June 2011
Intermediate to advanced
590 pages
19h 31m
English
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6Subclassing 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 UIView or one of its subclasses.
- A view knows how to draw itself on the application’s window.
A view exists within a hierarchy. The window (an instance of UIWindow) is 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 draw text and enable scrolling and zooming.
Figure 6.1 View that draws concentric circles
Creating a Custom View ...
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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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