Event when two SVG elements touch

Question

Is it possible in SVG, using any method, to call an even if two specific elements touch? Or would I have to code the long way, and figure out if their borders touch with complicated maths?

Answer 1

There are actually four methods available on the outermost SVG element for intersection handling in the SVG 1.1 DOM:

1. getIntersectionList
2. getEnclosureList
3. checkIntersection
4. checkEnclosure

Unfortunately I think the cross-browser support for these methods is still not great.

Answer 2

I don't think there are any built-in methods, but this guy wrote a Javascript library that detects collisions:

http://www.kevlindev.com/geometry/2D/intersections/index.htm

Looks pretty slick. It doesn't work in Firefox 3.6, but works in Chrome.

EDIT:

OK, there actually is a built-in method, but I don't know if it can be applied to anything besides rectangles. Erik Dahlström, the author of that post, hangs out on Stackoverflow, so he might have something to say about this.