script06.js

来自「图灵程序设计丛书 JavaScript基础教程源代码」· JavaScript 代码 · 共 53 行

window.onload = rolloverInit;

function rolloverInit() {
	for (var i=0; i<document.links.length; i++) {
		var linkObj = document.links[i];
		if (linkObj.className) {
			var imgObj = document.getElementById(linkObj.className);
			if (imgObj) {
				setupRollover(linkObj,imgObj);
			}
		}
	}
}

function setupRollover(thisLink,textImage) {
	thisLink.imgToChange = new Array;
	thisLink.outImage = new Array;
	thisLink.overImage = new Array;

	thisLink.imgToChange[0] = textImage;
	thisLink.onmouseout = rollOut;
	thisLink.onmouseover = rollOver;	
	
	thisLink.outImage[0] = new Image();
	thisLink.outImage[0].src = textImage.src;

	thisLink.overImage[0] = new Image();
	thisLink.overImage[0].src = "images/" + thisLink.id + "Text.gif";
	
	var rolloverObj = document.getElementById(thisLink.id + "Img");
	if (rolloverObj) {
		thisLink.imgToChange[1] = rolloverObj;

		thisLink.outImage[1] = new Image();
		thisLink.outImage[1].src = rolloverObj.src;
	
		thisLink.overImage[1] = new Image();
		thisLink.overImage[1].src = "images/" + thisLink.id + "_on.gif";
	} 
}

function rollOver() {
	for (var i=0;i<this.imgToChange.length; i++) {
		this.imgToChange[i].src = this.overImage[i].src;
	}
}

function rollOut() {
	for (var i=0;i<this.imgToChange.length; i++) {
		this.imgToChange[i].src = this.outImage[i].src;
	}
}