Add a new qt_args setting

See #2589

doc/help/settings.asciidoc

@@ -208,6 +208,7 @@
 |<<new_instance_open_target_window,new_instance_open_target_window>>|Which window to choose when opening links as new tabs.
 |<<prompt.filebrowser,prompt.filebrowser>>|Show a filebrowser in upload/download prompts.
 |<<prompt.radius,prompt.radius>>|The rounding radius for the edges of prompts.
+|<<qt_args,qt_args>>|Additional arguments to pass to Qt, without leading `--`.
 |<<scrolling.bar,scrolling.bar>>|Show a scrollbar.
 |<<scrolling.smooth,scrolling.smooth>>|Enable smooth scrolling for web pages.
 |<<session_default_name,session_default_name>>|The name of the session to save by default.
@@ -2604,6 +2605,15 @@ Type: <<types,Int>>
 
 Default: +pass:[8]+
 
+[[qt_args]]
+=== qt_args
+Additional arguments to pass to Qt, without leading `--`.
+With QtWebEngine, some Chromium arguments (see https://peter.sh/experiments/chromium-command-line-switches/ for a list) will work.
+
+Type: <<types,List>>
+
+Default: empty
+
 [[scrolling.bar]]
 === scrolling.bar
 Show a scrollbar.

qutebrowser/app.py

@@ -770,7 +770,7 @@ class Application(QApplication):
         """
         self._last_focus_object = None
 
-        qt_args = qtutils.get_args(args)
+        qt_args = config.qt_args(args)
         log.init.debug("Qt arguments: {}, based on {}".format(qt_args, args))
         super().__init__(qt_args)
 

qutebrowser/config/config.py

@@ -19,6 +19,7 @@
 
 """Configuration storage and config-related utilities."""
 
+import sys
 import copy
 import contextlib
 import functools
@@ -704,3 +705,25 @@ def late_init(save_manager):
 
     instance.init_save_manager(save_manager)
     configfiles.state.init_save_manager(save_manager)
+
+
+def qt_args(namespace):
+    """Get the Qt QApplication arguments based on an argparse namespace.
+
+    Args:
+        namespace: The argparse namespace.
+
+    Return:
+        The argv list to be passed to Qt.
+    """
+    argv = [sys.argv[0]]
+
+    if namespace.qt_flag is not None:
+        argv += ['--' + flag[0] for flag in namespace.qt_flag]
+
+    if namespace.qt_arg is not None:
+        for name, value in namespace.qt_arg:
+            argv += ['--' + name, value]
+
+    argv += ['--' + arg for arg in val.qt_args]
+    return argv

qutebrowser/config/configdata.yml

@@ -85,6 +85,19 @@ session_default_name:
 
     If this is set to null, the session which was last loaded is saved.
 
+qt_args:
+  type:
+    name: List
+    valtype: String
+    none_ok: true
+  default: []
+  desc: >-
+    Additional arguments to pass to Qt, without leading `--`.
+
+    With QtWebEngine, some Chromium arguments (see
+    https://peter.sh/experiments/chromium-command-line-switches/ for a list)
+    will work.
+
 ## auto_save
 
 auto_save.interval:

qutebrowser/utils/qtutils.py

@@ -29,7 +29,6 @@ Module attributes:
 
 import io
 import os
-import sys
 import operator
 import contextlib
 
@@ -138,27 +137,6 @@ def check_overflow(arg, ctype, fatal=True):
         return arg
 
 
-def get_args(namespace):
-    """Get the Qt QApplication arguments based on an argparse namespace.
-
-    Args:
-        namespace: The argparse namespace.
-
-    Return:
-        The argv list to be passed to Qt.
-    """
-    argv = [sys.argv[0]]
-
-    if namespace.qt_flag is not None:
-        argv += ['--' + flag[0] for flag in namespace.qt_flag]
-
-    if namespace.qt_arg is not None:
-        for name, value in namespace.qt_arg:
-            argv += ['--' + name, value]
-
-    return argv
-
-
 def check_print_compat():
     """Check if printing should work in the given Qt version."""
     # WORKAROUND (remove this when we bump the requirements to 5.3.0)

tests/unit/config/test_config.py

@@ -18,6 +18,7 @@
 
 """Tests for qutebrowser.config.config."""
 
