[CSS Grid Layout] Content Distribution support for grid.

[CSS Grid Layout] Content Distirbution support for grid.

Content Alignment is performed using the align-content and justify-content
CSS properties, however, the <content-distribution> values were not allowed
for Grid Layout until the last version of the spec.

The <content-distribution> values also consider the grid tracks as the
alignment subject but instead of moving them along the grid container's
free available space, it distribute such space around and/or between the
tracks.  

BUG=376823, 249451
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=194034

[jfernandez, 2015-03-31 15:51:20]

jfernandez@igalia.com changed reviewers:
+ esprehn@chromium.org, jchaffraix@chromium.org, leviw@chromium.org

[Julien - ping for review, 2015-04-15 14:13:59]

jchaffraix@chromium.org changed reviewers:
+ dsinclair@chromium.org

[Julien - ping for review, 2015-04-15 14:14:00]

https://codereview.chromium.org/1031853002/diff/20001/Source/core/layout/Layo...
File Source/core/layout/LayoutGrid.cpp (right):

https://codereview.chromium.org/1031853002/diff/20001/Source/core/layout/Layo...
Source/core/layout/LayoutGrid.cpp:454: tracksToStretch[i++] = tracks.data() +
trackIndex;
Alternatively:

tracksToStretch[tracksToStretch.size() - 1] = ....;

https://codereview.chromium.org/1031853002/diff/20001/Source/core/layout/Layo...
File Source/core/layout/LayoutGrid.h (right):

https://codereview.chromium.org/1031853002/diff/20001/Source/core/layout/Layo...
Source/core/layout/LayoutGrid.h:173: LayoutUnit m_columnsDistributionOffset;
Why do we need those members? They seem like transient information that we need
during layout but not after. That means that they would be better off being
passed during layout (or factored into Grid.SizingData.

[dsinclair, 2015-04-15 15:27:13]

https://codereview.chromium.org/1031853002/diff/20001/Source/core/layout/Layo...
File Source/core/layout/LayoutGrid.cpp (right):

https://codereview.chromium.org/1031853002/diff/20001/Source/core/layout/Layo...
Source/core/layout/LayoutGrid.cpp:441: bool needToStretch =
flexibleSizedTracksIndex.isEmpty() &&
!sizingData.contentSizedTracksIndex.isEmpty() && ((direction == ForColumns &&
style()->justifyContentDistribution() == ContentDistributionStretch) ||
(direction == ForRows && style()->alignContentDistribution() ==
ContentDistributionStretch));
nit: can this be done in two lines to make it easier to read?

[jfernandez, 2015-04-16 17:03:38]

New patch for review after applying the suggested changes.

https://codereview.chromium.org/1031853002/diff/20001/Source/core/layout/Layo...
File Source/core/layout/LayoutGrid.cpp (right):

https://codereview.chromium.org/1031853002/diff/20001/Source/core/layout/Layo...
Source/core/layout/LayoutGrid.cpp:441: bool needToStretch =
flexibleSizedTracksIndex.isEmpty() &&
!sizingData.contentSizedTracksIndex.isEmpty() && ((direction == ForColumns &&
style()->justifyContentDistribution() == ContentDistributionStretch) ||
(direction == ForRows && style()->alignContentDistribution() ==
ContentDistributionStretch));
On 2015/04/15 15:27:13, dsinclair wrote:
> nit: can this be done in two lines to make it easier to read?

Done.

https://codereview.chromium.org/1031853002/diff/20001/Source/core/layout/Layo...
Source/core/layout/LayoutGrid.cpp:454: tracksToStretch[i++] = tracks.data() +
trackIndex;
On 2015/04/15 14:14:00, Julien - OOO 18 Apr - 14 May wrote:
> Alternatively:
> 
> tracksToStretch[tracksToStretch.size() - 1] = ....;

This wouldn't work, because tracksToStretch was initialized with predefined
size:

Vector<GridTrack*> tracksToStretch(sizingData.contentSizedTracksIndex.size());

We could use 'append', if you think it'd be more efficient.

https://codereview.chromium.org/1031853002/diff/20001/Source/core/layout/Layo...
File Source/core/layout/LayoutGrid.h (right):

https://codereview.chromium.org/1031853002/diff/20001/Source/core/layout/Layo...
Source/core/layout/LayoutGrid.h:173: LayoutUnit m_columnsDistributionOffset;
On 2015/04/15 14:14:00, Julien - OOO 18 Apr - 14 May wrote:
> Why do we need those members? They seem like transient information that we
need
> during layout but not after. That means that they would be better off being
> passed during layout (or factored into Grid.SizingData.

I've finally moved the fields into the GridSizingData structure. Actually, the
only reason why they have to be stored is that I need them in the
findChildLocation function to deal with RTL direction.

[dsinclair, 2015-04-16 17:12:32]

lgtm

[jfernandez, 2015-04-20 09:02:05]

The CQ bit was checked by jfernandez@igalia.com

[commit-bot: I haz the power, 2015-04-20 09:03:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1031853002/40001

[jfernandez, 2015-04-20 11:24:29]

The CQ bit was checked by jfernandez@igalia.com

[jfernandez, 2015-04-20 11:24:30]

The patchset sent to the CQ was uploaded after l-g-t-m from
dsinclair@chromium.org
Link to the patchset: https://codereview.chromium.org/1031853002/#ps60001
(title: "Missing layout test expectations file.")

[commit-bot: I haz the power, 2015-04-20 11:25:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1031853002/60001

[commit-bot: I haz the power, 2015-04-20 16:41:46]

Committed patchset #4 (id:60001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=194034