commit 43a54d6cd7d55d8dc5912125674d580cd8cbf23c
author David Bokan <bokan@chromium.org> Fri Jan 18 20:15:13 2019
committer Commit Bot <commit-bot@chromium.org> Fri Jan 18 20:15:13 2019
tree aea82945b735c746df1bd0904d7541dc3f86221e
parent 0b28d34af9d37326ec0a94543dde7fc9f591538f

Add a "focusless" mode to spatial navigation

This CL adds a mode to spatial navigation so that navigating around the
page doesn't change focus.

Today, spatial navigation moves focus from element-to-element. This is
problematic on some pages since key events are sent to focused elements.
If an element calls preventDefault() on arrow key events, spatial
navigation becomes trapped. It also means users can't interact with
elements that user the arrow keys (e.g. range slider).

With this feature enabled, the spatial navigation controller keeps
track of the "interested" element. This is the element that's currently
highlighted by spatial navigation (i.e. the prevoiusly focused element).
As we navigate around the page, the controller changes this interested
element rather than changing focus.

In a future patch, we'll allow focusing and blurring the interested
element using other keyboard buttons.

Bug: 919158
Change-Id: I14b432a1a4b7b4762db692842fa196caa92ec7f4
Reviewed-on: https://chromium-review.googlesource.com/c/1408350
Reviewed-by: Emil A Eklund <eae@chromium.org>
Commit-Queue: David Bokan <bokan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#624254}