GenServer that re-resolves the active theme when the OS appearance flips.
Started automatically by use Mob.App. Subscribes to Mob.Device
:appearance and, on :color_scheme_changed, calls Mob.Theme.set/1
again with the theme the app registered as its "follow OS" theme (via
register_adaptive/1), but only while the active theme was set from that
module. Any other active theme stays put.
Which Mob.Theme.set/1 calls follow the OS
With MyApp.Theme.Adaptive registered:
Mob.Theme.set(MyApp.Theme.Adaptive)follows the OS.Mob.Theme.set({MyApp.Theme.Adaptive, primary: :rose_500})follows the OS and keeps the overrides on every flip.- A struct (
Mob.Theme.set(MyApp.Theme.Adaptive.theme())), a keyword list, or any other module is a fixed theme: the flip leaves it alone.
Why a GenServer
Mob.Theme.set/1 snapshots the theme into Application env at call
time; subsequent renders read from that env. To track an OS toggle
while the app is foregrounded, something has to listen for the
:appearance event and call set/1 again. A singleton process
fits — apps don't need per-screen handlers, and the framework owns
the wiring end-to-end.
Default registration
Mob.Theme.Adaptive is registered by default, so
Mob.Theme.set(Mob.Theme.Adaptive) (or use Mob.App, theme: Mob.Theme.Adaptive) follows the OS with no further setup. To use a
custom adaptive theme module instead, call
register_adaptive(MyApp.Theme.Adaptive).
Summary
Functions
Returns a specification to start this module under a supervisor.
Register module as the app's follow-OS theme. Whenever a
:color_scheme_changed event arrives while the active theme was set
from module (or {module, overrides}), the watcher calls
Mob.Theme.set/1 with it again to re-resolve.
Functions
Returns a specification to start this module under a supervisor.
See Supervisor.
@spec register_adaptive(module()) :: :ok
Register module as the app's follow-OS theme. Whenever a
:color_scheme_changed event arrives while the active theme was set
from module (or {module, overrides}), the watcher calls
Mob.Theme.set/1 with it again to re-resolve.
@spec start_link(keyword()) :: GenServer.on_start()