scan qrcodes with zxing embedded

gui/kivy/main_window.py

@@ -330,6 +330,26 @@ class ElectrumWindow(App):
         except:
             self.show_error(_('Could not start Barcode Scanner.') + ' ' + _('Please install the Barcode Scanner app from ZXing'))
 
+    def scan_qr_zxing(self, on_complete):
+        # uses zxing embedded lib
+        if platform != 'android':
+            return
+        from jnius import autoclass
+        from android import activity
+        PythonActivity = autoclass('org.renpy.android.PythonActivity')
+        IntentIntegrator = autoclass('com.google.zxing.integration.android.IntentIntegrator')
+        integrator = IntentIntegrator(PythonActivity.mActivity)
+        def on_qr_result(requestCode, resultCode, intent):
+            if requestCode == 0:
+                if resultCode == -1: # RESULT_OK:
+                    contents = intent.getStringExtra("SCAN_RESULT")
+                    if intent.getStringExtra("SCAN_RESULT_FORMAT") == 'QR_CODE':
+                        on_complete(contents)
+                    else:
+                        self.show_error("wrong format " + intent.getStringExtra("SCAN_RESULT_FORMAT"))
+        activity.bind(on_activity_result=on_qr_result)
+        integrator.initiateScan()
+
     def build(self):
         return Builder.load_file('gui/kivy/main.kv')