Some actions may be performed when scrcpy exits, currently:
- disable "show touches"
- restore "stay on while plugged in"
- power off screen
- restore "power mode" (to disable "turn screen off")
They are performed from a separate process so that they can be executed
even when scrcpy-server is killed (e.g. if the device is unplugged).
The clean up actions to perform were configured when scrcpy started.
Given that there is no method to read the current "power mode" in
Android, and that "turn screen off" can be applied at any time using an
scrcpy shortcut, there was no way to determine if "power mode" had to be
restored on exit. Therefore, it was always restored to "normal", even
when not necessary.
However, setting the "power mode" is quite fragile on some devices, and
may cause some issues, so it is preferable to call it only when
necessary (when "turn screen off" has actually been called).
For that purpose, make the scrcpy-server main process and the clean up
process communicate the actions to perform over a pipe (stdin/stdout),
so that they can be changed dynamically. In particular, when the power
mode is changed at runtime, notify the clean up process.
Refs 1beec99f8283713b1fbf0b3704eb4dceecc9a590
Refs #4456 <https://github.com/Genymobile/scrcpy/issues/4456>
Refs #4624 <https://github.com/Genymobile/scrcpy/issues/4624>
PR #4649 <https://github.com/Genymobile/scrcpy/pull/4649>
9efa162949