demo: add icon

demos/gtk-demo/Makefile.am

@@ -143,6 +143,35 @@ RESOURCES=	$(demos)			\
 		cssview.css			\
 		reset.css
 
+iconthemedir = $(datadir)/icons/hicolor
+
+appsicon16dir = $(iconthemedir)/16x16/apps
+appsicon22dir = $(iconthemedir)/22x22/apps
+appsicon24dir = $(iconthemedir)/24x24/apps
+appsicon32dir = $(iconthemedir)/32x32/apps
+appsicon48dir = $(iconthemedir)/48x48/apps
+appsicon256dir = $(iconthemedir)/256x256/apps
+
+dist_appsicon16_DATA = data/16x16/gtk3-demo.png
+dist_appsicon22_DATA = data/22x22/gtk3-demo.png
+dist_appsicon24_DATA = data/24x24/gtk3-demo.png
+dist_appsicon32_DATA = data/32x32/gtk3-demo.png
+dist_appsicon48_DATA = data/48x48/gtk3-demo.png
+dist_appsicon256_DATA = data/256x256/gtk3-demo.png
+
+update_icon_cache = gtk-update-icon-cache --ignore-theme-index --force
+
+install-data-hook: install-update-icon-cache
+uninstall-hook: uninstall-update-icon-cache
+
+install-update-icon-cache:
+	$(AM_V_at)$(POST_INSTALL)
+	test -n "$(DESTDIR)" || $(update_icon_cache) "$(iconthemedir)"
+
+uninstall-update-icon-cache:
+	$(AM_V_at)$(POST_UNINSTALL)
+	test -n "$(DESTDIR)" || $(update_icon_cache) "$(iconthemedir)"
+
 DISTCLEANFILES = demos.h
 
 -include $(top_srcdir)/git.mk