Package jebl.util
Class ProgressListener
- java.lang.Object
-
- jebl.util.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
-
-
Nested Class Summary
Nested Classes Modifier and Type Class Description static class
ProgressListener.Wrapper
A decorator progress listener which delegates all method calls to an internal progress listener.
-
Field Summary
Fields Modifier and Type Field Description static ProgressListener
EMPTY
A ProgressListener that ignores all events and always returns false fromisCanceled()
.
-
Constructor Summary
Constructors Constructor Description ProgressListener()
-
Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description void
addFeedbackAction(java.lang.String label, java.lang.String description, SimpleListener listener)
Adds an action that can choose to provide feedback.void
addFeedbackAction(java.lang.String label, SimpleListener listener)
Equivalent toaddFeedbackAction(label,"",listener)
abstract boolean
isCanceled()
This method must be implemented by all subclasses.void
removeFeedbackAction(java.lang.String label)
Removes a feedback action previously added usingaddFeedbackAction(String, jebl.util.SimpleListener)
.boolean
setImage(java.awt.Image image)
Set an image associated with the current progress.boolean
setIndeterminateProgress()
Sets indefinite progress (i.e.boolean
setMessage(java.lang.String message)
Set visible user message.boolean
setProgress(double fractionCompleted)
boolean
setProgress(int currentStep, int numberOfSteps)
Same as callingsetProgress(((double)currentStep)/numberOfSteps)
boolean
setProgress(long currentStep, long numberOfSteps)
Same as callingsetProgress(((double)currentStep)/numberOfSteps)
void
setTitle(java.lang.String title)
Sets a title associated with whatever is being done.
-
-
-
Field Detail
-
EMPTY
public static final ProgressListener EMPTY
A ProgressListener that ignores all events and always returns false fromisCanceled()
. Useful when you don't care about the progress results or canceling the operation.
-
-
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, callsetIndeterminateProgress()
instead.- Returns:
- true if the user has requested that this operation be canceled.
-
setProgress
public final boolean setProgress(int currentStep, int numberOfSteps)
Same as callingsetProgress(((double)currentStep)/numberOfSteps)
- Parameters:
currentStep
- between 0 and numberOfSteps inclusivenumberOfSteps
- 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)
Same as callingsetProgress(((double)currentStep)/numberOfSteps)
- Parameters:
currentStep
- between 0 and numberOfSteps inclusivenumberOfSteps
- 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, SimpleListener listener)
Equivalent toaddFeedbackAction(label,"",listener)
-
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 caselistener
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
-
removeFeedbackAction
public void removeFeedbackAction(java.lang.String label)
Removes a feedback action previously added usingaddFeedbackAction(String, jebl.util.SimpleListener)
.- Parameters:
label
- The label used as a parameter toaddFeedbackAction(String, jebl.util.SimpleListener)
-
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.
-
isCanceled
public abstract boolean isCanceled()
This method must be implemented by all subclasses. It is called fromsetProgress(double)
,setIndeterminateProgress()
andsetMessage(java.lang.String)
to determine the return value of these methods.- Specified by:
isCanceled
in interfaceCancelable
- Returns:
- true if the user has requested that this operation be canceled.
-
-