每天学习一点点---------------------------------------------------移动端的那些小东西
1.首先用的模块加载时seaJS

define(function(require, exports, module) {}）-------------------------加载模块。
module.exports = {   
            AssistiveTouch: AssistiveTouch
                    };----------------------------------------------暴露模块，方便调用。

2、我们需要获取点击 || 触摸位置(兼容)

function mousePosition(ev){    
if(ev.targetTouches&&ev.targetTouches[0]){
        return {x:ev.targetTouches[0].pageX, y:ev.targetTouches[0].pageY};    
}    
if(ev.touches&&ev.touches[0]){
        return {x:ev.touches[0].pageX, y:ev.touches[0].pageY};    
}    
if(ev.changedTouches&&ev.changedTouches[0]){
        return {x:ev.changedTouches[0].pageX, y:ev.changedTouches[0].pageY};    
}    
if(ev.pageX || ev.pageY){
        return {x:ev.pageX, y:ev.pageY};    
}    
return {        
          x:ev.clientX + document.body.scrollLeft - document.body.clientLeft,        
          y:ev.clientY + document.body.scrollTop - document.body.clientTop      
      };
}

3.控件对象本身

function AssistiveTouch(sets,clickFunc){
      var atClass=(sets.atClass)?sets.atClass:“”，
           imgUrl=(sets.imgUrl)?sets.imgUrl:",             //图片地址
           closeBtn=(sets.closeBtn)?sets.closeBtn:false;  // 图片按钮
           clipH=(sets.clipH)?sets.clipH:0;                //切割的高度
           clipW = (sets.clipW)?sets.clipW:0,              //切割宽度
           autoSide=(sets.autoSide)?sets.autoSide:false;   //自动停靠
    $(atClass).css("position","fixed");
    $(atClass).css("z-index","100");
    $(atClass).append('<div class="assistive-touch-content"></div>');   ----添加样式
    if(imgUrl){ $(".assistive-touch-content").css("background-image","url('"+imgUrl+"')");}
    if(closeBtn){
            $(atClass).append('<div class="assistive-touch-close-btn">×</div>');
            }
            $(".assistive-touch-close-btn").on(" click mouseup touchend",function(e){  //防止点击事件刺穿    
            window.event? window.event.cancelBubble = true : e.stopPropagation();    
            $(atClass).hide();
      }); ----------------------------------------------------点击关闭
      $(atClass).on("mousedown touchstart",function(e){
            var e=e||window.event;
            e.preventDefault();
            var mousePos=mousePosition(e);
            $(this).attr("moving","true");
            $(this).attr("offset-left",mousePos.x-$(this)[0].offsetLeft);
            $(this).attr("offset-top",mousePos.y-$(this)[0].offsetTop);
            $(this).attr("origin-left",mousePos.x);
            $(this).attr("origin-top",mousePos.y);
      })-------------------------------------------------开始触摸的位置
      $(atClass).on("mouseup touchend",function(e){
            if($(this).attr("moving")!="true")return; 
            var e=e||window.event;
            e.preventDefault();
            var mousePos=mousePosition(e);
            $(this).[0].style.left = (mousePos.x-$(this).attr("offset-left"))+"px";
            $(this)[0].style.top = (mousePos.y-$(this).attr("offset-top"))+"px";
      })-------------------------------------------------触摸中的位置
      $(atClass).on("mouseup touchend",function(e){
            var e=e||window.event;
            e.preventDefault();
            var windowHeight = document.documentElement.clientHeight||document.body.clientHeight;
            var windowWidth = document.documentElement.offsetWidth||document.body.offsetWidth;
            windowHeight += clipH;
            windowWidth += clipW;
            $(this).attr("moving","false");
            var mousePos = mousePosition(e);
            $(this)[0].style.top = (mousePos.y-$(this).attr("offset-top"))+"px";
            if(Math.abs(mousePos.x-$(this).attr("origin-left"))<=3||Math.abs(mousePos.y-$(this).attr("origin-top"))<=3){
                 $(this)[0].style.left = ($(this).attr("origin-left")-$(this).attr("offset-left"))+"px";
                 $(this)[0].style.top = ($(this).attr("origin-top")-$(this).attr("offset-top"))+"px"; 
                 $(this).click(function(e){
                       clickFunc($(".assistive-touch-content")[0],$(this)[0]);
                 });
                 $(this).click();
                 return;
            }
            $(".assistive-touch-close-btn").removeClass("right").removeClass('top');
            function sideOverflowFunc(t) {
                if(t[0].offsetLeft<0){
                    t[0].style.left = 0;
                }
                if((t[0].offsetTop+t[0].offsetHeight)>windowHeight){
                    t[0].style.top = (windowHeight - t[0].offsetHeight)+"px";
                }
                if((t[0].offsetLeft+t[0].offsetWidth)>windowWidth){
                    t[0].style.left = (windowWidth - t[0].offsetWidth)+"px";
                    $(".assistive-touch-close-btn").addClass("right");
                }
            }--------------------------------------------------------------------临界值处理
            function autoSideFunc(t){
                if (!autoSide)return;
                if(t[0].offsetTop<windowHeight/10){
                    t.animate({top:"0px"},200);
                    $(".assistive-touch-close-btn").addClass("top");
                    return;
                }else if(t[0].offsetTop+t[0].offsetHeight>windowHeight/10*9){
                    t.animate({top:(windowHeight-t[0].offsetHeight)+"px"},200);
                    return;
                }  
                if(t[0].offsetLeft+(t[0].offsetWidth/2)<=windowWidth/2){
                    t.animate({left:"0px"},200);
                }else{
                    t.animate({left:(windowWidth-t[0].offsetWidth)+"px"},200);
                    $(".assistive-touch-close-btn").addClass("right");
                }
           }--------------------------------------------------------------临界靠边的动画
           sideOverflowFunc($(this));
           autoSideFunc($(this));
      })------------------------------------------------------------------触摸结束的处理的位置
return $(atClass);--------------------------------------------------------返回对象
}

4.调用：

assTouch.AssistiveTouch({    
    atClass:".js_drap_img",    
    imgUrl:config.baseloc+"images/index/fenqi2_icon.png",
    closeBtn:false,    
    autoSide:true,    
    clipH:-50
},function(content,self){    
    com.jumpUrl("lend/frontstage.html?productId=1&footer=1&productType=2",config.USERCERTIFICATION);
});