Of Stack

Method for Circular Motion of JS Control Layer

  • 2021-06-29 06:22:50
  • OfStack

In this paper, the method of circular motion of JS control layer is illustrated with an example.Share it for your reference, as follows: 


<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" 
"http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title> Circular motion </title>
<script type = "text/javascript">
   window.onload = function(){
    var ctrlBtn = $id("ctrl");
    var isMove = true;
    oM = null;
    ctrlBtn.onclick = function(){
    if(isMove){
    moveByCircle();
    }else{
    clearInterval(oM);
    }
    isMove = !isMove;
    }
   }
   function moveByCircle(){
    var bacL = parseInt($id("clockBac").style.left);
    var bacT = parseInt($id("clockBac").style.top);
    var bacW = parseInt($id("clockBac").style.width);
    var bacH = parseInt($id("clockBac").style.height);
    var initL = bacL+bacW/2;
    var initT = bacT+bacH/2;
    var step = 0;
    var r = 65;
    $id("tt").style.left = initL+"px";
    $id("tt").style.top = initT+"px";
    var l = parseInt($id("tt").style.left);
    var t = parseInt($id("tt").style.top);
    oM = window.setInterval(function(){
     if (step == 360) {
      step = 1;
     }
     $id("tt").style.left = (l + r * Math.sin(step)) + "px";
     $id("tt").style.top = (t - r * Math.cos(step)) + "px";
     step += 3.14/30;
      var d = new Date();
      var hh = d.getHours();
      var mm = d.getMinutes();
      var ss = d.getSeconds();
      $id("ctrl").value = hh+":"+mm+":"+ss;
    }, 1000);
   }
   function $id(id){
    return document.getElementById(id);
   }
</script>
</head>
<body>
<div id = "tt" style ="width:10px;height:10px;background:red;position:absolute;top:105px;left:130px;"></div>
<input type = "button" id = "ctrl" style = "width:100px;position:absolute;"/>
<img src = "../img/clock.jpg" id = "clockBac" style ="width:200px;height:200px;top:100px;left:100px;position:absolute;z-index:-999"/>
</body>
</html>

More readers interested in JavaScript related content can view this site's topics: JavaScript Switching Special Effects and Techniques Summary, JavaScript Finding Algorithmic Techniques Summary, JavaScript Animation Special Effects and Techniques Summary, JavaScript Errors and Debugging Techniques Summary, JavaScript Data Structure and Algorithmic Techniques Summary,Summary of JavaScript Traversal Algorithms and Techniques and Summary of JavaScript Mathematical Operation Usage

I hope that the description in this paper will be helpful to everyone's JavaScript program design.

Related articles: