[PATCH weston 0/8] IVI Screen refactoring

[Natsume, Wataru (ADITJ/SWG)]

Hello Pekka-san, Emre-san,

It is fine with me as well. This refactoring removes duplicated logic in ivi-layout and results in lower maintenance effort.

Acked-by: Wataru Natsume <wnatsume at jp.adit-jv.com>

Best Regards,
Wataru Natsume

---
Wataru Natsume / 夏目 亘
Advanced Driver Information Technology
Software Group (ADITJ/SWG)
E-mail: wnatsume at jp.adit-jv.com
Tel: +81-(0)566-61-4551 / Extension 551-43644


-----Original Message-----
From: wayland-devel [mailto:wayland-devel-bounces at lists.freedesktop.org] On Behalf Of Pekka Paalanen
Sent: Friday, March 18, 2016 8:25 PM
To: Ucan, Emre (ADITG/SW1); wataru_natsume
Cc: Friedrich, Eugen (ADITG/SW1); wayland-devel at lists.freedesktop.org
Subject: Re: [PATCH weston 0/8] IVI Screen refactoring

On Thu, 17 Mar 2016 15:30:22 +0000
"Ucan, Emre (ADITG/SW1)" <eucan at de.adit-jv.com> wrote:

> Basic idea of the patch series is to use weston_output in public APIs.
> The controller plugins will call IVI Layout API with weston output 
> instead of ivi_layout_screen. This change simplifies the IVI Layout 
> API implementation, e.g.:
> 
> 1. Don't need to have id_screen. Weston output already has ID.
> 2. The screen resolution can be get from weston output directly.
> 3. Get screns API is unnecessary, because the compositor already has a
>    list of outputs.
> 
> Emre Ucan (8):
>   ivi-shell: remove id_screen
>   ivi-shell: remove ivi_layout_get_id_of_screen API
>   ivi-shell: remove ivi_layout_get_screen_resolution API
>   ivi-shell: remove ivi_layout_get_screens API
>   ivi-shell: use weston_output in public APIs
>   ivi-shell: implement get_screen_from_output
>   ivi-shell: remove ivi_layout_get_screen_from_id API
>   ivi-shell: remove ivi_layout_get_screen_output API
> 
>  ivi-shell/hmi-controller.c       |   99 +++++++--------------------
>  ivi-shell/ivi-layout-export.h    |   62 +++--------------
>  ivi-shell/ivi-layout.c           |  136 ++++++++++----------------------------
>  tests/ivi_layout-internal-test.c |  125 
> +++++------------------------------
>  4 files changed, 82 insertions(+), 340 deletions(-)
> 

Hi Emre,

I see this as an offical step towards removing the mid-layer called ivi-layout, and leaving it as a helper interface to realize the surface(/view)/layer/screen hierarchy. So the direction is for controllers to use more Weston core API rather than ivi-layout to eventually wrap all of Weston core API. Am I correct?

Can I get an Acked-by from someone else (Natsume-san?) that it is ok to move the ivi-layout architecture in this direction?

Personally I am happy to see things going in this direction.

Some details:

- Weston will aggressively re-use output ids, and does not guarantee
  any persistent mapping between an output (connector) and an id. Is
  this ok, or would you need more reliable screen ids?

- For get_screen_resolution, I would prefer a function for controllers
  to call to get it. That would be the perfect place to document what
  "screen resolution" actually means, because we have things like
  output scale and output transform, which ivi-layout has so far just
  assumed being identity. These parameters make the difference between
  the coordinate systems the shell uses to lay out surfaces, and the
  coordinate system on the monitor device. It would be ok to make this
  a Weston core function, provided it is accurately documented. Note,
  that output scale and transform are not controlled by the shell
  (at least yet).

Other than that, all the patches look good to me. I'll just wait for someone else to Ack this plan before trying to land this series.


Thanks,
pq