toolkit/test/accessibility/NodeHandler.java

   1 /*
   2  * This file is part of the LibreOffice project.
   3  *
   4  * This Source Code Form is subject to the terms of the Mozilla Public
   5  * License, v. 2.0. If a copy of the MPL was not distributed with this
   6  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   7  *
   8  * This file incorporates work covered by the following license notice:
   9  *
  10  *   Licensed to the Apache Software Foundation (ASF) under one or more
  11  *   contributor license agreements. See the NOTICE file distributed
  12  *   with this work for additional information regarding copyright
  13  *   ownership. The ASF licenses this file to you under the Apache
  14  *   License, Version 2.0 (the "License"); you may not use this file
  15  *   except in compliance with the License. You may obtain a copy of
  16  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  17  */
  18
  19 import java.util.Vector;
  20
  21
  22 /**
  23  * Map an arbitrary object into parts of a tree node.
  24  */
  25 abstract class NodeHandler
  26 {
  27     /** This vector is used as cache for the child objects.
  28     */
  29     protected Vector<AccessibleTreeNode> maChildList;
  30
  31
  32     public abstract NodeHandler createHandler (
  33         com.sun.star.accessibility.XAccessibleContext xContext);
  34
  35     public NodeHandler ()
  36     {
  37         maChildList = new Vector<AccessibleTreeNode> ();
  38     }
  39
  40     /** return the number of children this object has */
  41     public int getChildCount()
  42     {
  43         synchronized (maChildList)
  44         {
  45             return maChildList.size();
  46         }
  47     }
  48
  49     /**
  50      * return a child object. Complex
  51      * children have to be AccTreeNode instances.
  52      * @see AccTreeNode
  53      */
  54     public AccessibleTreeNode getChild (AccessibleTreeNode aParent, int nIndex)
  55     {
  56         synchronized (maChildList)
  57         {
  58             AccessibleTreeNode aChild = maChildList.get(nIndex);
  59             if (aChild == null)
  60             {
  61                 aChild = createChild (aParent, nIndex);
  62                 if (aChild == null)
  63                     aChild = new StringNode ("could not create child", aParent);
  64                 maChildList.set (nIndex, aChild);
  65             }
  66             return aChild;
  67         }
  68     }
  69
  70     public AccessibleTreeNode getChildNoCreate (int nIndex)
  71     {
  72         synchronized (maChildList)
  73         {
  74             return maChildList.get(nIndex);
  75         }
  76     }
  77
  78     /** Remove the specified child from the list of children.
  79     */
  80     public boolean removeChild (int nIndex)
  81     {
  82         try
  83         {
  84             synchronized (maChildList)
  85             {
  86                 System.out.println ("    removing child at position " + nIndex + ": "
  87                     + maChildList.get (nIndex));
  88                 maChildList.remove (nIndex);
  89             }
  90         }
  91         catch (Exception e)
  92         {
  93             return false;
  94         }
  95         return true;
  96     }
  97
  98     public int indexOf (AccessibleTreeNode aNode)
  99     {
 100         synchronized (maChildList)
 101         {
 102             return maChildList.indexOf (aNode);
 103         }
 104     }
 105
 106     /** Create a child object for the specified data.  This method is called
 107         usually from getChild and put there into the cache.
 108     */
 109     public abstract AccessibleTreeNode createChild (
 110         AccessibleTreeNode aParent, int nIndex);
 111
 112
 113     // The following methods support editing of children and actions.
 114     // They have default implementations for no actions and read-only.
 115
 116
 117     /** get names of supported actions */
 118     public String[] getActions (AccessibleTreeNode aNode)
 119     {
 120         return new String[] {};
 121     }
 122
 123     /** perform action */
 124     public void performAction (AccessibleTreeNode aNode, int nIndex)
 125     {
 126     }
 127
 128     /** Update all children.
 129     */
 130     public void update (AccessibleTreeNode aNode)
 131     {
 132     }
 133 }