Re: Fix some tooltip related problems

[martin rudalics]

>> The option `x-gtk-use-system-tooltips' decides whether to use system
>> or Emacs tooltips.  This is a user option and should never be set by
>> Lisp code.
>
> Then that doesn't satisfy what I requested:
>
>    "being able to choose for any given context which to use"
>                          ---------------------
>    "Can we let Lisp code (and so users too) decide, here or
>     there, which kind of tooltip to use (heavyweight "Emacs"
>     or lightweight "system")?"

Right.  Such decisions must be left to the user.

> And users on gtk-build systems can choose.  Choice should
> also be available to Lisp functions, as use cases differ.
> It's of course possible to let a user option allow for
> Lisp control or override/prevent it, au choix.
>
> Today, does changing the value of that user option change
> the behavior dynamically?  E.g., if you did change the
> value using a given Lisp function would the behavior change?
>
> If so then some specific contexts could, by default, use
> "Emacs" tooltips, while other contexts did not.

I'd rather advise to set `x-gtk-use-system-tooltips' once in the init
file and never change it during the session.

> For example, tooltip-dimming for mode-line mouseover
> could be done for non-Windows also, without imposing "Emacs"
> tooltips everywhere.  And users could prevent that dimming
> using option `x-gtk-use-system-tooltips'.
>
> Since that's apparently possible for more than just Windows,
> including for at least some GNU/Linux builds, that's what
> we should do by default.  I didn't propose it earlier
> because I thought you were saying that it is only Windows
> that supports faces in tooltips, and I know that we don't
> tailor default Emacs behavior for Windows only.

Please look into the implementation details of tooltips before
suggesting such things.

martin