* configure.in (HAVE_GCONF): Allow both HAVE_GCONF and HAVE_GSETTINGS.

* lisp/dynamic-setting.el (dynamic-setting-handle-config-changed-event): 
Update doc string.

* src/xsettings.c: Use both GConf and GSettings if both are available.
(store_config_changed_event): Add comment.
(dpyinfo_valid, store_font_name_changed, map_tool_bar_style)
(store_tool_bar_style_changed): New functions.
(store_monospaced_changed): Add comment. Call dpyinfo_valid.
(struct xsettings): Move font inside HAVE_XFT.
(GSETTINGS_TOOL_BAR_STYLE, GSETTINGS_FONT_NAME): New defines.
(GSETTINGS_MONO_FONT): Renamed from SYSTEM_MONO_FONT.
Move inside HAVE_XFT.
(something_changed_gsettingsCB): Renamed from something_changedCB.
Check for changes in GSETTINGS_TOOL_BAR_STYLE and GSETTINGS_FONT_NAME
also.
(GCONF_TOOL_BAR_STYLE, GCONF_FONT_NAME): New defines.
(GCONF_MONO_FONT): Renamed from SYSTEM_MONO_FONT. Move inside HAVE_XFT.
(something_changed_gconfCB): Renamed from something_changedCB.
Check for changes in GCONF_TOOL_BAR_STYLE and GCONF_FONT_NAME also.
(parse_settings): Move check for font inside HAVE_XFT.
(read_settings, apply_xft_settings): Add comment.
(read_and_apply_settings): Add comment.  Call map_tool_bar_style and
store_tool_bar_style_changed.  Move check for font inside HAVE_XFT and
call store_font_name_changed.
(xft_settings_event): Add comment.
(init_gsettings): Add comment.  Get values for GSETTINGS_TOOL_BAR_STYLE
and GSETTINGS_FONT_NAME.  Move check for fonts within HAVE_XFT.
(init_gconf): Add comment.  Get values for GCONF_TOOL_BAR_STYLE
and GCONF_FONT_NAME.  Move check for fonts within HAVE_XFT.
(xsettings_initialize): Call init_gsettings last.
(xsettings_get_system_font, xsettings_get_system_normal_font): Add
comment.

No need to define when HAVE_GSETTINGS || !HAVE_XFT.

(wait_reading_process_output): Add defined (HAVE_GSETTINGS) for
xg_select.

* xgselect.c: Add defined (HAVE_GSETTINGS).
(xgselect_initialize): Ditto.

* xsettings.c (store_monospaced_changed): Take new font as arg and
check for change against current_mono_font.
(EMACS_TYPE_SETTINGS): Remove this and related defines.
(emacs_settings_constructor, emacs_settings_get_property)
(emacs_settings_set_property, emacs_settings_class_init)
(emacs_settings_init, gsettings_obj): Remove.
(something_changedCB): New function for HAVE_GSETTINGS.
(something_changedCB): HAVE_GCONF: Call store_monospaced_changed
with value as argument.
(init_gsettings): Check that GSETTINGS_SCHEMA exists before calling
g_settings_new.  Do not create gsettings_obj.
Remove calls to g_settings_bind. Connect something_changedCB to
"changed".

Fixes: debbugs:8967

* xsettings.c: Include glib-object.h, gio/gio.h if HAVE_GSETTINGS.

* configure.in (gsettings): New option and check for GSettings.

* src/Makefile.in (SETTINGS_CFLAGS, SETTINGS_LIBS): Renamed from
GCONF_CFLAGS/LIBS.

* src/xsettings.c: Include glib.h if HAVE_GSETTINGS.
Let HAVE_GSETTINGS override HAVE_GCONF.
(store_monospaced_changed): New function.
(EMACS_SETTINGS): A new type derived from GObject to handle
GSettings notifications.
(emacs_settings_constructor, emacs_settings_get_property)
(emacs_settings_set_property, emacs_settings_class_init):
New functions.
(gsettings_client, gsettings_obj): New variables.
(GSETTINGS_SCHEMA): New define.
(something_changedCB): Call store_monospaced_changed.
(init_gsettings): New function.
(xsettings_initialize): Call init_gsettings.
(syms_of_xsettings): Initialize gsettings_client, gsettings_obj
to NULL.