Class Trigger

This Trigger class works around an inconvenient situation when using a general ValueHolder as trigger channel of a BufferedValueModel. BufferedValueHolder performs commit and flush events only if the trigger channel value reports a change. And a ValueHolder doesn't report a change if #setValue tries to set the current value. For example if you set Boolean.TRUE twice, the latter doesn't fire a property change event. The methods #triggerCommit and #triggerFlush check for the current state and guarantee that the appropriate PropertyChangeEvent is fired. On the other hand, the implementation minimizes the number of events necessary to commit or flush buffered values.

Constraints: The value is of type Boolean.

The following example delays the commit of a buffered value:

 ValueModel subject = new ValueHolder();
 Trigger trigger = new Trigger();
 BufferedValueModel buffer = new BufferedValueModel(subject, trigger);

 buffer.setValue("value");
 ...
 trigger.triggerCommit();