Implement requests for geolocation/notifications.

Closes #503.

qutebrowser/browser/webpage.py

@@ -64,6 +64,8 @@ class BrowserPage(QWebPage):
         self.downloadRequested.connect(self.on_download_requested)
         self.unsupportedContent.connect(self.on_unsupported_content)
         self.loadStarted.connect(self.on_load_started)
+        self.featurePermissionRequested.connect(
+            self.on_feature_permission_requested)
 
     if PYQT_VERSION > 0x050300:
         # WORKAROUND (remove this when we bump the requirements to 5.3.1)
@@ -258,6 +260,52 @@ class BrowserPage(QWebPage):
         else:
             self.error_occured = False
 
+    @pyqtSlot('QWebFrame', 'QWebPage::Feature')
+    def on_feature_permission_requested(self, frame, feature):
+        """Ask the user for approval for geolocation/notifications."""
+        bridge = objreg.get('message-bridge', scope='window',
+                            window=self._win_id)
+        q = usertypes.Question(bridge)
+        q.mode = usertypes.PromptMode.yesno
+
+        msgs = {
+            QWebPage.Notifications: 'show notifications',
+            QWebPage.Geolocation: 'access your location',
+        }
+        host = frame.url().host()
+        if host:
+            q.text = "Allow the website at {} to {}?".format(
+                frame.url().host(), msgs[feature])
+        else:
+            q.text = "Allow the website to {}?".format(msgs[feature])
+
+        yes_action = functools.partial(
+            self.setFeaturePermission, frame, feature,
+            QWebPage.PermissionGrantedByUser)
+        q.answered_yes.connect(yes_action)
+
+        no_action = functools.partial(
+            self.setFeaturePermission, frame, feature,
+            QWebPage.PermissionDeniedByUser)
+        q.answered_no.connect(no_action)
+
+        q.completed.connect(q.deleteLater)
+
+        self.featurePermissionRequestCanceled.connect(functools.partial(
+            self.on_feature_permission_cancelled, q, frame, feature))
+        self.loadStarted.connect(q.abort)
+
+        bridge.ask(q, blocking=False)
+
+    def on_feature_permission_cancelled(self, question, frame, feature,
+                                        cancelled_frame, cancelled_feature):
+        """Slot invoked when a feature permission request was cancelled.
+
+        To be used with functools.partial.
+        """
+        if frame is cancelled_frame and feature == cancelled_feature:
+            question.abort()
+
     def userAgentForUrl(self, url):
         """Override QWebPage::userAgentForUrl to customize the user agent."""
         ua = config.get('network', 'user-agent')