Trail: Creating a GUI With JFC/Swing
Lesson: Writing Event Listeners
Listeners Supported by Swing Components
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Listeners Supported by Swing Components

You can tell what kinds of events a component can fire by looking at the kinds of event listeners you can register on it. For example, the JComboBox class defines these listener registration methods:

Thus, a combo box supports action, item, and popup menu listeners in addition to the listener methods it inherits from JComponent.

Listeners supported by Swing components fall into two categories:

Listeners that All Swing Components Support

Because all Swing components descend from the AWT Component class, you can register the following listeners on any Swing component:

component listener
Listens for changes in the component's size, position, or visibility.
focus listener
Listens for whether the component gained or lost the keyboard focus.
key listener
Listens for key presses; key events are fired only by the component that has the current keyboard focus.
mouse listener
Listens for mouse clicks, mouse presses, mouse releases and mouse movement into or out of the component's drawing area.
mouse-motion listener
Listens for changes in the mouse cursor's position over the component.
mouse-wheel listener
Listens for mouse wheel movement over the component.
Hierarchy Listener
Listens for changes to a component's containment hierarchy of changed events.
Hierarchy Bounds Listener
Listens for changes to a component's containment hierarchy of moved and resized events.

All Swing components descend from the AWT Container class, but many of them are not used as containers. So, technically speaking, any Swing component can fire container events, which notify listeners that a component has been added to or removed from the container. Realistically speaking, however, only containers (such as panels and frames) and compound components (such as combo boxes) typically fire container events.

JComponent provides support for three more listener types. You can register an ancestor listener to be notified when a component's containment ancestors are added to or removed from a container, hidden, made visible, or moved. This listener type is an implementation detail which predated hierarchy listeners.

The other two listener types are part of the Swing components' conformance to the JavaBeans specification. Among other things, this means that Swing components support bound and constrained properties and notify listeners of changes to the properties. Property change listeners listen for changes to bound properties and are used by several Swing components, such as formatted text fields, to track changes on a component's bound properties. Also, property change listeners, as well as vetoable change listeners are used by builder tools to listen for changes on constrained properties. For more information refer to the Properties lesson in the JavaBeans trail.

Other Listeners that Swing Components Support

The following table lists Swing components and the specialized listeners they support, not including listeners supported by all Components, Containers, or JComponents. In many cases, the events are fired directly from the component. In other cases, the events are fired from the component's data or selection model. To find out the details for the particular component and listener you are interested in, go first to the component how-to section, and then if necessary to the listener how-to section.

This table lists Swing components with their specialized listeners
Component Action Listener Caret Listener Change Listener Document Listener,
Undoable Edit Listener
Item Listener List Selection Listener Window Listener Other Types of Listeners
button
checked
 
checked
 
checked
     
check box
checked
 
checked
 
checked
     
color chooser    
checked
         
combo box
checked
     
checked
     
dialog            
checked
 
editor pane  
checked
 
checked
      hyperlink
file chooser
checked
             
formatted text field
checked
checked
 
checked
       
frame            
checked
 
internal frame               internal frame
list          
checked
  list data
menu               menu
menu item
checked
 
checked
 
checked
    menu key
menu drag mouse
option pane                
password field
checked
checked
 
checked
       
popup menu               popup menu
progress bar    
checked
         
radio button
checked
 
checked
 
checked
     
slider    
checked
         
spinner    
checked
         
tabbed pane    
checked
         
table          
checked
    table model
table column model
cell editor
text area  
checked
 
checked
       
text field
checked
checked
 
checked
       
text pane  
checked
 
checked
        hyperlink
toggle button
checked
 
checked
 
checked
     
tree                 tree expansion
tree will expand
tree model
tree selection
viewport
(used by scrollpane)
   
checked
         

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