[Examples] Move several simpler, single-purpose examples to extras to ensure Travis does not time out.

examples_extra/BackgroundPropertySetting/Sample/ViewController.swift

@@ -0,0 +1,95 @@
+//
+//  ViewController.swift
+//  BackgroundPropertySetting
+//
+//  Created by Adlai Holler on 2/17/16.
+//  Copyright © 2016 Adlai Holler. All rights reserved.
+//
+
+import UIKit
+import AsyncDisplayKit
+
+final class ViewController: ASViewController, ASCollectionDelegate, ASCollectionDataSource {
+	let itemCount = 1000
+
+	let itemSize: CGSize
+	let padding: CGFloat
+	var collectionNode: ASCollectionNode {
+		return node as! ASCollectionNode
+	}
+
+	init() {
+		let layout = UICollectionViewFlowLayout()
+		(padding, itemSize) = ViewController.computeLayoutSizesForMainScreen()
+		layout.minimumInteritemSpacing = padding
+		layout.minimumLineSpacing = padding
+		super.init(node: ASCollectionNode(collectionViewLayout: layout))
+		navigationItem.rightBarButtonItem = UIBarButtonItem(title: "Color", style: .Plain, target: self, action: #selector(didTapColorsButton))
+		navigationItem.leftBarButtonItem = UIBarButtonItem(title: "Layout", style: .Plain, target: self, action: #selector(didTapLayoutButton))
+		collectionNode.delegate = self
+		collectionNode.dataSource = self
+		title = "Background Updating"
+	}
+
+	required init?(coder aDecoder: NSCoder) {
+	    fatalError("init(coder:) has not been implemented")
+	}
+
+	// MARK: ASCollectionDataSource
+
+	func collectionView(collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
+		return itemCount
+	}
+
+	func collectionView(collectionView: ASCollectionView, nodeBlockForItemAtIndexPath indexPath: NSIndexPath) -> ASCellNodeBlock {
+		return {
+			let node = DemoCellNode()
+			node.backgroundColor = UIColor.random()
+			node.childA.backgroundColor = UIColor.random()
+			node.childB.backgroundColor = UIColor.random()
+			return node
+		}
+	}
+
+	func collectionView(collectionView: ASCollectionView, constrainedSizeForNodeAtIndexPath indexPath: NSIndexPath) -> ASSizeRange {
+		return ASSizeRangeMake(itemSize, itemSize)
+	}
+
+	// MARK: Action Handling
+
+	@objc private func didTapColorsButton() {
+		let currentlyVisibleNodes = collectionNode.view.visibleNodes()
+		let queue = dispatch_get_global_queue(QOS_CLASS_DEFAULT, 0)
+		dispatch_async(queue) {
+			for case let node as DemoCellNode in currentlyVisibleNodes {
+				node.backgroundColor = UIColor.random()
+			}
+		}
+	}
+
+	@objc private func didTapLayoutButton() {
+		let currentlyVisibleNodes = collectionNode.view.visibleNodes()
+		let queue = dispatch_get_global_queue(QOS_CLASS_DEFAULT, 0)
+		dispatch_async(queue) {
+			for case let node as DemoCellNode in currentlyVisibleNodes {
+				node.state.advance()
+				node.setNeedsLayout()
+			}
+		}
+	}
+
+	// MARK: Static
+
+	static func computeLayoutSizesForMainScreen() -> (padding: CGFloat, itemSize: CGSize) {
+		let numberOfColumns = 4
+		let screen = UIScreen.mainScreen()
+		let scale = screen.scale
+		let screenWidth = Int(screen.bounds.width * screen.scale)
+		let itemWidthPx = (screenWidth - (numberOfColumns - 1)) / numberOfColumns
+		let leftover = screenWidth - itemWidthPx * numberOfColumns
+		let paddingPx = leftover / (numberOfColumns - 1)
+		let itemDimension = CGFloat(itemWidthPx) / scale
+		let padding = CGFloat(paddingPx) / scale
+		return (padding: padding, itemSize: CGSize(width: itemDimension, height: itemDimension))
+	}
+}