https://blog.toright.com/posts/3141/sencha-touch-2-%e6%95%99%e5%ad%b8-%e5%9f%ba%e6%9c%ac%e7%95%ab%e9%9d%a2%e5%85%83%e4%bb%b6%e8%88%87%e8%b3%87%e6%96%99%e6%93%8d%e4%bd%9c%e4%bb%8b%e7%b4%b9