Add a backend warning when using QtWebKit

qutebrowser/app.py

@@ -53,7 +53,7 @@
 from qutebrowser.keyinput import macros
 from qutebrowser.mainwindow import mainwindow, prompt
 from qutebrowser.misc import (readline, ipc, savemanager, sessions,
-                              crashsignal, earlyinit)
+                              crashsignal, earlyinit, objects)
 from qutebrowser.misc import utilcmds  # pylint: disable=unused-import
 from qutebrowser.utils import (log, version, message, utils, qtutils, urlutils,
                                objreg, usertypes, standarddir, error, debug)
@@ -202,7 +202,7 @@ def _process_args(args):
 
     process_pos_args(args.command)
     _open_startpage()
-    _open_quickstart(args)
+    _open_special_pages(args)
 
     delta = datetime.datetime.now() - earlyinit.START_TIME
     log.init.debug("Init finished after {}s".format(delta.total_seconds()))
@@ -319,23 +319,40 @@ def _open_startpage(win_id=None):
                     tabbed_browser.tabopen(url)
 
 
-def _open_quickstart(args):
-    """Open quickstart if it's the first start.
+def _open_special_pages(args):
+    """Open special notification pages which are only shown once.
+
+    Currently this is:
+      - Quickstart page if it's the first start.
+      - Legacy QtWebKit warning if needed.
 
     Args:
         args: The argparse namespace.
     """
     if args.basedir is not None:
-        # With --basedir given, don't open quickstart.
+        # With --basedir given, don't open anything.
         return
+
     state_config = objreg.get('state-config')
-    try:
-        quickstart_done = state_config['general']['quickstart-done'] == '1'
-    except KeyError:
-        quickstart_done = False
+    tabbed_browser = objreg.get('tabbed-browser', scope='window',
+                                window='last-focused')
+
+    # Legacy QtWebKit warning
+
+    needs_warning = (objects.backend == usertypes.Backend.QtWebKit and
+                     not qtutils.is_qtwebkit_ng())
+    warning_shown = state_config['general'].get('backend-warning-shown') == '1'
+
+    if not warning_shown and needs_warning:
+        tabbed_browser.tabopen(QUrl('qute://backend-warning'),
+                               background=False)
+        state_config['general']['backend-warning-shown'] = '1'
+
+    # Quickstart page
+
+    quickstart_done = state_config['general'].get('quickstart-done') == '1'
+
     if not quickstart_done:
-        tabbed_browser = objreg.get('tabbed-browser', scope='window',
-                                    window='last-focused')
         tabbed_browser.tabopen(
             QUrl('https://www.qutebrowser.org/quickstart.html'))
         state_config['general']['quickstart-done'] = '1'

qutebrowser/browser/qutescheme.py

@@ -30,6 +30,7 @@
 import time
 import urllib.parse
 import datetime
+import pkg_resources
 
 from PyQt5.QtCore import QUrlQuery, QUrl
 
@@ -431,3 +432,13 @@ def qute_help(url):
     else:
         data = utils.read_file(path)
         return 'text/html', data
+
+
+@add_handler('backend-warning')
+def qute_backend_warning(url):
+    """Handler for qute://backend-warning."""
+    html = jinja.render('backend-warning.html',
+                        distribution=version.distribution(),
+                        Distribution=version.Distribution,
+                        version=pkg_resources.parse_version)
+    return 'text/html', html

