- From: Andrea Rendine <master.skywalker.88@gmail.com>
- Date: Sun, 15 Mar 2015 18:02:49 +0100
- To: "public-html@w3.org LIST" <public-html@w3.org>
- Message-ID: <CAGxST9=ia---gtMWH5MXWdJ_Fa1nrsgpXapjPK3ubnG5WndNtw@mail.gmail.com>
The problem in the age of HTML4 could also be a poor implementation on the UAs side. The fact is, everybody resorted to use animated Flash image maps but nobody used native technology. Exactly what happened later for videos and animations (features for which the new elements <video> and <canvas> have been developed). And vendors have adapted. What I ask for is a correction of an existing feature which would help a lot for a number of reasons, also because the map itself does not need to be next to the image and can be in any other part of the page itself. Actually I had two different proposals, and I will write them here: 1. Maps should present coordinates relative to the default image dimensions (i.e. according to @width and @height, or to dimensions fetched from the image file). Visual user agents dealing with <area> elements inside <map@resize> should store coordinates starting values, then apply CSS transformations, storing width and height stretch/shrink ratio, then apply these ratios respectively to horizontal and vertical coordinates, and after these passages areas should be rendered properly. In order not to break with existing projects where maps are made with reference to the final apperance of the image, <map> should have a new boolean attribute @resize. Only image maps with this attribute should be resized with native UAs techniques. This is a first scenario. Its major issue is that it could be incompatible with JS solutions used in legacy installments: if JS is completely discarded, then resize scripts are disabled. But scripts used for animating areas would be lost as well, because there's no way to tell them apart (I don't even know if anything similar exists). 2. (secondary) IMHO this is a better idea but it requires some more guessing. Relative coordinates: numbers in the coords attributes could be expressed with percent values, so calculations would also be easier to achieve and more immediate to understand (it should be noted that this would require floating-point values in most cases, as integer numbers wouldn't be precise enough). I don't know what HTML4 used to say about percentage coordinates. What I do know is that modern user agents don't know what to do with percentage coordinates. Chrome treats them as pixel and that's all. IE and FF (they behave quite similarly in some case and this is weird) treat them as pixel for "rect" state, while circles and polygons disappear (I guess). 2015-03-06 3:12 GMT+01:00 Boris Zbarsky <bzbarsky@mit.edu>: > On 3/5/15 7:04 PM, Andrea Rendine wrote: > >> Coordinates in area elements are absolute >> and refer to distances and measures in pixels >> > > I believe in HTML 4 coordinates could be percentages and no one ever > implemented that... Would that help things somewhat? > > It can't be a matter of lacking interest on the part of authors and/or >> vendors: if the element is not usable as it is *today*, then of course >> nobody can effectively use it and vendors don't guess too much about an >> unused feature. >> > > The element wasn't used much at all for many years before people worried > about responsive design... I've never quite understood why, since it _is_ > in fact pretty useful, but that's the way it was. > > -Boris > > >
Received on Sunday, 15 March 2015 17:03:15 UTC