Use event_target to filter out mouse events

Fixes #2262

qutebrowser/browser/browsertab.py

@@ -486,10 +486,6 @@ class AbstractTab(QWidget):
 
     We use this to unify QWebView and QWebEngineView.
 
-    Class attributes:
-        WIDGET_CLASS: The class of the main widget recieving events.
-                      Needs to be overridden by subclasses.
-
     Attributes:
         history: The AbstractHistory for the current tab.
         registry: The ObjectRegistry associated with this tab.
@@ -523,8 +519,6 @@ class AbstractTab(QWidget):
     contents_size_changed = pyqtSignal(QSizeF)
     add_history_item = pyqtSignal(QUrl, QUrl, str)  # url, requested url, title
 
-    WIDGET_CLASS = None
-
     def __init__(self, win_id, mode_manager, parent=None):
         self.win_id = win_id
         self.tab_id = next(tab_id_gen)
@@ -553,7 +547,7 @@ class AbstractTab(QWidget):
         self._mode_manager = mode_manager
         self._load_status = usertypes.LoadStatus.none
         self._mouse_event_filter = mouse.MouseEventFilter(
-            self, widget_class=self.WIDGET_CLASS, parent=self)
+            self, parent=self)
         self.backend = None
 
         # FIXME:qtwebengine  Should this be public api via self.hints?
@@ -588,7 +582,7 @@ class AbstractTab(QWidget):
         self._load_status = val
         self.load_status_changed.emit(val.name)
 
-    def _event_target(self):
+    def event_target(self):
         """Return the widget events should be sent to."""
         raise NotImplementedError
 
@@ -603,7 +597,7 @@ class AbstractTab(QWidget):
         if getattr(evt, 'posted', False):
             raise AssertionError("Can't re-use an event which was already "
                                  "posted!")
-        recipient = self._event_target()
+        recipient = self.event_target()
         evt.posted = True
         QApplication.postEvent(recipient, evt)
 

qutebrowser/browser/mouse.py

@@ -64,8 +64,6 @@ class MouseEventFilter(QObject):
     """Handle mouse events on a tab.
 
     Attributes:
-        _widget_class: The class of the main widget getting the events.
-                       All other events are ignored.
         _tab: The browsertab object this filter is installed on.
         _handlers: A dict of handler functions for the handled events.
         _ignore_wheel_event: Whether to ignore the next wheelEvent.
@@ -73,9 +71,8 @@ class MouseEventFilter(QObject):
                                       done when the mouse is released.
     """
 
-    def __init__(self, tab, *, widget_class, parent=None):
+    def __init__(self, tab, *, parent=None):
         super().__init__(parent)
-        self._widget_class = widget_class
         self._tab = tab
         self._handlers = {
             QEvent.MouseButtonPress: self._handle_mouse_press,
@@ -207,9 +204,7 @@ class MouseEventFilter(QObject):
         evtype = event.type()
         if evtype not in self._handlers:
             return False
-        if not isinstance(obj, self._widget_class):
-            log.mouse.debug("Ignoring {} to {} which is not an instance of "
-                            "{}".format(event.__class__.__name__, obj,
-                                        self._widget_class))
+        if obj is not self._tab.event_target():
+            log.mouse.debug("Ignoring {} to {}".format(event.__class__.__name__, obj))
             return False
         return self._handlers[evtype](event)

qutebrowser/browser/webengine/webenginetab.py

@@ -452,8 +452,6 @@ class WebEngineTab(browsertab.AbstractTab):
 
     """A QtWebEngine tab in the browser."""
 
-    WIDGET_CLASS = QOpenGLWidget
-
     def __init__(self, win_id, mode_manager, parent=None):
         super().__init__(win_id=win_id, mode_manager=mode_manager,
                          parent=parent)
@@ -654,5 +652,5 @@ class WebEngineTab(browsertab.AbstractTab):
         except AttributeError:
             log.stub('contentsSizeChanged, on Qt < 5.7')
 
-    def _event_target(self):
+    def event_target(self):
         return self._widget.focusProxy()

qutebrowser/browser/webkit/webkittab.py

@@ -590,8 +590,6 @@ class WebKitTab(browsertab.AbstractTab):
 
     """A QtWebKit tab in the browser."""
 
-    WIDGET_CLASS = webview.WebView
-
     def __init__(self, win_id, mode_manager, parent=None):
         super().__init__(win_id=win_id, mode_manager=mode_manager,
                          parent=parent)
@@ -717,5 +715,5 @@ class WebKitTab(browsertab.AbstractTab):
         frame.contentsSizeChanged.connect(self._on_contents_size_changed)
         frame.initialLayoutCompleted.connect(self._on_history_trigger)
 
-    def _event_target(self):
+    def event_target(self):
         return self._widget