/*
* @(#)Action.java 1.30 03/12/19
*
* Copyright 2004 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
package javax.swing;
import java.awt.*;
import java.awt.event.*;
import java.beans.*;
/**
* The <code>Action</code> interface provides a useful extension to the
* <code>ActionListener</code>
* interface in cases where the same functionality may be accessed by
* several controls.
* <p>
* In addition to the <code>actionPerformed</code> method defined by the
* <code>ActionListener</code> interface, this interface allows the
* application to define, in a single place:
* <ul>
* <li>One or more text strings that describe the function. These strings
* can be used, for example, to display the flyover text for a button
* or to set the text in a menu item.
* <li>One or more icons that depict the function. These icons can be used
* for the images in a menu control, or for composite entries in a more
* sophisticated user interface.
* <li>The enabled/disabled state of the functionality. Instead of having
* to separately disable the menu item and the toolbar button, the
* application can disable the function that implements this interface.
* All components which are registered as listeners for the state change
* then know to disable event generation for that item and to modify the
* display accordingly.
* </ul>
* Certain containers, including menus and tool bars, know how to add an
* <code>Action</code> object. When an <code>Action</code> object is added
* to such a container, the container:
* <ol type="a">
* <li>Creates a component that is appropriate for that container
* (a tool bar creates a button component, for example).
* <li>Gets the appropriate property(s) from the <code>Action</code> object to
* customize the component (for example, the icon image and flyover text).
* <li>Checks the initial state of the <code>Action</code> object to determine
* if it is enabled or disabled, and renders the component in the
* appropriate fashion.
* <li>Registers a listener with the <code>Action</code> object so that is
* notified of state changes. When the <code>Action</code> object changes
* from enabled to disabled,
* or back, the container makes the appropriate revisions to the
* event-generation mechanisms and renders the component accordingly.
* </ol>
* For example, both a menu item and a toolbar button could access a
* <code>Cut</code> 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 <code>Cut</code> action-object can then be added to a
* menu and to a tool bar. Each container does the appropriate things with the
* object, and invokes its <code>actionPerformed</code> 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.
* <p>
* This interface can be added to an existing class or used to create an
* adapter (typically, by subclassing <code>AbstractAction</code>).
* The <code>Action</code> object
* can then be added to multiple <code>Action</code>-aware containers
* and connected to <code>Action</code>-capable
* components. The GUI controls can then be activated or
* deactivated all at once by invoking the <code>Action</code> object's
* <code>setEnabled</code> method.
* <p>
* Note that <code>Action</code> implementations tend to be more expensive
* in terms of storage than a typical <code>ActionListener</code>,
* which does not offer the benefits of centralized control of
* functionality and broadcast of property changes. For this reason,
* you should take care to only use <code>Action</code>s where their benefits
* are desired, and use simple <code>ActionListener</code>s elsewhere.
*
* @version 1.30 12/19/03
* @author Georges Saab
* @see AbstractAction
*/
public interface Action extends ActionListener {
/**
* Useful constants that can be used as the storage-retrieval key
* when setting or getting one of this object's properties (text
* or icon).
*/
/**
* Not currently used.
*/
public static final String DEFAULT = "Default";
/**
* The key used for storing the <code>String</code> name
* for the action, used for a menu or button.
*/
public static final String NAME = "Name";
/**
* The key used for storing a short <code>String</code>
* description for the action, used for tooltip text.
*/
public static final String SHORT_DESCRIPTION = "ShortDescription";
/**
* The key used for storing a longer <code>String</code>
* description for the action, could be used for context-sensitive help.
*/
public static final String LONG_DESCRIPTION = "LongDescription";
/**
* The key used for storing a small <code>Icon</code>, such
* as <code>ImageIcon</code>, for the action, used for toolbar buttons.
*/
public static final String SMALL_ICON = "SmallIcon";
/**
* The key used to determine the command <code>String</code> for the
* <code>ActionEvent</code> that will be created when an
* <code>Action</code> is going to be notified as the result of
* residing in a <code>Keymap</code> associated with a
* <code>JComponent</code>.
*/
public static final String ACTION_COMMAND_KEY = "ActionCommandKey";
/**
* The key used for storing a <code>KeyStroke</code> to be used as the
* accelerator for the action.
*
* @since 1.3
*/
public static final String ACCELERATOR_KEY="AcceleratorKey";
/**
* The key used for storing a <code>KeyEvent</code> to be used as
* the mnemonic for the action.
*
* @since 1.3
*/
public static final String MNEMONIC_KEY="MnemonicKey";
/**
* Gets one of this object's properties
* using the associated key.
* @see #putValue
*/
public Object getValue(String key);
/**
* Sets one of this object's properties
* using the associated key. If the value has
* changed, a <code>PropertyChangeEvent</code> is sent
* to listeners.
*
* @param key a <code>String</code> containing the key
* @param value an <code>Object</code> value
*/
public void putValue(String key, Object value);
/**
* Sets the enabled state of the <code>Action</code>. When enabled,
* any component associated with this object is active and
* able to fire this object's <code>actionPerformed</code> method.
* If the value has changed, a <code>PropertyChangeEvent</code> is sent
* to listeners.
*
* @param b true to enable this <code>Action</code>, false to disable it
*/
public void setEnabled(boolean b);
/**
* Returns the enabled state of the <code>Action</code>. When enabled,
* any component associated with this object is active and
* able to fire this object's <code>actionPerformed</code> method.
*
* @return true if this <code>Action</code> is enabled
*/
public boolean isEnabled();
/**
* Adds a <code>PropertyChange</code> listener. Containers and attached
* components use these methods to register interest in this
* <code>Action</code> object. When its enabled state or other property
* changes, the registered listeners are informed of the change.
*
* @param listener a <code>PropertyChangeListener</code> object
*/
public void addPropertyChangeListener(PropertyChangeListener listener);
/**
* Removes a <code>PropertyChange</code> listener.
*
* @param listener a <code>PropertyChangeListener</code> object
* @see #addPropertyChangeListener
*/
public void removePropertyChangeListener(PropertyChangeListener listener);
}
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