qutebrowser/html/backend-warning.html

@@ -0,0 +1,90 @@
+{% extends "styled.html" %}
+
+{% block style %}
+{{super()}}
+.note {
+    font-size: smaller;
+    color: grey;
+}
+
+.mono {
+    font-family: monospace;
+}
+{% endblock %}
+
+{% block content %}
+<h1>Legacy QtWebKit backend</h1>
+
+<span class="note">Note this warning will only appear once. Use <span class="mono">:open
+qute://backend-warning</span> to show it again at a later time.</span>
+
+<p>
+    You're using qutebrowser with the legacy QtWebKit backend. It's still the
+    default until a few remaining issues are sorted out. If you can, it's
+    strongly suggested to switch earlier, as legacy QtWebKit has known security
+    issues and also breaks things on various websites.
+</p>
+
+<h2>Using QtWebEngine instead</h2>
+
+<span class="note">This is usually the better choice if you aren't using Nouveau graphics, and
+don't need any features which are currently unavailable with QtWebEngine (like
+the <span class="mono">qute://settings</span> page or caret browsing).</span>
+
+{% macro install_webengine(package) -%}
+    You should be able to install <span class="mono">{{ package }}</span> and start qutebrowser with <span class="mono">--backend webengine</span> to use the new backend.
+{%- endmacro %}
+
+{% macro please_open_issue() -%}
+    If you know more, please <a href="https://github.com/qutebrowser/qutebrowser/issues/new">open an issue</a>!
+{%- endmacro %}
+
+<p>
+{% if distribution.parsed == Distribution.ubuntu %}
+    {% if distribution.version >= version('17.04') %}
+        {{ install_webengine('python3-pyqt5.qtwebengine') }}
+    {% elif distribution.version >= version('16.04') %}
+        QtWebEngine is only available in Ubuntu's repositories since 17.04, but you can <a href="https://github.com/qutebrowser/qutebrowser/blob/master/INSTALL.asciidoc#installing-qutebrowser-with-tox">install qutebrowser via tox</a> with <span class="mono">tox -e mkvenv-pypi</span> to use the new backend.
+    {% else %}
+        Unfortunately, no easy way is known to install QtWebEngine on Ubuntu &lt; 16.04. {{ please_open_issue() }}
+    {% endif %}
+{% elif distribution.parsed == Distribution.debian %}
+    {% if distribution.version >= version('9') %}
+        {{ install_webengine('python3-pyqt5.qtwebengine') }}
+    {% else %}
+        Unfortunately, no easy way is known to install QtWebEngine on Debian &lt; 9. {{ please_open_issue() }}
+    {% endif %}
+{% elif distribution.parsed in [Distribution.arch, Distribution.manjaro] %}
+    {{ install_webengine('qt5-webengine') }}
+{% elif distribution.parsed == Distribution.void %}
+    {{ install_webengine('python-PyQt5-webengine') }}
+{% elif distribution.parsed == Distribution.fedora %}
+    {{ install_webengine('qt5-qtwebengine') }}
+{% elif distribution.parsed == Distribution.opensuse %}
+    {{ install_webengine('libqt5-qtwebengine') }}
+{% else %}
+    There's no information available for your system. {{ please_open_issue() }}
+{% endif %}
+</p>
+
+<h2>Using QtWebKit-NG instead</h2>
+
+<span class="note" >This is a drop-in replacement for legacy QtWebKit. Note <b>private browsing won't work with it properly</b> until its next release.</span>
+
+<p>
+{% if distribution.parsed == Distribution.debian and distribution.version >= version('9') %}
+    There are unofficial QtWebKit-NG packages <a href="http://repo.paretje.be/unstable/">available</a>.
+{% elif distribution.parsed in [Distribution.ubuntu, Distribution.debian] %}
+    No easy way is known to install QtWebKit-NG on your system.
+    There are unofficial QtWebKit-NG packages <a href="http://repo.paretje.be/unstable/">available</a>, but they are intended for Debian Unstable.
+    {{ please_open_issue() }}
+{% elif distribution.parsed in [Distribution.arch, Distribution.manjaro] %}
+    You should be able to install <span class="mono">qt5-webkit-ng</span> via <span class="mono">pacman</span>.
+{% elif distribution.parsed == Distribution.gentoo %}
+    There's an unofficial <a href="https://gist.github.com/annulen/309569fb61e5d64a703c055c1e726f71">ebuild</a> available.
+{% else %}
+    There's no information available for your system. {{ please_open_issue() }}
+{% endif %}
+</p>
+
+{% endblock %}