svl/source/notify/lstner.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/lstner.hxx>
  21
  22 #include <svl/hint.hxx>
  23 #include <svl/SfxBroadcaster.hxx>
  24 #include <sal/backtrace.hxx>
  25 #include <sal/log.hxx>
  26
  27 #include <algorithm>
  28 #include <cassert>
  29 #include <deque>
  30 #include <memory>
  31 #include <map>
  32
  33 typedef std::deque<SfxBroadcaster*> SfxBroadcasterArr_Impl;
  34
  35 struct SfxListener::Impl
  36 {
  37     SfxBroadcasterArr_Impl maBCs;
  38 #ifdef DBG_UTIL
  39     std::map<SfxBroadcaster*, std::unique_ptr<sal::BacktraceState>>
  40         maCallStacks;
  41 #endif
  42 };
  43
  44 // simple ctor of class SfxListener
  45
  46 SfxListener::SfxListener() : mpImpl(new Impl)
  47 {
  48 }
  49
  50 // copy ctor of class SfxListener
  51
  52 SfxListener::SfxListener( const SfxListener &rListener ) : mpImpl(new Impl)
  53 {
  54     for ( size_t n = 0; n < rListener.mpImpl->maBCs.size(); ++n )
  55         StartListening( *rListener.mpImpl->maBCs[n] );
  56 }
  57
  58 // unregisters the SfxListener from its SfxBroadcasters
  59
  60 SfxListener::~SfxListener() COVERITY_NOEXCEPT_FALSE
  61 {
  62     // unregister at all remaining broadcasters
  63     for ( size_t nPos = 0; nPos < mpImpl->maBCs.size(); ++nPos )
  64     {
  65         SfxBroadcaster *pBC = mpImpl->maBCs[nPos];
  66         pBC->RemoveListener(*this);
  67     }
  68 }
  69
  70
  71 // unregisters a specific SfxBroadcaster
  72
  73 void SfxListener::RemoveBroadcaster_Impl( SfxBroadcaster& rBroadcaster )
  74 {
  75     auto it = std::find( mpImpl->maBCs.begin(), mpImpl->maBCs.end(), &rBroadcaster );
  76     if (it != mpImpl->maBCs.end()) {
  77         mpImpl->maBCs.erase( it );
  78 #ifdef DBG_UTIL
  79         mpImpl->maCallStacks.erase( &rBroadcaster );
  80 #endif
  81     }
  82 }
  83
  84
  85
  86 /**
  87  Registers a specific SfxBroadcaster.
  88
  89  Some code uses duplicates as a kind of ref-counting thing i.e. they add and remove listeners
  90  on different code paths, and they only really stop listening when the last EndListening() is called.
  91 */
  92 void SfxListener::StartListening(SfxBroadcaster& rBroadcaster, DuplicateHandling eDuplicateHanding)
  93 {
  94     bool bListeningAlready = IsListening( rBroadcaster );
  95
  96 #ifdef DBG_UTIL
  97     if (bListeningAlready && eDuplicateHanding == DuplicateHandling::Unexpected)
  98     {
  99         auto f = mpImpl->maCallStacks.find( &rBroadcaster );
 100         SAL_WARN("svl", "previous StartListening call came from: " << sal::backtrace_to_string(f->second.get()));
 101     }
 102 #endif
 103     assert(!(bListeningAlready && eDuplicateHanding == DuplicateHandling::Unexpected) && "duplicate listener, try building with DBG_UTIL to find the other insert site.");
 104
 105     if (!bListeningAlready || eDuplicateHanding != DuplicateHandling::Prevent)
 106     {
 107         rBroadcaster.AddListener(*this);
 108         mpImpl->maBCs.push_back( &rBroadcaster );
 109 #ifdef DBG_UTIL
 110         mpImpl->maCallStacks.emplace( &rBroadcaster, sal::backtrace_get(10) );
 111 #endif
 112         assert(IsListening(rBroadcaster) && "StartListening failed");
 113     }
 114 }
 115
 116 // unregisters a specific SfxBroadcaster
 117
 118 void SfxListener::EndListening( SfxBroadcaster& rBroadcaster, bool bRemoveAllDuplicates )
 119 {
 120     SfxBroadcasterArr_Impl::iterator beginIt = mpImpl->maBCs.begin();
 121     do
 122     {
 123         SfxBroadcasterArr_Impl::iterator it = std::find( beginIt, mpImpl->maBCs.end(), &rBroadcaster );
 124         if ( it == mpImpl->maBCs.end() )
 125         {
 126             break;
 127         }
 128         rBroadcaster.RemoveListener(*this);
 129         beginIt = mpImpl->maBCs.erase( it );
 130 #ifdef DBG_UTIL
 131         mpImpl->maCallStacks.erase( &rBroadcaster );
 132 #endif
 133     }
 134     while ( bRemoveAllDuplicates );
 135 }
 136
 137
 138 // unregisters all Broadcasters
 139
 140 void SfxListener::EndListeningAll()
 141 {
 142     // Attention: when optimizing this: respect side effects of RemoveListener!
 143     while ( !mpImpl->maBCs.empty() )
 144     {
 145         SfxBroadcaster *pBC = mpImpl->maBCs.front();
 146         pBC->RemoveListener(*this);
 147         mpImpl->maBCs.pop_front();
 148     }
 149 #ifdef DBG_UTIL
 150     mpImpl->maCallStacks.clear();
 151 #endif
 152 }
 153
 154
 155 bool SfxListener::IsListening( SfxBroadcaster& rBroadcaster ) const
 156 {
 157     return mpImpl->maBCs.end() != std::find( mpImpl->maBCs.begin(), mpImpl->maBCs.end(), &rBroadcaster );
 158 }
 159
 160 sal_uInt16 SfxListener::GetBroadcasterCount() const
 161 {
 162     return mpImpl->maBCs.size();
 163 }
 164
 165 SfxBroadcaster* SfxListener::GetBroadcasterJOE( sal_uInt16 nNo ) const
 166 {
 167     return mpImpl->maBCs[nNo];
 168 }
 169
 170
 171 // base implementation of notification handler
 172
 173 void SfxListener::Notify( SfxBroadcaster& rBroadcaster, const SfxHint& )
 174 {
 175     (void) rBroadcaster;
 176     assert(IsListening(rBroadcaster));
 177 }
 178
 179 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */