/* ComponentInputMap.java --
   Copyright (C) 2002, 2004  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
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02110-1301 USA.

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making a combined work based on this library.  Thus, the terms and
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permission to link this library with independent modules to produce an
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package javax.swing;


/**
 * An {@link InputMap} that is associated with a particular {@link JComponent}.
 * The component is notified when its <code>ComponentInputMap</code> changes.
 *
 * @author Andrew Selkirk
 * @author Michael Koch
 */
public class ComponentInputMap extends InputMap
{
  /**
   * The component to notify.
   */
  private JComponent component;

  /**
   * Creates <code>ComponentInputMap</code> object that notifies the given
   * component about changes to it.
   *
   * @param comp the component to notify
   *
   * @exception IllegalArgumentException if comp is null
   */
  public ComponentInputMap(JComponent comp)
  {
    if (comp == null)
      throw new IllegalArgumentException();
    
    this.component = comp;
  }

  /**
   * Puts a new entry into the <code>InputMap</code>.
   * If actionMapKey is null an existing entry will be removed.
   *
   * @param keystroke the keystroke for the entry
   * @param value the action.
   */
  public void put(KeyStroke keystroke, Object value)
  {
    super.put(keystroke, value);
    if (component != null)
      component.updateComponentInputMap(this);
  }

  /**
   * Clears the <code>InputMap</code>.
   */
  public void clear()
  {
    super.clear();
    if (component != null)
      component.updateComponentInputMap(this);
  }

  /**
   * Remove an entry from the <code>InputMap</code>.
   *
   * @param keystroke the key of the entry to remove
   */
  public void remove(KeyStroke keystroke)
  {
    super.remove(keystroke);
    if (component != null)
      component.updateComponentInputMap(this);
  }

  /**
   * Sets a parent for this <code>ComponentInputMap</code>.
   *
   * @param parentMap the new parent
   *
   * @exception IllegalArgumentException if parentMap is not a
   * <code>ComponentInputMap</code> or not associated with the same component
   */
  public void setParent(InputMap parentMap)
  {
    if (parentMap != null && !(parentMap instanceof ComponentInputMap))
      throw new IllegalArgumentException("ComponentInputMaps can only have " +
                                         "ComponentInputMaps for parents");
    
    if (parentMap != null && 
        ((ComponentInputMap) parentMap).getComponent() != component)
      throw new 
        IllegalArgumentException("ComponentInputMaps' parents must " +
                                 "be associated with the same JComponents");
   
    super.setParent(parentMap);
    if (component != null)
      component.updateComponentInputMap(this);
  }

  /**
   * Returns the component to notify about changes.
   *
   * @return a <code>JComponent</code> object
   */
  public JComponent getComponent()
  {
    return component;
  }
}