Add pixbufcache class

All packages exporting pixbuf loaders should inherit this class in order
to generate the correct postinst/postrm scriptlets.

[YOCTO #3852]

(From OE-Core rev: 61afa98f96f5c62473cb2db383b48d3d23c5d7ac)

Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/pixbufcache.bbclass

@@ -0,0 +1,50 @@
+#
+# This class will generate the proper postinst/postrm scriptlets for pixbuf
+# packages.
+#
+
+DEPENDS += "qemu-native"
+inherit qemu
+
+PIXBUF_PACKAGES ??= "${PN}"
+
+#
+# On host, the postinstall MUST return 1 because we do not know if the intercept
+# hook will succeed. If it does succeed, than the packages will be marked as
+# installed.
+#
+pixbufcache_common() {
+if [ "x$D" != "x" ]; then
+	$INTERCEPT_DIR/postinst_intercept update_pixbuf_cache ${PKG} libdir=${libdir} bindir=${bindir}
+	exit 1
+fi
+
+# Update the pixbuf loaders in case they haven't been registered yet
+GDK_PIXBUF_MODULEDIR=${libdir}/gdk-pixbuf-2.0/2.10.0/loaders gdk-pixbuf-query-loaders --update-cache
+
+if [ -x ${bindir}/gtk-update-icon-cache ] && [ -d ${datadir}/icons ]; then
+    for icondir in /usr/share/icons/*; do
+        if [ -d ${icondir} ]; then
+            gtk-update-icon-cache -t -q ${icondir}
+        fi
+    done
+fi
+}
+
+python populate_packages_append() {
+    pixbuf_pkgs = d.getVar('PIXBUF_PACKAGES', True).split()
+
+    for pkg in pixbuf_pkgs:
+        bb.note("adding pixbuf postinst and postrm scripts to %s" % pkg)
+        postinst = d.getVar('pkg_postinst_%s' % pkg, True) or d.getVar('pkg_postinst', True)
+        if not postinst:
+            postinst = '#!/bin/sh\n'
+        postinst += d.getVar('pixbufcache_common', True)
+        d.setVar('pkg_postinst_%s' % pkg, postinst)
+
+        postrm = d.getVar('pkg_postrm_%s' % pkg, True) or d.getVar('pkg_postrm', True)
+        if not postrm:
+            postrm = '#!/bin/sh\n'
+        postrm += d.getVar('pixbufcache_common', True)
+        d.setVar('pkg_postrm_%s' % pkg, postrm)
+}