tweetBooth/ButtonHandler.py at master · mikeloether/tweetBooth · GitHub

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#!/usr/bin/env python
# Classes to handle button presses

import time
import RPi.GPIO as GPIO

import config


class ButtonHandler(object):
    def __init__(self):
        pass

    # wait_for_buttons()
    # Argument 'buttons' can be one or more of these characters:
    #    'l' - left button
    #    'r' - right button
    #    's' - select button
    # If arg 'turn_off_after' is True, then all button LEDs will be switched off after button press
    def wait_for_buttons(self, buttons, turn_off_after=True):
        # Turn on the button LEDs
        self.light_button_leds(buttons, True)

        time.sleep(0.2)  # Debounce

        # Keep track of how long we have been waiting for a button press
        self.start_time = time.time()

        while True:
            # Check the button states
            if 's' in buttons and self.button_is_down(config.button_pin_select):
                if turn_off_after:
                    self.light_button_leds(buttons, False)
                return 's'
            elif 'l' in buttons and self.button_is_down(config.button_pin_left):
                if turn_off_after:
                    self.light_button_leds(buttons, False)
                return 'l'
            elif 'r' in buttons and self.button_is_down(config.button_pin_right):
                if turn_off_after:
                    self.light_button_leds(buttons, False)
                return 'r'
            elif self.button_is_down(config.button_pin_exit):
                return 'exit'

            # If we've been waiting for a button press for longer than screen_saver_seconds secs
            # then go into screen_saver mode.
            if time.time() - self.start_time > config.screen_saver_seconds:
                return 'screensaver'

    def button_is_down(self, button_pin):
        is_up = GPIO.input(button_pin)
        return not is_up

    def light_button_leds(self, buttons, turn_on):
        if 's' in buttons:
            GPIO.output(config.led_pin_select, turn_on)
        if 'l' in buttons:
            GPIO.output(config.led_pin_left, turn_on)
        if 'r' in buttons:
            GPIO.output(config.led_pin_right, turn_on)

    def flash_button_leds(self, buttons, interval_secs, stop_event):
        while not stop_event.is_set():
            self.light_button_leds(buttons, False)
            time.sleep(interval_secs)
            self.light_button_leds(buttons, True)
            time.sleep(interval_secs)