On Wed, Sep 6, 2017 at 4:45 PM, Pekka Paalanen <ppaala...@gmail.com> wrote: > Popups (e.g. menus) in Wayland use protocol that provides the server > with: > - the relationship to the window which the popup is for, and > - the input event identity that triggered the popup. > > These are required on Wayland: the parent window is required for > positioning and stacking, and the input event identity determines > whether the popup is valid. > > X11 protocol does not necessarily provide these. On X11, the client > puts a window at x,y and makes an input grab. That's it. > > You would have to infer from x,y and the X11 window stack which X11 > window might be the parent (if it even exists) and guess what input > event might have triggered the popup (there might not be any) to be > able to translate that into Wayland. > > Xwayland would also need to guess that the input grab is related to > showing the window to be able to combine the two actions into a popup > request on Wayland. > > I hope this gives you an idea why it is so hard to try to translate > window management from X11 to Wayland protocol. Writing an X11 window > manager is extremely painful to begin with, making one that can > translate into Wayland is much more painful because of the fundamental > design differences. The "out-of-band" design of putting an X11 WM in a > Wayland compositor and using X11 to manage X11 windows is the > compromise to get things working.
You're absolutely right, X clients will never use Wayland's builtin popup and transient logic, and with all of X's quirks, there will always have to be an X server somewhere. Where does the whole construction fail if the little bit of XWM logic is in Xwayland? Going a little farther, I'm imagining toplevel X client windows, clients isolated or not, arranged in the (essentially arbitrary and virtual) X coordinate space such that none overlap, each corresponding with a wl_surface, with everything on top done by the X server and/or via subsurfaces. That leaves the little WM shim dealing with decoration if required, close, resize, and grabs. How the compositor positions or stacks is irrelevant. Cheers, Joseph _______________________________________________ wayland-devel mailing list wayland-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/wayland-devel
