Textbox make the text shrink to fit

Textbox make the text shrink to fit

HTML

<script src="https://rawgithub.com/kangax/fabric.js/master/dist/fabric.js"></script>
<canvas id="c" width="600" height="600"></canvas>

CSS

canvas {
    border: 1px solid #999;
}

JavaScript

var canvas = new fabric.Canvas('c');
var t1 = new fabric.Textbox('MyText', {
    width: 150,
    top: 5,
    left: 5,
    fontSize: 16,
    textAlign: 'center',
    fixedWidth: 150
});

canvas.on('text:changed', function(opt) {
  var t1 = opt.target;
  if (t1.width > t1.fixedWidth) {
    t1.fontSize *= t1.fixedWidth / (t1.width + 1);
    t1.width = t1.fixedWidth;
  }
});

canvas.add(t1);