JavaScript 移动端电子书翻页效果实现方案

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0, maximum-scale=1.0, user-scalable=no">
    <title>手机端书本翻页效果</title>
    <style type="text/css">
      * {
        padding: 0;
        margin: 0;
      }
 
      html,
      body {
        height: 100%;
        width: 100%;
      }
 
      #magazine {
        width: 100%;
        height: 100%;
        position: relative;
        overflow: hidden;
         
      }
 
      #pages {
        width: 100%;
        height: 100%;
        position: relative;
        z-index: 1;
      }
      #pages div.turn-page{
        background: #fff;
      }
      #content{
        height: 0;
        overflow: hidden;
        width: 100%;
      }
      #contentText{
        width: 100%;
      }
       
      /* 这里是内容的样式,修改时候,一起修改 */
      div.turn-page,#contentText{
        white-space: pre-wrap;
        box-sizing: border-box;
        padding: 0 10px;
      }
       
       
      #alert{
        position: absolute;
        bottom: 40px;
        left: 50%;
        transform: translateX(-50%);
        background: rgba(0,0,0,0.6);
        border-radius: 4px;
        color: #fff;
        z-index: 10;
        font-size: 12px;
        padding: 6px 10px;
        display: none;
      }
    </style>
  </head>
  <body>
 
    <div id="magazine">
      <div id="pages"></div>
      <div id="content">
        <div id="contentText"></div>
      </div>
    </div>
    <div id="alert"></div>
    <script type="text/javascript" src="js/jquery-3.3.1.min.js"></script>
    <script type="text/javascript" src="js/turn.js"></script>
     
    <script type="text/javascript">
      var writeStr = ""
       
      //模拟请求文本数据
      $.get("./js/data.txt",function(data){
        initPage(data);
      })
       
 
      function initPage(writeStr){
        if(!writeStr){
          return ;
        }
       
        var $wrap = $("#magazine");
        var $page = $("#pages");
        var w =$page.width(); //窗口的宽度
        var h = $page.height(); //窗口的高度
        console.log(h)
        var $content = $("#contentText");
         
        $content.html(writeStr);
        var len = writeStr.length; //总长度
        var cH = $content.height(); //总高度
        var pageStrNum; //每页大概有多少个字符
        if(cH > h){
          pageStrNum = (h / cH )*len; //每页大概有多少个字符
          var obj = overflowhiddenTow($content,writeStr,h);
          $page.append('<div>'+obj.curr+'</div>');
          while(obj.next && obj.next.length > 0){
            obj = overflowhiddenTow($content, obj.next,h);
            $page.append('<div>'+obj.curr+'</div>');
          }
        }else{
          return ;
        }
         
        //文字切割算法
        function overflowhiddenTow($texts, str , at) {
          var throat = pageStrNum;
          var tempstr = str.substring(0, throat);
          var len = str.length;
          $texts.html(tempstr);
          //取的字节较少,应该增加
          while ($texts.height() < at && throat < len) {
            throat = throat + 2;
            tempstr = str.substring(0, throat);
            $texts.html(tempstr);
          }
          //取的字节较多,应该减少
          while ($texts.height() > at && throat > 0) {
            throat = throat - 2;
            tempstr = str.substring(0, throat);
            $texts.html(tempstr);
          }
           
          return {
            curr:str.substring(0,throat),
            next:str.substring(throat)
          }
         
        }
         
        $page.turn({
          width: w,
          height: h,
          elevation: 50,
          display: 'single',
          gradients: true,
          autoCenter: true,
          when: {
            start: function() {},
            turning: function(e, page, view) {},
            turned: function(e, page, view) {
               
            }
          }
        });
         
         
         
        var moveObj = null;
        var endObj = null;
         
        function getPoint(e) {
          var obj = e;
          if (e.targetTouches && e.targetTouches.length > 0) {
            obj = e.targetTouches[0];
          }
          return obj;
        }
         
         
        $wrap.on("touchstart mousedown", function(e) {
          var obj = getPoint(e);
          moveObj = {
            x: obj.clientX
          };
        });
        $wrap.on("touchmove mousemove", function(e) {
          var obj = getPoint(e);
          endObj = {
            x: obj.clientX
          };
        });
         
         
        $wrap.on("touchend mouseup", function(e) {
          if (moveObj && endObj) {
            var mis = endObj.x - moveObj.x;
            if (Math.abs(mis) > 30) {
              var pageCount = $page.turn("pages"); //总页数
              var currentPage = $page.turn("page"); //当前页
              if (mis > 0) {
                if (currentPage > 1) {
                  $page.turn('page', currentPage - 1);
                } else {
                  console.log("已经是第一页")
                  showAlert('已经是第一页');
                }
              } else {
                if (currentPage < pageCount) {
                  $page.turn('page', currentPage + 1);
                } else {
                  console.log("最后一页");
                  showAlert('已经是最后一页');
                }
              }
         
            }
         
          }
          moveObj = null;
          endObj = null;
        });
         
        var $alert = $("#alert");
        var timer = null;
        function showAlert(msg){
          clearTimeout(timer);
          $alert.text(msg);
          $alert.fadeIn();
          timer = setTimeout(function(){
            $alert.fadeOut();
          },1000)
        }
      }
    </script>
  </body>
</html>