PLAT-97349: Support VirtualList to have Scroller as an item

[0x64]

Checklist

• [x] I have read and understand the contribution guide
• [ ] A CHANGELOG entry is included
• [ ] At least one test case is included for this feature or bug fix
• [ ] Documentation was added or is not needed
• [ ] This is an API breaking change

Issue Resolved / Feature Added

When Scroller elements are items of VirtualList element, spotlight navigation by 5-way key does not work properly.

Resolution

• Fixed native scrollable components (that catch scroll event to update its contents) to check which scrollable area is actually scrolled in nested cases.
• Fixed lists to get data-index attribute value from a node inside of an item on keypress.
• Fixed Scrollables to set data-index attribute value to its most outer node to be handled properly when it is an item of a list.
• Added a prop for a container configuration to Scroller to support 'last-focused' rule.

Additional Considerations

A list moves spotlight simply to the next item, and the spotlight moves the first child of a scroller if the item is a scroller. Because a scroller's container is a spotlight container, this is expected behavior.

Links

PLAT-97349

Comments

[codecov[bot]]

Codecov Report

Merging #2663 (9477ce5) into develop (16e8f48) will decrease coverage by 0.10%. The diff coverage is 8.19%.

@@             Coverage Diff             @@
##           develop    #2663      +/-   ##
===========================================
- Coverage    47.00%   46.89%   -0.11%     
===========================================
  Files          263      263              
  Lines        11584    11611      +27     
  Branches      2771     2776       +5     
===========================================
  Hits          5445     5445              
- Misses        4557     4579      +22     
- Partials      1582     1587       +5     

Impacted Files	Coverage Δ
packages/moonstone/Scrollable/Scrollable.js	27.91% <ø> (ø)
packages/moonstone/Scrollable/ScrollableNative.js	5.32% <ø> (ø)
packages/ui/Scrollable/ScrollableNative.js	1.80% <0.00%> (-0.01%)	:arrow_down:
packages/moonstone/VirtualList/VirtualListBase.js	29.44% <2.94%> (-2.31%)	:arrow_down:
packages/ui/Scrollable/Scrollable.js	55.13% <14.28%> (-0.24%)	:arrow_down:
packages/spotlight/src/container.js	87.19% <50.00%> (ø)
packages/moonstone/Scroller/Scroller.js	30.64% <100.00%> (+0.56%)	:arrow_up:

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