[PATCH weston 00/14] IVI Layout API Cleanup

[Bryce Harrington]

On Mon, Feb 29, 2016 at 03:31:46PM +0000, Ucan, Emre (ADITG/SW1) wrote:
> Hi Pekka,
> 
> Best regards
> 
> > -----Original Message-----
> > From: Pekka Paalanen [mailto:ppaalanen at gmail.com]
> > Sent: Montag, 29. Februar 2016 16:15
> > To: Ucan, Emre (ADITG/SW1); Wataru Natsume
> > Cc: Bryce Harrington; wayland-devel at lists.freedesktop.org
> > Subject: Re: [PATCH weston 00/14] IVI Layout API Cleanup
> > 
> > On Mon, 29 Feb 2016 08:04:05 +0000
> > "Ucan, Emre (ADITG/SW1)" <eucan at de.adit-jv.com> wrote:
> > 
> > > Hello Bryce,
> > >
> > > As far as I know, there are two controller plugins which are using ivi
> > > layout interface. 1. HMI controller
> > > 	2. IVI controller in Genivi Wayland IVI Extension
> > >
> > > I updated the hmi controller for these changes, and ivi controller
> > > does not use these APIs.
> > >
> > > Furthermore, IVI Layout APIs are internal. It is quite often that
> > > weston plugins gets break after a major release because of either API
> > > changes or data struct changes.
> > 
> > Hi,
> > 
> > Weston plugins can break on every minor bump, yes, but here we are talking
> > about controller plugins which might follow different rules set by the
> > ivi_layout ABI.
> > 
> > However, as long as controller plugins also use Weston ABI in addition to
> > ivi_layout ABI, they are susceptible to break as often as Weston plugins.
> > 
> > > For example, we have an input plugin in Wayland IVI Extension which
> > > replaces the default grab interfaces. The plugin does not compile with
> > > 1.10 weston because weston_pointer data struct is changed after 1.9.
> > 
> > I presume that is a Weston plugin.
> 
> Yes
> 
> > 
> > > > -----Original Message-----
> > > > From: Bryce Harrington [mailto:bryce at osg.samsung.com]
> > > > Sent: Freitag, 26. Februar 2016 19:03
> > > > To: Ucan, Emre (ADITG/SW1)
> > > > Cc: wayland-devel at lists.freedesktop.org
> > > > Subject: Re: [PATCH weston 00/14] IVI Layout API Cleanup
> > > >
> > > > On Fri, Feb 26, 2016 at 03:57:56PM +0000, Ucan, Emre (ADITG/SW1)
> > > > wrote:
> > > > > I removed the get APIs, because the same information can be get
> > > > > from ivi_layout_get_properties_of_surface/layer APIs. Therefore,
> > > > > these APIs are redundant.
> > > >
> > > > Looks like a good cleanup, but do we have any concerns about API
> > > > stability in dropping these getter/setters?
> > 
> > Even though I called for it several times, it seems the ABI stability guarantees
> > were never documented anywhere, so I suppose the standard Weston
> > plugin rules apply. At least on a quick glance I cannot find any comment to
> > that effect.
> 
> I think the stability rules for IVI layout should be the same as standart weston plugins.
> We cannot realize some usecases with ivi-shell, which we want to have, e.g: same ivi-surface on many layers/screens.
> We have to most likely break ABI again to realize these usecases.
> 
> Where is a good place to write down the ABI stability rules, do you think ? ivi-shell/README, maybe ?

I don't know if there is a convention for where ABI stability rules are
indicated, but that would probably be the first place I'd check.

> > The controller plugin API does however use the size of struct
> > ivi_layout_interface to detect API compatiblity. Now that the struct grows
> > smaller, this check does not work, yet the ABI does break, and requires at
> > least rebuilding all controller plugins. If we want to maintain the ABI, the
> > fields in struct ivi_layout_interface should be set to NULL or a generic
> > function that complains and aborts, not removed.
> > 
> > Natsume-san, do you have an opinion?
> > 
> > From my behalf this is a welcome simplification, so consider the whole series
> > Acked-by: Pekka Paalanen <pekka.paalanen at collabora.co.uk> anyway.

Thanks for the clarifications; as I mentioned the changes themselves
look technically fine, so given the clarification on the ABI situation,
I can add my:

Reviewed-by: Bryce Harrington <bryce at osg.samsung.com>

Holding off on landing until we hear confirmation from Natsume-san.

Bryce

> > Thanks,
> > pq
> > 
> > > > > Furthermore, I removed *_set_position/dimension APIs, because
> > > > > position and dimension can be set by
> > > > > ivi_layout_surface/layer_set_destination_rectangle APIs.
> > > > >
> > > > > I adjusted ivi-layout-transition.c, ivi shell test code and
> > > > > hmi-controller.c for these changes.
> > > > >
> > > > > Emre Ucan (14):
> > > > >   ivi-shell: remove ivi_layout_surface_get_visibility API
> > > > >   ivi-shell: remove ivi_layout_layer_get_visibility API
> > > > >   ivi-shell: remove ivi_layout_surface_get_opacity API
> > > > >   ivi-shell: remove ivi_layout_layer_get_opacity API
> > > > >   ivi-shell: remove ivi_layout_surface_get_position API
> > > > >   ivi-shell: remove ivi_layout_layer_get_position API
> > > > >   ivi-shell: remove ivi_layout_surface_get_dimension API
> > > > >   ivi-shell: remove ivi_layout_layer_get_dimension API
> > > > >   ivi-shell: remove ivi_layout_surface_get_orientation API
> > > > >   ivi-shell: remove ivi_layout_layer_get_orientation API
> > > > >   ivi-shell: remove ivi_layout_surface_set_position API
> > > > >   ivi-shell: remove ivi_layout_layer_set_position API
> > > > >   ivi-shell: remove ivi_layout_surface_set_dimension API
> > > > >   ivi-shell: remove ivi_layout_layer_set_dimension API
> > > > >
> > > > >  ivi-shell/hmi-controller.c        |   17 ++-
> > > > >  ivi-shell/ivi-layout-export.h     |  127 --------------------
> > > > >  ivi-shell/ivi-layout-private.h    |   17 +--
> > > > >  ivi-shell/ivi-layout-transition.c |   19 ++-
> > > > >  ivi-shell/ivi-layout.c            |  237
> > > > > +------------------------------------
> > > > > ivi-shell/ivi-shell.c             |    7 +-
> > > > > tests/ivi_layout-internal-test.c  |  220
> > > > > +++++-----------------------------
> > > > > tests/ivi_layout-test-plugin.c    |  126 +++++--------------- 8
> > > > > files changed, 85 insertions(+), 685 deletions(-)
> > > > >
> > > > > --
> > > > > 1.7.9.5
> 
> Emre Ucan
> Software Group I (ADITG/SW1)
> 
> Tel. +49 5121 49 6937