Make qutebrowser aware of settings requiring a restart

See #3270

doc/help/settings.asciidoc

@@ -254,7 +254,7 @@
 |<<url.searchengines,url.searchengines>>|Search engines which can be used via the address bar.
 |<<url.start_pages,url.start_pages>>|Page(s) to open at the start.
 |<<url.yank_ignored_parameters,url.yank_ignored_parameters>>|URL parameters to strip with `:yank url`.
-|<<window.hide_wayland_decoration,window.hide_wayland_decoration>>|Hide the window decoration when using wayland (requires restart).
+|<<window.hide_wayland_decoration,window.hide_wayland_decoration>>|Hide the window decoration when using wayland.
 |<<window.title_format,window.title_format>>|Format to use for the window title. The same placeholders like for
 |<<zoom.default,zoom.default>>|Default zoom level.
 |<<zoom.levels,zoom.levels>>|Available zoom levels.
@@ -2989,7 +2989,8 @@ Default:
 
 [[window.hide_wayland_decoration]]
 === window.hide_wayland_decoration
-Hide the window decoration when using wayland (requires restart).
+Hide the window decoration when using wayland.
+This setting requires a restart.
 
 Type: <<types,Bool>>
 

qutebrowser/config/configdata.py

@@ -48,6 +48,7 @@ class Option:
     backends = attr.ib()
     raw_backends = attr.ib()
     description = attr.ib()
+    restart = attr.ib(default=False)
 
 
 @attr.s
@@ -190,7 +191,7 @@ def _read_yaml(yaml_data):
     migrations = Migrations()
     data = utils.yaml_load(yaml_data)
 
-    keys = {'type', 'default', 'desc', 'backend'}
+    keys = {'type', 'default', 'desc', 'backend', 'restart'}
 
     for name, option in data.items():
         if set(option.keys()) == {'renamed'}:
@@ -215,7 +216,8 @@ def _read_yaml(yaml_data):
             default=option['default'],
             backends=_parse_yaml_backends(name, backends),
             raw_backends=backends if isinstance(backends, dict) else None,
-            description=option['desc'])
+            description=option['desc'],
+            restart=option.get('restart', False))
 
     # Make sure no key shadows another.
     for key1 in parsed:

qutebrowser/config/configdata.yml

@@ -95,6 +95,7 @@ backend:
       - webengine: Use QtWebEngine (based on Chromium).
       - webkit: Use QtWebKit (based on WebKit, similar to Safari).
   default: webengine
+  restart: true
   desc: >-
     Backend to use to display websites.
 
@@ -109,8 +110,6 @@ backend:
     resource hungry than QtWebKit and has a couple of missing features in
     qutebrowser, but is generally the preferred choice.
 
-    This setting requires a restart.
-
 
 ## qt
 
@@ -123,6 +122,7 @@ qt.args:
     valtype: String
     none_ok: true
   default: []
+  restart: true
   desc: >-
     Additional arguments to pass to Qt, without leading `--`.
 
@@ -130,8 +130,6 @@ qt.args:
     https://peter.sh/experiments/chromium-command-line-switches/ for a list)
     will work.
 
-    This setting requires a restart.
-
 force_software_rendering:
   renamed: qt.force_software_rendering
 
@@ -139,30 +137,29 @@ qt.force_software_rendering:
   type: Bool
   default: false
   backend: QtWebEngine
+  restart: true
   desc: >-
     Force software rendering for QtWebEngine.
 
     This is needed for QtWebEngine to work with Nouveau drivers.
 
-    This setting requires a restart.
-
 qt.force_platform:
   type:
     name: String
     none_ok: true
   default: null
+  restart: true
   desc: >-
     Force a Qt platform to use.
 
     This sets the `QT_QPA_PLATFORM` environment variable and is useful to force
     using the XCB plugin when running QtWebEngine on Wayland.
 
-    This setting requires a restart.
-
 
 qt.highdpi:
   type: Bool
   default: false
+  restart: true
   desc: >-
     Turn on Qt HighDPI scaling.
 
@@ -173,8 +170,6 @@ qt.highdpi:
     As an alternative to this, it's possible to set font sizes and the
     `zoom.default` setting.
 
-    This setting requires a restart.
-
 ## auto_save
 
 auto_save.interval:
@@ -1437,7 +1432,8 @@ url.yank_ignored_parameters:
 window.hide_wayland_decoration:
   type: Bool
   default: false
-  desc: Hide the window decoration when using wayland (requires restart).
+  restart: true
+  desc: Hide the window decoration when using wayland.
 
 window.title_format:
   type:

scripts/dev/src2asciidoc.py

@@ -416,6 +416,8 @@ def _generate_setting_option(f, opt):
     f.write('[[{}]]'.format(opt.name) + "\n")
     f.write("=== {}".format(opt.name) + "\n")
     f.write(opt.description + "\n")
+    if opt.restart:
+        f.write("This setting requires a restart.\n")
     f.write("\n")
     typ = opt.typ.get_name().replace(',', ',')
     f.write('Type: <<types,{typ}>>\n'.format(typ=typ))