Graphical Interface Events
Whenever you interact with your application’s user interface, the
application receives an event from the windowing system to let it know that
something happened. Some events come from the mouse, such as mouse clicks, mouse movements, and mouse drags. Other
events come from the keyboard, such as key presses and key releases. Every
component generates events. Different components generate different
events as dictated by their purpose (and their L&F). For example,
pressing a JButton
generates an
ActionEvent
(which is really just a
converted mouse event). The ActionEvent
class bundles up interesting stuff
like which button the event came from, when the button was pressed,
whether any modifier keys (such as Shift or Ctrl) were pressed at the
time of the event, and so on.
While the event-dispatching and -handling mechanism is grounded in
the world of AWT (and beyond the scope of this book), we do want you to
know what events the various Swing components generate—and when. The
what of the events is discussed in conjunction with
each of the components. As we introduce components like JTextField
, JButton
, and JTable
, we show the events that they fire and
the methods you use to attach listeners and catch the events.
The when of the events is a bit more
difficult to describe. Rather than attempt to list every possible
scenario for every component, we’ve built a small utility: EEL, the
Every Event Listener. The EEL
class implements every listener interface from ...
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