qutebrowser/qutebrowser/misc/backendproblem.py
Gyorgy Orban 98c6b49cde use enum module instead or usertypes.enum
Remove the usertypes.enum from the source and use
the standard enum module instead.
Enum start number is available since python 3.5
2017-11-02 18:56:11 +01:00

376 lines
13 KiB
Python

# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:
# Copyright 2017 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
#
# This file is part of qutebrowser.
#
# qutebrowser is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# qutebrowser is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with qutebrowser. If not, see <http://www.gnu.org/licenses/>.
"""Dialogs shown when there was a problem with a backend choice."""
import os
import sys
import functools
import html
import ctypes
import ctypes.util
import enum
import attr
from PyQt5.QtCore import Qt
from PyQt5.QtWidgets import (QApplication, QDialog, QPushButton, QHBoxLayout,
QVBoxLayout, QLabel, QMessageBox)
from PyQt5.QtNetwork import QSslSocket
from qutebrowser.config import config
from qutebrowser.utils import usertypes, objreg, version, qtutils, log, utils
from qutebrowser.misc import objects, msgbox
_Result = enum.IntEnum(
'_Result',
['quit', 'restart', 'restart_webkit', 'restart_webengine'],
start=QDialog.Accepted + 1)
@attr.s
class _Button:
"""A button passed to BackendProblemDialog."""
text = attr.ib()
setting = attr.ib()
value = attr.ib()
default = attr.ib(default=False)
def _other_backend(backend):
"""Get the other backend enum/setting for a given backend."""
other_backend = {
usertypes.Backend.QtWebKit: usertypes.Backend.QtWebEngine,
usertypes.Backend.QtWebEngine: usertypes.Backend.QtWebKit,
}[backend]
other_setting = other_backend.name.lower()[2:]
return (other_backend, other_setting)
def _error_text(because, text, backend):
"""Get an error text for the given information."""
other_backend, other_setting = _other_backend(backend)
return ("<b>Failed to start with the {backend} backend!</b>"
"<p>qutebrowser tried to start with the {backend} backend but "
"failed because {because}.</p>{text}"
"<p><b>Forcing the {other_backend.name} backend</b></p>"
"<p>This forces usage of the {other_backend.name} backend by "
"setting the <i>backend = '{other_setting}'</i> option "
"(if you have a <i>config.py</i> file, you'll need to set "
"this manually).</p>".format(
backend=backend.name, because=because, text=text,
other_backend=other_backend, other_setting=other_setting))
class _Dialog(QDialog):
"""A dialog which gets shown if there are issues with the backend."""
def __init__(self, because, text, backend, buttons=None, parent=None):
super().__init__(parent)
vbox = QVBoxLayout(self)
other_backend, other_setting = _other_backend(backend)
text = _error_text(because, text, backend)
label = QLabel(text, wordWrap=True)
label.setTextFormat(Qt.RichText)
vbox.addWidget(label)
hbox = QHBoxLayout()
buttons = [] if buttons is None else buttons
quit_button = QPushButton("Quit")
quit_button.clicked.connect(lambda: self.done(_Result.quit))
hbox.addWidget(quit_button)
backend_button = QPushButton("Force {} backend".format(
other_backend.name))
backend_button.clicked.connect(functools.partial(
self._change_setting, 'backend', other_setting))
hbox.addWidget(backend_button)
for button in buttons:
btn = QPushButton(button.text, default=button.default)
btn.clicked.connect(functools.partial(
self._change_setting, button.setting, button.value))
hbox.addWidget(btn)
vbox.addLayout(hbox)
def _change_setting(self, setting, value):
"""Change the given setting and restart."""
config.instance.set_obj(setting, value, save_yaml=True)
save_manager = objreg.get('save-manager')
save_manager.save_all(is_exit=True)
if setting == 'backend' and value == 'webkit':
self.done(_Result.restart_webkit)
elif setting == 'backend' and value == 'webengine':
self.done(_Result.restart_webengine)
else:
self.done(_Result.restart)
def _show_dialog(*args, **kwargs):
"""Show a dialog for a backend problem."""
cmd_args = objreg.get('args')
if cmd_args.no_err_windows:
text = _error_text(*args, **kwargs)
print(text, file=sys.stderr)
sys.exit(usertypes.Exit.err_init)
dialog = _Dialog(*args, **kwargs)
status = dialog.exec_()
quitter = objreg.get('quitter')
if status in [_Result.quit, QDialog.Rejected]:
pass
elif status == _Result.restart_webkit:
quitter.restart(override_args={'backend': 'webkit'})
elif status == _Result.restart_webengine:
quitter.restart(override_args={'backend': 'webengine'})
elif status == _Result.restart:
quitter.restart()
else:
assert False, status
sys.exit(usertypes.Exit.err_init)
def _nvidia_shader_workaround():
"""Work around QOpenGLShaderProgram issues.
NOTE: This needs to be called before _handle_nouveau_graphics, or some
setups will segfault in version.opengl_vendor().
