genode/repos/os/include/framebuffer_session/connection.h

/*
 * \brief  Connection to frame-buffer service
 * \author Norman Feske
 * \date   2008-08-22
 */

/*
 * Copyright (C) 2008-2013 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__CONNECTION_H_
#define _INCLUDE__FRAMEBUFFER_SESSION__CONNECTION_H_

#include <framebuffer_session/client.h>
#include <util/arg_string.h>
#include <base/connection.h>

namespace Framebuffer { class Connection; }


class Framebuffer::Connection : public Genode::Connection<Session>,
                                public Session_client
{
	private:

		/**
		 * Create session and return typed session capability
		 */
		Session_capability _connect(unsigned width, unsigned height,
		                            Mode::Format format)
		{
			using namespace Genode;

			enum { ARGBUF_SIZE = 128 };
			char argbuf[ARGBUF_SIZE];

			/* donate ram quota for storing server-side meta data */
			Genode::strncpy(argbuf, "ram_quota=8K", sizeof(argbuf));

			/* set optional session-constructor arguments */
			if (width)
				Arg_string::set_arg(argbuf, sizeof(argbuf), "fb_width", width);
			if (height)
				Arg_string::set_arg(argbuf, sizeof(argbuf), "fb_height", height);
			if (format != Mode::INVALID)
				Arg_string::set_arg(argbuf, sizeof(argbuf), "fb_format", format);

			return session(argbuf);
		}

	public:

		/**
		 * Constructor
		 *
		 * \param width   desired frame-buffer width
		 * \param height  desired frame-buffer height
		 * \param mode    desired pixel format
		 *
		 * The specified values are not enforced. After creating the
		 * session, you should validate the actual frame-buffer attributes
		 * by calling the 'info' method of the frame-buffer interface.
		 */
		Connection(unsigned     width  = 0,
		           unsigned     height = 0,
		           Mode::Format format = Mode::INVALID)
		:
			Genode::Connection<Session>(_connect(width, height, format)),
			Session_client(cap())
		{ }
};

#endif /* _INCLUDE__FRAMEBUFFER_SESSION__CONNECTION_H_ */