add qrdata

kivyblocks/qrdata.py

@@ -0,0 +1,186 @@
+''' Kivy Widget that accepts data and displays qrcode
+'''
+
+from threading import Thread
+from functools import partial
+
+from kivy.factory import Factory
+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
+import qrcode
+
+
+Builder.load_string('''
+<QRCodeWidget>
+    on_parent: if args[1]: qrimage.source = self.loading_image
+    canvas.before:
+        # Draw white Rectangle
+        Color:
+            rgba: root.background_color
+        Rectangle:
+            size: self.size
+            pos: self.pos
+    canvas.after:
+        Color:
+            rgba: .5, .5, .5, 1 if root.show_border else 0
+        Line:
+            width: dp(1.333)
+            points:
+                dp(2), dp(2),\
+                self.width - dp(2), dp(2),\
+                self.width - dp(2), self.height - dp(2),\
+                dp(2), self.height - dp(2),\
+                dp(2), dp(2)
+    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):
+
+    show_border = BooleanProperty(True)
+    '''Whether to show border around the widget.
+
+    :data:`show_border` is a :class:`~kivy.properties.BooleanProperty`,
+    defaulting to `True`.
+    '''
+
+    data = StringProperty(None, allow_none=True)
+    ''' Data using which the qrcode is generated.
+
+    :data:`data` is a :class:`~kivy.properties.StringProperty`, defaulting to
+    `None`.
+    '''
+
+    background_color = ListProperty((1, 1, 1, 1))
+    ''' Background color of the background of the widget to be displayed
+    behind the qrcode.
+
+    :data:`background_color` is a :class:`~kivy.properties.ListProperty`,
+    defaulting to `(1, 1, 1, 1)`.
+    '''
+
+    loading_image = StringProperty('data/images/image-loading.gif')
+    '''Intermediate image to be displayed while the widget ios being loaded.
+    
+    :data:`loading_image` is a :class:`~kivy.properties.StringProperty`,
+    defaulting to `'data/images/image-loading.gif'`.
+    '''
+
+    def __init__(self, **kwargs):
+        super(QRCodeWidget, self).__init__(**kwargs)
+        self.addr = None
+        self.qr = None
+        self._qrtexture = None
+
+    def on_data(self, instance, value):
+        if not (self.canvas or value):
+            return
+        img = self.ids.get('qrimage', None)
+
+        if not img:
+            # if texture hasn't yet been created delay the texture updation
+            Clock.schedule_once(lambda dt: self.on_data(instance, value))
+            return
+        img.anim_delay = .25
+        img.source = self.loading_image
+        Thread(target=partial(self.generate_qr, value)).start()
+
+    def generate_qr(self, value):
+        self.set_addr(value)
+        self.update_qr()
+
+    def set_addr(self, addr):
+        if self.addr == addr:
+            return
+        MinSize = 210 if len(addr) < 128 else 500
+        self.setMinimumSize((MinSize, MinSize))
+        self.addr = addr
+        self.qr = None
+
+    def update_qr(self):
+        if not self.addr and self.qr:
+            return
+        QRCode = qrcode.QRCode
+        L = qrcode.constants.ERROR_CORRECT_L
+        addr = self.addr
+        try:
+            self.qr = qr = QRCode(
+                version=None,
+                error_correction=L,
+                box_size=10,
+                border=0,
+                )
+            qr.add_data(addr)
+            qr.make(fit=True)
+        except Exception as e:
+            print(e)
+            self.qr=None
+        self.update_texture()
+
+    def setMinimumSize(self, size):
+        # currently unused, do we need this?
+        self._texture_size = size
+
+    def _create_texture(self, k, dt):
+        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.addr:
+            return
+
+        matrix = self.qr.get_matrix()
+        k = len(matrix)
+        
+        # create the texture in main UI thread otherwise
+        # this will lead to memory corruption
+        Clock.schedule_once(partial(self._create_texture, k), -1)
+        
+        
+        cr, cg, cb, ca = self.background_color[:]
+        cr, cg, cb = 255, 255, 255
+        ###used bytearray for python 3.5 eliminates need for btext
+        buff = bytearray()
+        for r in range(k):
+            for c in range(k):
+                buff.extend([0, 0, 0] if matrix[r][c] else [cr, cg, cb])
+
+        # then blit the buffer
+        # join not neccesarry when using a byte array 
+        # buff =''.join(map(chr, buff))
+        # update texture in UI thread.
+        Clock.schedule_once(lambda dt: self._upd_texture(buff))
+
+    def _upd_texture(self, buff):
+        texture = self._qrtexture
+        if not texture:
+            # if texture hasn't yet been created delay the texture updation
+            Clock.schedule_once(lambda dt: self._upd_texture(buff))
+            return
+        
+        texture.blit_buffer(buff, colorfmt='rgb', bufferfmt='ubyte')
+        texture.flip_vertical()
+        img = self.ids.qrimage
+        img.anim_delay = -1
+        img.texture = texture
+        img.canvas.ask_update()
+
+Factory.register('QRCodeWidget',QRCodeWidget)
+
+if __name__ == '__main__':
+    from kivy.app import runTouchApp
+    import sys
+    data = str(sys.argv[1:])
+    runTouchApp(QRCodeWidget(data=data))

requirements.txt

@@ -1,6 +1,7 @@
 jinja2
 kivy
 ffpyplayer
+qrcode
 pillow
 requests
 git+https://github.com/yumoqing/kivycalendar