[webkit-dev] rfc: Spatial Navigation feature for WebCore

[tonikitoo (Antonio Gomes)]

Hi,

The Spatial Navigation feature "consists in the ability to navigate
between focusable elements, such as hyperlinks and form controls,
within a structured document or user interface according to the
spatial location." [1]. It is currently implemented in some desktop
browsers including newer Opera versions and Firefox, as well as vastly
used on non-touch mobile browsers.

[1] http://en.wikipedia.org/wiki/Spatial_navigation

During the last week I've moved forward in this feature implementation
within WebCore in bug 18662 [2], and now I think it has reached a
point where comments and official reviews are required to get this in
at some point.

[2] https://bugs.webkit.org/show_bug.cgi?id=18662

About the newer version of the patch (at the time of writing [3]):

* It implements a super-precedence based algorithm, falling back into
the classic Euclidean Distance approach. Details in the patch.
* Is turned off by default, but has has toggle on/off API for QtWebKit
also pending review in bug 33714.
* It includes layout tests for some edge-cases, and a patch hook Qt
DRT in bug 33715.

[3] https://bugs.webkit.org/attachment.cgi?id=46576

This patch also skips the above added tests in Win, Mac and Gtk DRT,
but followup bugs will track adding support for them. Also, known
issues like "form integration" and other listed in the bug are also to
be covered in follow up bugs (some already under implementation).

Thanks in advance.

-- 
--Antonio