bug#31880: 26.1; VC mode line popup when clicked is off screen

[Robert Pluim <rpluim@gmail.com>]

martin rudalics <rudalics@gmx.at> writes:

>> Yet another instance of a disagreement between how GTK and X calculate
>> pixels. Who will rid me of this turbulent mix?
>
> In xg_show_tooltip we have
>
>       gtk_window_move (x->ttip_window, root_x / xg_get_scale (f),
> 		       root_y / xg_get_scale (f));
>
> I suppose this is TRT with a scaled display because root_x and root_y
> are unscaled and hence we have to scale them to get the appropriate
> coordinates for scaled displays.  Right?
>
> Then what happens when we turn off GTK tooltips on a scaled display by
> setting 'x-gtk-use-system-tooltips' to nil?  IIUC the tooltip will now
> appear at the "wrong" position.  Or am I missing something?

When not using GTK tooltips, we end up using XMoveResizeWindow (near
the end of Fx_show_tip), which wants device pixel positions, which is
what compute_tip_xy produces, so the tooltip appears in the right
place.

Robert