/* TreeSelectionEvent.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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General Public License for more details.

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02110-1301 USA.

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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
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package javax.swing.event;

import java.util.EventObject;

import javax.swing.tree.TreePath;
import javax.swing.tree.TreeSelectionModel;

/**
 * An event that carries information about a change to a 
 * {@link TreeSelectionModel}.
 * 
 * @see TreeSelectionListener
 * 
 * @author Andrew Selkirk
 */
public class TreeSelectionEvent extends EventObject 
{

  /**
   * The paths that have been added or removed from the selection.
   */
  protected TreePath[] paths;

  /**
   * Flags indicating if the paths were added (<code>true</code>) or removed
   * (<code>false</code>) from the selection.
   */
  protected boolean[] areNew;

  /**
   * The old lead selection path (may be <code>null</code>).
   */
  protected TreePath oldLeadSelectionPath;

  /**
   * The new lead selection path (may be <code>null</code>).
   */
  protected TreePath newLeadSelectionPath;

  /**
   * Creates a new <code>TreeSelectionEvent</code>.
   * 
   * @param source  the source (usually a {@link TreeSelectionModel}, 
   *                <code>null</code> not permitted).
   * @param paths  an array of the paths that have been added to or removed 
   *     from the selection.
   * @param areNew  a flag for each path where <code>true</code> indicates the
   *     corresponding path has been added to the selection and 
   *     <code>false</code> indicates the path has been removed.
   * @param oldLeadSelectionPath  the old lead selection path (<code>null</code>
   *     permitted).
   * @param newLeadSelectionPath  the new lead selection path (<code>null</code>
   *     permitted).
   *
   * @throws IllegalArgumentException if <code>source</code> is 
   *     <code>null</code>.
   */
  public TreeSelectionEvent(Object source, TreePath[] paths,
			    boolean[] areNew, TreePath oldLeadSelectionPath,
			    TreePath newLeadSelectionPath)
  {
    super(source);
    this.paths					= paths;
    this.areNew					= areNew;
    this.oldLeadSelectionPath	= oldLeadSelectionPath;
    this.newLeadSelectionPath	= newLeadSelectionPath;
  }

  /**
   * Creates a new <code>TreeSelectionEvent</code>.
   * 
   * @param source  the event source (usually a {@link TreeSelectionModel},
   *     <code>null</code> not permitted).
   * @param path  the path.
   * @param isNew <code>true</code> indicates that <code>path</code> has been 
   *     added to the selection, and <code>false</code> indicates that it has 
   *     been removed.
   * @param oldLeadSelectionPath  the old lead selection path (<code>null</code>
   *     permitted).
   * @param newLeadSelectionPath  the new lead selection path (<code>null</code>
   *     permitted).
   *                              
   * @throws IllegalArgumentException if <code>source</code> is 
   *     <code>null</code>.
   */
  public TreeSelectionEvent(Object source, TreePath path,
			    boolean isNew, TreePath oldLeadSelectionPath,
			    TreePath newLeadSelectionPath)
  {
    super(source);
    this.paths = new TreePath[]{path};
    this.areNew = new boolean[]{isNew};
    this.oldLeadSelectionPath	= oldLeadSelectionPath;
    this.newLeadSelectionPath	= newLeadSelectionPath;
  }

  /**
   * Returns the first path element.
   * 
   * @return The first path element.
   * 
   * @see #getPaths()
   */
  public TreePath getPath()
  {
    return paths[0];
  } 

  /**
   * Returns an array of the paths that changed in the selection.
   * 
   * @return The paths that changed in the selection.
   * 
   * @see #isAddedPath(TreePath)
   */
  public TreePath[] getPaths()
  {
    return (TreePath[]) paths.clone();
  } 

  /**
   * Returns <code>true</code> if the path returned by {@link #getPath()} has
   * been added to the selection, and <code>false</code> if it has been
   * removed.
   * 
   * @return A boolean.
   * 
   * @see #isAddedPath(int)
   */
  public boolean isAddedPath()
  {
    return areNew[0];
  } 

  /**
   * Returns <code>true</code> if <code>path</code> has been added to the 
   * selection, and <code>false</code> if the path has been removed from the
   * selection.
   * 
   * @param path  the path to check.
   * 
   * @return A flag indicating whether the path has been added to, or removed
   *     from, the selection.
   *     
   * @throw IllegalArgumentException if <code>path</code> is not one of the
   *     paths in {@link #getPaths()}.
   *     
   * @see #isAddedPath(int)
   */
  public boolean isAddedPath(TreePath path)
  {
    for (int i = paths.length - 1; i >= 0; i--)
      if (paths[i].equals(path))
        return areNew[i];

    throw new IllegalArgumentException("Unknown 'path' argument.");
  } 

  /**
   * Returns <code>true</code> if the path at the specified index has been 
   * added to the selection, and <code>false</code> if the path has been 
   * removed from the selection.
   * 
   * @param index  the path index.
   * 
   * @return A flag indicating whether the path has been added to, or removed
   *     from, the selection.
   *     
   * @since 1.3
   * 
   * @see #isAddedPath(TreePath)
   */
  public boolean isAddedPath(int index)
  {
    return areNew[index];
  }

  /**
   * Returns the old lead selection path.
   * 
   * @return The old lead selection path (possibly <code>null</code>).
   * 
   * @see #getNewLeadSelectionPath()
   */
  public TreePath getOldLeadSelectionPath()
  {
    return oldLeadSelectionPath;
  } 

  /**
   * Returns the new lead selection path.
   * 
   * @return The new lead selection path (possibly <code>null</code>).
   * 
   * @see #getOldLeadSelectionPath()
   */
  public TreePath getNewLeadSelectionPath()
  {
    return newLeadSelectionPath;
  }

  /**
   * Creates a shallow copy of this <code>TreeSelectionEvent</code>, replacing
   * the source with <code>source</code>.
   * 
   * @param source  the new event source (<code>null</code> not permitted).
   * 
   * @return A cloned event with another event source.
   * 
   * @throws IllegalArgumentException if <code>source</code> is 
   *     <code>null</code>.
   */
  public Object cloneWithSource(Object source)
  {
    return new TreeSelectionEvent (source, paths, areNew, oldLeadSelectionPath,
        newLeadSelectionPath);
  } 

}