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From 2012.igem.org

/* Smooth scrolling Changes links that link to other parts of this page to scroll smoothly to those links rather than jump to them directly, which can be a little disorienting. sil, http://www.kryogenix.org/ v1.0 2003-11-11 v1.1 2005-06-16 wrap it up in an object

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var ss = { fixAllLinks: function() { // Get a list of all links in the page var allLinks = document.getElementsByTagName('a'); // Walk through the list for (var i=0;i<allLinks.length;i++) { var lnk = allLinks[i]; if ((lnk.href && lnk.href.indexOf('#') != -1) && ( (lnk.pathname == location.pathname) || ('/'+lnk.pathname == location.pathname) ) && (lnk.search == location.search)) { // If the link is internal to the page (begins in #) // then attach the smoothScroll function as an onclick // event handler ss.addEvent(lnk,'click',ss.smoothScroll); } } }, smoothScroll: function(e) { // This is an event handler; get the clicked on element, // in a cross-browser fashion if (window.event) { target = window.event.srcElement; } else if (e) { target = e.target; } else return; // Make sure that the target is an element, not a text node // within an element if (target.nodeName.toLowerCase() != 'a') { target = target.parentNode; } // Paranoia; check this is an A tag if (target.nodeName.toLowerCase() != 'a') return; // Find the <a name> tag corresponding to this href // First strip off the hash (first character) anchor = target.hash.substr(1); // Now loop all A tags until we find one with that name var allLinks = document.getElementsByTagName('a'); var destinationLink = null; for (var i=0;i<allLinks.length;i++) { var lnk = allLinks[i]; if (lnk.name && (lnk.name == anchor)) { destinationLink = lnk; break; } } if (!destinationLink) destinationLink = document.getElementById(anchor); // If we didn't find a destination, give up and let the browser do // its thing if (!destinationLink) return true; // Find the destination's position var destx = destinationLink.offsetLeft; var desty = destinationLink.offsetTop; var thisNode = destinationLink; while (thisNode.offsetParent && (thisNode.offsetParent != document.body)) { thisNode = thisNode.offsetParent; destx += thisNode.offsetLeft; desty += thisNode.offsetTop; } // Stop any current scrolling clearInterval(ss.INTERVAL); cypos = ss.getCurrentYPos(); ss_stepsize = parseInt((desty-cypos)/ss.STEPS); ss.INTERVAL =setInterval('ss.scrollWindow('+ss_stepsize+','+desty+',"'+anchor+'")',10); // And stop the actual click happening if (window.event) { window.event.cancelBubble = true; window.event.returnValue = false; } if (e && e.preventDefault && e.stopPropagation) { e.preventDefault(); e.stopPropagation(); } }, scrollWindow: function(scramount,dest,anchor) { wascypos = ss.getCurrentYPos(); isAbove = (wascypos < dest); window.scrollTo(0,wascypos + scramount); iscypos = ss.getCurrentYPos(); isAboveNow = (iscypos < dest); if ((isAbove != isAboveNow) || (wascypos == iscypos)) { // if we've just scrolled past the destination, or // we haven't moved from the last scroll (i.e., we're at the // bottom of the page) then scroll exactly to the link window.scrollTo(0,dest); // cancel the repeating timer clearInterval(ss.INTERVAL); // and jump to the link directly so the URL's right location.hash = anchor; } }, getCurrentYPos: function() { if (document.body && document.body.scrollTop) return document.body.scrollTop; if (document.documentElement && document.documentElement.scrollTop) return document.documentElement.scrollTop; if (window.pageYOffset) return window.pageYOffset; return 0; }, addEvent: function(elm, evType, fn, useCapture) { // addEvent and removeEvent // cross-browser event handling for IE5+, NS6 and Mozilla // By Scott Andrew if (elm.addEventListener){ elm.addEventListener(evType, fn, useCapture); return true; } else if (elm.attachEvent){ var r = elm.attachEvent("on"+evType, fn); return r; } else { alert("Handler could not be removed"); } } } ss.STEPS = 30; //设置滑动速度 ss.addEvent(window,"load",ss.fixAllLinks);