dnl Copyright © 2010, 2014 Nick Bowler
dnl
dnl License WTFPL2: Do What The Fuck You Want To Public License, version 2.
dnl This is free software: you are free to do what the fuck you want to.
dnl There is NO WARRANTY, to the extent permitted by law.

dnl DX_LIB_GTK2([min-version], [action-if-ok], [action-if-failed])
dnl
dnl Search for a working GTK+-2 installation.  If such a library is found,
dnl appropriate compiler and linker flags are stored in GTK_CFLAGS and
dnl GTK_LIBS, respectively, and the action-if-ok is performed (may be empty).
dnl If no suitable library is found, then action-if-failed is performed if
dnl non-empty, oherwise configure will stop with a fatal error.
AC_DEFUN([DX_LIB_GTK2], [dnl
DX_LIB_SETUP([gtk], [GTK+])dnl
DX_LIB_PKGCONFIG_FLAGS([gtk], [gtk+-2.0])
AC_MSG_CHECKING([for GTK+ at least version m4_default([$1], [2.0])])
DX_LIB_SEARCH_LINK([gtk],
	[m4_apply([_DX_LIB_GTK2_TEST], m4_split([$1], [\.]))],
	[
		[[$GTK_CFLAGS], [$GTK_LIBS]],
		[[$dx_cv_gtk_pkg_cflags], [$dx_cv_gtk_pkg_libs],
			[test x"$dx_cv_gtk_pkg_found" = x"yes"]],
	])
AS_IF([test x"$dx_cv_gtk_lib_found" = x"yes"], [$2],
	[m4_default([$3], [AC_MSG_FAILURE([dnl
GTK+ version m4_default([$1], [2.0]) or newer is required.  The latest
version may be found at <ftp://ftk.gtk.org/>.
m4_newline([DX_LIB_USERFLAG_BLURB([gtk], [GTK+])])
m4_newline([DX_LIB_PKGCONFIG_BLURB([gtk], [GTK+])])
])])])])

dnl Internal test program for GTK+.  Check that the version numbers in the
dnl header are sufficient and that some important functions are defined.
m4_define([_DX_LIB_GTK2_TEST], [AC_LANG_PROGRAM([dnl
#include <gtk/gtk.h>
@%:@if !GTK_CHECK_VERSION(m4_do(
	[m4_default([$1], [2]), ],
	[m4_default([$2], [0]), ],
	[m4_default([$3], [0]))])
DX_LIB_COMPILE_ERROR([insufficient GTK version])
#endif
], [dnl
int argc = 0;
char *arg = NULL;
char **argv = &arg;
gtk_init(&argc, &argv);
gtk_main();
])])