April 2010
Beginner to intermediate
480 pages
10h 9m
English
Content preview from iPhone Programming: The Big Nerd Ranch Guide
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6. Subclassing UIView
In previous chapters, you’ve created several views: a UIButton, a UILabel, etc. But what exactly is a view?
• A view is an instance of a subclass of UIView.
• A view knows how to draw itself on the application’s window.
• A view is arranged within a hierarchy: the window (an instance of UIWindow) is itself a view and the root of the hierarchy. It has subviews (that appear on the window). Those views can also have subviews.
• A view handles touch events.
In this chapter, you are going to create your own UIView subclass that fills the screen with concentric circles as shown in Figure 6.1. You will also learn how to add text and enable scrolling and zooming.
Figure 6.1. View that draws concentric circles
Creating a Custom ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
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I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.