__init__.py

import cap1xxx


__version__ = '0.0.2'


captouch = None
auto_leds = True

PADS = list(range(1, 7))
NAMES = ['Back', 'A', 'B', 'C', 'D', 'Enter']
LEDMAP = [5, 4, 3, 2, 1, 0]
NUMMAP = [1, 2, 3, 4, 5, 6]

_on_press = [None] * 6
_on_release = [None] * 6
_is_setup = False


def on_touch(pad, handler=None):
    """Register a function to be called when a pad or pads are hit.

    The function should expect one argument: event. You can look at event.pad to determine which pad was hit.

    :param pad: A single integer 1 to 6, a pad name (Back, A, B, C, D, Enter), or a list
    :param handler: The handler function to call on hit
    """
    global _on_press

    setup()

    if handler is None:
        def decorate(handler):
            global _on_press
            _bind_handler(_on_press, pad, handler)

        return decorate

    _bind_handler(_on_press, pad, handler)


def on_release(pad, handler=None):
    """Register a function to be called when a pad or pads are released.

    The function should expect one argument: event. You can look at event.pad to determine which pad was released.

    :param pad: A single integer from 1 to 6, a pad name (Back, A, B, C, D, Enter), or a list
    :param handler: The handler function to call on release
    """
    global _on_release

    setup()

    if handler is None:
        def decorate(handler):
            global _on_release
            _bind_handler(_on_release, pad, handler)

        return decorate

    _bind_handler(_on_release, pad, handler)


def _bind_handler(target, pad, handler):
    if type(pad) == list:
        for p in pad:
            channel = _pad_to_channel(p)
            target[channel] = handler
    else:
        channel = _pad_to_channel(pad)
        target[channel] = handler


def _pad_to_channel(pad):
    try:
        if type(pad) == str:
            return NAMES.index(pad)
        else:
            return NUMMAP.index(pad)

    except ValueError:
        raise ValueError("Invalid touch pad {}. Should be one of \"{}\" or \"{}\"".format(pad, ', '.join(NAMES), ', '.join(str(x) for x in NUMMAP)))


def _handle_press(event):
    global _on_press
    channel = event.channel
    event.name = NAMES[channel]
    event.pad = NUMMAP[channel]

    if auto_leds:
        captouch.set_led_state(LEDMAP[channel], True)

    if callable(_on_press[channel]):
        try:
            _on_press[channel](event)
        except TypeError:
            _on_press[channel]()


def _handle_release(event):
    global _on_release
    channel = event.channel
    event.name = NAMES[channel]
    event.pad = NUMMAP[channel]

    if auto_leds:
        captouch.set_led_state(LEDMAP[channel], False)

    if callable(_on_release[channel]):
        try:
            _on_release[channel](event)
        except TypeError:
            _on_release[channel]()


def led_on(pad):
    """Turn on an LED corresponding to a single pad.

    :param pad: A single integer from 1 to 6 or a pad name (Back, A, B, C, D, Enter), corresponding to the pad whose LED you want to turn on.

    """

    set_led(pad, True)


def all_off():
    """Turn off all LEDs"""

    for pad in PADS:
        led_off(pad)


def all_on():
    """Turn on all LEDs"""

    for pad in PADS:
        led_on(pad)


def led_off(pad):
    """Turn off an LED corresponding to a single pad.

    :param pad: A single integer from 1 to 6 or a pad name (Back, A, B, C, D, Enter), corresponding to the pad whose LED you want to turn off.

    """

    set_led(pad, False)


def set_led(pad, value):
    setup()
    idx = _pad_to_channel(pad)
    led = LEDMAP[idx]
    captouch.set_led_state(led, value)


def setup():
    global _is_setup, captouch

    if _is_setup:
        return True

    captouch = cap1xxx.Cap1166(i2c_addr=0x2c)

    for x in range(6):
        captouch.on(x, event='press', handler=_handle_press)
        captouch.on(x, event='release', handler=_handle_release)

    # Unlink the LEDs since Touch pHAT's LEDs don't match up with the channels
    captouch._write_byte(cap1xxx.R_LED_LINKING, 0b00000000)

    _is_setup = True