[gegl-gtk] build: fix build of vala example when gegl-gtk is not installed

[Øyvind Kolås <ok src gnome org>]

commit eb1057b76bf05417234ba1428d5f542d864813db
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Wed Feb 21 13:42:22 2018 +0100

    build: fix build of vala example when gegl-gtk is not installed

 configure.ac              |    5 +++--
 examples/vala/Makefile.am |   26 ++++++++++++++++----------
 2 files changed, 19 insertions(+), 12 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 5cc0efa..4844a14 100644
--- a/configure.ac
+++ b/configure.ac
@@ -262,11 +262,12 @@ AC_SUBST([GIRDIR])
 # Check Vala
 ########################
 
-AC_ARG_WITH(vala, [  --enable-vala           build with Vala support])
+AC_ARG_WITH(vala, [  --without-vala          build with Vala support])
 
 have_vapigen="no"
-if test "x$enable_vala" == "xyes"; then
+if test "x$enable_vala" != "xno"; then
 
+  AM_PROG_VALAC([0.34.0])
   AC_PATH_PROG(VAPIGEN, vapigen, no)
   if test "$VAPIGEN" = "no"; then
     have_vapigen="no  (vapigen executable not found)"
diff --git a/examples/vala/Makefile.am b/examples/vala/Makefile.am
index 1392955..49ba7f3 100644
--- a/examples/vala/Makefile.am
+++ b/examples/vala/Makefile.am
@@ -1,19 +1,25 @@
 
 if HAVE_VALA
 
-VALA_FILES = $(wildcard $(srcdir)/*.vala)
-EXTRA_DIST = $(VALA_FILES)
-bins   = $(subst $(srcdir)/,,$(VALA_FILES:.vala=))
+bin_PROGRAMS = gegl-gtk-basic
 
-vapi_dir = ../../gegl-gtk
-vala_pkg = gegl-gtk@GEGL_GTK_GTK_VERSION@-@GEGL_GTK_API_VERSION@
+gegl_gtk_basic_CFLAGS = \
+       $(GEGL_CFLAGS) \
+       $(GTK_CFLAGS) \
+       -I$(top_builddir)/gegl-gtk \
+       -I$(top_srcdir)/gegl-gtk
 
-all-local: $(bins)
+gegl_gtk_basic_LDFLAGS = \
+       $(GEGL_LIBS) \
+       $(GTK_LIBS) \
+       $(top_builddir)/gegl-gtk/libgegl-gtk@GEGL_GTK_GTK_VERSION@-@GEGL_GTK_API_VERSION@.la
 
-gegl-gtk-basic: gegl-gtk-basic.vala $(vapi_dir)/$(vala_pkg).vapi
-       valac --pkg $(vala_pkg) --vapidir=@VAPIDIR@ --vapidir=$(vapi_dir) -o $@ $< 
+gegl_gtk_basic_SOURCES = \
+       gegl-gtk-basic.vala
 
-clean-local:
-       rm -f $(bins)
+gegl_gtk_basic_VALAFLAGS = \
+       --vapidir=$(top_builddir)/gegl-gtk \
+       --vapidir=$(top_srcdir)/gegl-gtk \
+       --pkg gegl-gtk@GEGL_GTK_GTK_VERSION@-@GEGL_GTK_API_VERSION@
 
 endif # HAVE_VALA