José Donor iDonJose

1. The Layer Tree

Core Animation's original name is Layer Kit

Core Animation is a compositing engine; its job is to compose different pieces of visual content on the screen, and to do so as fast as possible. The content in question is divided into individual layers stored in a hierarchy known as the layer tree. This tree forms the underpinning for all of UIKit, and for everything that you see on the screen in an iOS application.

In UIView, tasks such as rendering, layout and animation are all managed by a Core Animation class called CALayer. The only major feature of UIView that isn’t handled by CALayer is user interaction.

There are four hierarchies, each performing a different role:

	protocol NibInstantiatable {
	static var NibName: String { get }
	}

	extension NibInstantiatable {

	static var NibName: String { return String(Self) }

	static func instantiate() -> Self {
	return instantiateWithName(NibName)

	@implementation UIApplication (AppVersion)

	+ (NSString *) appVersion
	{
	return [[NSBundle mainBundle] objectForInfoDictionaryKey: @"CFBundleShortVersionString"];
	}

	+ (NSString *) build
	{
	return [[NSBundle mainBundle] objectForInfoDictionaryKey: (NSString *)kCFBundleVersionKey];

	<?xml version="1.0" encoding="UTF-8"?>
	<Bucket
	type = "2"
	version = "2.0">
	<Breakpoints>

	<!-- All Exceptions -->
	<BreakpointProxy
	BreakpointExtensionID = "Xcode.Breakpoint.ExceptionBreakpoint">
	<BreakpointContent

	require 'rubygems'
	require 'yaml'

	# A demonstration of YAML anchors, references and handling of nested values
	# For more info, see:
	# http://atechie.net/2009/07/merging-hashes-in-yaml-conf-files/

	stooges = YAML::load( File.read('stooges.yml') )
	# => {
	# "default" => {

José Donor iDonJose

1. The Layer Tree

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