Bug 158818 – <attachment> elements jump around a lot around when subtitle text changes slightly

• Component: New Bugs
• Status: RESOLVED FIXED

[Tim Horton]

<attachment> elements jump around a lot around when subtitle text changes slightly

[Tim Horton]

Created attachment 281402 [details]
Patch

[Tim Horton]

<rdar://problem/24450270>

[Simon Fraser (smfr)]

Comment on attachment 281402 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=281402&action=review

> Source/WebCore/rendering/RenderThemeMac.mm:2603
> +    context.translate(FloatSize((paintRect.width() - attachmentIconBackgroundSize) / 2, 0));

You probably want to round down to avoid putting drawing on half-pixel boundaries. Or pixel snap.

[Build Bot]

Comment on attachment 281402 [details]
Patch

Attachment 281402 [details] did not pass ios-sim-ews (ios-simulator-wk2):
Output: http://webkit-queues.webkit.org/results/1509668

New failing tests:
fast/attachment/attachment-subtitle-resize.html

[Build Bot]

Created attachment 281412 [details]
Archive of layout-test-results from ews122 for ios-simulator-wk2

The attached test failures were seen while running run-webkit-tests on the ios-sim-ews.
Bot: ews122  Port: ios-simulator-wk2  Platform: Mac OS X 10.11.4

[Darin Adler]

Comment on attachment 281402 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=281402&action=review

> Source/WebCore/rendering/RenderAttachment.h:54
> +    LayoutUnit m_minimumIntrinsicWidth;

Does anything ever need to reset this to zero?

[Tim Horton]

(In reply to comment #6)
> Comment on attachment 281402 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=281402&action=review
> 
> > Source/WebCore/rendering/RenderAttachment.h:54
> > +    LayoutUnit m_minimumIntrinsicWidth;
> 
> Does anything ever need to reset this to zero?

I haven't yet come up with a good way to know that it's OK to shrink, so for now any particular attachment will always only grow. Given the currently limited use case of <attachment> this is likely OK, but if we want it to be more generally useful we'll probably have to come up with something (reset it on a deferrable timer? just give up on intrinsic sizing and give it a fixed width? something smarter?).

[Tim Horton]

http://trac.webkit.org/changeset/202117