Advanced Programming Topics: Canvas and Video Các khả năng nền tảng duy nhất của iPhone và iPod touch cho phép các nhà phát triển để tạo ra các ứng dụng sáng tạo bên trong của điện thoại di động Safari mà vượt qua được những ứng dụng web bình thường "Web app" | 6 Advanced Programming Topics Canvas and Video The unique platform capabilities of iPhone and iPod touch enable developers to create innovative applications inside of Mobile Safari that go beyond the normal Web app fare. Mobile Safari s support for the canvas element opens drawing and animation capabilities in an ordinary HTML page that was previously available only by using Flash or Java. What s more deep inside the heart of these two Apple devices lies the best portable audio and video media player that money can buy. As an application developer you can take advantage of these iPod capabilities by seamlessly integrating multimedia into your mobile applications. However once you begin to open up these capabilities of Mobile Safari or the device itself you need to be sure that you are working with an iPhone and iPod touch rather than a desktop browser. So I ll start by showing you how to identify the user agent for iPhone and iPod touch. Identifying the User Agent for iPhone and iPod touch When you are trying to identify the capabilities of the browser requesting your Web site or application you generally want to avoid detecting the user agent and use object detection instead. However if you are developing an application designed exclusively for iPhone iPod touch or need Safari-specific features such as canvas then user agent detection is a valid option. Therefore this chapter assumes you are creating a Mobile Safari-specific application. Chapter 8 discusses using media queries in general Web contexts. Chapter 6 Advanced Programming Topics Canvas and Video The Mobile Safari user agent string for iPhone closely resembles the user agent for Safari on other platforms. However it contains an iPhone platform name and the mobile version number. Depending on the version of Mobile Safari it will look something like this Mozilla iPhone U CPU like Mac OS X en AppleWebKit 420 KHTML like Gecko Version Mobile 1A543a Safari Here s a breakdown of the various .
