The Blockers For GTK4: Constraint-Based Layout, Finished OpenGL Renderer & More

At last week's annual GUADEC GNOME developer conference, the state of the GTK4 tool-kit was a hot discussion item.

Red Hat's Matthias Clasen has written a new GTK+ blog-post to discuss the happenings from the developer meetings last week. When it comes to the current GTK3, they are going to focus on API stability now but will introduce new APIs where worthwhile like in the areas of color emoji support and client/server-side negotiation protocol support for Wayland.

For GTK4 they have come up with a list of blocker items to finish before they can think about releasing GTK+ 4.0. Those blocker items include finishing a constraint-based layout, support for defining states/transitions in UI files, designer support, converting keyboard handling to event controllers, non-fallback text rendering, finished the OpenGL renderer, clean support for sub-surfaces in GDK, no more root windows in GDK, and cleaning up the event code.

The OpenGL renderer for GTK4 has fallen behind with the work so far focusing on their shiny new Vulkan renderer. Thus they need to get their OpenGL renderer back up to speed, abstracting common parts, and porting more code to its OpenGL equivalent from Vulkan. In the future they may also end up introducing a legacy OpenGL/GLES renderer and a modern OpenGL implementation, but not initially.

More details on this GTK4 progress via the GTK.org blog.