handleEvent()),
each event-handling method can be used
for only one particular type of event.
We recommend that you avoid the all-purpose method, if possible,
and instead override the event-handling method
that's specific to the type of event you need to handle.
This approach tends to have fewer unintended side effects.
When an event occurs,
the event-handling method that matches the event type is called.
Specifically, the Event is first passed
to the handleEvent() method,
which (in the default implementation of handleEvent())
calls the appropriate method for the event type.
All the event-handling methods
have at least one argument (the Event)
and return a boolean value.
The return value indicates
whether the method completely handled the event.
By returning false,
the event handler indicates
that the event should continue
to be passed up the component hierarchy.
By returning true,
the event handler indicates
that the event should not be forwarded any further.
The handleEvent() method
should almost always return super.handleEvent(),
to ensure that all events are forwarded to the appropriate
event-handling method.
Important:
Like drawing methods,
all event handler methods must execute quickly!
Otherwise, they'll destroy the perceived performance of your program.
If you need to perform some lengthy operation as the result of
an event,
do it by starting up another thread
(or sending a request to another thread)
to perform the operation.
For help on using threads,
see
Threads of Control
.