Canvas Programming: The Clock in HTML

Canvas Programming: The Clock in Simple HTML/JavaScript Editor

In the text window you see a text of the HTML and javascript - the canvas clock The clock code here originates from
http://developer.mozilla.org/en/Canvas_tutorial/Basic_animations

You can edit and type as much HTML or JavaScript (or a mixture of both) as you like.

To return from the text use BACK button of the browser or close the extra window

<body>
<canvas id="canvas" width="300" height="300"></canvas>
<script>
//   FROM  http://developer.mozilla.org/en/Canvas_tutorial/Basic_animations
init();

function init(){
  clock();
  setInterval(clock,1000);
}
function clock(){
  var now = new Date();
  var ctx = document.getElementById('canvas').getContext('2d');
  ctx.save();
  ctx.clearRect(0,0,150,150);
  ctx.translate(75,75);
  ctx.scale(0.4,0.4);
  ctx.rotate(-Math.PI/2);
  ctx.strokeStyle = "black";
  ctx.fillStyle = "white";
  ctx.lineWidth = 8;
  ctx.lineCap = "round";

// Hour marks
  ctx.save();
  for (i=0;i<12;i++){
    ctx.beginPath();
    ctx.rotate(Math.PI/6);
    ctx.moveTo(100,0);
    ctx.lineTo(120,0);
    ctx.stroke();
  }
  ctx.restore();

// Minute marks
  ctx.save();
  ctx.lineWidth = 5;
  for (i=0;i<60;i++){
    if (i%5!=0) {
      ctx.beginPath();
      ctx.moveTo(117,0);
      ctx.lineTo(120,0);
      ctx.stroke();
    }
    ctx.rotate(Math.PI/30);
  }
  ctx.restore();
  
  var sec = now.getSeconds();
  var min = now.getMinutes();
  var hr  = now.getHours();
  hr = hr>=12 ? hr-12 : hr;

ctx.fillStyle = "black";

// write Hours
  ctx.save();
  ctx.rotate( hr*(Math.PI/6) + (Math.PI/360)*min + (Math.PI/21600)*sec )
  ctx.lineWidth = 14;
  ctx.beginPath();
  ctx.moveTo(-20,0);
  ctx.lineTo(80,0);
  ctx.stroke();
  ctx.restore();

// write Minutes
  ctx.save();
  ctx.rotate( (Math.PI/30)*min + (Math.PI/1800)*sec )
  ctx.lineWidth = 10;
  ctx.beginPath();
  ctx.moveTo(-28,0);
  ctx.lineTo(112,0);
  ctx.stroke();
  ctx.restore();
  
  // Write seconds
  ctx.save();
  ctx.rotate(sec * Math.PI/30);
  ctx.strokeStyle = "#D40000";
  ctx.fillStyle = "#D40000";
  ctx.lineWidth = 6;
  ctx.beginPath();
  ctx.moveTo(-30,0);
  ctx.lineTo(83,0);
  ctx.stroke();
  ctx.beginPath();
  ctx.arc(0,0,10,0,Math.PI*2,true);
  ctx.fill();
  ctx.beginPath();
  ctx.arc(95,0,10,0,Math.PI*2,true);
  ctx.stroke();
  ctx.fillStyle = "#555";
  ctx.arc(0,0,3,0,Math.PI*2,true);
  ctx.fill();
  ctx.restore();

ctx.beginPath();
  ctx.lineWidth = 14;
  ctx.strokeStyle = '#325FA2';
  ctx.arc(0,0,142,0,Math.PI*2,true);
  ctx.stroke();

ctx.restore();
}

</script>
</body>

Clear the input

The idea of putting this together is mine (L. Kocbach)
I am frustrated by the way examples are presented. This definitely is a great approach ....
simple and working
The clock code here originates from
http://developer.mozilla.org/en/Canvas_tutorial/Basic_animations
This simple idea of HTML + Javascript interpreter is originally by (Richard Bowles) http://richardbowles.tripod.com/edres/editor.htm