/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( false ),

	_state_millis( 0 ),

	_state_duration_done( 0 ),

	_pending_event( 0 ),

	_send_interim( false ),

	_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 && _send_interim && !send_interim )

		_ignore_next_unpress = true;

	// set mode

	_send_interim = send_interim;

}

void Button::update()

{

	// get time

	unsigned long millis = ::millis();

	// get state and check for change

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

	if( state != _state )

	{

		// if we're not sending interim presses, we care about when the button

		// is being unpressed

		if( !_send_interim && !state )

		{

			// are we being told to ignore the next unpress?

			if( _ignore_next_unpress )

				_ignore_next_unpress = false;

			else

			{

				// check through events to see if the button was pressed long

				// enough to trigger one

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

				{

					// if this event is in the future, we can stop looking

					if( _state_millis < (unsigned long)_event_times[ a ] )

						break;

					// trigger it

					_pending_event = a + 1;

				}

			}

		}

		// reset state

		_state = state;

		_state_millis = millis;

		_state_duration_done = 0;

	}

	// if we are sending interim presses, we care about all the time that the

	// button is being pressed

	if( _send_interim && state )

	{

		// calculate new duration for this state

		unsigned long duration = millis - _state_millis;

		// check through events to see if the button has been pressed long

		// enough to trigger one

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

		{

			// if this event is in the future, we can stop looking

			if( duration < (unsigned long)_event_times[ a ] )

				break;

			// if this event happened since the previous update, trigger it

			if( _state_duration_done < (unsigned long)_event_times[ a ] )

				_pending_event = a + 1;

		}

		// update the duration we've accounted for

		_state_duration_done = duration;

	}

}

int Button::get_event()

{

	int event = _pending_event;

	_pending_event = 0;

	return event;

}