gtk-demo: Split out demo sources from Makefile.am

This way, we can share the demo listing to be used in other build
Makefile-based build systems, such as the auxiliary NMake Makefiles used
to generate the various sources.

demos/gtk-demo/Makefile.am

@@ -1,87 +1,15 @@
 ## Makefile.am for gtk+/demos
 include $(top_srcdir)/Makefile.decl
-
+include $(srcdir)/demos-sources.mak
-## These should be in the order you want them to appear in the
-## demo app, which means alphabetized by demo title, not filename
-demos_base =					\
-	application_demo.c			\
-	assistant.c				\
-	builder.c				\
-	button_box.c				\
-	changedisplay.c				\
-	clipboard.c				\
-	colorsel.c				\
-	combobox.c				\
-	css_accordion.c                         \
-	css_basics.c				\
-	css_blendmodes.c			\
-	css_multiplebgs.c			\
-	css_pixbufs.c				\
-	css_shadows.c				\
-	cursors.c				\
-	dialog.c				\
-	drawingarea.c				\
-	editable_cells.c			\
-	entry_buffer.c				\
-	entry_completion.c			\
-	event_axes.c				\
-	expander.c  				\
-        filtermodel.c				\
-	fishbowl.c				\
-	foreigndrawing.c			\
-	gestures.c				\
-	glarea.c				\
-	headerbar.c				\
-	hypertext.c				\
-	iconview.c				\
-	iconview_edit.c				\
-	images.c				\
-	infobar.c				\
-	links.c					\
-	listbox.c				\
-	flowbox.c				\
-	list_store.c				\
-	markup.c				\
-	menus.c					\
-	modelbutton.c				\
-	offscreen_window.c			\
-	offscreen_window2.c			\
-	overlay.c				\
-	overlay2.c				\
-	paint.c					\
-	panes.c					\
-	pickers.c				\
-	pixbufs.c				\
-	popover.c				\
-	printing.c				\
-	revealer.c				\
-	rotated_text.c				\
-	scale.c					\
-	search_entry.c				\
-	search_entry2.c				\
-	shortcuts.c				\
-	sidebar.c				\
-	sizegroup.c				\
-	spinbutton.c				\
-	spinner.c				\
-	stack.c					\
-	tabs.c					\
-	textmask.c				\
-	textview.c				\
-	textscroll.c				\
-	theming_style_classes.c			\
-	toolpalette.c				\
-	transparent.c				\
-	tree_store.c
 
 demos_opt =
 
 if BUILD_FONT_DEMO
-demos_opt += font_features.c
+demos_opt += $(font_features_demo)
 endif
 
 if OS_UNIX
-demos_opt += pagesetup.c
+demos_opt += $(page_setup_demo)
 endif
 
 demos = $(demos_base) $(demos_opt)

demos/gtk-demo/demos-sources.mak

@@ -0,0 +1,75 @@
+## These should be in the order you want them to appear in the
+## demo app, which means alphabetized by demo title, not filename
+demos_base =					\
+	application_demo.c			\
+	assistant.c				\
+	builder.c				\
+	button_box.c				\
+	changedisplay.c				\
+	clipboard.c				\
+	colorsel.c				\
+	combobox.c				\
+	css_accordion.c                         \
+	css_basics.c				\
+	css_blendmodes.c			\
+	css_multiplebgs.c			\
+	css_pixbufs.c				\
+	css_shadows.c				\
+	cursors.c				\
+	dialog.c				\
+	drawingarea.c				\
+	editable_cells.c			\
+	entry_buffer.c				\
+	entry_completion.c			\
+	event_axes.c				\
+	expander.c  				\
+        filtermodel.c				\
+	fishbowl.c				\
+	foreigndrawing.c			\
+	gestures.c				\
+	glarea.c				\
+	headerbar.c				\
+	hypertext.c				\
+	iconview.c				\
+	iconview_edit.c				\
+	images.c				\
+	infobar.c				\
+	links.c					\
+	listbox.c				\
+	flowbox.c				\
+	list_store.c				\
+	markup.c				\
+	menus.c					\
+	modelbutton.c				\
+	offscreen_window.c			\
+	offscreen_window2.c			\
+	overlay.c				\
+	overlay2.c				\
+	paint.c					\
+	panes.c					\
+	pickers.c				\
+	pixbufs.c				\
+	popover.c				\
+	printing.c				\
+	revealer.c				\
+	rotated_text.c				\
+	scale.c					\
+	search_entry.c				\
+	search_entry2.c				\
+	shortcuts.c				\
+	sidebar.c				\
+	sizegroup.c				\
+	spinbutton.c				\
+	spinner.c				\
+	stack.c					\
+	tabs.c					\
+	textmask.c				\
+	textview.c				\
+	textscroll.c				\
+	theming_style_classes.c			\
+	toolpalette.c				\
+	transparent.c				\
+	tree_store.c
+
+font_features_demo = font_features.c
+page_setup_demo = pagesetup.c