Re: mouse-drag-and-drop-region

[Eli Zaretskii <eliz@gnu.org>]

> From: Alex <agrambot@gmail.com>
> Cc: rudalics@gmx.at,  tak.kunihiro@gmail.com,  emacs-devel@gnu.org
> Date: Wed, 15 Nov 2017 16:03:17 -0600
> 
> >> I suppose (display-graphic-p) should be supplied as the 2nd argument to
> >> `tooltip-show', then?
> >
> > display-multi-frame-p is more appropriate.
> 
> That appears to be an alias to `display-graphic-p'.

That's an implementation detail.  But even if it will always remain
the alias, using it still conveys the intent more clearly that
display-graphic-p, don't you agree?

> > But I think the tooltip should not be shown at all on TTY frames, it
> > looks unnecessary and even silly to show the dragged text in the echo
> > area.
> 
> That sounds better.  Though I wonder if tooltips could be shown in TTY
> frames using a method similar to how `x-popup-menu' displays a menu in
> them?

No, it can't.  TTY menus pre-empt the command loop, so they cannot be
shown during mouse-tracking, AFAIR.

> >> I also noticed that when dragging in an X window, the tooltip flickers
> >> quite a bit. Is there any easy remedy for this?
> >
> > We constantly redisplay the tooltip frame, don't we?  Or does this
> > happen only with GTK tooltips?
> 
> I don't know the details, but it appears that there are some redisplay
> cycles that don't show the tooltip, leading to flickering.
> 
> I've only tested this with GTK tooltips so far.

Does the flickering disappear if you set x-gtk-use-system-tooltips to
nil?

> There's also a side issue that subsequent mouse-movement events appear
> to only be generated after moving a character rather than by a
> configurable amount of pixels, which leads to the tooltip movement being
> a bit jerky.

If that, too, disappears when GTK tooltips are not used, then maybe
it's due to the way we show GTK tooltips.