Merge pull request #9073 from accumulator/android_qr_scanner_fix

qml: don't unbind/unregister the ActivityResultListener from within the ActivityResultListener handler func

electrum/gui/qml/components/main.qml

@@ -413,7 +413,7 @@ ApplicationWindow
     Component {
         id: _scanDialog
         QRScanner {
-            //onClosed: destroy()
+            onFinished: destroy()
         }
     }
     Component {

electrum/gui/qml/qeqrscanner.py

@@ -1,6 +1,6 @@
 import os
 
-from PyQt6.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, QObject
+from PyQt6.QtCore import pyqtProperty, pyqtSignal, pyqtSlot, QObject, Qt
 from PyQt6.QtGui import QGuiApplication
 
 from electrum.util import send_exception_to_crash_reporter, UserFacingException
@@ -10,7 +10,7 @@ from electrum.i18n import _
 
 
 if 'ANDROID_DATA' in os.environ:
-    from jnius import autoclass, cast
+    from jnius import autoclass
     from android import activity
 
     jpythonActivity = autoclass('org.kivy.android.PythonActivity').mActivity
@@ -23,10 +23,18 @@ class QEQRScanner(QObject):
 
     found = pyqtSignal()
 
+    finished = pyqtSignal()
+
     def __init__(self, parent=None):
         super().__init__(parent)
         self._hint = _("Scan a QR code.")
         self._scan_data = ""  # decoded qr code result
+        self.finished.connect(self._unbind, Qt.ConnectionType.QueuedConnection)
+
+        self.destroyed.connect(lambda: self.on_destroy())
+
+    def on_destroy(self):
+        self._unbind()
 
     @pyqtProperty(str)
     def hint(self):
@@ -49,34 +57,34 @@ class QEQRScanner(QObject):
         if 'ANDROID_DATA' not in os.environ:
             self._scan_qr_non_android()
             return
-        SimpleScannerActivity = autoclass("org.electrum.qr.SimpleScannerActivity")
-        intent = jIntent(jpythonActivity, SimpleScannerActivity)
+        jSimpleScannerActivity = autoclass("org.electrum.qr.SimpleScannerActivity")
+        intent = jIntent(jpythonActivity, jSimpleScannerActivity)
         intent.putExtra(jIntent.EXTRA_TEXT, jString(self._hint))
 
-        def on_qr_result(requestCode, resultCode, intent):
-            try:
-                if resultCode == -1:  # RESULT_OK:
-                    #  this doesn't work due to some bug in jnius:
-                    # contents = intent.getStringExtra("text")
-                    contents = intent.getStringExtra(jString("text"))
-                    #self._logger.info(f"on_qr_result. {contents=!r}")
-                    self.scanData = contents
-                    self.found.emit()
-            except Exception as e:  # exc would otherwise get lost
-                send_exception_to_crash_reporter(e)
-            finally:
-                activity.unbind(on_activity_result=on_qr_result)
-        activity.bind(on_activity_result=on_qr_result)
+        activity.bind(on_activity_result=self.on_qr_activity_result)
         jpythonActivity.startActivityForResult(intent, 0)
 
+    def on_qr_activity_result(self, requestCode, resultCode, intent):
+        try:
+            if resultCode == -1:  # RESULT_OK:
+                contents = intent.getStringExtra(jString("text"))
+                self.scanData = contents
+                self.found.emit()
+        except Exception as e:  # exc would otherwise get lost
+            send_exception_to_crash_reporter(e)
+        finally:
+            self.finished.emit()
+
     @pyqtSlot()
-    def close(self):
-        pass
+    def _unbind(self):
+        if 'ANDROID_DATA' in os.environ:
+            activity.unbind(on_activity_result=self.on_qr_activity_result)
 
     def _scan_qr_non_android(self):
         data = QGuiApplication.clipboard().text()
         self.scanData = data
         self.found.emit()
+        self.finished.emit()
         return
         # from electrum import qrscanner
         # from .qeapp import ElectrumQmlApplication