TAILIEUCHUNG - Lập trình iPhone part 13

Màn hình iPhone, sắc nét, sáng, 160 điểm ảnh / inch hiển thị cảm ứng, thật sự là một thứ của vẻ đẹp và một kiệt tác của kỹ thuật. màn hình đa chạm của iPhone là một trong những yếu tố quan trọng trong khả năng sử dụng to lớn của iPhone | .13 Chap Taps Touches and Gestures he iPhone screen with its crisp bright 160 pixels per inch touch-sensitive display is truly a thing of beauty and a masterpiece of engineering. The iPhone s multitouch screen is one of the key factors in iPhone s tremendous usability. Because the screen can detect multiple touches at the same time and track them independently applications are able to detect a wide range of gestures giving the user power that goes beyond the interface. Suppose you are in the Mail application exploring your inbox and you decide to delete an e-mail. You could tap the Edit button select the row and then tap the Delete button that s three steps. Or you could just swipe your finger across the row you want to delete and then tap the Delete button that pops up two steps. This example is just one of the countless gestures that are made possible by iPhone s multitouch screen. You can pinch your fingers together to zoom into a picture or reverse pinch to zoom out. You can double-tap a frame in Mobile Safari to zoom so that the frame takes up your entire screen. You can swipe two fingers across a scrollable view such as a long web page or e-mail message and the view will scroll up and down along with your fingers. In this chapter we re going to look at the underlying architecture that lets you detect gestures. You ll learn how to detect the most common ones and learn how to create and detect a completely new gesture. 401 402 CHAPTER 13 Taps Touches and Gestures Multitouch Terminology Before we dive into the architecture let s go over some basic vocabulary. First a gesture is any sequence of events that happens from the time you touch the screen with one or more fingers until you lift your fingers off the screen. No matter how long it takes as long as one or more fingers are still against the screen you are still inside a gesture unless a system event such as an incoming phone call interrupts it . A gesture is passed through the system inside an event. Events

Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.