Compatibility layers

Posted Jan 18, 2026 9:39 UTC (Sun) by swilmet (subscriber, #98424)
In reply to: GTK-2-on-3 wrapper by gioele
Parent article: Debian discusses removing GTK 2 for forky

The GTK project removes *all* deprecated API in the next major version. So to ease the port, compatibility layers could be created for some features.

For example GtkTreeView (tree and list widget, quite a complex beast) is deprecated in GTK 4, so it'll go away in GTK 5. GtkTreeView could be maintained in a separate module to still provide that API for GTK 5.

The same for GtkUIManager (deprecated in GTK 3 and so removed from GTK 4). It could be maintained for GTK 4 as a compatibility layer.

Perhaps it's time to create a gtk-legacy module. Classic desktop environments (Cinnamon and its X-apps, or MATE) would benefit from it.

Another, complementary way would be a gtk-future module, back-porting some new APIs to a previous major version.