281684 - BoxObjects's offsetRect weird

Status: NEW

(Core :: DOM: Core & HTML, defect, P5)

Description

[Boris Zbarsky [:bzbarsky]]

The boxobject gets the offsetrect in the coordinates of the innermost frame of
the root element containing the target frame.

This seems wrong.  I'll post a testcase where this leads to an offset of 0 when
I believe we should be getting a nonzero offset.

It seems to me that we want to be using coordinates relative to the _outermost_
frame containing the target frame...

Neil, is the behavior of this function actually specified, anywhere?

Comment 1

[Boris Zbarsky [:bzbarsky]]

Attachment: Testcase showing the problem

Comment 2

[[e-mail]]

I don't really care what coordinate system box objects use as long as it agrees
with events. (And no, I don't know what coordinate system they use either.)

Comment 3

[Boris Zbarsky [:bzbarsky]]

Which exact event coordinate system?  Our events expose screenX/Y, clientX/Y,
layerX/Y, and pageX/Y.  None of those are in the same coordinate system as the
current BoxObject code in all situations, nor would they be with my proposed change.

pageX/Y comes closest, I think, except when there are non-root scrollable frames
or events in popups involved...

Comment 4

[[e-mail]]

To clarify, the tree body frame has a method AdjustEventCoordsToBoxCoordSpace
that needs to be kept in sync with any box coordinate changes.

Comment 5

[Boris Zbarsky [:bzbarsky]]

Er... that method already seems to be out of sync (eg if the tree is inside a
scrollable div that's scrolled, the two sets of coordinates should be off from
each other, as far as I can tell).

Is there any documentation _anywhere_ on what boxObject and event should use as
their various coordinate systems?

Comment 6

[Boris Zbarsky [:bzbarsky]]

Actually, it looks like the HTML offset* code has the same problem.  In brief,
both places seem to be assuming that frame ==
GetPrimaryFrameFor(frame->mContent).  That's really not a good assumption...

Comment 7

[Boris Zbarsky [:bzbarsky]]

Note also bug 291351    	

Comment 8

[Firefox Bug Husbandry Bot]

https://bugzilla.mozilla.org/show_bug.cgi?id=1472046

Move all DOM bugs that haven’t been updated in more than 3 years and has no one currently assigned to P5.

If you have questions, please contact :mdaly.