ozone/platform/wayland: Ensure that globals are bound with supported versions

ozone/platform/wayland: Ensure that globals are bound with supported versions

Also, make sure that test objects inherit the versions from the parent.

BUG=578890
Committed: https://crrev.com/65f0685b1d98f975c8fcd16bef72789410fa8bbb
Cr-Commit-Position: refs/heads/master@{#376052}

[Michael Forney, 2016-02-17 05:34:48]

Description was changed from

==========
ozone/platform/wayland: Ensure globals are bound with supported versions

Also, make sure that test objects inherit the versions from the parent.

BUG=578890
==========

to

==========
ozone/platform/wayland: Ensure globals are bound with supported versions

Also, make sure that test objects inherit the versions from the parent.

BUG=578890
==========

[Michael Forney, 2016-02-17 05:35:01]

Description was changed from

==========
ozone/platform/wayland: Ensure globals are bound with supported versions

Also, make sure that test objects inherit the versions from the parent.

BUG=578890
==========

to

==========
ozone/platform/wayland: Ensure that globals are bound with supported versions

Also, make sure that test objects inherit the versions from the parent.

BUG=578890
==========

[Michael Forney, 2016-02-17 05:50:50]

forney@google.com changed reviewers:
+ spang@chromium.org

[Michael Forney, 2016-02-17 05:50:51]

This is in preparation for adding input handling, for which it is much more
important to get interface versioning correct (version 4 of wl_keyboard adds the
repeat_info event that we need, and version 5 of wl_pointer dramatically changes
the way events are sent).

[spang, 2016-02-17 23:25:03]

https://codereview.chromium.org/1698043005/diff/20001/ui/ozone/platform/wayla...
File ui/ozone/platform/wayland/wayland_display.cc (right):

https://codereview.chromium.org/1698043005/diff/20001/ui/ozone/platform/wayla...
ui/ozone/platform/wayland/wayland_display.cc:112: registry, name,
std::min(version, kMaxCompositorVersion));
Should

version < 4

be an error? Or is the code actually prepared to deal with old servers?

Same for the others. If the server doesn't support the one you tested against,
are we expecting that to actually work?

[Michael Forney, 2016-02-17 23:44:24]

On 2016/02/17 23:25:03, spang wrote:
>
https://codereview.chromium.org/1698043005/diff/20001/ui/ozone/platform/wayla...
> File ui/ozone/platform/wayland/wayland_display.cc (right):
> 
>
https://codereview.chromium.org/1698043005/diff/20001/ui/ozone/platform/wayla...
> ui/ozone/platform/wayland/wayland_display.cc:112: registry, name,
> std::min(version, kMaxCompositorVersion));
> Should
> 
> version < 4
> 
> be an error? Or is the code actually prepared to deal with old servers?

It should work with any version in [1..4].

Version 2 added a set_buffer_transform request, version 3 added a
set_buffer_scale request, and version 4 (only in wayland 1.10 released
yesterday) added a damage_buffer request. These are optional requests that the
client may choose to use, and since we don't use any of them (yet) we are
compatible with all current versions.

Later, if we start handling high-DPI buffers (and don't want to deal with
servers that don't support set_buffer_scale), we might add kMinCompositorVersion
= 3, and ignore the wl_compositor global if the server's maximum supported
version is less than that.

> Same for the others. If the server doesn't support the one you tested against,
> are we expecting that to actually work?

The version that the server advertises is the maximum supported version. The
client can bind any version less than or equal to the advertised version.

See https://wayland.freedesktop.org/docs/html/ch04.html#sect-Protocol-Versioning
for more information.

[spang, 2016-02-17 23:50:57]

On 2016/02/17 23:44:24, Michael Forney wrote:
> On 2016/02/17 23:25:03, spang wrote:
> >
>
https://codereview.chromium.org/1698043005/diff/20001/ui/ozone/platform/wayla...
> > File ui/ozone/platform/wayland/wayland_display.cc (right):
> > 
> >
>
https://codereview.chromium.org/1698043005/diff/20001/ui/ozone/platform/wayla...
> > ui/ozone/platform/wayland/wayland_display.cc:112: registry, name,
> > std::min(version, kMaxCompositorVersion));
> > Should
> > 
> > version < 4
> > 
> > be an error? Or is the code actually prepared to deal with old servers?
> 
> It should work with any version in [1..4].
> 
> Version 2 added a set_buffer_transform request, version 3 added a
> set_buffer_scale request, and version 4 (only in wayland 1.10 released
> yesterday) added a damage_buffer request. These are optional requests that the
> client may choose to use, and since we don't use any of them (yet) we are
> compatible with all current versions.
> 
> Later, if we start handling high-DPI buffers (and don't want to deal with
> servers that don't support set_buffer_scale), we might add
kMinCompositorVersion
> = 3, and ignore the wl_compositor global if the server's maximum supported
> version is less than that.
> 
> > Same for the others. If the server doesn't support the one you tested
against,
> > are we expecting that to actually work?
> 
> The version that the server advertises is the maximum supported version. The
> client can bind any version less than or equal to the advertised version.
> 
> See
https://wayland.freedesktop.org/docs/html/ch04.html#sect-Protocol-Versioning
> for more information.

Right, I was talking about our code. We obviously have to consider what APIs are
missing or what semantics change when binding to "old" versions. Since you've
already done that, lgtm.

[Michael Forney, 2016-02-18 00:22:05]

The CQ bit was checked by forney@google.com

[commit-bot: I haz the power, 2016-02-18 00:22:22]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1698043005/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1698043005/20001

[commit-bot: I haz the power, 2016-02-18 00:47:50]

Description was changed from

==========
ozone/platform/wayland: Ensure that globals are bound with supported versions

Also, make sure that test objects inherit the versions from the parent.

BUG=578890
==========

to

==========
ozone/platform/wayland: Ensure that globals are bound with supported versions

Also, make sure that test objects inherit the versions from the parent.

BUG=578890
==========

[commit-bot: I haz the power, 2016-02-18 00:47:50]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-02-18 00:49:41]

Description was changed from

==========
ozone/platform/wayland: Ensure that globals are bound with supported versions

Also, make sure that test objects inherit the versions from the parent.

BUG=578890
==========

to

==========
ozone/platform/wayland: Ensure that globals are bound with supported versions

Also, make sure that test objects inherit the versions from the parent.

BUG=578890

Committed: https://crrev.com/65f0685b1d98f975c8fcd16bef72789410fa8bbb
Cr-Commit-Position: refs/heads/master@{#376052}
==========

[commit-bot: I haz the power, 2016-02-18 00:49:42]

Patchset 2 (id:??) landed as
https://crrev.com/65f0685b1d98f975c8fcd16bef72789410fa8bbb
Cr-Commit-Position: refs/heads/master@{#376052}