IOS Android Ipad 多点触摸通用js 库(2)

p>document.getElementsByTagName('head')[0].appendChild(meta);

p> 

p>meta = document.createElement('meta');

p>meta.setAttribute('name', 'viewport');

p>meta.setAttribute('content', 'width=device-width; initial-scale=1.0; maximum-scale=1.0; user-scalable=0;');

p>document.getElementsByTagName('head')[0].appendChild(meta);

p> 

p>meta = document.createElement('meta');

p>meta.setAttribute('name', 'viewport');

p>meta.setAttribute('content', 'width=device-width');

p>document.getElementsByTagName('head')[0].appendChild(meta);

p> 

p>var TouchType =

p>{

p>Up: 1,

p>Down: 2,

p>Left: 3,

p>Right: 4,

p>Zoom: 5

p>}

p> 

p>function documentTouchEvent(event) {

p>//只跟踪一次触摸

p>if (event.touches.length == 1) {

p>switch (event.type) {

p>case "touchstart":

p>event.preventDefault(); //阻止滚动

p>break;

p>case "touchend":

p>event.preventDefault(); //阻止滚动

p>break;

p>case "touchmove":

p>event.preventDefault(); //阻止滚动

p>break;

p>}

p>}

p>}

p> 

p>document.addEventListener("touchstart", documentTouchEvent, false);

p>document.addEventListener("touchend", documentTouchEvent, false);

p>document.addEventListener("touchmove", documentTouchEvent, false);

p> 

p>//计算两坐标直线距离

p>function CoordinateDistance(x1, y1, x2, y2) {

p>return Math.sqrt(Math.pow(x1 - x2, 2) + Math.pow(y1 - y2, 2));

p>}

p> 

p>//计算缩放比

p>function Scaling(x1, y1, x2, y2, x3, y3, x4, y4) {

p>return (CoordinateDistance(x2, y2, x4, y4) / CoordinateDistance(x1, y1, x3, y3)).toFixed(2);

p>}

p> 

p>function YXMTouch(TouchObjId, MinDelay, LogObjId, IsLog, CallBack) {

p>var minTime = MinDelay;

p>var startTime = 0;

p>var SX = 0;

p>var SY = 0;

p>var EX = 0;

p>var EY = 0;

p>var SX1 = 0;

p>var SY1 = 0;

p>var EX1 = 0;

p>var EY1 = 0;

p>var output = document.getElementById(LogObjId);

p>var isLog = IsLog == null ? false : IsLog;

p> 

p>function handleTouchEvent(event) {

p>switch (event.type) {

p>case "touchstart":

p>SX = event.touches[0].clientX;

p>SY = event.touches[0].clientY;

p>if (this.isLog)

p>output.innerHTML = "触摸开始0 (" + SX + "," + SY + ")" + "\n";

p>try {

p>SX1 = event.touches[1].clientX;

p>SY1 = event.touches[1].clientY;

p>if (this.isLog)

p>output.innerHTML = "触摸开始1 (" + SX1 + "," + SY1 + ")" + "\n";

p>}

p>catch (err) { }

p>startTime = event.timeStamp;

p> 

p>break;

p>case "touchend":

p>startTime = 0;

p>if (this.isLog)

p>output.innerHTML += "触摸结束 (" + event.changedTouches[0].clientX + "," + event.changeTouches[0].clientY + ")" + "\n";