Re: Fix some tooltip related problems

[martin rudalics <rudalics@gmx.at>]

 >> 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