/* AbstractCellEditor.java --
   Copyright (C) 2002, 2004, 2005, 2006, 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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any later version.

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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
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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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combination.

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
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package javax.swing;

import java.io.Serializable;
import java.util.EventObject;

import javax.swing.event.CellEditorListener;
import javax.swing.event.ChangeEvent;
import javax.swing.event.EventListenerList;

/**
 * An abstract superclass for table and tree cell editors. This provides some
 * common shared functionality.
 *
 * @author Andrew Selkirk
 */
public abstract class AbstractCellEditor
  implements CellEditor, Serializable
{
  private static final long serialVersionUID = -1048006551406220959L;

  /**
   * Our Swing event listeners.
   */
  protected EventListenerList listenerList;

  /**
   * The cached ChangeEvent.
   */
  protected transient ChangeEvent changeEvent;

  /**
   * Creates a new instance of AbstractCellEditor.
   */
  public AbstractCellEditor() 
  {
    listenerList = new EventListenerList();
    changeEvent = new ChangeEvent(this);
  }

  /**
   * Returns <code>true</code> if the cell is editable using
   * <code>event</code>, <code>false</code>
   * if it's not. The default behaviour is to return <code>true</code>.
   *
   * @param event an event
   *
   * @return <code>true</code> if the cell is editable using
   *     <code>event</code>, <code>false</code> if it's not
   */
  public boolean isCellEditable(EventObject event) 
  {
    return true;
  } 

  /**
   * Returns <code>true</code> if the editing cell should be selected,
   * <code>false</code> otherwise. This is usually returning <code>true</code>,
   * but in some special cases it might be useful not to switch cell selection
   * when editing one cell.
   *
   * @param event an event
   *
   * @return <code>true</code> if the editing cell should be selected,
   *     <code>false</code> otherwise
   */
  public boolean shouldSelectCell(EventObject event) 
  {
    return true;
  }

  /**
   * Stop editing the cell and accept any partial value that has been entered
   * into the cell.
   *
   * @return <code>true</code> if editing has been stopped successfully,
   *     <code>false</code>otherwise
   */
  public boolean stopCellEditing() 
  {
    fireEditingStopped();
    return true;
  }

  /**
   * Stop editing the cell and do not accept any partial value that has
   * been entered into the cell.
   */
  public void cancelCellEditing() 
  {
    fireEditingCanceled();
  } 

  /**
   * Adds a CellEditorListener to the list of CellEditorListeners of this
   * CellEditor.
   *
   * @param listener the CellEditorListener to add
   */
  public void addCellEditorListener(CellEditorListener listener)
  {
    listenerList.add(CellEditorListener.class, listener);
  }

  /**
   * Removes the specified CellEditorListener from the list of the
   * CellEditorListeners of this CellEditor.
   *
   * @param listener the CellEditorListener to remove
   */
  public void removeCellEditorListener(CellEditorListener listener)
  {
    listenerList.remove(CellEditorListener.class, listener);
  }
	
  /**
   * Returns the list of CellEditorListeners that have been registered
   * in this CellEditor.
   *
   * @return the list of CellEditorListeners that have been registered
   *     in this CellEditor
   *
   * @since 1.4
   */
  public CellEditorListener[] getCellEditorListeners()
  {
    return (CellEditorListener[]) listenerList.getListeners(
        CellEditorListener.class);
  }

  /**
   * Notifies all registered listeners that the editing of the cell has has been
   * stopped.
   */
  protected void fireEditingStopped()
  {
    CellEditorListener[] listeners = getCellEditorListeners();

    for (int index = 0; index < listeners.length; index++)
      {
        listeners[index].editingStopped(changeEvent);
      }
  }

  /**
   * Notifies all registered listeners that the editing of the cell has
   * has been canceled.
   */
  protected void fireEditingCanceled()
  {
    CellEditorListener[] listeners = getCellEditorListeners();

    for (int index = 0; index < listeners.length; index++)
      {
        listeners[index].editingCanceled(changeEvent);
      }
  }
}