Properly work around Qt 5.11 keyboard focus issues

Please let this be the last attempt... :D

Fixes #3939
Supersedes #3921
Reverts ae295a7f65
See #3661

This should not regress #3872. Might affect #3834 in some way.

qutebrowser/browser/mouse.py

@@ -22,7 +22,7 @@
 from PyQt5.QtCore import QObject, QEvent, Qt, QTimer
 
 from qutebrowser.config import config
-from qutebrowser.utils import message, log, usertypes
+from qutebrowser.utils import message, log, usertypes, qtutils
 from qutebrowser.keyinput import modeman
 
 
@@ -54,6 +54,11 @@ class ChildEventFilter(QObject):
                 obj, child))
             assert obj is self._widget
             child.installEventFilter(self._filter)
+
+            if qtutils.version_check('5.11', compiled=False, exact=True):
+                # WORKAROUND for https://bugreports.qt.io/browse/QTBUG-68076
+                QTimer.singleShot(0, self._widget.setFocus)
+
         return False
 
 

qutebrowser/browser/webengine/webenginetab.py

@@ -789,8 +789,6 @@ class WebEngineTab(browsertab.AbstractTab):
             url: The QUrl to open.
             predict: If set to False, predicted_navigation is not emitted.
         """
-        # WORKAROUND for https://bugreports.qt.io/browse/QTBUG-68076
-        self._widget.setFocus()
         self._saved_zoom = self.zoom.factor()
         self._openurl_prepare(url, predict=predict)
         self._widget.load(url)

qutebrowser/mainwindow/tabbedbrowser.py

@@ -490,6 +490,7 @@ class TabbedBrowser(QWidget):
         else:
             self.widget.setCurrentWidget(tab)
             # WORKAROUND for https://bugreports.qt.io/browse/QTBUG-68076
+            # Still seems to be needed with Qt 5.11.1
             tab.setFocus()
 
         tab.show()