Class LinearUndoEnforcer

  • All Implemented Interfaces:
    IOperationApprover

    public final class LinearUndoEnforcer
    extends LinearUndoViolationDetector

    An operation approver that enforces a strict linear undo. It does not allow the undo or redo of any operation that is not the latest available operation in all of its undo contexts. This class may be instantiated by clients.

    Since:
    3.1
    • Constructor Detail

      • LinearUndoEnforcer

        public LinearUndoEnforcer()
        Create an instance of LinearUndoEnforcer.
    • Method Detail

      • allowLinearRedoViolation

        protected IStatus allowLinearRedoViolation​(IUndoableOperation operation,
                                                   IUndoContext context,
                                                   IOperationHistory history,
                                                   IAdaptable uiInfo)
        Description copied from class: LinearUndoViolationDetector
        Return a status indicating whether a linear redo violation is allowable. A linear redo violation is defined as a request to redo a particular operation even if it is not the most recently added operation to the redo history.
        Specified by:
        allowLinearRedoViolation in class LinearUndoViolationDetector
        Parameters:
        operation - the operation for which a linear redo violation has been detected.
        context - the undo context in which the linear redo violation exists
        history - the operation history containing the operation
        uiInfo - the IAdaptable (or null) provided by the caller in order to supply UI information for prompting the user if necessary. When this parameter is not null, it should minimally contain an adapter for the org.eclipse.swt.widgets.Shell.class.
        Returns:
        the IStatus describing whether the redo violation is allowed. The redo will not proceed if the status severity is not OK, and the caller requesting the redo will be returned the status that caused the rejection. Specific status severities will not be interpreted by the history.
      • allowLinearUndoViolation

        protected IStatus allowLinearUndoViolation​(IUndoableOperation operation,
                                                   IUndoContext context,
                                                   IOperationHistory history,
                                                   IAdaptable uiInfo)
        Description copied from class: LinearUndoViolationDetector
        Return a status indicating whether a linear undo violation is allowable. A linear undo violation is defined as a request to undo a particular operation even if it is not the most recently added operation to the undo history.
        Specified by:
        allowLinearUndoViolation in class LinearUndoViolationDetector
        Parameters:
        operation - the operation for which a linear undo violation has been detected.
        context - the undo context in which the linear undo violation exists
        history - the operation history containing the operation
        uiInfo - the IAdaptable (or null) provided by the caller in order to supply UI information for prompting the user if necessary. When this parameter is not null, it should minimally contain an adapter for the org.eclipse.swt.widgets.Shell.class.
        Returns:
        the IStatus describing whether the undo violation is allowed. The undo will not proceed if the status severity is not OK, and the caller requesting the undo will be returned the status that caused the rejection. Specific status severities will not be interpreted by the history.