smileyborg

// UICollectionView Objective-C example

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
        
    NSIndexPath *selectedIndexPath = [[self.collectionView indexPathsForSelectedItems] firstObject];
    if (selectedIndexPath != nil) {
        id<UIViewControllerTransitionCoordinator> coordinator = self.transitionCoordinator;
        if (coordinator != nil) {
            [coordinator animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext> context) {

chriseidhof

import Foundation

protocol Channel: IteratorProtocol {
    func send(_ value: Element?)
}

/// A blocking channel for sending values.
///
/// `send` and `receive` must run in separate separate execution contexts, otherwise you get a deadlock.
final class BlockingChannel<A>: Channel {

shaps80

//
//  AppDelegate.swift
//  Scheduling
//
//  Created by Shaps Benkau on 19/02/2018.
//  Copyright © 2018 152percent Ltd. All rights reserved.
//

import UIKit

gokselkoksal

public class Channel<Value> {
    
    private class Subscription {
        
        weak var object: AnyObject?
        private let notifyBlock: (Value) -> Void
        private let queue: DispatchQueue
        
        var isValid: Bool {
            return object != nil

tclementdev

libdispatch efficiency tips

The libdispatch is one of the most misused API due to the way it was presented to us when it was introduced and for many years after that, and due to the confusing documentation and API. This page is a compilation of important things to know if you're going to use this library. Many references are available at the end of this document pointing to comments from Apple's very own libdispatch maintainer (Pierre Habouzit).

My take-aways are:

• You should create very few, long-lived, well-defined queues. These queues should be seen as execution contexts in your program (gui, background work, ...) that benefit from executing in parallel. An important thing to note is that if these queues are all active at once, you will get as many threads running. In most apps, you probably do not need to create more than 3 or 4 queues.

• Go serial first, and as you find performance bottle necks, measure why, and if concurrency helps, apply with care, always validating under system pressure. Reuse

shaps80

//
//  UserDefaults.swift
//  
//  Created by Shaps Benkau on 24/05/2018.
//  Copyright © 2018 152percent Ltd. All rights reserved.
//

import Foundation

#if os(iOS)

myell0w

extension UIView {
    func findFirstSuperview<T>(ofClass viewClass: T.Type, where predicate: (T) -> Bool) -> T? where T: UIView {
        var view: UIView? = self
        while view != nil {
            if let typedView = view as? T, predicate(typedView) {
                break
            }

            view = view?.superview
        }

chriseidhof

//
//  Library.swift
//  LabelLayout
//
//  Created by Chris Eidhof on 09.09.18.
//  Copyright © 2018 objc.io. All rights reserved.
//

import UIKit

joshavant

extension UIView {
    @objc func exerciseAmbiguityInLayoutRepeatedly() {
        if self.hasAmbiguousLayout {
            Timer.scheduledTimer(timeInterval: 0.5,
                                 target: self,
                                 selector: #selector(UIView.exerciseAmbiguityInLayout),
                                 userInfo: nil,
                                 repeats: true)
        }
    }

michaeleisel

// Note that this checker is always running, even when the app is in the background (where it doesn't matter if the main thread is blocked)
// You'll have to add more code if you don't want the checker to run while the app is in the background
final class ANRChecker {
    private let ANRThreshold: CFTimeInterval = 5

    // This variable may be accessed from multiple threads at the same time. It won't cause issues, but if you want prevent the thread sanitizer from complaining, you can add locking around it or w/e
    private lazy var lastResponseTime: CFTimeInterval = CACurrentMediaTime()

    func beginChecking() {
        updateLastResponseTime()