rgb-matrix-visualizer/qr.py

#!/usr/bin/env python3

# Uses the Python QR code image generator:
# https://github.com/lincolnloop/python-qrcode
#
# ----------------------------------------------------------------------------
# "THE BEER-WARE LICENSE" (Revision 42):
# <xythobuz@xythobuz.de> wrote this file.  As long as you retain this notice
# you can do whatever you want with this stuff. If we meet some day, and you
# think this stuff is worth it, you can buy me a beer in return.   Thomas Buck
# ----------------------------------------------------------------------------

import time
import qrcode
import util

class PicoImage():
    def getpixel(self, xy):
        x, y = xy
        return self.data[y][x]

class QRScreen:
    def __init__(self, g, d, t = 10.0, h = None, f = None, c1 = (0, 0, 0), c2 = (255, 255, 255)):
        self.gui = g
        self.data = d
        self.time = t
        self.heading = h
        self.font = f
        self.c1 = c1
        self.c2 = c2

        if isinstance(self.data, str):
            # Generate QR code with library
            qr = qrcode.QRCode(
                box_size = 1,
                border = 0,
            )
            qr.add_data(self.data)
            qr.make(fit = True)

            if util.isPi():
                # work-around for weird bug in old qrcode lib?
                if (self.c1 == (0, 0, 0)) and (self.c2 == (255, 255, 255)):
                    self.image = qr.make_image(fill_color = "black", back_color = "white")
                    self.c1 = (0, 0, 0)
                    self.c2 = (255, 255, 255)
                elif (self.c1 == (255, 255, 255)) and (self.c2 == (0, 0, 0)):
                    self.image = qr.make_image(fill_color = "white", back_color = "black")
                    self.c1 = (255, 255, 255)
                    self.c2 = (0, 0, 0)
                else:
                    raise RuntimeError("QR colors other than black/white not supported on Pi")
            else:
                self.image = qr.make_image(fill_color = self.c1, back_color = self.c2)
        else:
            # Show pre-generated QR code image
            self.image = PicoImage()
            self.image.height = len(self.data)
            self.image.width = len(self.data[0])
            self.image.data = self.data

        if self.heading != None:
            DrawText = util.getTextDrawer()
            self.text = DrawText(self.gui, self.c1, self.c2)
            self.yOff = self.gui.height - self.image.height
        else:
            self.yOff = int((self.gui.height - self.image.height) / 2)

        self.xOff = int((self.gui.width - self.image.width) / 2)

        self.restart()

    def restart(self):
        self.start = time.time()

    def finished(self):
        return (time.time() - self.start) >= self.time

    def draw(self):
        # fill border, if needed
        if self.c2 != (0, 0, 0):
            for x in range(0, self.gui.width):
                for y in range(0, self.yOff):
                    self.gui.set_pixel(x, y, self.c2)
                for y in range(0, self.gui.height - self.image.height - self.yOff):
                    self.gui.set_pixel(x, y + self.yOff + self.image.height, self.c2)
            for y in range(0, self.image.height):
                for x in range(0, self.xOff):
                    self.gui.set_pixel(x, y + self.yOff, self.c2)
                for x in range(0, self.gui.width - self.image.width - self.xOff):
                    self.gui.set_pixel(x + self.xOff + self.image.width, y + self.yOff, self.c2)

        if self.heading != None:
            self.text.text(self.heading, self.font, 0, True, -10)

        for x in range(0, self.image.width):
            for y in range(0, self.image.height):
                v = self.image.getpixel((x, y))
                if isinstance(v, int):
                    v = (v, v, v)
                self.gui.set_pixel(x + self.xOff, y + self.yOff, v)

if __name__ == "__main__":
    import util
    import os

    t = util.getTarget()

    d = QRScreen(t, "Hello World", 10.0, "Drinks:", "tom-thumb", (255, 255, 255), (0, 0, 0))

    # dump generated QR image to console, for embedding in Pico script
    print("Dumping QR image to qr_tmp.txt")
    with open("qr_tmp.txt", "w") as f:
        f.write("# QR code image for \"" + d.data + "\"" + os.linesep)
        f.write("# size:" + str(d.image.width) + "x" + str(d.image.height) + os.linesep)
        f.write("qr_data = [" + os.linesep)
        for y in range(0, d.image.height):
            f.write("    [" + os.linesep)
            for x in range(0, d.image.width):
                s = str(d.image.getpixel((x, y)))
                f.write("        " + s + "," + os.linesep)
            f.write("    ]," + os.linesep)
        f.write("]" + os.linesep)

    t.loop(d.draw)