MSXEventDistributor.cc

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#include "MSXEventDistributor.hh"
#include "MSXEventListener.hh"
#include "stl.hh"
#include <cassert>
 
namespace openmsx {
 
MSXEventDistributor::~MSXEventDistributor()
{
        assert(listeners.empty());
}
 
bool MSXEventDistributor::isRegistered(MSXEventListener* listener) const
{
        return contains(listeners, listener);
}
 
void MSXEventDistributor::registerEventListener(MSXEventListener& listener)
{
        assert(!isRegistered(&listener));
        listeners.push_back(&listener);
}
 
void MSXEventDistributor::unregisterEventListener(MSXEventListener& listener)
{
        move_pop_back(listeners, rfind_unguarded(listeners, &listener));
}
 
void MSXEventDistributor::distributeEvent(const Event& event, EmuTime::param time)
{
        // Iterate over a copy because signalMSXEvent() may indirect call back into
        // registerEventListener().
        //   e.g. signalMSXEvent() -> .. -> PlugCmd::execute() -> .. ->
        //        Connector::plug() -> .. -> Joystick::plugHelper() ->
        //        registerEventListener()
        // 'listenersCopy' could be a local variable. But making it a member
        // variable allows to reuse the allocated vector-capacity.
        listenersCopy = listeners;
        for (auto& l : listenersCopy) {
                if (isRegistered(l)) {
                        // it's possible the listener unregistered itself
                        // (but is still present in the copy)
                        l->signalMSXEvent(event, time);
                }
        }
}
 
} // namespace openmsx