- From: Dr. Olaf Hoffmann <Dr.O.Hoffmann@gmx.de>
- Date: Sat, 6 Dec 2008 13:46:02 +0100
- To: www-svg@w3.org, dleeling@comfsm.fm
Of course, it would be very nice and helpful both for users and authors, if such user-agents like the Geckos, Opera, WebKit, Batik/Squiggle, Konqueror+KSVG, the Adobe plugin would have some items in the content menu about the presentation of text information like the content of the elements title, desc and metadata on demand. For example one button for 'Display text alternative of the complete document', another one for 'Display text alternatives for the current element' and 'Display text alternative for the current group'. Would be even better starting with such a display to be able to open the text information for parent elements and children elements, if required. Unfortunately such accessibility approaches and approaches for simple educational purposes are currently not present or not very useful in those viewers. Opera presents the title elements as tooltip. Batik/Squiggle title and desc. As already noted, this has the tendency to give authors the idea, that they put content inside the title and desc, that is (only) useful as a tooltip, what is a problem for the variant of an accessibility alternative text only presentation. However, for the given examples, as far as I understand this, this content fits both for the title or the desc element and I would work as intended in Batik/Squiggle, noted as title in Opera too. And there is no title attribute. If present without a prefix and interpreted by Firefox, this indicates an even bigger problem, because without a prefix this should be indicated as an error in SVG1.1, in SVGT1.2 it should be ignored. Especially for SVG1.1 there are maybe viewers having this correct and strict error processing rules implemented, therefore such documents should be never published to avoid annoyance for users of these proper viewers by corrupted documents. What works both in Geckos and Opera is SVG1.1 combined with CSS :hover for groups containing text elements, something like this: CSS: g text.tooltip { display: none } g:hover text.tooltip { display: inline } SVG1.1: <g fill="violet" stroke="darkmagenta" stroke-width="1"> <text class="tooltip" x="6965" y="-5950" font-size="10">Clerodendrum inerme (ilau)</text> <circle cx="6970" cy="-5950" r="2" /> <circle cx="6960" cy="-5950" r="2" /> </g> Discussion: This does not work in the Adobe plugin or in Batik/Squiggle, because they seem not to interprete :hover; Konqueror+KSVG1 ignores the CSS completely. Because it is done with CSS, this pop-up functionality is decorative only. However because without styling the text information is visible and related to the group, this is a not really bad solution concerning accessibility. SVGT1.2 has this new attributes to indicate the role or functionality more precisely, but for this tiny profile it is explicitly noted, that authors may not rely on external stylesheets as required here to note the :hover. Therefore currently these two methods cannot be combined. There are several useful methods in SVG to provide such text information within a valid SVG document. But there is no trivial method making such information accessible with any user-agent unfortunately.
Received on Saturday, 6 December 2008 12:51:37 UTC