/elec/propeller-clock

/*

 * button.cc

 *

 * Copyright (C) 2011 Tim Marston <tim@ed.am> and Dan Marston.

 *

 * This file is part of propeller-clock (hereafter referred to as "this

 * program"). See http://ed.am/dev/software/arduino/propeller-clock for more

 * information.

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU Lesser 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 Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

#include <Arduino.h>

#include <button.h>

Button::Button( int pin )

	:

	_pin( pin ),

	_state_last( false ),

	_millis_state( 0 ),

	_millis_done( 0 ),

	_pending_event( 0 ),

	_interim_event( 0 ),

	_send_interim( true ),

	_ignore_next_unpress( false )

{

}

void Button::set_event_times( int event_times[] )

{

	_event_times = event_times;

}

void Button::set_press_mode( bool send_interim )

{

	// if the button is down and we're switching from sending interim presses

	// to not sending interim presses, we need to ignore the next unpress, or

	// this button press may trigger events while being presses *and* events

	// when it is unpressed.

	if( _state_last && _send_interim && !send_interim )

		_ignore_next_unpress = true;

	// set mode

	_send_interim = send_interim;

}

void Button::update()

{

	// get time

	unsigned long millis = ::millis();

	// get button state

	bool state = digitalRead( _pin )? false : true;

	// if the button is pressed

	if( state )

	{

		// if it has just been pressed, record the time now and reset how much

		// of the press we have already generated events for

		if( !_state_last ) {

			_millis_state = millis;

			_millis_done = 0;

		}

		// calculate time that has elapsed in total this press

		unsigned long elapsed = millis - _millis_state;

		// look through the events to see if any need to be triggered

		for( int a = 0; _event_times[ a ]; a++ )

		{

			// if this event is in the future, stop

			if( (unsigned)_event_times[ a ] > elapsed ) break;

			// if this event has already been triggered, skip

			if( (unsigned)_event_times[ a ] <= _millis_done ) continue;

			// trigger event

			if( _send_interim )

				_pending_event = a + 1;

			else

				_interim_event = a + 1;

		}

		// update the amount of press we have processed

		_millis_done = elapsed;

	}

	// if the button has just become unpressed and we're not sending interim

	// events, we'll need to trigger it now

	if( !state && _state_last && !_send_interim )

	{

		// unless we're being told not to, trigger any interim events

		if( _ignore_next_unpress )

			_ignore_next_unpress = false;

		else

			_pending_event = _interim_event;

		// clear any interim event

		_interim_event = 0;

	}

	// update our state

	_state_last = state;

}

int Button::get_event()

{

	int event = _pending_event;

	_pending_event = 0;

	return event;

}