svl/source/notify/SfxBroadcaster.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include <svl/SfxBroadcaster.hxx>
  21
  22 #include <svl/hint.hxx>
  23 #include <svl/lstner.hxx>
  24 #include <tools/debug.hxx>
  25
  26 #include <algorithm>
  27 #include <cassert>
  28 #include <vector>
  29
  30
  31 typedef std::vector<SfxListener*> SfxListenerArr_Impl;
  32
  33 struct SfxBroadcaster::Impl
  34 {
  35     /** Contains the positions of removed listeners. */
  36     std::vector<size_t>     m_RemovedPositions;
  37     SfxListenerArr_Impl     m_Listeners;
  38 };
  39
  40 // broadcast immediately
  41
  42 void SfxBroadcaster::Broadcast( const SfxHint &rHint )
  43 {
  44     // notify all registered listeners exactly once
  45     for (size_t i = 0; i < mpImpl->m_Listeners.size(); ++i)
  46     {
  47         SfxListener *const pListener = mpImpl->m_Listeners[i];
  48         if (pListener)
  49             pListener->Notify( *this, rHint );
  50     }
  51 }
  52
  53 // unregister all listeners
  54
  55 SfxBroadcaster::~SfxBroadcaster() COVERITY_NOEXCEPT_FALSE
  56 {
  57     Broadcast( SfxHint(SfxHintId::Dying) );
  58
  59     // remove all still registered listeners
  60     for (size_t i = 0; i < mpImpl->m_Listeners.size(); ++i)
  61     {
  62         SfxListener *const pListener = mpImpl->m_Listeners[i];
  63         if (pListener)
  64             pListener->RemoveBroadcaster_Impl(*this);
  65     }
  66 }
  67
  68
  69 // simple ctor of class SfxBroadcaster
  70
  71 SfxBroadcaster::SfxBroadcaster() : mpImpl(new Impl)
  72 {
  73 }
  74
  75
  76 // copy ctor of class SfxBroadcaster
  77
  78
  79 SfxBroadcaster::SfxBroadcaster( const SfxBroadcaster &rBC ) : mpImpl(new Impl)
  80 {
  81     for (size_t i = 0; i < rBC.mpImpl->m_Listeners.size(); ++i)
  82     {
  83         SfxListener *const pListener = rBC.mpImpl->m_Listeners[i];
  84         if (pListener)
  85             pListener->StartListening( *this );
  86     }
  87 }
  88
  89
  90 // add a new SfxListener to the list
  91
  92 void SfxBroadcaster::AddListener( SfxListener& rListener )
  93 {
  94     DBG_TESTSOLARMUTEX();
  95     if (mpImpl->m_RemovedPositions.empty())
  96     {
  97         mpImpl->m_Listeners.push_back(&rListener);
  98     }
  99     else
 100     {
 101         size_t targetPosition = mpImpl->m_RemovedPositions.back();
 102         mpImpl->m_RemovedPositions.pop_back();
 103         assert(mpImpl->m_Listeners[targetPosition] == nullptr);
 104         mpImpl->m_Listeners[targetPosition] = &rListener;
 105     }
 106 }
 107
 108
 109 // forward a notification to all registered listeners
 110
 111 void SfxBroadcaster::Forward(SfxBroadcaster& rBC, const SfxHint& rHint)
 112 {
 113     for (size_t i = 0; i < mpImpl->m_Listeners.size(); ++i)
 114     {
 115         SfxListener *const pListener = mpImpl->m_Listeners[i];
 116         if (pListener)
 117             pListener->Notify( rBC, rHint );
 118     }
 119 }
 120
 121
 122 // remove one SfxListener from the list
 123
 124 void SfxBroadcaster::RemoveListener( SfxListener& rListener )
 125 {
 126     DBG_TESTSOLARMUTEX();
 127
 128     // First, check the slots either side of the last removed slot, makes a significant
 129     // difference when the list is large.
 130     int positionOfRemovedElement = -1;
 131     if (!mpImpl->m_RemovedPositions.empty())
 132     {
 133         auto i = mpImpl->m_RemovedPositions.back();
 134         if (i < mpImpl->m_Listeners.size() - 2 && mpImpl->m_Listeners[i+1] == &rListener)
 135         {
 136             positionOfRemovedElement = i + 1;
 137         }
 138         else if (i > 0 && mpImpl->m_Listeners[i-1] == &rListener)
 139         {
 140             positionOfRemovedElement = i-1;
 141         }
 142     }
 143     // then scan the whole list if we didn't find it
 144     if (positionOfRemovedElement == -1)
 145     {
 146         SfxListenerArr_Impl::iterator aIter = std::find(
 147                 mpImpl->m_Listeners.begin(), mpImpl->m_Listeners.end(), &rListener);
 148         positionOfRemovedElement = std::distance(mpImpl->m_Listeners.begin(), aIter);
 149     }
 150     // DO NOT erase the listener, set the pointer to 0
 151     // because the current continuation may contain this->Broadcast
 152     mpImpl->m_Listeners[positionOfRemovedElement] = nullptr;
 153     mpImpl->m_RemovedPositions.push_back(positionOfRemovedElement);
 154 }
 155
 156 bool SfxBroadcaster::HasListeners() const
 157 {
 158     return (GetListenerCount() != 0);
 159 }
 160
 161 size_t SfxBroadcaster::GetListenerCount() const
 162 {
 163     assert(mpImpl->m_Listeners.size() >= mpImpl->m_RemovedPositions.size());
 164     return mpImpl->m_Listeners.size() - mpImpl->m_RemovedPositions.size();
 165 }
 166
 167 size_t SfxBroadcaster::GetSizeOfVector() const
 168 {
 169     return mpImpl->m_Listeners.size();
 170 }
 171
 172 SfxListener* SfxBroadcaster::GetListener( size_t nNo ) const
 173 {
 174     return mpImpl->m_Listeners[nNo];
 175 }
 176
 177
 178 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */