src/libcamera/event_dispatcher.cpp


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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
 * Copyright (C) 2019, Google Inc.
 *
 * event_dispatcher.cpp - Event dispatcher
 */

#include <libcamera/event_dispatcher.h>

#include "log.h"

/**
 * \file event_dispatcher.h
 */

namespace libcamera {

LOG_DEFINE_CATEGORY(Event)

/**
 * \class EventDispatcher
 * \brief Interface to manage the libcamera events and timers
 *
 * The EventDispatcher class allows the integration of the application event
 * loop with libcamera by abstracting how events and timers are managed and
 * processed.
 *
 * To listen to events, libcamera creates EventNotifier instances and registers
 * them with the dispatcher with registerEventNotifier(). The event notifier
 * \ref EventNotifier::activated signal is then emitted by the dispatcher
 * whenever the event is detected.
 *
 * To set timers, libcamera creates Timer instances and registers them with the
 * dispatcher with registerTimer(). The timer \ref Timer::timeout signal is then
 * emitted by the dispatcher when the timer times out.
 */

EventDispatcher::~EventDispatcher()
{
}

/**
 * \fn EventDispatcher::registerEventNotifier()
 * \brief Register an event notifier
 * \param[in] notifier The event notifier to register
 *
 * Once the \a notifier is registered with the dispatcher, the dispatcher will
 * emit the notifier \ref EventNotifier::activated signal whenever a
 * corresponding event is detected on the notifier's file descriptor. The event
 * is monitored until the notifier is unregistered with
 * unregisterEventNotifier().
 *
 * Registering multiple notifiers for the same file descriptor and event type is
 * not allowed and results in undefined behaviour.
 */

/**
 * \fn EventDispatcher::unregisterEventNotifier()
 * \brief Unregister an event notifier