Package jebl.util

Class ProgressListener

  • All Implemented Interfaces:
    Cancelable
    Direct Known Subclasses:
    BasicProgressListener, CompositeProgressListener, ProgressListener.Wrapper

    public abstract class ProgressListener
    extends java.lang.Object
    implements Cancelable
    Version:
    $Id: ProgressListener.java 1068 2010-09-08 23:59:59Z matt_kearse $ ProgressListener guarantees the following contract: A call to any of the methods setProgress(), setMessage(), isCanceled() and setIndeterminateProgress() at a given time yields the same result as a call to another of these methods would have resulted at the same time. Once the task whose progress we are observing has been canceled, calls to either of these methods reflect this. This does not prevent subclasses from introducing a way to "reset" a ProgressListener that was previously canceled from not being canceled any more. Any object may exhibit undefined behaviour when dealing with a ProgressListener that is not fulfilling this contract.
    Author:
    Matt Kearse
    • Field Detail

      • EMPTY

        public static final ProgressListener EMPTY
        A ProgressListener that ignores all events and always returns false from isCanceled(). Useful when you don't care about the progress results or canceling the operation.
    • Constructor Detail

      • ProgressListener

        public ProgressListener()
    • Method Detail

      • setProgress

        public final boolean setProgress​(double fractionCompleted)
        Parameters:
        fractionCompleted - a number between 0 and 1 inclusive representing the fraction of the operation completed. If you are unsure of the fraction completed, call setIndeterminateProgress() instead.
        Returns:
        true if the user has requested that this operation be canceled.
      • setProgress

        public final boolean setProgress​(int currentStep,
                                         int numberOfSteps)
        Parameters:
        currentStep - between 0 and numberOfSteps inclusive
        numberOfSteps - the total number of steps. Must be greater than 0.
        Returns:
        true if the user has requested that this operation be canceled.
      • setProgress

        public final boolean setProgress​(long currentStep,
                                         long numberOfSteps)
        Parameters:
        currentStep - between 0 and numberOfSteps inclusive
        numberOfSteps - the total number of steps. Must be greater than 0.
        Returns:
        true if the user has requested that this operation be canceled.
      • setIndeterminateProgress

        public final boolean setIndeterminateProgress()
        Sets indefinite progress (i.e. "some progress has happened, but I don't know how close we are to finishing").
        Returns:
        true if the user has requested that this operation be canceled.
      • setMessage

        public final boolean setMessage​(java.lang.String message)
        Set visible user message.
        Parameters:
        message - a user visible message. If this is null, it will be automatically replaced with an empty string.
        Returns:
        true if the user has requested that this operation be canceled.
      • setImage

        public final boolean setImage​(java.awt.Image image)
        Set an image associated with the current progress. A progress listener may choose to optionally display this image wherever is appropriate.
        Parameters:
        image - an image
        Returns:
        true if the user has requested that this operation be canceled.
      • addFeedbackAction

        public void addFeedbackAction​(java.lang.String label,
                                      java.lang.String description,
                                      SimpleListener listener)
        Adds an action that can choose to provide feedback. For example, an operation may choose to provide a "Skip to next step" button alongside the cancel button. There is no requirement that a ProgressListener actually present this to the user - it may choose to ignore this method, in which case listener will never be fired.
        Parameters:
        label - a label describing this feedback action. For example, "Skip to next step"
        listener - a listener to be notified when the user chooses to invoke this action
      • setTitle

        public void setTitle​(java.lang.String title)
        Sets a title associated with whatever is being done. This will not necessarily even be presented to the user, but typically will be presented as the title of a progress window.
        Parameters:
        title - the title of a progress window (if any). Must not be null.