See https://bugs.launchpad.net/ubuntu/+source/python-qt4/+bug/941826
"""
assert objects.backend == usertypes.Backend.QtWebEngine, objects.backend
if utils.is_linux:
ctypes.CDLL(ctypes.util.find_library("GL"), mode=ctypes.RTLD_GLOBAL)
def _handle_nouveau_graphics():
assert objects.backend == usertypes.Backend.QtWebEngine, objects.backend
if os.environ.get('QUTE_SKIP_NOUVEAU_CHECK'):
return
if version.opengl_vendor() != 'nouveau':
return
if (os.environ.get('LIBGL_ALWAYS_SOFTWARE') == '1' or
'QT_XCB_FORCE_SOFTWARE_OPENGL' in os.environ):
return
button = _Button("Force software rendering", 'qt.force_software_rendering',
True)
_show_dialog(
backend=usertypes.Backend.QtWebEngine,
because="you're using Nouveau graphics",
text="<p>There are two ways to fix this:</p>"
"<p><b>Forcing software rendering</b></p>"
"<p>This allows you to use the newer QtWebEngine backend (based "
"on Chromium) but could have noticable performance impact "
"(depending on your hardware). "
"This sets the <i>qt.force_software_rendering = True</i> option "
"(if you have a <i>config.py</i> file, you'll need to set this "
"manually).</p>",
buttons=[button],
)
# Should never be reached
assert False
def _handle_wayland():
assert objects.backend == usertypes.Backend.QtWebEngine, objects.backend
if os.environ.get('QUTE_SKIP_WAYLAND_CHECK'):
return
platform = QApplication.instance().platformName()
if platform not in ['wayland', 'wayland-egl']:
return
if 'DISPLAY' in os.environ:
# XWayland is available, but QT_QPA_PLATFORM=wayland is set
button = _Button("Force XWayland", 'qt.force_platform', 'xcb')
_show_dialog(
backend=usertypes.Backend.QtWebEngine,
because="you're using Wayland",
text="<p>There are two ways to fix this:</p>"
"<p><b>Force Qt to use XWayland</b></p>"
"<p>This allows you to use the newer QtWebEngine backend "
"(based on Chromium). "
"This sets the <i>qt.force_platform = 'xcb'</i> option "
"(if you have a <i>config.py</i> file, you'll need to set "
"this manually).</p>",
buttons=[button],
)
else:
# XWayland is unavailable
_show_dialog(
backend=usertypes.Backend.QtWebEngine,
because="you're using Wayland without XWayland",
text="<p>There are two ways to fix this:</p>"
"<p><b>Set up XWayland</b></p>"
"<p>This allows you to use the newer QtWebEngine backend "
"(based on Chromium). "
)
# Should never be reached
assert False
@attr.s
class BackendImports:
"""Whether backend modules could be imported."""
webkit_available = attr.ib(default=None)
webengine_available = attr.ib(default=None)
webkit_error = attr.ib(default=None)
webengine_error = attr.ib(default=None)
def _try_import_backends():
"""Check whether backends can be imported and return BackendImports."""
# pylint: disable=unused-variable
results = BackendImports()
try:
from PyQt5 import QtWebKit
from PyQt5 import QtWebKitWidgets
except ImportError as e:
results.webkit_available = False
results.webkit_error = str(e)
else:
if qtutils.is_new_qtwebkit():
results.webkit_available = True
else:
results.webkit_available = False
results.webkit_error = "Unsupported legacy QtWebKit found"
try:
from PyQt5 import QtWebEngineWidgets
except ImportError as e:
results.webengine_available = False
results.webengine_error = str(e)
else:
results.webengine_available = True
assert results.webkit_available is not None
assert results.webengine_available is not None
if not results.webkit_available:
assert results.webkit_error is not None
if not results.webengine_available:
assert results.webengine_error is not None
return results
def _handle_ssl_support(fatal=False):
"""Check for full SSL availability.
If "fatal" is given, show an error and exit.
"""
text = ("Could not initialize QtNetwork SSL support. If you use "
"OpenSSL 1.1 with a PyQt package from PyPI (e.g. on Archlinux "
"or Debian Stretch), you need to set LD_LIBRARY_PATH to the path "
"of OpenSSL 1.0. This only affects downloads.")
if QSslSocket.supportsSsl():
return
if fatal:
errbox = msgbox.msgbox(parent=None,
title="SSL error",
text="Could not initialize SSL support.",
icon=QMessageBox.Critical,
plain_text=False)
errbox.exec_()
sys.exit(usertypes.Exit.err_init)
assert not fatal
log.init.warning(text)
def _check_backend_modules():
"""Check for the modules needed for QtWebKit/QtWebEngine."""
imports = _try_import_backends()
if imports.webkit_available and imports.webengine_available:
return
elif not imports.webkit_available and not imports.webengine_available:
text = ("<p>qutebrowser needs QtWebKit or QtWebEngine, but neither "
"could be imported!</p>"
"<p>The errors encountered were:<ul>"
"<li><b>QtWebKit:</b> {webkit_error}"
"<li><b>QtWebEngine:</b> {webengine_error}"
"</ul></p>".format(
webkit_error=html.escape(imports.webkit_error),
webengine_error=html.escape(imports.webengine_error)))
errbox = msgbox.msgbox(parent=None,
title="No backend library found!",
text=text,
icon=QMessageBox.Critical,
plain_text=False)
errbox.exec_()
sys.exit(usertypes.Exit.err_init)
elif objects.backend == usertypes.Backend.QtWebKit:
if imports.webkit_available:
return
assert imports.webengine_available
_show_dialog(
backend=usertypes.Backend.QtWebKit,
because="QtWebKit could not be imported",
text="<p><b>The error encountered was:</b><br/>{}</p>".format(
html.escape(imports.webkit_error))
)
elif objects.backend == usertypes.Backend.QtWebEngine:
if imports.webengine_available:
return
assert imports.webkit_available
_show_dialog(
backend=usertypes.Backend.QtWebEngine,
because="QtWebEngine could not be imported",
text="<p><b>The error encountered was:</b><br/>{}</p>".format(
html.escape(imports.webengine_error))
)
# Should never be reached
assert False
def init():
_check_backend_modules()
if objects.backend == usertypes.Backend.QtWebEngine:
_handle_ssl_support()
_handle_wayland()
_nvidia_shader_workaround()
_handle_nouveau_graphics()
else:
assert objects.backend == usertypes.Backend.QtWebKit, objects.backend
_handle_ssl_support(fatal=True)