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Interface java.awt.swing.Action

Implementing Classes:
AbstractAction

public interface Action
extends ActionListener
The JFC Action interface defines a fundamental unit of a program's operation. This interface allows different components to access the same functionality, which can be enabled or disabled in a single step.

In addition to the actionPerformed method defined by the ActionListener interface, this interface allows the application to define, in a single place:

Containers in the Swing set like menus and toolbars know how to add an Action object, as well as other components, using a version of the add method. When an Action object is added to such a container, the container:
  1. Creates a component that is appropriate for that container (a toolbar creates a button component, for example).
  2. Gets the appropriate property(s) from the Action object to customize the component (for example, the icon image and flyover text).
  3. Checks the intial state of the Action object to determine if it is enabled or disabled, and renders the component in the appropriate fashion.
  4. Registers a listener with the Action object so that is notified of state changes. When the Action object changes from enabled to disabled, or back, the container makes the appropriate revisions to the event-generation mechanisms and renders the component accordingly.
For example, both a menu item and a toolbar button could access a Cut action object. The text associated with the object is specified as "Cut", and an image depicting a pair of scissors is specified as its icon. The Cut action-object can then be added to a menu and to a toolbar. Each container does the appropriate things with the object, and invokes its actionPerformed method when the component associated with it is activated. The application can then disable or enable the application object without worrying about what user-interface components are connected to it.

...REVISIT...SUBJECT TO CHANGE........................................... Applications can also define and use Action objects and attach them to an existing component, rather than adding them to an Action-aware container. For example, a JButton can be attached to an Action object using the JButton's addActionListener method. The result is the same as if the button were in an Action-aware container -- the button listens and responds to the Action-objects state and customizes itself using the Action-object's properties. ...END REVISIT............................................................

This interface can be added to an existing class or used to create an adapter (typically, by subclassing AbstractAction). The Action object can then be added to multiple action-aware containers and connected to Action-capable components. The GUI controls can then be activated or deactivated all at once by invoking the Action object's setEnabled method.

See Also:
AbstractAction

Field Summary
static String  DEFAULT
Useful constants that can be used as the storage-retreival key when setting or getting one of this object's properties (text or icon).
static String  LONG_DESCRIPTION
 
static String  NAME
 
static String  SHORT_DESCRIPTION
 
static String  SMALL_ICON
 
 

Method Summary
void  addPropertyChangeListener(PropertyChangeListener listener)
Add or remove a PropertyChange listener.
Object  getValue(String key)
Puts/gets one of this object's properties using the associated key.
boolean  isEnabled()
 
void  putValue(String key, Object value)
 
void  removePropertyChangeListener(PropertyChangeListener listener)
 
void  setEnabled(boolean b)
Sets/tests the enabled state of the Action.
 

Field Detail

DEFAULT

public static final String DEFAULT
Useful constants that can be used as the storage-retreival key when setting or getting one of this object's properties (text or icon).

NAME

public static final String NAME

SHORT_DESCRIPTION

public static final String SHORT_DESCRIPTION

LONG_DESCRIPTION

public static final String LONG_DESCRIPTION

SMALL_ICON

public static final String SMALL_ICON
Method Detail

getValue

public Object getValue(String key)
Puts/gets one of this object's properties using the associated key. If the value has changed, a PropertyChangeEvent will be sent to listeners.

putValue

public void putValue(String key,
                     Object value)

setEnabled

public void setEnabled(boolean b)
Sets/tests the enabled state of the Action. When enabled, any component associated with this object is active and able to fire this object's actionPerformed method.

isEnabled

public boolean isEnabled()

addPropertyChangeListener

public void addPropertyChangeListener(PropertyChangeListener listener)
Add or remove a PropertyChange listener. Containers and attached components use these methods to register interest in this Action object. When its enabled state or other property changes, the registered listeners are informed of the change.

removePropertyChangeListener

public void removePropertyChangeListener(PropertyChangeListener listener)

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