Re: [PATCH v5 0/1] MR11178: winewayland: Implement xdg-popup for unmanaged windows.

[Etaash Mathamsetty (＠etaash.mathamsetty)]

On Sat Jun 20 08:08:58 2026 +0000, Rémi Bernon wrote:
> Any reason we don't simply use xdg_popup instead of subsurface? IIUC
> this is only there for the case owner itself is a subsurface, but if
> every surface was an xdg_surface (eventually xdg_popup) we wouldn't need
> the subsurface case?
Windows' child windows map almost perfectly to wayland subsurfaces. And xdg-popup is intended to be a temporary.
Few other reasons:
1. Alpha modifier on the toplevel is only applied on subsurfaces not popups. (The spec wording doesn't say this, but it's supposed to. I'll make a MR to Wayland protocols eventually)
2. When a toplevel is unmapped or roleless (no WS_VISIBLE) during initialization but an app creates child windows on it we can still utilize subsurfaces to configure the window so when the toplevel gains WS_VISIBLE all the subsurfaces are set up. (At least this is how I assume windows would work too, but I'm not sure)
3. xdg-popup has issues on compositors wrt keeping the windows together. For example on kwin if I minimize a window with a pop-up open then the pop-up doesn't minimize with the toplevel. This is a compositor bug afaik but numerous compositors share this bug. If we try to use subsurfaces in the cases where it makes sense we avoid problems.

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https://gitlab.winehq.org/wine/wine/-/merge_requests/11178#note_143753