Bug 47669 – Title-Element has no popup on <svg>-Elements, but on <g>

• Component: SVG
• Status: RESOLVED FIXED

[Holger Jeromin]

Created attachment 70736 [details]
SVG Demo for a title in svg and g element

The standard http://www.w3.org/TR/SVG/struct.html#DescriptionAndTitleElements defines:
"Each container element [...] in an SVG drawing can supply [...] a ‘title’ description string" where

http://www.w3.org/TR/SVG/intro.html#TermContainerElement defines an container element as
"Specifically: ‘a’, ‘defs’, ‘glyph’, ‘g’, ‘marker’, ‘mask’, ‘missing-glyph’, ‘pattern’, ‘svg’, ‘switch’ and ‘symbol’."

However a title element is only rendered as a popup at mouseover in <g>, but not in a <svg> Element as you can see in the attached demo.

[Andreas Kling]

From SVGStyledElement::title() in WebCore/svg/SVGStyledElement.cpp:
// According to spec, we should not return titles when hovering over <svg> elements (those 
// <title> elements are the title of the document, not a tooltip) so we instantly return.
if (hasTagName(SVGNames::svgTag))
    return String();

[Holger Jeromin]

(In reply to comment #1)
> From SVGStyledElement::title() in WebCore/svg/SVGStyledElement.cpp:
> // According to spec, we should not return titles when hovering over <svg> elements (those 
> // <title> elements are the title of the document, not a tooltip) so we instantly return.
> if (hasTagName(SVGNames::svgTag))
>     return String();

I see. 

I have not found this spec, but the title could not be the title of the document, if they are nested. The SVG Spec only references to the "outermost svg element".

[Holger Jeromin]

Created attachment 70836 [details]
SVG Demo for a title in root svg, svg and g element

[Holger Jeromin]

(In reply to comment #2)
> (In reply to comment #1)
> > From SVGStyledElement::title() in WebCore/svg/SVGStyledElement.cpp:
> > // According to spec, we should not return titles when hovering over <svg> elements (those 
> > // <title> elements are the title of the document, not a tooltip) so we instantly return.
> > if (hasTagName(SVGNames::svgTag))
> >     return String();
> 
> I see. 
> 
> I have not found this spec, but the title could not be the title of the document, if they are nested. The SVG Spec only references to the "outermost svg element".

Firefox 4 shows the tooltip on svg-elements, but not on the outmost svg  https://bugzilla.mozilla.org/show_bug.cgi?id=547854 

Uploaded a new testcase.

[Rob Buis]

Created attachment 70957 [details]
Trivial patch

[Rob Buis]

I uploaded a trivial patch to provide behaviour such as FireFox 4. I waited with the testcase implementation(which should be easy by just checking the title attribute) because for instance
Opera does not give a tooltip for svg elements either.
Cheers,

Rob.

[Andreas Kling]

Comment on attachment 70957 [details]
Trivial patch

View in context: https://bugs.webkit.org/attachment.cgi?id=70957&action=review

> WebCore/svg/SVGStyledElement.cpp:72
> +        SVGSVGElement* svg = static_cast<SVGSVGElement*>(const_cast<SVGStyledElement*>(this));

Would read better like this IMO:
const SVGSVGElement* svg = static_cast<const SVGSVGElement*>(this);

[Holger Jeromin]

(In reply to comment #6)
> I uploaded a trivial patch to provide behaviour such as FireFox 4. I waited with the testcase implementation(which should be easy by just checking the title attribute) because for instance

Thanks.
It would be very nice, if this changes would land in the webkit source.

> Opera does not give a tooltip for svg elements either.

I filed a bug in the opera bug wizard (DSK-316141) as well as in Microsoft Connect 
https://connect.microsoft.com/IE/feedback/details/614675/title-element-has-no-tooltip-on-svg-elements

Perhaps it is too late for IE9 since MS marked the beta as feature complete.
Holger

[Nikolas Zimmermann]

Comment on attachment 70957 [details]
Trivial patch

Looks fine, r=me but Andreas suggestion is correct.

[Eric Seidel (no email)]

Attachment 70957 [details] was posted by a committer and has review+, assigning to Rob Buis for commit.

[Rob Buis]

Hi Eric,

(In reply to comment #10)
> Attachment 70957 [details] was posted by a committer and has review+, assigning to Rob Buis for commit.

This was landed in r70617, I guess I forgot to close, doing that now :)
Cheers,

Rob.