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 // broadcast immediately
  31
  32 void SfxBroadcaster::Broadcast(const SfxHint& rHint)
  33 {
  34     // notify all registered listeners exactly once
  35     for (size_t i = 0; i < m_Listeners.size(); ++i)
  36     {
  37         SfxListener* const pListener = m_Listeners[i];
  38         if (pListener)
  39             pListener->Notify(*this, rHint);
  40     }
  41 }
  42
  43 // unregister all listeners
  44
  45 SfxBroadcaster::~SfxBroadcaster() COVERITY_NOEXCEPT_FALSE
  46 {
  47     Broadcast(SfxHint(SfxHintId::Dying));
  48
  49     // remove all still registered listeners
  50     for (size_t i = 0; i < m_Listeners.size(); ++i)
  51     {
  52         SfxListener* const pListener = m_Listeners[i];
  53         if (pListener)
  54             pListener->RemoveBroadcaster_Impl(*this);
  55     }
  56 }
  57
  58 // copy ctor of class SfxBroadcaster
  59
  60 SfxBroadcaster::SfxBroadcaster(const SfxBroadcaster& rOther)
  61 {
  62     for (size_t i = 0; i < rOther.m_Listeners.size(); ++i)
  63     {
  64         SfxListener* const pListener = rOther.m_Listeners[i];
  65         if (pListener)
  66             pListener->StartListening(*this);
  67     }
  68 }
  69
  70 // add a new SfxListener to the list
  71
  72 void SfxBroadcaster::AddListener(SfxListener& rListener)
  73 {
  74     DBG_TESTSOLARMUTEX();
  75     if (m_RemovedPositions.empty())
  76     {
  77         m_Listeners.push_back(&rListener);
  78     }
  79     else
  80     {
  81         size_t targetPosition = m_RemovedPositions.back();
  82         m_RemovedPositions.pop_back();
  83         assert(m_Listeners[targetPosition] == nullptr);
  84         m_Listeners[targetPosition] = &rListener;
  85     }
  86 }
  87
  88 // forward a notification to all registered listeners
  89
  90 void SfxBroadcaster::Forward(SfxBroadcaster& rBC, const SfxHint& rHint)
  91 {
  92     for (size_t i = 0; i < m_Listeners.size(); ++i)
  93     {
  94         SfxListener* const pListener = m_Listeners[i];
  95         if (pListener)
  96             pListener->Notify(rBC, rHint);
  97     }
  98 }
  99
 100 // remove one SfxListener from the list
 101
 102 void SfxBroadcaster::RemoveListener(SfxListener& rListener)
 103 {
 104     DBG_TESTSOLARMUTEX();
 105
 106     // First, check the slots either side of the last removed slot, makes a significant
 107     // difference when the list is large.
 108     int positionOfRemovedElement = -1;
 109     if (!m_RemovedPositions.empty())
 110     {
 111         auto i = m_RemovedPositions.back();
 112         if (i < m_Listeners.size() - 2 && m_Listeners[i + 1] == &rListener)
 113         {
 114             positionOfRemovedElement = i + 1;
 115         }
 116         else if (i > 0 && m_Listeners[i - 1] == &rListener)
 117         {
 118             positionOfRemovedElement = i - 1;
 119         }
 120     }
 121     // then scan the whole list if we didn't find it
 122     if (positionOfRemovedElement == -1)
 123     {
 124         auto aIter = std::find(m_Listeners.begin(), m_Listeners.end(), &rListener);
 125         positionOfRemovedElement = std::distance(m_Listeners.begin(), aIter);
 126     }
 127     // DO NOT erase the listener, set the pointer to 0
 128     // because the current continuation may contain this->Broadcast
 129     m_Listeners[positionOfRemovedElement] = nullptr;
 130     m_RemovedPositions.push_back(positionOfRemovedElement);
 131 }
 132
 133 bool SfxBroadcaster::HasListeners() const { return (GetListenerCount() != 0); }
 134
 135 size_t SfxBroadcaster::GetListenerCount() const
 136 {
 137     assert(m_Listeners.size() >= m_RemovedPositions.size());
 138     return m_Listeners.size() - m_RemovedPositions.size();
 139 }
 140
 141 size_t SfxBroadcaster::GetSizeOfVector() const { return m_Listeners.size(); }
 142
 143 SfxListener* SfxBroadcaster::GetListener(size_t nNo) const { return m_Listeners[nNo]; }
 144
 145 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */