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