tailieunhanh - Professionali Phone and iPod touch Programming phần 2

Khi bạn phát triển các ứng dụng cho iPhone và iPod touch, một trong xem xét thiết kế quan trọng mà bạn cần để khoan vào tâm thức của bạn là ngón tay không phải là một con chuột. Trên máy tính, người dùng có thể sử dụng một loạt các thiết bị đầu vào - chẳng hạn như một Mighty Mouse của Apple, | Chapter 1 The iPhone and iPod touch Development Platform .u. AT T 1 24 PM Figure 1-10 Application emulating Apple UI design The Finger Is Not a Mouse As you develop applications for iPhone and iPod touch one key design consideration that you need to drill into your consciousness is that the finger is not a mouse. On the desktop a user can use a variety of input devices such as an Apple Mighty Mouse a Logitech trackball or a laptop touchpad. But on screen the mouse pointer for each of these pieces of hardware is always identical in shape size and behavior. However on iPhone and iPod touch the pointing device is always going to be unique. Ballerinas for example will probably input with tiny thin fingers while NFL players will use big fat input devices. Most of the rest of us will fall somewhere in between. Additionally fingers are also not nearly as precise as mouse pointers are making interface sizing and positioning issues very important whether you are creating an iPhone iPod touch-friendly Web site or a full-fledged iPhone iPod touch application. Additionally finger input does not always correspond to a mouse input. A mouse has a left click right click scroll and mouse move. In contrast a finger has a tap flick drag and pinch. However as an application developer you will want to manage what types of gestures your application supports. Some 8 Chapter 1 The iPhone and iPod touch Development Platform of the gestures that are used for browsing Web sites such as the double-tap zoom are actually not something you want to support inside of an iPhone and iPod touch application. Table 1-2 displays the gestures that are supported on iPhone and iPod touch as well as an indication as to whether this type of gesture should be supported on a Web site or application. However as Chapter 5 explains in detail you will not have programmatic access to managing all of these inputs inside of Mobile Safari. Table 1-2 Finger Gestures Gesture Result Web site App Tap Equivalent to a mouse