SfxBroadcaster.cxx

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#include <svl/SfxBroadcaster.hxx>
 
#include <svl/hint.hxx>
#include <svl/lstner.hxx>
#include <tools/debug.hxx>
 
#include <algorithm>
#include <cassert>
#include <vector>
 
// broadcast immediately
 
void SfxBroadcaster::Broadcast(const SfxHint& rHint)
{
    // notify all registered listeners exactly once
    size_t nSize = m_Listeners.size();
    for (size_t i = 0; i < nSize; ++i)
    {
        SfxListener* const pListener = m_Listeners[i];
        if (pListener)
            pListener->Notify(*this, rHint);
    }
}
 
// unregister all listeners
 
SfxBroadcaster::~SfxBroadcaster() COVERITY_NOEXCEPT_FALSE
{
    Broadcast(SfxHint(SfxHintId::Dying));
 
    // remove all still registered listeners
    for (size_t i = 0; i < m_Listeners.size(); ++i)
    {
        SfxListener* const pListener = m_Listeners[i];
        if (pListener)
            pListener->RemoveBroadcaster_Impl(*this);
    }
}
 
// copy ctor of class SfxBroadcaster
 
SfxBroadcaster::SfxBroadcaster(const SfxBroadcaster& rOther)
{
    for (size_t i = 0; i < rOther.m_Listeners.size(); ++i)
    {
        SfxListener* const pListener = rOther.m_Listeners[i];
        if (pListener)
            pListener->StartListening(*this);
    }
}
 
// add a new SfxListener to the list
 
void SfxBroadcaster::AddListener(SfxListener& rListener)
{
    DBG_TESTSOLARMUTEX();
    if (m_RemovedPositions.empty())
    {
        m_Listeners.push_back(&rListener);
    }
    else
    {
        size_t targetPosition = m_RemovedPositions.back();
        m_RemovedPositions.pop_back();
        assert(m_Listeners[targetPosition] == nullptr);
        m_Listeners[targetPosition] = &rListener;
    }
}
 
// forward a notification to all registered listeners
 
void SfxBroadcaster::Forward(SfxBroadcaster& rBC, const SfxHint& rHint)
{
    for (size_t i = 0; i < m_Listeners.size(); ++i)
    {
        SfxListener* const pListener = m_Listeners[i];
        if (pListener)
            pListener->Notify(rBC, rHint);
    }
}
 
// remove one SfxListener from the list
 
void SfxBroadcaster::RemoveListener(SfxListener& rListener)
{
    DBG_TESTSOLARMUTEX();
 
    // First, check the slots either side of the last removed slot, makes a significant
    // difference when the list is large.
    int positionOfRemovedElement = -1;
    if (!m_RemovedPositions.empty())
    {
        auto i = m_RemovedPositions.back();
        if (i < m_Listeners.size() - 2 && m_Listeners[i + 1] == &rListener)
        {
            positionOfRemovedElement = i + 1;
        }
        else if (i > 0 && m_Listeners[i - 1] == &rListener)
        {
            positionOfRemovedElement = i - 1;
        }
    }
    // then scan the whole list if we didn't find it
    if (positionOfRemovedElement == -1)
    {
        auto aIter = std::find(m_Listeners.begin(), m_Listeners.end(), &rListener);
        positionOfRemovedElement = std::distance(m_Listeners.begin(), aIter);
    }
    // DO NOT erase the listener, set the pointer to 0
    // because the current continuation may contain this->Broadcast
    m_Listeners[positionOfRemovedElement] = nullptr;
    m_RemovedPositions.push_back(positionOfRemovedElement);
}
 
void SfxBroadcaster::ForAllListeners(std::function<bool(SfxListener*)> f) const
{
    for (size_t i = 0; i < m_Listeners.size(); ++i)
    {
        SfxListener* const pListener = m_Listeners[i];
        if (pListener)
            f(pListener);
    }
}
 
bool SfxBroadcaster::HasListeners() const { return GetListenerCount() != 0; }
 
size_t SfxBroadcaster::GetListenerCount() const
{
    return m_Listeners.size() - m_RemovedPositions.size();
}
 
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