scummvm/common/osd_message_queue.h
2021-12-26 18:48:43 +01:00

83 lines
2.2 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef COMMON_OSD_MESSAGE_QUEUE_H
#define COMMON_OSD_MESSAGE_QUEUE_H
#include "common/events.h"
#include "common/singleton.h"
#include "common/str.h"
#include "common/ustr.h"
#include "common/queue.h"
#include "common/mutex.h"
namespace Common {
/**
* @defgroup common_osd_message_queue OSD message queue
* @ingroup common
*
* @brief API for managing the queue of On Screen Display (OSD) messages.
* @{
*/
/**
* Queue OSD messages from any thread to be displayed by the graphic thread.
*/
class OSDMessageQueue : public Singleton<OSDMessageQueue>, public EventSource {
public:
OSDMessageQueue();
~OSDMessageQueue();
void registerEventSource();
enum {
kMinimumDelay = 1000 /** < Minimum delay between two OSD messages (in milliseconds) */
};
/**
* Add a message to the OSD message queue.
*/
void addMessage(const Common::U32String &msg);
/**
* Common::EventSource interface
*
* The OSDMessageQueue registers itself as an event source even if it does not
* actually produce events as a mean to be polled periodically by the GUI or
* engine code.
*
* The periodical polling is used to update the OSD messages.
*/
bool pollEvent(Common::Event &event) override;
private:
Mutex _mutex;
Queue<U32String> _messages;
uint32 _lastUpdate;
};
/** @} */
} // End of namespace Common
#endif