http://snippets.dzone.com/posts Fri, 29 Aug 2008 12:53:07 GMT DZone Snippets: delta code http://snippets.dzone.com/posts/show/5337 This code was originally copied from <a href="http://adomas.org/javascript-mouse-wheel/">Mouse wheel programming in JavaScript</a> [adomas.org]. I replaced about 5 lines of code to get the mousewheel controlling the zoom feature in the <a href="http://snippets.dzone.com/posts/show/5336">makeZoom.svg</a> [dzone.com] file. <br /> <br /><code> <br /> /** This is high-level function; REPLACE IT WITH YOUR CODE. <br /> * It must react to delta being more/less than zero. <br /> */ <br />function zoomInOut(delta) { <br /> if (delta >= 0) <br /> zoomIn() <br /> else <br /> zoomOut() <br />} <br /> <br />function wheel(event){ <br /> var delta = 0; <br /> if (!event) event = window.event; <br /> if (event.wheelDelta) { <br /> delta = event.wheelDelta/120; <br /> if (window.opera) delta = -delta; <br /> } else if (event.detail) { <br /> delta = -event.detail/3; <br /> } <br /> if (delta) <br /> zoomInOut(delta); <br /> if (event.preventDefault) <br /> event.preventDefault(); <br /> event.returnValue = false; <br />} <br /> <br />/* Initialization code. */ <br />if (window.addEventListener) <br /> window.addEventListener('DOMMouseScroll', wheel, false); <br />window.onmousewheel = document.onmousewheel = wheel; <br /></code> Tue, 08 Apr 2008 16:14:22 GMT http://snippets.dzone.com/posts/show/5337 jrobertson (James Robertson)