+import sys
 import copy
 import types
 import logging
@@ -27,6 +28,7 @@ import pytest
 from PyQt5.QtCore import QObject, QUrl
 from PyQt5.QtGui import QColor
 
+from qutebrowser import qutebrowser
 from qutebrowser.commands import cmdexc
 from qutebrowser.config import config, configdata, configexc, configfiles
 from qutebrowser.utils import objreg, usertypes
@@ -982,3 +984,51 @@ def test_late_init(init_patch, monkeypatch, fake_save_manager, mocker, errors):
         assert '<b>Error text</b>: Exception' in text
     else:
         assert not msgbox_mock.called
+
+
+class TestQtArgs:
+
+    @pytest.fixture
+    def parser(self, mocker):
+        """Fixture to provide an argparser.
+
+        Monkey-patches .exit() of the argparser so it doesn't exit on errors.
+        """
+        parser = qutebrowser.get_argparser()
+        mocker.patch.object(parser, 'exit', side_effect=Exception)
+        return parser
+
+    @pytest.mark.parametrize('args, expected', [
+        # No Qt arguments
+        (['--debug'], [sys.argv[0]]),
+        # Qt flag
+        (['--debug', '--qt-flag', 'reverse'], [sys.argv[0], '--reverse']),
+        # Qt argument with value
+        (['--qt-arg', 'stylesheet', 'foo'],
+         [sys.argv[0], '--stylesheet', 'foo']),
+        # --qt-arg given twice
+        (['--qt-arg', 'stylesheet', 'foo', '--qt-arg', 'geometry', 'bar'],
+         [sys.argv[0], '--stylesheet', 'foo', '--geometry', 'bar']),
+        # --qt-flag given twice
+        (['--qt-flag', 'foo', '--qt-flag', 'bar'],
+         [sys.argv[0], '--foo', '--bar']),
+    ])
+    def test_qt_args(self, config_stub, args, expected, parser):
+        """Test commandline with no Qt arguments given."""
+        parsed = parser.parse_args(args)
+        assert config.qt_args(parsed) == expected
+
+    def test_qt_both(self, config_stub, parser):
+        """Test commandline with a Qt argument and flag."""
+        args = parser.parse_args(['--qt-arg', 'stylesheet', 'foobar',
+                                  '--qt-flag', 'reverse'])
+        qt_args = config.qt_args(args)
+        assert qt_args[0] == sys.argv[0]
+        assert '--reverse' in qt_args
+        assert '--stylesheet' in qt_args
+        assert 'foobar' in qt_args
+
+    def test_with_settings(self, config_stub, parser):
+        parsed = parser.parse_args(['--qt-flag', 'foo'])
+        config_stub.val.qt_args = ['bar']
+        assert config.qt_args(parsed) == [sys.argv[0], '--foo', '--bar']

tests/unit/utils/test_qtutils.py

@@ -36,7 +36,6 @@ import pytest
 from PyQt5.QtCore import (QDataStream, QPoint, QUrl, QByteArray, QIODevice,
                           QTimer, QBuffer, QFile, QProcess, QFileDevice)
 
-from qutebrowser import qutebrowser
 from qutebrowser.utils import qtutils
 import overflow_test_cases
 
@@ -119,51 +118,6 @@ class TestCheckOverflow:
         assert newval == repl
 
 
-class TestGetQtArgs:
-
-    """Tests for get_args."""
-
-    @pytest.fixture
-    def parser(self, mocker):
-        """Fixture to provide an argparser.
-
-        Monkey-patches .exit() of the argparser so it doesn't exit on errors.
-        """
-        parser = qutebrowser.get_argparser()
-        mocker.patch.object(parser, 'exit', side_effect=Exception)
-        return parser
-
-    @pytest.mark.parametrize('args, expected', [
-        # No Qt arguments
-        (['--debug'], [sys.argv[0]]),
-        # Qt flag
-        (['--debug', '--qt-flag', 'reverse'], [sys.argv[0], '--reverse']),
-        # Qt argument with value
-        (['--qt-arg', 'stylesheet', 'foo'],
-         [sys.argv[0], '--stylesheet', 'foo']),
-        # --qt-arg given twice
-        (['--qt-arg', 'stylesheet', 'foo', '--qt-arg', 'geometry', 'bar'],
-         [sys.argv[0], '--stylesheet', 'foo', '--geometry', 'bar']),
-        # --qt-flag given twice
-        (['--qt-flag', 'foo', '--qt-flag', 'bar'],
-         [sys.argv[0], '--foo', '--bar']),
-    ])
-    def test_qt_args(self, args, expected, parser):
-        """Test commandline with no Qt arguments given."""
-        parsed = parser.parse_args(args)
-        assert qtutils.get_args(parsed) == expected
-
-    def test_qt_both(self, parser):
-        """Test commandline with a Qt argument and flag."""
-        args = parser.parse_args(['--qt-arg', 'stylesheet', 'foobar',
-                                  '--qt-flag', 'reverse'])
-        qt_args = qtutils.get_args(args)
-        assert qt_args[0] == sys.argv[0]
-        assert '--reverse' in qt_args
-        assert '--stylesheet' in qt_args
-        assert 'foobar' in qt_args
-
-
 @pytest.mark.parametrize('os_name, qversion, expected', [
     ('linux', '5.2.1', True),  # unaffected OS
     ('linux', '5.4.1', True),  # unaffected OS