Writing Event Listeners

Events Generated by Swing Components

This section summarizes what events can be generated by which Swing components, focusing on the events that typical programs handle. Events generated by Swing components fall into three categories:

• Commonly Handled Events that All Swing Components Can Generate
• Other Commonly Handled Events
• Events Not Commonly Handled

Commonly Handled Events that All Swing Components Can Generate

Because all Swing components descend from the AWT Component class, all Swing components support the following AWT-defined events:

Component Events

Notify listeners of changes in the component's size, position, or visibility.

Focus Events

Notify listeners that the component gained or lost the ability to receive keyboard input.

Key Events

Notify listeners of key presses; generated only by the component that has the current keyboard focus.

Mouse Events

Notify listeners of mouse clicks and the user moving the cursor into or out of the component's drawing area.

Mouse Motion Events

Notify listeners of changes in the cursor's position over the component.

Although all Swing components descend from the AWT Container class, many of them aren't used as containers. So technically speaking any Swing component can generate container events, which notify listeners that a component has been added to or removed from the container. However, realistically speaking only containers such as panels, frames, and so on, generate container events.

Other Commonly Handled Events

The following table lists commonly handled events that various Swing components generate.

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Note: An asterisk '*' in a column header indicates an AWT-defined event. All other event types in the table are defined in javax.swing.event.

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Swing Component	Types of Events Generated and Commonly Handled
	action *	caret	change	document	internal frame	item *	list selection	undoable edit	window *
ColorSelectionModel    ( JColorChooser's default selection model.) Note: This is not a JComponent subclass!			X
Document    ( JTextComponent's data model.) Note: This is not a JComponent subclass!				X				X
JButton	X		X			X
JCheckBox	X		X			X
JComboBox	X					X
JDialog									X
JEditorPane		X
JFileChooser	X
JFrame									X
JInternalFrame					X
JList							X
JMenuItem	X		X			X
JOptionpane									X
JPasswordField	X	X
JProgressBar			X
JRadioButton	X		X			X
JSlider			X
JTabbedPane			X
JTextArea		X
JTextComponent		X
JTextField	X	X
JTextPane		X
JToggleButton	X		X			X
JViewport			X
ListSelectionModel    ( JList's default selection model.) Note: This is not a JComponent subclass!							X
Timer Note: This is not a JComponent subclass!	X

Events Not Commonly Handled

For the record, this section lists other events that Swing components can generate but that typical programs don't need to handle.

All components that inherit from JComponent can generate the events described in the following list.

Ancestor Events

A component generates ancestor events when one of its containment ancestors is added to or removed from a container, hidden, made visible, or moved. This event type is an implementation detail and can generally be ignored.

Property Change Events

Defined in java.beans Swing components generate this type of event because they are JavaBeans compliant. Beans use property change events to implement bound properties.

Vetoable Change Events

Defined in java.beans Swing components generate this type of event because they are JavaBeans compliant. Beans use vetoable change events to implement constrained properties.

The following table lists all the other events defined in javax.swing.event not previously mentioned. [PENDING: make these api links?] [PENDING: this tutorial *should* cover the table and tree events]

Cell Editor Events	Menu Key Events	Tree Expansion Events
Hyperlink Events	Menu Events	Tree Model Events
List Data Events	Popup Menu Events	Tree Selection Events
Menu Drag Mouse Events	Table Model Events	Tree Will Expand Events

Writing Event Listeners