<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>手机端触屏手指滑动方向及拖动层</title>
<meta content="width=device-width,initial-scale=1.0,minimum-scale=1.0,user-scalable=no,maximum-scale=1.0" id="viewport" name="viewport">
<script type="text/javascript">
var touch_screen = { //方向
direction: {
_clientX: 0,
_clientY: 0,
_moveX: 0,
_moveY: 0,
_startX: 0,
_startY: 0,
_object: null,
_direction: "no",
_controller: true,
//开始滑动、拖动
start: function() {
var self = this,
obj = self._object;
obj.addEventListener('touchstart', function(e) {
self._startX = e.touches[0].pageX;
self._startY = e.touches[0].pageY;
self._clientX = e.touches[0].clientX - parseInt(this.offsetLeft);
self._clientY = e.touches[0].clientY - parseInt(this.offsetTop);
self.move();
}, false);
obj.addEventListener('touchend', function(e) {
self._controller = true;
}, false);
},
//拖动滑动时
move: function() {
var self = this;
self._object.addEventListener('touchmove', function(e) {
if(self._controller) {
var endX, endY;
endX = e.changedTouches[0].pageX;
endY = e.changedTouches[0].pageY;
var direction = self.get_slide_direction(self._startX, self._startY, endX, endY);
switch(direction) {
case 0:
self._direction = "no";
break;
case 1:
self._direction = "right";
break;
case 2:
self._direction = "left";
break;
case 3:
self._direction = "down";
break;
case 4:
self._direction = "up";
break;
default:
}
self._controller = false;
}
e.preventDefault();
self._moveX = e.touches[0].clientX - self._clientX;
self._moveY = e.touches[0].clientY - self._clientY;
this.style.left = self._moveX + 'px';
this.style.top = self._moveY + 'px';
this.innerHTML = self._moveX + "|" + self._moveY + "|" + self._direction
}, false);
},
//计算滑动角度
get_slide_angle: function(a, b) {
return Math.atan2(a, b) * 180 / Math.PI;
},
//根据角度给出方向
get_slide_direction: function(a, b, c, d) {
var dy = b - d;
var dx = c - a;
var result = 0;
if(Math.abs(dx) < 2 && Math.abs(dy) < 2) {
return result
}
var angle = this.get_slide_angle(dx, dy);
if(angle >= -45 && angle < 45) {
result = 4;
} else if(angle >= 45 && angle < 135) {
result = 1;
} else if(angle >= -135 && angle < -45) {
result = 2;
} else if((angle >= 135 && angle <= 180) || (angle >= -180 && angle < -135)) {
result = 3;
}
return result;
},
//通过一个dom对象进行初始化
init: function(a) {
var class_clone = function(source) {
var result = {};
for(var key in source) {
result[key] = typeof source[key] === "object" ? class_clone(source[key]) : source[key];
}
return result;
}
var self = class_clone(touch_screen.direction);
self._object = document.getElementById(a);
if(!self._object) {
alert('bind_object is not an object');
return false;
}
self.start();
}
}
}
//页面加载完成
window.onload = function() {
touch_screen.direction.init("test_div");
touch_screen.direction.init("test_div2");
}
</script>
<style type="text/css">
#test_div,
#test_div2 {
100px;
height: 100px;
line-height: 100px;
text-align: center;
background: #999;
position: absolute;
left: 0;
top: 0;
}
</style>
</head>
<body>
<div id="test_div"></div>
<div id="test_div2"></div>
</body>
</html>