iris/boot-programs/metronome.ccp

#pypp 0
// Iris: micro-kernel for a capability-based operating system.
// boot-programs/metronome.ccp: Userspace program.
// Copyright 2009 Bas Wijnen <wijnen@debian.org>
//
// 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/>.

#include "devices.hh"
#include "keys.hh"

Kernel::Num start ():
	Kernel::schedule ()
	kdebug ("metronome started\n")
	Buzzer buzzer = Kernel::my_parent.get_device <Buzzer> ()
	Keyboard kbd = Kernel::my_parent.get_device <Keyboard> ()
	Kernel::Cap key = Kernel::my_receiver.create_capability (0)
	kbd.set_cb (key)
	// Frequency of the pulse train in millihertz.
	unsigned mHz = 1000
	// Frequency of single pulses in hertz.
	unsigned freq = 1000
	bool running (false)
	while true:
		Kernel::wait ()
		switch Kernel::recv.protected_data.l:
			case ~0:
				if running:
					buzzer.beep (freq, 10, ~0)
					Kernel::my_receiver.set_alarm (HZ * 1000 / mHz)
				break
			case 0:
				if Kernel::recv.data[0].l & Keyboard::RELEASE:
					break
				switch Kernel::recv.data[0].l:
					case Key::VOLUME_UP:
						freq = freq * 11 / 10
						break
					case Key::VOLUME_DOWN:
						freq = freq * 9 / 10
						break
					case Key::LEFT:
						mHz = mHz * 99 / 100
						break
					case Key::RIGHT:
						mHz = mHz * 101 / 100
						break
					case Key::UP:
						mHz = mHz * 11 / 10
						break
					case Key::DOWN:
						mHz = mHz * 9 / 10
						break
					case Key::P:
						running = !running
						if running:
							Kernel::my_receiver.set_alarm (0)
						break
				break
			default:
				kdebug ("huh?\n")
				break