Bug 25277 – If there is no line wrapping, a caret can leave its containing block but it shouldn't leave its root line box

• Status: RESOLVED
• Resolution: FIXED
• Component: Layout and Rendering

[Justin Garcia]

If there is no line wrapping, a caret can leave its containing block but it shouldn't leave its root line box.  

Otherwise I believe it can be clipped by the containing blocks outline.  Test case forthcoming.

<rdar://problem/6800956>

[Justin Garcia]

Created attachment 29593 [details]
patch

Comment on attachment 29593 [details]
patch

You should add a reference to the test to the WebCore ChangeLog.

I don't think this covers all cases. Not all textAlign() values that are not LEFT should behave the same, and I think in most cases (maybe even for LEFT and RIGHT) the behavior also needs to take style()->direction() into account, because that's how we decide on which side of the block the overflow goes. See the logic in RenderBlock::computeHorizontalPositionsForLine().

[Justin Garcia]

(In reply to comment #2)
> Not all textAlign() values that are not LEFT should behave the same

oops!  will fix...

[Justin Garcia]

Created attachment 29597 [details]
patch

patch with new test case to cover the case that dan mentioned, where the text-align is right but the direction is LTR.  In that case we spill over to the right off the block like we do in other direction:LTR cases.

Comment on attachment 29597 [details]
patch

r=me
There's a problem with this and earlier caret painting patches in that the difference between correct and incorrect behavior in the pixel test is below our detection threshold. I am not sure what to do about it (maybe use the Mac SPI that's exposed via DRT for getting caret rects?), but addressing that is not part of this bug.

[Simon Fraser (smfr)]

Maybe caretWidth should be settable at runtime via a CSS property, or DRT API, and we can make it really fat?

I don't think we want a CSS property for it, but maybe a WebView SPI.

[Justin Garcia]

I'll correct the test description to say that the problem is that the caret paints over the focus halo a bit (rather than getting clipped).

[Justin Garcia]

http://trac.webkit.org/changeset/42634

[Justin Garcia]

and http://trac.webkit.org/changeset/42635