Since we are on a mission to eliminate as much GTK and GLib code as possible, how about directly interfacing with the StatusNotifierItem interface, and using the org.gtk.Menu/com.canonical.dbusmenu interfaces for menus instead of the Ayatana Indicators library and GTK? Also the StatusNotifierItem interfaces allow us to include ARGB pixmaps directly (example: org.freedesktop.StatusNotifierItem.IconPixmap), avoiding the use of temporary files or messing with icon themes and they also include support for tooltips (org.freedesktop.StatusNotifierItem.ToolTip)

Supporting X11 desktops that only have support for the legacy systray protocol or desktops that dont support the menu-over-DBus protocols is a dilemma though, but I do have a solution as previously discussed in the closed PR.

Also, see the new GTK-free, pure GLib implementation of the Ayatana indicators library for details and help: https://github.com/AyatanaIndicators/libayatana-appindicator-glib