[PATCH weston 00/10] weston wayland-protocols migration

[Bryce Harrington]

On Fri, Nov 06, 2015 at 10:39:12AM +0800, Jonas Ådahl wrote:
> On Thu, Nov 05, 2015 at 12:21:21PM +0200, Pekka Paalanen wrote:
> > On Wed,  4 Nov 2015 16:49:49 +0800
> > Jonas Ådahl <jadahl at gmail.com> wrote:
> > > Things that seemed more weston specific was weston_ prefixed. The
> > > screenshooter protocol and the desktop shell protocol fell into this
> > > category.
> > 
> > Speaking of prefixes, do we have an idea what protocols should use the
> > wl_ prefix and what shouldn't?
> > 
> > I have had the feeling that wl_ is only Wayland core. But what does
> > Wayland core mean? And wl_shell is an exception already.
> > 
> > Should we restrict wl_ to only for things in wayland.xml? Probably not,
> > as I think wl_ in e.g. wl_scaler is justified since it's a "low-level"
> > generic feature, and yet wl_scaler will not be added into wayland.xml.
> > 
> > Perhaps wl_ prefix should be reserved for extensions that are usable
> > regardless of a shell or environment. I'm not sure if the input method
> > extensions would be eligible for wl_ or not, or what to do with
> > fullscreen shell.
> > 
> > xdg_shell is setting a precedent for using xdg_ prefix for all
> > desktoppy but still DE-agnostic extensions, and I think that is fine.
> 
> We discussed this last night on IRC and you expressed that you thought
> that the wl_ prefix should be limited to only libwayland-client and
> libwayland-server and nothing else.
> 
> The resulting idea after that discussion was to use the wp_ prefix
> instead of wl_ prefix for future protocols with the exception of the
> rare cases where new interfaces actually have to be added to
> wayland.xml. I don't know of any examples or plans where this is needed
> yet.
> 
> This means wl_scaler would become wp_scaler, wl_fullscreen would become
> wp_fullscreen, wl_presentation wp_presentation, etc.

I can live with that, although I suspect I'll always read it as Word
Perfect rather than Wayland Protocol...
 
> We also somewhat concluded that generic sounding name (linux_) should
> also be prefixed, meaning linux_dmabuf will become wp_linux_dmabuf, but
> maybe we should really use some other prefix for non-generic protocols?
> I'm not sure.

Agreed on prefixing these.

> Regarding the xdg_ prefix, nothing in particular was concluded. I'm not
> sure wp_xdg_ is desirable, but maybe its not that bad. We'll have to
> bite this bullet the next time xdg_shell changes, or if some other
> protocol depending on xdg_shell is introduced. Opinions? Stay with xdg_?
> wp_xdg_? wpxdg? wxdg? wp_desktop_shell? Something else?

This is probably going to require some debate... which is why I
suggested leaving it as a special case so as not to derail the rest of
the effort.  But, I do think it too should be renamed, and I feel fairly
strongly that in doing so we should just discard "xdg" from the name.
Here's my thinking:

1.  "xdg" is a prefix used by an actual real open source project which
isn't us.  We're not using it inappropriately or anything, but still.
We wouldn't name a protocol kde_foo_thingee to make it more acceptable
to kde folks.

2.  As a corollary to #1, using it might suggest the protocol is
something *external* to wayland and not sanctioned by us.  Just as if we
prefixed it kde_ people would reasonably assume it was a KDE thing, not
wayland.

3.  While there is I guess you could say "marketing" value in including
"XDG" in the name as a way to promote cross-desktop adoption, if it did
have any such value in the past, we're beyond that point now.

4.  Many people probably won't know what "XDG" stands for anyway.  We
would do as well to just call it wp_common_desktop_shell and it'd be
more comprehensible to the average person and no less cross-desktoppy.

5.  I don't think it's really that important that we especially label a
protocol as cross-desktop.  After all, the implication is that all
Wayland protocols are intended to be widely usable.  I don't think we'd
push a protocol that is usable by only one desktop environment, so in
that sense xdg_ is kind of redundant with wl_ (or wp_).

6.  As this is a protocol we want to be standardized, that we want to
actively maintain, and that we want used broadly by Wayland-based
projects, it seems right to give it a simple, prominent name like
wp_desktop_shell.

Anyway, that's my long-winded +1 vote for renaming xdg-shell to
wp_desktop_shell.

Bryce