float.js

这是matlab的一个小程序

<!--
self.onError=null;
currentX = currentY = 0;
whichIt = null;
lastScrollX = 0; lastScrollY = 0;
NS = (document.layers) ? 1 : 0;
IE = (document.all) ? 1: 0;
function heartBeat()
{
	if(IE) { diffY = document.body.scrollTop; diffX = document.body.scrollLeft; }
	if(NS) { diffY = self.pageYOffset; diffX = self.pageXOffset; }
	if(diffY != lastScrollY)
	{
		percent = .1 * (diffY - lastScrollY);
		if(percent > 0) percent = Math.ceil(percent);
		else percent = Math.floor(percent);
		if(IE) document.all.floater.style.pixelTop += percent;
		if(NS) document.floater.top += percent;
		lastScrollY = lastScrollY + percent;
	}
	if(diffX != lastScrollX)
	{
		percent = .1 * (diffX - lastScrollX);
		if(percent > 0) percent = Math.ceil(percent);
		else percent = Math.floor(percent);
		if(IE) document.all.floater.style.pixelLeft += percent;
		if(NS) document.floater.left += percent;
		lastScrollX = lastScrollX + percent;
	}

}

function checkFocus(x,y)
{

	stalkerx = document.floater.pageX;
	stalkery = document.floater.pageY;
	stalkerwidth = document.floater.clip.width;
	stalkerheight = document.floater.clip.height;
	if( (x > stalkerx && x < (stalkerx+stalkerwidth)) && (y > stalkery && y < (stalkery+stalkerheight))) return true;
	else return false;

}

function grabIt(e) {
	if(IE)
	{
		whichIt = event.srcElement;
		while (whichIt.id.indexOf("floater") == -1)
		{
			whichIt = whichIt.parentElement;
			if (whichIt == null) { return true; }
		}
		whichIt.style.pixelLeft = whichIt.offsetLeft;
		whichIt.style.pixelTop = whichIt.offsetTop;
		currentX = (event.clientX + document.body.scrollLeft);
		currentY = (event.clientY + document.body.scrollTop);
	}
	else
	{
		window.captureEvents(Event.MOUSEMOVE);
		if(checkFocus (e.pageX,e.pageY))
		{
			whichIt = document.floater;
			StalkerTouchedX = e.pageX-document.floater.pageX;
			StalkerTouchedY = e.pageY-document.floater.pageY;
		}

	}
	return true;
}

function moveIt(e) {

	if (whichIt == null) { return false; }
	if(IE) {
		newX = (event.clientX + document.body.scrollLeft);
		newY = (event.clientY + document.body.scrollTop);
		distanceX = (newX - currentX);    distanceY = (newY - currentY);
		currentX = newX;    currentY = newY;
		whichIt.style.pixelLeft += distanceX;
		whichIt.style.pixelTop += distanceY;
		if(whichIt.style.pixelTop < document.body.scrollTop) whichIt.style.pixelTop = document.body.scrollTop;
		if(whichIt.style.pixelLeft < document.body.scrollLeft) whichIt.style.pixelLeft = document.body.scrollLeft;
		if(whichIt.style.pixelLeft > document.body.offsetWidth - document.body.scrollLeft - whichIt.style.pixelWidth - 20) whichIt.style.pixelLeft = document.body.offsetWidth - whichIt.style.pixelWidth - 20;
		if(whichIt.style.pixelTop > document.body.offsetHeight + document.body.scrollTop - whichIt.style.pixelHeight - 5) whichIt.style.pixelTop = document.body.offsetHeight + document.body.scrollTop - whichIt.style.pixelHeight - 5;
		event.returnValue = false;
	}
	else
	{
		whichIt.moveTo(e.pageX-StalkerTouchedX,e.pageY-StalkerTouchedY);
		if(whichIt.left < 0+self.pageXOffset) whichIt.left = 0+self.pageXOffset;
		if(whichIt.top < 0+self.pageYOffset) whichIt.top = 0+self.pageYOffset;
		if( (whichIt.left + whichIt.clip.width) >= (window.innerWidth+self.pageXOffset-17)) whichIt.left = ((window.innerWidth+self.pageXOffset)-whichIt.clip.width)-17;
		if( (whichIt.top + whichIt.clip.height) >= (window.innerHeight+self.pageYOffset+50)) whichIt.top = ((window.innerHeight+self.pageYOffset)-whichIt.clip.height)-17;
		return false;
	}
	return false;
}

function dropIt() {
	whichIt = null;
	if(NS) window.releaseEvents (Event.MOUSEMOVE);
	return true;
}
if(NS) {
	window.captureEvents(Event.MOUSEUPEvent.MOUSEDOWN);
	window.onmousedown = grabIt;
	window.onmousemove = moveIt;
	window.onmouseup = dropIt;
}
if(IE) {
	document.onmousedown = grabIt;
	document.onmousemove = moveIt;
	document.onmouseup = dropIt;
}
if(NS || IE) action = window.setInterval("heartBeat()",1);
-->