html5圆形进度条加载按钮效果

<script type="text/javascript" src="js/classie.js"></script>
<script type="text/javascript" src="js/uiProgressButton.js"></script>
<script type="text/javascript">
[].slice.call( document.querySelectorAll( '.progress-button' ) ).forEach( function( bttn, pos ) {
	new UIProgressButton( bttn, {
		callback : function( instance ) {
			var progress = 0,
				interval = setInterval( function() {
					progress = Math.min( progress + Math.random() * 0.1, 1 );
					instance.setProgress( progress );

					if( progress === 1 ) {
						instance.stop( pos === 1 || pos === 3 ? -1 : 1 );
						clearInterval( interval );
					}
				}, 150 );
		}
	} );
} );
</script>