Difficulties with Wayland D&D protocol - D&D source persistence

[Martin Stransky]

Hi folks,

I'd like to point out how Wayland D&D protocol limits real life 
applications.

Main limitation is a requirement that D&D source window has to be kept 
opened and D&D is cancelled otherwise.

That's especially painful with popups. See this Mozilla bug and video 
attached there [1].

What's the problem?

- When a popup window is source of D&D (a bookmark entry on the example 
here), we can't close it.

- It's difficult to do D&D to another popup as the source one has to me 
kept opened. That means we need to show popups which are not intended to 
be shown together:
  - if the popups are adjacent, xdg-positoner can be used.
  - if the popups are not adjacent (an example on the clip), 
wl_subsurface popup has to be used with its consequences (buggy 
compositor/gtk3 implementation).

So may be the D&D source persistence condition relaxed?

Thanks,
Martin

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=1797046

-- 
Martin Stransky
Software Engineer / Red Hat, Inc