We now let the Installer to call the TextInputSources API. Since macOS
12, users are prompted to allow enabling of third-party IMEs in
Preferences.app the momemnt TISRegisterInputSource or
TISEnableInputSource is called. By moving the activation to the
Installer, a user will clearly see that it's the Installer that wants to
enable the IME.
In addition, we had to make necessary changes so that on macOS 12 and
later, the Installer always enable the default input source. This is due
to the observation that the kTISPropertyInputSourceIsEnabled becomes
unreliable on macOS 12--it may be true even if the user has removed the
input mode from their active input mode list in Preferences.app.
Lukhnos Liu
zonble
Mengjuei