LUMIERA.clone/src/include/display-facade.h

147 lines
4.7 KiB
C++

/*
DISPLAY-FACADE.h - accessing a display for outputting frames
Copyright (C) Lumiera.org
2009, Hermann Vosseler <Ichthyostega@web.de>
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/** @file display-facade.h
** Experimental Interface, allowing the Dummy-Player to access the
** video display widget in the GUI. While, generally speaking, the GUI
** controls the application and thus acts on its own, it might expose some
** services to the lower layers.
**
** In the Dummy-Player design study, the lumiera::Display interface serves
** to hand over calculated frames to the GUI for displaying them in a viewer.
**
** @deprecated This is a first draft as of 1/2009, and likely to be superseded
** by a better design, where rather the \em provider of an output facility
** registers with the OutputManager in the core.
**
** @see [corresponding implementation](\ref display-service.hpp)
** @see stage::GuiFacade
** @see dummy-player-facade.h
**
*/
#ifndef STAGE_INTERFACE_DISPLAY_H
#define STAGE_INTERFACE_DISPLAY_H
#include "include/display-handles.h"
#ifdef __cplusplus /* ============== C++ Interface ================= */
#include "lib/depend.hpp"
#include "lib/handle.hpp"
namespace lumiera {
/**************************************************************//**
* Interface for outputting frames to an (already allocated) viewer
* or display. The viewer is addressed by an "slot" handle, which the
* client receives from some other public interface. This reflects
* the fact that is's not up to the client to create an display or
* viewer; rather they are provided by some internal facility and
* the client code is handed out an display handle in the course
* of a larger interaction, like starting a player. This way,
* when the client code actually is about to produce output,
* he can allocate the slot and obtain a Displayer (functor)
* for pushing the frames out. (Users of the C Language Interface
* have to carry out these steps manually and also have to care
* for cleaning up and deallocating the slot).
*
* @note This is a first draft version of a rather important interface.
* The current version as of 1/2009 just serves a mockup player
* implementation. You can expect this interface to change
* considerably if we get at devising the real player.
*
* @see dummy-player-facade.hpp
* @see stage::PlaybackController
*
*/
class Display
{
public:
/** get an implementation instance of this service */
static lib::Depend<Display> facade;
/**
* Functor for pushing frames to the display.
* While one client is holding such a Sink handle,
* the corresponding DisplayerSlot is locked for
* exclusive use by this client.
*/
class Sink
: public lib::Handle<lumiera_displaySlot>
{
public:
/** push a frame up to the display, calling
* through the CL Interface.
* @see DisplayService::allocate */
inline void
operator() (LumieraDisplayFrame frame)
{
impl().put_ (&impl(),frame);
}
};
/** allocate an already existing display/viewer for output
* @return a functor representing the frame sink */
virtual Sink getHandle(LumieraDisplaySlot) =0;
virtual ~Display(); ///< this is an interface
};
} // namespace lumiera
extern "C" {
#endif /* =========================== CL Interface ===================== */
#include "common/interface.h"
LUMIERA_INTERFACE_DECLARE (lumieraorg_Display, 0
, LUMIERA_INTERFACE_SLOT (void, allocate,(LumieraDisplaySlot) )
, LUMIERA_INTERFACE_SLOT (void, release,(LumieraDisplaySlot) )
, LUMIERA_INTERFACE_SLOT (void, put,(LumieraDisplaySlot, LumieraDisplayFrame))
);
#ifdef __cplusplus
}
#endif
#endif