You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 

125 lines
3.3 KiB

''' Kivy Widget that accepts data and displays qrcode
'''
from threading import Thread
from functools import partial
import qrcode
from kivy.uix.floatlayout import FloatLayout
from kivy.graphics.texture import Texture
from kivy.properties import StringProperty
from kivy.properties import ObjectProperty, StringProperty, ListProperty,\
BooleanProperty
from kivy.lang import Builder
from kivy.clock import Clock
Builder.load_string('''
<QRCodeWidget>
canvas.before:
# Draw white Rectangle
Color:
rgba: root.background_color
Rectangle:
size: self.size
pos: self.pos
canvas.after:
Color:
rgba: root.foreground_color
Rectangle:
size: self.size
pos: self.pos
Image
id: qrimage
pos_hint: {'center_x': .5, 'center_y': .5}
allow_stretch: True
size_hint: None, None
size: root.width * .9, root.height * .9
''')
class QRCodeWidget(FloatLayout):
data = StringProperty(None, allow_none=True)
background_color = ListProperty((1, 1, 1, 1))
foreground_color = ListProperty((0, 0, 0, 0))
def __init__(self, **kwargs):
super(QRCodeWidget, self).__init__(**kwargs)
self.data = None
self.qr = None
self._qrtexture = None
def on_data(self, instance, value):
if not (self.canvas or value):
return
self.update_qr()
def set_data(self, data):
if self.data == data:
return
MinSize = 210 if len(data) < 128 else 500
self.setMinimumSize((MinSize, MinSize))
self.data = data
self.qr = None
def update_qr(self):
if not self.data and self.qr:
return
L = qrcode.constants.ERROR_CORRECT_L
data = self.data
self.qr = qr = qrcode.QRCode(
version=None,
error_correction=L,
box_size=10,
border=0,
)
qr.add_data(data)
qr.make(fit=True)
self.update_texture()
def setMinimumSize(self, size):
# currently unused, do we need this?
self._texture_size = size
def _create_texture(self, k):
self._qrtexture = texture = Texture.create(size=(k,k), colorfmt='rgb')
# don't interpolate texture
texture.min_filter = 'nearest'
texture.mag_filter = 'nearest'
def update_texture(self):
if not self.qr:
return
matrix = self.qr.get_matrix()
k = len(matrix)
# create the texture
self._create_texture(k)
buff = []
bext = buff.extend
cr, cg, cb, ca = self.background_color[:]
cr, cg, cb = cr*255, cg*255, cb*255
for r in range(k):
for c in range(k):
bext([0, 0, 0] if matrix[k-1-r][c] else [cr, cg, cb])
# then blit the buffer
buff = bytes(buff)
# update texture
self._upd_texture(buff)
def _upd_texture(self, buff):
texture = self._qrtexture
texture.blit_buffer(buff, colorfmt='rgb', bufferfmt='ubyte')
img = self.ids.qrimage
img.anim_delay = -1
img.texture = texture
img.canvas.ask_update()
if __name__ == '__main__':
from kivy.app import runTouchApp
import sys
data = str(sys.argv[1:])
runTouchApp(QRCodeWidget(data=data))