During the past years (and especially last cycle) I’ve worked to push a number of features upstream from Builder into GtkSourceView. Not only does this improve the ecosystem for all applications, but it reduces the number of things we need to maintain downstream in Builder as we move to GTK 4.
That included a new completion engine, a new snippet engine with tooltips based on expansion points, updated gutter and gutter renderer designs, the editor overview map, background patterns, sysprof tracing integration, and most recently interactive tooltips.
You can read our nightly generated documentation to learn about it. In particular, GtkSourceHover is attached to the
GtkSourceView and can have GtkSourceHoverProviders registered with it. Implementing that interface will be familiar to those who’ve implemented completion providers, as they work in a similar way.
This came from Builder where we have interactive tooltips for things like breakpoints, documentation, and symbol information. Other applications using GtkSourceView may find it useful when implementing Language Server Protocol’s hover providers.