>I am not sure if the protocol guarantees when >`wl_surface::preferred_buffer_scale` is sent (or >`wp_fractional_scale_v1::preferred_scale` in fractional scale case)
They will always come before the xdg_shelll.configure event. It is documented in xdg_surface top level comment ``` The compositor will reply with initial wl_surface state such as wl_surface.preferred_buffer_scale followed by an xdg_surface.configure event. The client must acknowledge it and is then allowed to attach a buffer to map the surface. ``` (https://wayland.app/protocols/xdg-shell#xdg_surface) In Qt client terms, the QExposeEvent is driven by the first xdg_shelll.configure event arriving. There is no need for additional round trips. Technically speaking a roundtrip is also not a guarantee that the event will have been delivered. David -- Development mailing list [email protected] https://lists.qt-project.org/listinfo/development
