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<html>
<head>
<title>youngpup.net: ypSimpleScroll demo</title>
<script language="javascript">
/* =======================================================
* ypSimpleScroll
* 3/11/2001
*
// dhtml scrolling panel featuring scrolling in any
// direction, smooth frame-dropping animation, and a
// few other goodies.
//
// 3/25/2001
// added scrolling in any direction and initTop, initLeft
// constructor parameters - with only 1k...
//
// 3/30/2001
// fixed bug that occured when if you called scrollTo( )
// and the new position was the same as the current
// position. that was stupid.
//
// 4/02/2001
// small bug fix - on some browsers, on slow connections
// the script would not run at all. to be sure the doc
// is done loading before .load() is called, the author
// must now call the .load() method in the onload handler
// for the page.
//
// 8/22/2001
// if you tried to scroll before page was loaded it threw
// an error. this should be fixed now.
//
//
* http://www.youngpup.net/
//
// =======================================================
// ypSimpleScroll( id, left, top, width, height, speed,
// contentWidth, initScrollLeft,
// initScrollTop )
//
// last three parameters are optional.
* ======================================================= */
// basic methods.
ypSimpleScroll.prototype.scrollNorth = function() { this.startScroll(90) }
ypSimpleScroll.prototype.scrollSouth = function() { this.startScroll(270) }
ypSimpleScroll.prototype.scrollWest = function() { this.startScroll(180) }
ypSimpleScroll.prototype.scrollEast = function() { this.startScroll(0) }
// start scrolling in an arbitrary direction, with an optional arbitrary speed.
// if no speed is provided, the default speed from the constructor parameter is used.
ypSimpleScroll.prototype.startScroll = function(deg, speed) {
if (this.loaded)
{
if (this.aniTimer) window.clearTimeout(this.aniTimer)
this.overrideScrollAngle(deg)
this.speed = speed ? speed : this.origSpeed
this.lastTime = (new Date()).getTime() - this.y.minRes
this.aniTimer = window.setTimeout(this.gRef + ".scroll()", this.y.minRes)
}
}
// kills pending calls to .scroll(), resets speed
ypSimpleScroll.prototype.endScroll = function() {
if (this.loaded)
{
window.clearTimeout(this.aniTimer)
this.aniTimer = 0;
this.speed = this.origSpeed
}
}
// override the current angle from startScroll() with a new angle
// this method should not be used with scrollTo() because it will
// override the angle created by the first two params to scrollTo().
ypSimpleScroll.prototype.overrideScrollAngle = function(deg) {
if (this.loaded)
{
deg = deg % 360
if (deg % 90 == 0) {
var cos = deg == 0 ? 1 : deg == 180 ? -1 : 0
var sin = deg == 90 ? -1 : deg == 270 ? 1 : 0
} else {
var angle = deg * Math.PI / 180
var cos = Math.cos(angle)
var sin = Math.sin(angle)
sin = -sin
}
this.fx = cos / (Math.abs(cos) + Math.abs(sin))
this.fy = sin / (Math.abs(cos) + Math.abs(sin))
this.stopH = deg == 90 || deg == 270 ? this.scrollLeft : deg < 90 || deg > 270 ? this.scrollW : 0
this.stopV = deg == 0 || deg == 180 ? this.scrollTop : deg < 180 ? 0 : this.scrollH
}
}
// override the speed for the current scroll.
// should not be used with scrollTo, unless you want to
// override the speed computed from the aniLen param of scrollTo()
ypSimpleScroll.prototype.overrideScrollSpeed = function(speed) {
if (this.loaded) this.speed = speed
}
// scroll to an arbitrary position in two dimensions over in
// an arbitrary lenth of time.
ypSimpleScroll.prototype.scrollTo = function(stopH, stopV, aniLen) {
if (this.loaded)
{
if (stopH != this.scrollLeft || stopV != this.scrollTop) {
if (this.aniTimer) window.clearTimeout(this.aniTimer)
this.lastTime = (new Date()).getTime()
var dx = Math.abs(stopH - this.scrollLeft)
var dy = Math.abs(stopV - this.scrollTop)
var d = Math.sqrt(Math.pow(dx,2) + Math.pow(dy,2))
this.fx = (stopH - this.scrollLeft) / (dx + dy)
this.fy = (stopV - this.scrollTop) / (dx + dy)
this.stopH = stopH
this.stopV = stopV
this.speed = d / aniLen * 1000
window.setTimeout(this.gRef + ".scroll()", this.y.minRes)
}
}
}
// jump to an arbitrary position in two dimensions.
