Getting absolute coordinates from a DOM element

re: Getting absolute coordinates from a DOM element

Nathanael Jones — Wed, 12 Mar 2008 02:37:19 GMT

jQuery does a good job at it with the offset() method. I really like the way jQuery is chainable and how properties are implemented.

Seriously study jQuery! I've found it to be the best, easiest, and least intrusive.

re: Getting absolute coordinates from a DOM element

Bertrand Le Roy — Thu, 06 Mar 2008 17:43:26 GMT

@Atanas: yes, we're currently doing a test pass with the IE8 beta and we know of a few problems. getLocation is one API where we have literally thousands of test cases and where new browsers are likely to break the current code because of how tied it is to browser bug workarounds.

re: Getting absolute coordinates from a DOM element

Atanas Korchev — Thu, 06 Mar 2008 09:25:39 GMT

Are you aware of any issues with getLocation and the recently released beta 1 of IE8? I've checked the autocomplete extender and its dropdown seems a bit off:

www.asp.net/.../AutoComplete.aspx

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Mon, 11 Feb 2008 19:39:27 GMT

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re: Getting absolute coordinates from a DOM element

Bertrand Le Roy — Sat, 09 Feb 2008 22:55:17 GMT

Fine, seeing all the feedback I'm getting on that, I'll find a way to publish that publicly. I'll try to see if we can come up with a simplified version that would look like ACID for getLocation. Stay tuned.

(technically, grabbing the screenshot involves some .NET/pInvoke wizardry, but nothing too intense, basically to get a BitMap object from any window handle and then you're in business)

re: Getting absolute coordinates from a DOM element

Matthias Bruch — Sat, 09 Feb 2008 11:25:28 GMT

Thanks for the blog entry. I really liked it to read about all that problems ... I always just did a loop through the dom to find out the coordinates, and "corrected" that by hardcoded values (for the browser differences) ...

But as interesting as your post was, could you explain a little bit more how that console app does the screenshots? As I saw in the comments, I'm not the only one who's interested in that ;-) ...

re: Getting absolute coordinates from a DOM element

Bertrand Le Roy — Tue, 05 Feb 2008 18:00:58 GMT

Something self-written. We wrote a .NET console app that grabs the screenshot and finds rectangles of a given color.

re: Getting absolute coordinates from a DOM element

ThomasH — Tue, 05 Feb 2008 08:44:53 GMT

Not quite. I was after the 'analysis' part you mention. How is this performed? Are you using a tool like ImageMagic, or something self-written? How do you detect the rectangles and squares and the deviation from the expected values?

re: Getting absolute coordinates from a DOM element

Bertrand Le Roy — Fri, 01 Feb 2008 20:19:38 GMT

Thomas: the element we got getLocation from has a border of a specific color, and what we position absolutely to check the coordinates are two squares of a different color on the top left and bottom right. The analysis program scans the image for those rectangles and squares of specific colors. Does that answer your question?

re: Getting absolute coordinates from a DOM element

Bertrand Le Roy — Fri, 01 Feb 2008 20:07:12 GMT

Dave (infinitiesloop): I like the idea of an acid test for getLocation. By the way, our simplified version of the test that runs on every checkin does include the most pathological cases and comes close to that definition. It lacks the generality of the full test but it has the advantage that because the expected coordinates for each browser are hard coded, it doesn't need the screenshot analysis so it's much easier to run.