Styling slot fallback content with ::slotted()

Styling slot fallback content with ::slotted()

::slotted() in CSS selectors should match fallback contents
and style them if the slot has no assigned nodes.

This problem was originally raised at
https://github.com/w3c/webcomponents/issues/631
and the conclusion was to apply style rules to
slot fallback content where ::slotted() selector
matches.

BUG=703984

[kochi, 2017-04-04 09:28:50]

The CQ bit was checked by kochi@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-04 09:29:12]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-04 10:42:51]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-04 10:42:52]

Dry run: This issue passed the CQ dry run.

[kochi, 2017-04-12 05:39:02]

The CQ bit was checked by kochi@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-12 05:39:21]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[kochi, 2017-04-12 05:40:43]

Description was changed from

==========
Styling slot fallback content with ::slotted()

::slotted() style rules should match fallback contents if the
slot has no slotted contents.

BUG=703984
==========

to

==========
Styling slot fallback content with ::slotted()

::slotted() in CSS selectors should match fallback contents
and style them if the slot has no assigned nodes.

BUG=703984
==========

[kochi, 2017-04-12 06:48:38]

The CQ bit was checked by kochi@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-12 06:48:53]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[kochi, 2017-04-12 06:49:12]

Patchset #4 (id:60001) has been deleted

[commit-bot: I haz the power, 2017-04-12 08:27:34]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-12 08:27:35]

Dry run: This issue passed the CQ dry run.

[kochi, 2017-04-12 08:28:11]

Description was changed from

==========
Styling slot fallback content with ::slotted()

::slotted() in CSS selectors should match fallback contents
and style them if the slot has no assigned nodes.

BUG=703984
==========

to

==========
Styling slot fallback content with ::slotted()

::slotted() in CSS selectors should match fallback contents
and style them if the slot has no assigned nodes.

This problem is originally raised at
https://github.com/w3c/webcomponents/issues/631
and the conclusion was to apply ::slotted() rules to
fallback content.

BUG=703984
==========

[kochi, 2017-04-12 08:28:11]

kochi@chromium.org changed reviewers:
+ hayato@chromium.org, rune@opera.com

[kochi, 2017-04-12 08:30:24]

Description was changed from

==========
Styling slot fallback content with ::slotted()

::slotted() in CSS selectors should match fallback contents
and style them if the slot has no assigned nodes.

This problem is originally raised at
https://github.com/w3c/webcomponents/issues/631
and the conclusion was to apply ::slotted() rules to
fallback content.

BUG=703984
==========

to

==========
Styling slot fallback content with ::slotted()

::slotted() in CSS selectors should match fallback contents
and style them if the slot has no assigned nodes.

This problem was originally raised at
https://github.com/w3c/webcomponents/issues/631
and the conclusion was to apply style rules to
slot fallback content where ::slotted() selector
matches.

BUG=703984
==========

[kochi, 2017-04-12 08:31:13]

PTAL

[hayato, 2017-04-13 05:50:40]

https://codereview.chromium.org/2789363002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/css/SelectorChecker.cpp (right):

https://codereview.chromium.org/2789363002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/css/SelectorChecker.cpp:127: if (!slot) {
Looks the dupe of code. It would be better to extract the similar code as a
function.

https://codereview.chromium.org/2789363002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp (right):

https://codereview.chromium.org/2789363002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp:277: }
I don't think this is correct. Can this handle nested slots?
Please add a test for that.

e.g.
<slot><slot>fallback</slot></slot>

[kochi, 2017-04-14 02:15:13]

https://codereview.chromium.org/2789363002/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp (right):

https://codereview.chromium.org/2789363002/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/css/resolver/StyleResolver.cpp:277: }
On 2017/04/13 05:50:40, hayato wrote:
> I don't think this is correct. Can this handle nested slots?
> Please add a test for that.
> 
> e.g.
> <slot><slot>fallback</slot></slot>

Good catch, let me work on it.

[kochi, 2017-04-14 05:26:08]

The CQ bit was checked by kochi@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-14 05:26:24]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-04-14 06:47:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-14 06:47:46]

Dry run: This issue passed the CQ dry run.

[kochi, 2017-04-14 07:01:53]

The CQ bit was checked by kochi@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-04-14 07:02:04]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[kochi, 2017-04-14 07:04:52]

PTAL

[hayato, 2017-04-14 08:06:04]

The CL is not correct. W have chatted offline.

kochi@,
Please see https://dom.spec.whatwg.org/#find-flattened-slotables carefully.

You are expected to have an *inverse function*, reversing "find flattened
slotables":

- "find flattened slotables" is: (a slot -> a list of nodes)
- "what is needed" is: (a node -> a list of slots)

If you need further help, please feel free to ask me.

[commit-bot: I haz the power, 2017-04-14 08:58:42]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2017-04-14 08:58:44]

Dry run: This issue passed the CQ dry run.

[kochi, 2017-04-18 02:34:47]

On 2017/04/14 08:06:04, hayato wrote:
> The CL is not correct. W have chatted offline.
> 
> kochi@,
> Please see https://dom.spec.whatwg.org/#find-flattened-slotables carefully.
> 
> You are expected to have an *inverse function*, reversing "find flattened
> slotables":
> 
> - "find flattened slotables" is: (a slot -> a list of nodes)
> - "what is needed" is: (a node -> a list of slots)
> 
> If you need further help, please feel free to ask me.

Thanks, let me work on the fix and please hold your reviews until
I have another patchset.

[rune, 2017-04-18 07:07:55]

You probably need to modify the style invalidation code as well.