Myndex

Let's Flip For Color

Q: I want my text color to switch to black or white, depending on the background color the user chooses. Just where is that flip point?

Short Answer:

Calculate the luminance (Y) of the given color, and flip the text either black or white based on a pre-determined middle contrast figure. For a typical sRGB display, flip to white when Y < 0.36 (i.e. 36%)

Longer Answer

First I want to acknowledge the massive amount of misinformation on the internet on this particular subject. The fact this field is still a subject of active research and unsettled science adds to the fun. I came to this conclusion as the result of the last few years of research into a new contrast prediction method for readability.

The field of visual perception is dense and abstract, as well as developing, so it is common for misunderstandings to exist. For instance, HSV and HSL are not even close to perceptually accurate. For that you need a perceptually uniform model such as CIELAB or CIELUV or CIECAM02 etc

aibo-cora

import Foundation
import AVFoundation
import CoreMedia

class Converter {
    static func configureSampleBuffer(pcmBuffer: AVAudioPCMBuffer) -> CMSampleBuffer? {
        let audioBufferList = pcmBuffer.mutableAudioBufferList
        let asbd = pcmBuffer.format.streamDescription

        var sampleBuffer: CMSampleBuffer? = nil

eneko

Xcode deinit breakpoint for UIViewController

This breakpoint provides an easy way to track view controller deinitialization (deallocation) in UIKit-based applications. This can help finding memory leaks caused by retain cycles preventing view controllers from being deinitialized when dismissed or popped.

From Cédric Luthi's tweet in 2017:

Useful Xcode breakpoint. When you dismiss a controller and you don’t hear the pop sound (or see the log), you probably have a retain cycle.

IsaacXen

WWDC                                2006  2007  2008  2009
2010 2011 2012 2013 2014 

Umity

//
//  Created by はるふ on 2017/12/11.
//  Copyright © 2017年 ha1f. All rights reserved.
//

import Foundation
import CoreImage
import AVFoundation

extension CIFilter {

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) {

0xced

{
  "People" : [
    "😀",
    "😃",
    "😄",
    "😁",
    "😆",
    "😅",
    "😂",
    "🤣",

JohnSundell

target 'MyTarget' do
    use_frameworks!

    # Post installation script that enables the Swift 4.2 compiler's
    # legacy 4.1 mode for 4.2-incompatible pods
    post_install do |installer|
      incompatiblePods = ['PodA', 'PodB']

      installer.pods_project.targets.each do |target|
          if incompatiblePods.include? target.name

nicklockwood

// Swift's untyped errors are a goddam PiTA. Here's the pattern I use to try to work around this.
// The goal is basically to try to guarantee that every throwing function in the app throws an
// ApplicationError instead of some unknown error type. We can't actually enforce this statically
// But by following this convention we can simplify error handling

enum ApplicationError: Error, CustomStringConvertible {
    
  // These are application-specific errors that may need special treatment
  case specificError1
  case specificError2(SomeType)

rtrouton

iOS 10.2 Simulator: https://devimages-cdn.apple.com/downloads/xcode/simulators/com.apple.pkg.iPhoneSimulatorSDK10_2-10.2.1.1484185528.dmg
iOS 10.1 Simulator: https://devimages-cdn.apple.com/downloads/xcode/simulators/com.apple.pkg.iPhoneSimulatorSDK10_1-10.1.1.1476902849.dmg
iOS 10.0 Simulator: https://devimages-cdn.apple.com/downloads/xcode/simulators/com.apple.pkg.iPhoneSimulatorSDK10_0-10.0.1.1474488730.dmg
iOS 9.3 Simulator: https://devimages.apple.com.edgekey.net/downloads/xcode/simulators/com.apple.pkg.iPhoneSimulatorSDK9_3-9.3.1.1460411551.dmg
iOS 9.2 Simulator: https://devimages.apple.com.edgekey.net/downloads/xcode/simulators/com.apple.pkg.iPhoneSimulatorSDK9_2-9.2.1.1451951473.dmg
iOS 9.1 Simulator: https://devimages.apple.com.edgekey.net/downloads/xcode/simulators/com.apple.pkg.iPhoneSimulatorSDK9_1-9.1.1.1446593668.dmg
iOS 9.0 Simulator: https://devimages.apple.com.edgekey.net/downloads/xcode/simulators/com.apple.pkg.iPhoneSimulatorSDK9_0-9.0.1.1443554484.dmg
iOS 8.4 Simulator: https://devimages.a