timeLimitsManager: Add new state machine for screen time limits
This implements wellbeing screen time limits in gnome-shell. It depends on a few changes in other modules:
- New settings schemas in gsettings-desktop-schemas
- A settings UI in gnome-control-center
- User documentation in gnome-user-docs
It implements the design from https://gitlab.gnome.org/Teams/Design/settings-mockups/-/blob/master/wellbeing/wellbeing.png.
The core of the implementation is TimeLimitsManager, which is a state
machine which uses the user’s session state from logind to track how long
the user has been in an active session, in aggregate, during the day. If
this total exceeds their limit for the day, the state machine changes
state.
The user’s session activity history (basically, when they logged in and out for the past 14 weeks) is kept in a state file in their home directory. This is used by gnome-shell to count usage across reboots in a single day, and in the future it will also be used to provide usage history in gnome-control-center, so the user can visualise their historic computer usage at a high level, for the past several weeks.
The TimeLimitsDispatcher is based on top of this, and controls showing
notifications and screen fades to make the user aware of whether they’ve
used the computer for too long today, as per their preferences.
Unit tests are included to check that TimeLimitsManager works, in
particular with its loading and storing of the history file. The unit
tests provide mock implementations of basic GLib clock functions, the
logind D-Bus proxy and Gio.Settings in order to test the state machine in
faster-than-real-time.
Signed-off-by: Philip Withnall pwithnall@gnome.org