
The POINTER_EMULATED flag was a convenience to filter either side of smooth/discrete events that we should ignore based on the source. This distinction was challenged, first by v120 mice that use Clutter smooth events to deliver semi-discrete changes, second by commit e0c4b2b241 ("backends/native: Mark the emulated smooth scroll event as such") which made the smooth events be flagged as emulated, and the discrete whole-step events marked as real. This distinction feels convenient for the time being, since upper layers might be confused by real smooth scroll events without finish flags. Adapt to this change at MetaWaylandPointer so that we drop the POINTER_EMULATED check, and the events are perhaps filtered based on their source and the preferred wl_seat version of the client that we are talking to. This handles the whole grid of combinations: - wheel sources with wl_seat >=8 result in wl_pointer.axis_value120 from "emulated" smooth scroll events, with value120 information. - wheel sources with wl_seat < 8 result in wl_pointer.axis_discrete from "real" discrete scroll events. - finger/continuous sources prefer smooth events. Previously, always non-emulated for those. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3642>
Mutter
Mutter is a Wayland display server and X11 window manager and compositor library.
When used as a Wayland display server, it runs on top of KMS and libinput. It implements the compositor side of the Wayland core protocol as well as various protocol extensions. It also has functionality related to running X11 applications using Xwayland.
When used on top of Xorg it acts as a X11 window manager and compositing manager.
It contains functionality related to, among other things, window management, window compositing, focus tracking, workspace management, keybindings and monitor configuration.
Internally it uses a fork of Cogl, a hardware acceleration abstraction library used to simplify usage of OpenGL pipelines, as well as a fork of Clutter, a scene graph and user interface toolkit.
Mutter is used by, for example, GNOME Shell, the GNOME core user interface, and by Gala, elementary OS's window manager. It can also be run standalone, using the command "mutter", but just running plain mutter is only intended for debugging purposes.
Contributing
To contribute, open merge requests at https://gitlab.gnome.org/GNOME/mutter.
It can be useful to first look at the GNOME Handbook and the documentation and API references below first.
Documentation
- Coding style and conventions
- Git conventions
- Code overview
- Building and Running
- Debugging
- Monitor configuration
API Reference
- Meta: https://mutter.gnome.org/meta/
- Clutter: https://mutter.gnome.org/clutter/
- Cally: https://mutter.gnome.org/cally/
- Cogl: https://mutter.gnome.org/cogl/
- CoglPango: https://mutter.gnome.org/cogl-pango/
- Mtk: https://mutter.gnome.org/mtk/
License
Mutter is distributed under the terms of the GNU General Public License, version 2 or later. See the COPYING file for detalis.