893147 - select dropdown mispositioned when perspective is used

Status: NEW

(Core :: Layout: Form Controls, defect)

Description

[aaron]

Attachment: index.html

User Agent: Mozilla/5.0 (Windows NT 6.1; rv:22.0) Gecko/20100101 Firefox/22.0 (Beta/Release)
Build ID: 20130618035212

Steps to reproduce:

Create an element with a select input inside it, give the element's parent "perspective" property in css, then use translate 3d on the element. 


Actual results:

 When the select dropdown is opened it will not be translated along with the dropdown header.


Expected results:

The dropdown menu should have been translated.

Comment 1

[Boris Zbarsky [:bzbarsky]]

Timothy, is this different from bug 870518?

Comment 2

[Timothy Nikkel (:tnikkel)]

(In reply to Boris Zbarsky (:bz) from comment #1)
> Timothy, is this different from bug 870518?

I think so. That bug is about scaling, this bug is a bit different.

The "perspective: 900px;" rule on the body means we get a 3d transform matrix on the body frame that isn't 2d (ie gfx3DMatrix::Is2D returns false). We currently only support select dropdowns that have been translated by transforms that are 2d (nsComboboxControlFrame::GetCSSTransformTranslation does this). Although perhaps we can improve this by just getting the whole transfrom from the select to the root frame and then check if it has CanDraw2D (instead of rejecting any non-2d transform we find along the way to the root).

Comment 3

[Timothy Nikkel (:tnikkel)]

The translate3d part doesn't really matter, we correctly determine that it is a 2d-only transform and it works in that case, the perspective is the part that trips the 3d transform code.

Comment 4

[aaron]

Additionally I just found this bug affecting text boxes as well as select boxes.

Comment 5

[Timothy Nikkel (:tnikkel)]

Do you mean the auto complete drop down for text boxes?

Comment 6

[aaron]

No, the highlighted text field does not open in the right location, ie. focus on a text box and type into it and the text will appear in the un-translated position.

Comment 7

[Timothy Nikkel (:tnikkel)]

That sounds like a different bug, can you please file a new bug and cc me?

Comment 8

[aaron]

I'm sorry this was actually not a defect, I jumped to the conclusion since it was so similar, apologies.

Comment 10

[dbuc]

Attachment: input-translate-bug.png

Comment 11

[dbuc]

(In reply to danieljb2 from comment #10)
> Created attachment 8425842 [details]
> input-translate-bug.png

As you can see, this bug affects text inputs as well (and presumably others). The resulting UI bug makes basic combinations of transform styles and inputs unusable.