ypSimpleScroll.prototype.jumpTo = function(nx, ny) {
if (this.loaded)
{
nx = Math.min(Math.max(nx, 0), this.scrollW)
ny = Math.min(Math.max(ny, 0), this.scrollH)
this.scrollLeft = nx
this.scrollTop = ny
if (this.y.ns4)this.content.moveTo(-nx, -ny)
else {
this.content.style.left = -nx + "px"
this.content.style.top = -ny + "px"
}
}
}
// =========================================================================
// =============================== private =================================
// =========================================================================
ypSimpleScroll.minRes = 10
ypSimpleScroll.ie = document.all ? 1 : 0
ypSimpleScroll.ns4 = document.layers ? 1 : 0
ypSimpleScroll.dom = document.getElementById ? 1 : 0
ypSimpleScroll.mac = navigator.platform == "MacPPC"
ypSimpleScroll.mo5 = document.getElementById && !document.all ? 1 : 0
// recursively calls itself to animate
ypSimpleScroll.prototype.scroll = function() {
this.aniTimer = window.setTimeout(this.gRef + ".scroll()", this.y.minRes)
var nt = (new Date()).getTime()
var d = Math.round((nt - this.lastTime) / 1000 * this.speed)
if (d > 0)
{
var nx = d * this.fx + this.scrollLeft
var ny = d * this.fy + this.scrollTop
var xOut = (nx >= this.scrollLeft && nx >= this.stopH) || (nx <= this.scrollLeft && nx <= this.stopH)
var yOut = (ny >= this.scrollTop && ny >= this.stopV) || (ny <= this.scrollTop && ny <= this.stopV)
//window.status = nx + " " + this.fx + " " + this.scrollLeft + " " + this.stopH + " | " + ny + " " + this.fy + " " + this.scrollTop + " " + this.stopV + " : " + d
if (nt - this.lastTime != 0 &&
((this.fx == 0 && this.fy == 0) ||
(this.fy == 0 && xOut) ||
(this.fx == 0 && yOut) ||
(this.fx != 0 && this.fy != 0 && xOut && yOut)))
{
this.jumpTo(this.stopH, this.stopV)
this.endScroll()
}
else {
this.jumpTo(nx, ny)
this.lastTime = nt
}
}
}
// constructor
function ypSimpleScroll(id, left, top, width, height, speed, contentWidth, initLeft, initTop)
{
var y = this.y = ypSimpleScroll
if (!initLeft) initLeft = 0
if (!initTop) initTop = 0
if (!contentWidth) contentWidth = width
// fix for netscape4 first-page bug.
if (document.layers && !y.ns4) history.go(0)
if (y.ie || y.ns4 || y.dom) {
this.loaded = false
this.id = id
this.origSpeed = speed
this.aniTimer = false
this.op = ""
this.lastTime = 0
this.clipH = height
this.clipW = width
this.scrollTop = initTop
this.scrollLeft = initLeft
// global reference to this object
this.gRef = "ypSimpleScroll_"+id
eval(this.gRef+"=this")
var d = document
d.write('<style type="text/css">')
d.write('#' + this.id + 'Container { left:' + left + 'px; top:' + top + 'px; width:' + width + 'px; height:' + height + 'px; clip:rect(0 ' + width + ' ' + height + ' 0); overflow:hidden; }')
d.write('#' + this.id + 'Container, #' + this.id + 'Content { position:absolute; }')
d.write('#' + this.id + 'Content { left:' + (-initLeft) + 'px; top:' + (-initTop) + 'px; width:' + contentWidth + 'px; }')
d.write('</style>')
}
}
// once the nceesary objects are present in the DOM, this gathers some info about them.
ypSimpleScroll.prototype.load = function() {
var d, lyrId1, lyrId2
d = document
lyrId1 = this.id + "Container"
lyrId2 = this.id + "Content"
this.container = this.y.dom ? d.getElementById(lyrId1) : this.y.ie ? d.all[lyrId1] : d.layers[lyrId1]
this.content = obj2 = this.y.ns4 ? this.container.layers[lyrId2] : this.y.ie ? d.all[lyrId2] : d.getElementById(lyrId2)
this.docH = Math.max(this.y.ns4 ? this.content.document.height : this.content.offsetHeight, this.clipH)
this.docW = Math.max(this.y.ns4 ? this.content.document.width : this.content.offsetWidth, this.clipW)
this.scrollH = this.docH - this.clipH
this.scrollW = this.docW - this.clipW
this.loaded = true
this.scrollLeft = Math.max(Math.min(this.scrollLeft, this.scrollW),0)
this.scrollTop = Math.max(Math.min(this.scrollTop, this.scrollH),0)
this.jumpTo(this.scrollLeft, this.scrollTop)
}
</script>
<script language="javascript">
var test = new ypSimpleScroll("myScroll", 20, 50, 150, 250, 100)
</script>
<style type="text/css">
<!--
/* just basic text formatting - nothing special */
@import "/_common/demo.css";
-->
</style>
</head>
<body onload="test.load()">
<a id="down" href="#"
onmousedown="test.scrollSouth(); return false;"
onmousemove="return false;"
onmouseout="test.endScroll();"
onmouseup="test.endScroll();"
onclick="return false;"
>down</a>
<a href="#"
onmousedown="test.scrollNorth(); return false;"
onmousemove="return false;"
onmouseout="test.endScroll();"
onmouseup="test.endScroll();"
onclick="return false;"
>up</a>
<- <b>mousedown</b> over these links to activate the scroller.
<div id="myScrollContainer">
<div id="myScrollContent">
<p>this here is a bunch of content.</p>
<p>the reason i've taken the time to write actual content is because <a href="http://www.jesterworld.net/" target="_blank">brandon</a> bitched that there wasn't any.</p>
<p>before it was just fake content in here. actually, it was the word "content" repeated over and over.</p>
<p>i guess he's got a point, tho. on some OS's it was hard to tell anything was happening when it was the same word over and over.</p>
<p>speaking of different OS's, mac and win9x users will be happy to note that ypSimpleScroll uses the same nifty frame-dropping animation algorithm that most other yp-components use. this means that all users, regardless of their platform or processor speed, will see the scroll box move at the same speed.</p>
<p>"smoothness" is definately compromised on some crappy systems (win 9x), but atleast the user won't be sitting around for an hour waiting for the damned thing to scroll...</p>
</div>
</div>
</body>
</html>
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