Bound Properties and Status Methods
SwingWorker supports bound properties, which are useful for communicating with other threads. Two bound properties are predefined:
state. As with all bound properties,
state can be used to trigger event-handling tasks on the event dispatch thread.
By implementing a property change listener, a program can track changes to
state, and other bound properties. For more information, refer to How to Write a Property Change Listener in Writing Event Listeners.
progress Bound Variable
progress bound variable is an
int value that can range from 0 to 100. It has a predefined setter method (the protected
SwingWorker.setProgress ) and a predefined getter method (the public
progress to update a
ProgressBar control from a background task. For a detailed discussion of this example, refer to How to Use Progress Bars in Using Swing Components.
state Bound Variable
state bound variable indicates where the
SwingWorker object is in its lifecycle. The bound variable contains an enumeration value of type
SwingWorker.StateValue. Possible values are:
The state during the period from the construction of the object until just before
The state during the period from shortly before
doInBackgroundis invoked until shortly before
- The state for the remainder of the existence of the object.
The current value of the
state bound variable is returned by
Two methods, part of the
Future interface, also report on the status of the background task. As we saw in Canceling Background Tasks,
true if the task has been canceled. In addition,
true if the task has finished, either normally, or by being cancelled.