qml: add QR code imageprovider using qrcode/PIL

adds buildozer 'pillow' recipe to requirements

add initial PoC on qml receive tab

contrib/android/buildozer_qml.spec

@@ -51,7 +51,8 @@ requirements =
     libsecp256k1,
     cryptography,
     pyqt5sip,
-    pyqt5
+    pyqt5,
+    pillow
 
 # (str) Presplash of the application
 #presplash.filename = %(source.dir)s/gui/kivy/theming/splash.png

electrum/gui/qml/components/Receive.qml

@@ -0,0 +1,32 @@
+import QtQuick 2.6
+import QtQuick.Layouts 1.0
+import QtQuick.Controls 2.0
+import QtQuick.Controls.Material 2.0
+
+import org.electrum 1.0
+
+Pane {
+    id: rootItem
+    visible: Daemon.currentWallet !== undefined
+
+    ColumnLayout {
+        width: parent.width
+        spacing: 20
+
+        Image {
+            id: img
+        }
+
+        TextField {
+            id: text
+        }
+
+        Button {
+            text: 'generate'
+            onClicked: {
+                img.source = 'image://qrgen/' + text.text
+            }
+        }
+    }
+
+}

electrum/gui/qml/components/WalletMainView.qml

@@ -63,11 +63,9 @@ Item {
             currentIndex: tabbar.currentIndex
 
             Item {
-
-                ColumnLayout {
-                    width: parent.width
-                    y: 20
-                    spacing: 20
+                Receive {
+                    id: receive
+                    anchors.fill: parent
                 }
             }
 

electrum/gui/qml/qeapp.py

@@ -10,7 +10,7 @@ from .qeconfig import QEConfig
 from .qedaemon import QEDaemon, QEWalletListModel
 from .qenetwork import QENetwork
 from .qewallet import QEWallet
-from .qeqr import QEQR
+from .qeqr import QEQR, QEQRImageProvider
 from .qewalletdb import QEWalletDB
 from .qebitcoin import QEBitcoin
 
@@ -36,6 +36,9 @@ class ElectrumQmlApplication(QGuiApplication):
         self.engine = QQmlApplicationEngine(parent=self)
         self.engine.addImportPath('./qml')
 
+        self.qr_ip = QEQRImageProvider()
+        self.engine.addImageProvider('qrgen', self.qr_ip)
+
         self.context = self.engine.rootContext()
         self._singletons['config'] = QEConfig(config)
         self._singletons['network'] = QENetwork(daemon.network)
@@ -63,7 +66,7 @@ class ElectrumQmlApplication(QGuiApplication):
 
     def message_handler(self, line, funct, file):
         # filter out common harmless messages
-        if re.search('file:///.*TypeError:\ Cannot\ read\ property.*null$', file):
+        if re.search('file:///.*TypeError: Cannot read property.*null$', file):
             return
         self.logger.warning(file)
 

electrum/gui/qml/qeqr.py

@@ -1,8 +1,15 @@
 from PyQt5.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, QObject, QUrl
+from PyQt5.QtGui import QImage
+from PyQt5.QtQuick import QQuickImageProvider
 
 from electrum.logging import get_logger
 
-#from PIL import Image
+import qrcode
+#from qrcode.image.styledpil import StyledPilImage
+#from qrcode.image.styles.moduledrawers import *
+
+from PIL import Image, ImageQt
+
 from ctypes import *
 
 class QEQR(QObject):
@@ -11,22 +18,25 @@ class QEQR(QObject):
         self._text = text
 
     _logger = get_logger(__name__)
-    scan_ready_changed = pyqtSignal()
 
-    _ready = True
+    scanReadyChanged = pyqtSignal()
+    imageChanged = pyqtSignal()
+
+    _scanReady = True
+    _image = None
 
     @pyqtSlot('QImage')
     def scanImage(self, image=None):
-        if not self._ready:
+        if not self._scanReady:
             self._logger.warning("Already processing an image. Check 'ready' property before calling scanImage")
             return
-        self._ready = False
-        self.scan_ready_changed.emit()
+        self._scanReady = False
+        self.scanReadyChanged.emit()
 
         pilimage = self.convertToPILImage(image)
         self.parseQR(pilimage)
 
-        self._ready = True
+        self._scanReady = True
 
     def logImageStats(self, image):
         self._logger.info('width: ' + str(image.width()))
@@ -47,13 +57,32 @@ class QEQR(QObject):
         memmove(c_buf, c_void_p(rawimage.__int__()), numbytes)
         buf2 = bytes(buf)
 
-        return None #Image.frombytes('RGBA', (image.width(), image.height()), buf2, 'raw')
+        return Image.frombytes('RGBA', (image.width(), image.height()), buf2, 'raw')
 
     def parseQR(self, image):
         # TODO
         pass
 
-    @pyqtProperty(bool, notify=scan_ready_changed)
-    def ready(self):
-        return self._ready
+    @pyqtProperty(bool, notify=scanReadyChanged)
+    def scanReady(self):
+        return self._scanReady
 
+    @pyqtProperty('QImage', notify=imageChanged)
+    def image(self):
+        return self._image
+
+class QEQRImageProvider(QQuickImageProvider):
+    def __init__(self, parent=None):
+        super().__init__(QQuickImageProvider.Image)
+
+    _logger = get_logger(__name__)
+
+    def requestImage(self, qstr, size):
+        self._logger.debug('QR requested for %s' % qstr)
+        qr = qrcode.QRCode(version=1, box_size=8, border=2)
+        qr.add_data(qstr)
+        qr.make(fit=True)
+
+        pimg = qr.make_image(fill_color='black', back_color='white') #image_factory=StyledPilImage, module_drawer=CircleModuleDrawer())
+        qimg = ImageQt.ImageQt(pimg)
+        return qimg, qimg.size()