/* Action.java --
   Copyright (C) 2002, 2004, 2005 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath is distributed in the hope that it will be useful, but
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
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package javax.swing;

import java.awt.event.ActionListener;
import java.beans.PropertyChangeListener;

/**
 * Provides a convenient central point of control for some task
 * that can be triggered by more than one control in a Swing user interface
 * (for example, a menu item and a toolbar button).
 * 
 * @see AbstractButton#setAction(Action)
 * 
 * @author Ronald Veldema (rveldema@cs.vu.nl)
 * @author Andrew Selkirk
 */
public interface Action extends ActionListener {

  /**
   * A key to access the default property for the action (this is not used).
   */
  String DEFAULT = "Default";

  /**
   * A key to access the long description for the action.
   */
  String LONG_DESCRIPTION = "LongDescription";

  /**
   * A key to access the name for the action.
   */
  String NAME = "Name";

  /**
   * A key to access the short description for the action (the short
   * description is typically used as the tool tip text).
   */
  String SHORT_DESCRIPTION = "ShortDescription";

  /**
   * A key to access the icon for the action.
   */
  String SMALL_ICON = "SmallIcon";

  /**
   * A key to access the {@link KeyStroke} used as the accelerator for the
   * action.
   */
  String ACCELERATOR_KEY = "AcceleratorKey";

  /**
   * A key to access the action command string for the action.
   */
  String ACTION_COMMAND_KEY = "ActionCommandKey";

  /**
   * A key to access the mnemonic for the action.
   */
  String MNEMONIC_KEY = "MnemonicKey";

  /**
   * Returns the value associated with the specified key.
   * 
   * @param key  the key (not <code>null</code>).
   * 
   * @return The value associated with the specified key, or 
   *         <code>null</code> if the key is not found.
   */
  Object getValue(String key);

  /**
   * Sets the value associated with the specified key and sends a 
   * {@link java.beans.PropertyChangeEvent} to all registered listeners.  
   * The standard keys are defined in this interface: {@link #NAME}, 
   * {@link #SHORT_DESCRIPTION}, {@link #LONG_DESCRIPTION}, 
   * {@link #SMALL_ICON}, {@link #ACTION_COMMAND_KEY}, 
   * {@link #ACCELERATOR_KEY} and {@link #MNEMONIC_KEY}. Any existing value 
   * associated with the key will be overwritten.  
   * 
   * @param key  the key (not <code>null</code>).
   * @param value  the value (<code>null</code> permitted).
   */
  void putValue(String key, Object value);

  /**
   * Returns the flag that indicates whether or not this action is enabled.
   * 
   * @return The flag.
   */
  boolean isEnabled();

  /**
   * Sets the flag that indicates whether or not this action is enabled.  If
   * the value changes, a {@link java.beans.PropertyChangeEvent} is sent to 
   * all registered listeners.
   * 
   * @param b  the new value of the flag.
   */
  void setEnabled(boolean b);

  /**
   * Registers a listener to receive notification whenever one of the
   * action's properties is modified.
   * 
   * @param listener  the listener.
   */
  void addPropertyChangeListener(PropertyChangeListener listener);

  /**
   * Deregisters a listener so that it no longer receives notification of
   * changes to the action's properties. 
   * 
   * @param listener  the listener.
   */
  void removePropertyChangeListener(PropertyChangeListener listener);

} // Action