeRequest

        public UndoChangeRequest​(java.lang.Object originator,
                                 NamedObj context)
        Construct a change request to be executed in the specified context. The undo stack associated with the specified context will be used. That stack is the one returned by UndoStackAttribute.getUndoInfo().
        Parameters:
        originator - The originator of the change request.
        context - The context in which to execute the MoML.
        See Also:
        UndoStackAttribute
    • Method Detail

      • getContext

        public NamedObj getContext()
        Return the context specified in the constructor, or null if none was specified.
        Returns:
        The context.
      • _execute

        protected void _execute()
                         throws java.lang.Exception
        Execute the change by invoking undo on the undo stack of the context specified in the constructor.
        Specified by:
        _execute in class ChangeRequest
        Throws:
        java.lang.Exception - If an exception is thrown while evaluating the request.