Add HiDPI theme for better scaling, hi-res displays

Install SVG-based HiDPI theme alongside the PNG-based theme.
This should be used for better icon scaling, specifically when
Scaling is set to 2x or 3x. PNG may be a bit faster to load,
so the SVG HiDPI theme is optional.

Using the HiDPI theme will fix issues where the wrong icons are shown in
some places with scaling enabled (like the Places sidebars in file managers).
It should also fix and blurry icon issues, especially with scaling enabled.
The PNG non-HiDPI theme restricted the amount of zoom steps the icons had
in file managers with scaling enabled, so this should resolve that as well.

Fixes shimmerproject#124
Fixes shimmerproject#317
Fixes shimmerproject#362
Fixes shimmerproject#403

Makefile.in

@@ -13,16 +13,19 @@ install:
 	install -d $(DESTDIR)/$(PREFIX)/share/icons
 	cp -rf build/elementary-xfce $(DESTDIR)/$(PREFIX)/share/icons
 	cp -rf build/elementary-xfce-dark $(DESTDIR)/$(PREFIX)/share/icons
+	cp -rf build/elementary-xfce-hidpi $(DESTDIR)/$(PREFIX)/share/icons;
 	@echo
 	@echo The icon-theme cache has not yet been regenerated, which means your changes may not be visible yet. Please run 'make icon-caches' next.
 
 uninstall:
 	rm -rf $(DESTDIR)/$(PREFIX)/share/icons/elementary-xfce
 	rm -rf $(DESTDIR)/$(PREFIX)/share/icons/elementary-xfce-dark
+	rm -rf $(DESTDIR)/$(PREFIX)/share/icons/elementary-xfce-hidpi
 
 icon-caches:
 	gtk-update-icon-cache -f $(DESTDIR)/$(PREFIX)/share/icons/elementary-xfce
 	gtk-update-icon-cache -f $(DESTDIR)/$(PREFIX)/share/icons/elementary-xfce-dark
+	gtk-update-icon-cache -f $(DESTDIR)/$(PREFIX)/share/icons/elementary-xfce-hidpi
 
 test: builddir $(SUBDIRS)
 	chmod +x ./svgtopng/pngtheme.sh
@@ -41,6 +44,13 @@ builddir:
 	rm build/elementary-xfce/CONTRIBUTORS && cp CONTRIBUTORS build/elementary-xfce
 	rm build/elementary-xfce/LICENSE && cp LICENSE build/elementary-xfce
 	rm build/elementary-xfce/README.md && cp README.md build/elementary-xfce
+	mkdir -p build/elementary-xfce-hidpi && cp -R elementary-xfce/. build/elementary-xfce-hidpi
+	mv build/elementary-xfce-hidpi/index-hidpi.theme build/elementary-xfce-hidpi/index.theme
+	rm build/elementary-xfce-hidpi/AUTHORS && cp AUTHORS build/elementary-xfce-hidpi
+	rm build/elementary-xfce-hidpi/CONTRIBUTORS && cp CONTRIBUTORS build/elementary-xfce-hidpi
+	rm build/elementary-xfce-hidpi/LICENSE && cp LICENSE build/elementary-xfce-hidpi
+	rm build/elementary-xfce-hidpi/README.md && cp README.md build/elementary-xfce-hidpi
+	find build/elementary-xfce-hidpi -mindepth 1 -maxdepth 1 -type d -exec sh -c "ln -sr '{}' '{}'@2x" \; -exec sh -c "ln -sr '{}' '{}'@3x" \;
 
 .PHONY: all $(SUBDIRS)