a59a992daa
StScrollView applies the policy of whether to show or hide the scroll bar, and with the AUTOMATIC policy the scroll bar should be hidden as soon as the content of the scroll view is small enough to fit without scrolling. Now we only know about the final size of the content when we're inside st_scroll_view_allocate(), so that's where we can decide whether the scroll bar should be visible or not. Clutter really doesn't like calling clutter_actor_show/hide() in the middle of an allocation cycle though, so what we do instead is saving the state into priv->vscrollbar_visible, and then just not painting the scroll bar based on that in a paint() vfunc override. This approach is not great for several reasons, it means we also have to override pick() and finally it means the paint volume of the scroll bar is incorrect. While the greatest solution to this would be to just hide/show the scroll bar inside the allocate() function as it is possible in gtk, we have an established pattern for this kind of case too: We usually allocate a 0-sized rect for the thing we want to hide, so let's do that instead. A nice side effect is that we can conveniently drop another paint() and pick() vfunc override. Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2190>
GNOME Shell
GNOME Shell provides core user interface functions for the GNOME desktop, like switching to windows and launching applications. GNOME Shell takes advantage of the capabilities of modern graphics hardware and introduces innovative user interface concepts to provide a visually attractive and easy to use experience.
For more information about GNOME Shell, including instructions on how to build GNOME Shell from source and how to get involved with the project, see the project wiki.
Bugs should be reported to the GNOME bug tracking system. Please refer to the Schedule wiki page to see the supported versions.
Contributing
To contribute, open merge requests at https://gitlab.gnome.org/GNOME/gnome-shell.
Commit messages should follow the GNOME commit message
guidelines. If a merge request
fixes an existing issue, it is good practice to append the full issue URL
to each commit message. Try to always prefix commit subjects with a relevant
topic, such as panel: or status/network:, and it's always better to write
too much in the commit message body than too little.
Default branch
The default development branch is main. If you still have a local
checkout under the old name, use:
git checkout master
git branch -m master main
git fetch
git branch --unset-upstream
git branch -u origin/main
git symbolic-ref refs/remotes/origin/HEAD refs/remotes/origin/main
License
GNOME Shell is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for details.