genode/os/include/framebuffer_session/framebuffer_session.h

/*
 * \brief  Framebuffer session interface
 * \author Norman Feske
 * \date   2006-07-10
 */

/*
 * Copyright (C) 2006-2012 Genode Labs GmbH
 *
 * This file is part of the Genode OS framework, which is distributed
 * under the terms of the GNU General Public License version 2.
 */

#ifndef _INCLUDE__FRAMEBUFFER_SESSION__FRAMEBUFFER_SESSION_H_
#define _INCLUDE__FRAMEBUFFER_SESSION__FRAMEBUFFER_SESSION_H_

#include <base/signal.h>
#include <dataspace/capability.h>
#include <session/session.h>

namespace Framebuffer {

	/**
	 * Framebuffer mode info as returned by 'Framebuffer::Session::mode()'
	 */
	struct Mode
	{
		public:

			/**
			 * Pixel formats
			 */
			enum Format { INVALID, RGB565 };

			static Genode::size_t bytes_per_pixel(Format format)
			{
				if (format == RGB565) return 2;
				return 0;
			}

		private:

			int    _width, _height;
			Format _format;

		public:

			Mode() : _width(0), _height(0), _format(INVALID) { }

			Mode(int width, int height, Format format)
			: _width(width), _height(height), _format(format) { }

			int    width()  const { return _width; }
			int    height() const { return _height; }
			Format format() const { return _format; }

			/**
			 * Return number of bytes per pixel
			 */
			Genode::size_t bytes_per_pixel() const {
				return bytes_per_pixel(_format); }
	};


	struct Session : Genode::Session
	{
		static const char *service_name() { return "Framebuffer"; }

		virtual ~Session() { }

		/**
		 * Request dataspace representing the logical frame buffer
		 */
		virtual Genode::Dataspace_capability dataspace() = 0;

		/**
		 * Release framebuffer, free dataspace
		 *
		 * By calling this function, the framebuffer client enables the server
		 * to reallocate the framebuffer dataspace on mode changes. Prior
		 * calling this function, the client should have detached the dataspace
		 * from its local address space.
		 */
		virtual void release() = 0;

		/**
		 * Request current display-mode properties
		 */
		virtual Mode mode() const = 0;

		/**
		 * Register signal handler to be notified on mode changes
		 *
		 * The framebuffer server may support changing the display mode on the
		 * fly. For example, a virtual framebuffer presented in a window may
		 * get resized according to the window dimensions. By installing a
		 * signal handler for mode changes, the framebuffer client can respond
		 * to such changes. From the client's perspective, the original mode
		 * stays in effect until the client calls 'release()'. After having
		 * released the framebuffer, the new mode can be obtained using the
		 * 'mode()' function and a new framebuffer dataspace can be requested
		 * by calling 'dataspace()'.
		 */
		virtual void mode_sigh(Genode::Signal_context_capability sigh) = 0;

		/**
		 * Flush specified pixel region
		 *
		 * \param x,y,w,h  region to be updated on physical frame buffer
		 */
		virtual void refresh(int x, int y, int w, int h) = 0;


		/*********************
		 ** RPC declaration **
		 *********************/

		GENODE_RPC(Rpc_dataspace, Genode::Dataspace_capability, dataspace);
		GENODE_RPC(Rpc_release, void, release);
		GENODE_RPC(Rpc_mode, Mode, mode);
		GENODE_RPC(Rpc_refresh, void, refresh, int, int, int, int);
		GENODE_RPC(Rpc_mode_sigh, void, mode_sigh, Genode::Signal_context_capability);

		GENODE_RPC_INTERFACE(Rpc_dataspace, Rpc_release, Rpc_mode,
		                     Rpc_mode_sigh, Rpc_refresh);
	};
}

#endif /* _INCLUDE__FRAMEBUFFER_SESSION__FRAMEBUFFER_SESSION_H_ */