[webkit-reviews] review requested: [Bug 40197] Enhance the hit testing to take a rectangle instead of a point : [Attachment 57979] first in-progress patch

[bugzilla-daemon at webkit.org]

Grace Kloba <klobag at gmail.com> has asked  for review:
Bug 40197: Enhance the hit testing to take a rectangle instead of a point
https://bugs.webkit.org/show_bug.cgi?id=40197

Attachment 57979: first in-progress patch
https://bugs.webkit.org/attachment.cgi?id=57979&action=review

------- Additional Comments from Grace Kloba <klobag at gmail.com>
This is an in-progress patch. The goal is to get the feedback from the broader
audience.

The key change is EventHandler::hitTestResultAtPoint(). If the pointPadding is
(0, 0), the functionality should be identical as before. If pointPadding is not
empty, we will do a region test. Inside the returned HitTestResult, besides
innerNode() you can also get a list of Node overlapped with the "fat" point by
calling rawNodeList(). The Nodes are ordered based on z-order.

There are couple of open issues.
1. currently all the Nodes are in the same widget/frame as the innerNode(), do
we need to support Nodes from different frames? (See code in EventHandler.cpp)

2. currently it doesn't extend isPointInOverflowControl() for the region test,
is it needed? (See RenderBlock.cpp)

3. currently it doesn't support SVG. (See RenderSVGRoot.cpp)

4. currently there is no special treatment for transform3D as I don't know what
to do. (See RenderLayer.cpp)

5. need suggestion on writing layout test