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637

answers:

1
+1  Q: 

java.awt.Component.dispatchEvent()'s purpose and behavior

Most of the tutorials and documentation that I've been reading seem to indicate that most component communication takes place by subscription using listeners.

The Java docs indicate that java.awt.Component#dispatchEvent(AWTEvent e):

Dispatches an event to this component or one of its sub components. Calls processEvent before returning for 1.1-style events which have been enabled for the Component.

Given that listeners seem commonplace, what is the purpose of dispatchEvent and how / where is the dispatched event received?

+2  A: 

The component has to receive the events to dispatch somewhere. This is where a component receives the events. The events come from the EventQueue.

Tom Hawtin - tackline  2010-01-20 19:10:29
So this would likely be used internally by Java as it notices an event coming in from the OS/Gui system, such as native mouse clicks, etc., and not for inter-component communication where you have full programmatic control over the events?
Kaleb Pederson  2010-01-20 19:16:27
How do you mean? It's not for day-to-day code. And you can't override it.
Tom Hawtin - tackline  2010-01-20 19:28:42
In other words, I really don't need to use it because I can create my own events and event listeners. The raw AWT code may use it to dispatch certain events, but I need not concern myself with it because I will be notified of the events through some listener where relevant.
Kaleb Pederson  2010-01-20 20:30:28

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