* java/org/gnu/emacs/EmacsNative.java (setEmacsParams): New arg
UIMODE.
(sendConfigurationChanged): New args DETAIL and UI_MODE.
* java/org/gnu/emacs/EmacsNoninteractive.java (main1): Provide
an undefined UI mode.
* java/org/gnu/emacs/EmacsService.java (EmacsService): New field
uiMode.
(onCreate): Initialize this field at start-up and provide the
same to setEmacsParams.
(onConfigurationChanged): If the UI mode has been altered,
generate a configuration changed event to match.
* src/android.c (android_ui_mode): New variable.
(setEmacsParams): New argument UI_MODE. Initialize the same
from this variable.
* src/androidgui.h (enum android_configuration_changed): New
enum.
(struct android_configuration_changed_event): New field
`DETAIL'. Convert fields providing specifics into a union of
display density information and a UI mode integer.
* src/androidterm.c (handle_one_android_event): Handle both
manners of configuration change events.
(android_term_init): Initialize Vtoolkit_theme from UI mode
provided at start-up.
* src/frame.c (syms_of_frame): Always define Vtoolkit_theme.
Define Qtoolkit_theme_set_functions.
* src/gtkutil.c (xg_update_dark_mode_for_all_displays):
* src/w32term.c (w32_read_socket): Generate special toolkit
theme events, rather than executing hooks directly within the
read_socket callback.
* src/keyboard.c (kbd_buffer_get_event)
<TOOLKIT_THEME_CHANGED_EVENT>: Run Qtoolkit_theme_set_functions
and set Vtoolkit_theme from event->ie.arg.
* src/termhooks.h (enum event_kind): New event
TOOLKIT_THEME_CHANGED_EVENT.