javaunohelper/com/sun/star/lib/uno/helper/WeakBase.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 package com.sun.star.lib.uno.helper;
  20 import com.sun.star.uno.XWeak;
  21 import com.sun.star.uno.XAdapter;
  22 import com.sun.star.lang.XTypeProvider;
  23 import com.sun.star.uno.Type;
  24 import java.util.ArrayList;
  25 import java.util.Map;
  26 import java.util.HashMap;
  27
  28
  29 /** This class can be used as the base class for UNO components. It implements the capability
  30  *  to be kept weak (com.sun.star.uno.XWeak) and it implements com.sun.star.lang.XTypeProvider
  31  *  which is necessary for using the component with StarBasic.
  32  */
  33 public class WeakBase implements XWeak, XTypeProvider
  34 {
  35     // Contains all WeakAdapter which have been created in this class
  36     // They have to be notified when this object dies
  37     private WeakAdapter m_adapter;
  38
  39     protected static Map<Class<?>,Type[]> _mapTypes = new HashMap<Class<?>,Type[]>();
  40
  41     /** Method of XWeak. The returned XAdapter implementation can be used to keep
  42      * a weak reference to this object.
  43      * @return a com.sun.star.uno.XAdapter implementation.
  44      */
  45     synchronized public XAdapter queryAdapter()
  46     {
  47         if (m_adapter == null)
  48             m_adapter= new WeakAdapter(this);
  49         return m_adapter;
  50     }
  51
  52     /** Override of Object.finalize. When there are no references to this object anymore
  53      * then the garbage collector calls this method. Thereby causing the adapter object
  54      * to be notified. The adapter, in turn, notifies all listeners (com.sun.star.uno.XReference)
  55      */
  56     @Override
  57     protected void finalize() throws java.lang.Throwable
  58     {
  59         if (m_adapter != null)
  60             m_adapter.referentDying();
  61         super.finalize();
  62     }
  63
  64     /** Method of XTypeProvider. It returns an array of Type objects which represent
  65      * all implemented UNO interfaces of this object.
  66      * @return Type objects of all implemented interfaces.
  67      */
  68     public Type[] getTypes()
  69     {
  70         Type[] arTypes= _mapTypes.get( getClass());
  71         if (arTypes == null)
  72         {
  73             ArrayList<Type> vec= new ArrayList<Type>();
  74             Class currentClass= getClass();
  75             do
  76             {
  77                 Class interfaces[]= currentClass.getInterfaces();
  78                 for(int i = 0; i < interfaces.length; ++ i)
  79                 {
  80                     // Test if it is a UNO interface
  81                     if (com.sun.star.uno.XInterface.class.isAssignableFrom((interfaces[i])))
  82                         vec.add(new Type(interfaces[i]));
  83                 }
  84                 // get the superclass the currentClass inherits from
  85                 currentClass= currentClass.getSuperclass();
  86             } while (currentClass != null);
  87
  88             Type types[]= vec.toArray(new Type[vec.size()]);
  89             _mapTypes.put(getClass(), types);
  90             arTypes= types;
  91         }
  92         return arTypes;
  93     }
  94
  95     /** Obsolete method of XTypeProvider.
  96      */
  97     public byte[] getImplementationId()
  98     {
  99         return new byte[0];
 100     }
 101 }