examples/ch04/01-drawing-app.html

<!doctype html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Drawing App</title>
    <link rel="stylesheet" href="../include/style.css">
  </head>
  <body>
    <header>
      Example from <a href="http://amzn.com/1430236655?tag=html5anim-20"><em>Foundation HTML5 Animation with JavaScript</em></a>
    </header>
    <canvas id="canvas" width="400" height="400"></canvas>
    <aside>Click and draw with the mouse.</aside>
    
    <script src="../include/utils.js"></script>
    <script>
    window.onload = function () {
      var canvas = document.getElementById('canvas'),
          context = canvas.getContext('2d'),
          mouse = utils.captureMouse(canvas);

      canvas.addEventListener('mousedown', function () {
        context.beginPath();
        context.moveTo(mouse.x, mouse.y);
        canvas.addEventListener('mousemove', onMouseMove, false);
      }, false);

      canvas.addEventListener('mouseup', function () {
        canvas.removeEventListener('mousemove', onMouseMove, false);
      }, false);

      function onMouseMove () {
        context.lineTo(mouse.x, mouse.y);
        context.stroke();
      }
    };
    </script>
  </body>
</html>