Re: [gentoo-dev] [RFC] Global USE=gui

[Raymond Jennings]

use case:  Telling a package to build a gui without deciding which one to
build.  Also helps in cases where you have package A that can only build a
qt gui, and package B that can build both qt and gtk, and package C that
can build gtk only.  You want to have a gui for all three, but you don't
want to hav epackage B build both guis and at the same time while you may
prefer qt, you don't want to leave package C without a gui.

On Thu, Jun 2, 2016 at 7:20 AM, Ian Stakenvicius <axs@g.o> wrote:

> On 01/06/16 10:13 PM, waltdnes@××××××××.org wrote:
> > On Wed, Jun 01, 2016 at 07:56:41PM +0200, Micha?? Górny wrote
> >
> >> waltdnes@××××××××.org wrote:
> >>
> >>>   I see this as at least a redundancy, if not a problem.  First, let's
> >>> look at the general case.  An optional "UI" (User Interface) is also
> >>> selected...
> >>> * via the "tools" useflag 78 times in use.local.desc
> >>> * via the "ncurses" useflag 10 times in use.local.desc.
> >>> * for a lot of ebuilds via the "ncurses" useflag in use.desc (So why
> >>>   does "ncurses" show up in use.local.desc ???)
> >>>
> >>>  There is no need for an additional "TUI" (Text User Interface) use
> flag
> >>> for these cases.  "tools" and/or "ncurses" tells you enough.
> Similarly,
> >>> "GUI" is grab-bag of gtk2/gtk3/qt4/qt5/X/Wayland/whatever.  The only
> >>> thing they have in common is a hard-coded dependancy on graphics libs.
> >>> "GUI" is an implicit dependancy of
> gtk2/gtk3/qt4/qt5/X/Wayland/whatever.
> >>> Using any of them tells you enough.  What do we accomplish by requiring
> >>> one more USE flag?  This will also make dependancy resolution of
> ebuilds
> >>> more complex, i.e. slower.  Why?
> >>
> >> Simple regular users don't want to be concerned with choice of toolkit
> >> for every single package, as long as a GUI is provided.
> >
> >   Then put one of X/xorg/wayland/mir/qt4/qt5/gtk2/gtk3/fltk into USE in
> > make.conf.  This will *FORCE* a gui where applicable.
> >
>
>
> The whole point of USE=gui is to get away from needing to do that.
> Those flags should be used to choose -which- gui toolkit users want
> when one is available, not to choose IF a gui should be built or not.
> Take my example into account, i don't want anything qt based if I can
> avoid it, but i definitely want wpa-gui.  Right now I only get wpa-gui
> if I enable USE=qt4 (or USE=qt5 presumably) on wpa_supplicant.  I'm
> not going to set that globally though because I don't want to choose
> qt4 based front-ends for anything else, and having to guess for every
> random package when i don't care so that I can set a package.use entry
> for it is annoying.
>
>
> >> Furthermore, this matches the recommended USE flag design where the
> >> more important flags are provided as feature flags, while specific
> >> dependency choice flags are minor.
> >
> >   This is going to require *THREE* levels of flags, with the first one
> > being totally unnecessary...
> >
> > Level 1) GUI
> >
> > Level 2) X or xorg or Wayland or Mir
> >
> > Level 3) qt4 or qt5 or gtk2 or gtk3 or fltk
>
>
> 1 - USE=gui is for optional gui-or-no-gui, so yes in this scheme its
> needed.
>
> 2 - If X or Wayland or Mir support is available in a package, then yes
> -- also i don't see a way that we don't need these.
>
> 3 - toolkit selection choices when a package supports multiple (but
> only chooses one) is also a yes.  AND, because we're not tying any-gui
> to one of these flags it means that users are free to set just the one
> variant that they prefer, globally, instead of having to mess about
> per-package.  It also means we can get rid of any or all of these
> particular flags from profiles (except for 'gnome' or 'plasma' or the
> desktop-variant-specific ones).
>
> The point here is that if there's an app (say, wpa_supplicant as
> mentioned before) that provides a gui tool but no options as to what
> that tool needs in terms of toolkit etc, we can -just- have USE=gui
> control whether or not it's built.  It'll pull in qt because qt is
> what it needs, and if someone is dead set against having qt in their
> system then they'll know from the dependency tree.  There's no need to
> peg the individual toolkit to packages like this just to enable a gui.
>
>
> >
> >   Let me re-phrase my question... is there *ANY* set of circumstances
> > under which any of X/xorg/wayland/mir/qt4/qt5/gtk2/gtk3/fltk USE flag
> > can be set for a package *WITHOUT* requiring a gui?  I can see any of X
> > or xorg or Wayland or Mir being a requirement for any of
> > qt4/qt5/gtk2/gtk3/fltk.  But any of the Level 2 or Level 3 flags *FORCES*
> > a GUI of one sort or another.
>
>
> Likely there is but I'd need to search.  Extending libraries mostly --
> cairo, pango etc.. for X vs no-X, avahi for gtk*/qt* ...
>
>
>
>
>