onDraw firing twice

[relez]

Hi there, I am trying to add this feature into my Cordova app and I just noticed that the event onDraw is being fired twice when I draw the pattern.

My code is very simple:

var pattern = new PatternLock(
        '#mypattern', 
        {
            matrix: [4,4], 
            radius: 20,
            onDraw: function(pattern) {
                pattern.disable();
            }
        }
    );

Any reason why? Thanks!