Quick Tips To Support Dark Mode In Your iOS App | iOS 13

All you need to know about Dark Mode on iOS 13

Overview? With iOS 13 and above people can adopt a dark appearance where Apple docs says user can use settings to make their devices automatically switch to dark mode when ambient is low and this will help you to put focus on your content.

Development Environment? As as iOS developer you’ve to use Xcode 11 with iOS 13 SDK and above, iOS will automatically update system controls such as switches, collection-views etc. If you are migrating your existing app to dark in that case you will have to adapt the colours. 

How to define colours for each mode?

System Colours? iOS 13 SDK includes new system colours so if you adapt these system colours your app will automatically support dark and light mode, You can use it via Storyboard as well as programmatically (Some example below)

Custom Colors? Yes it’s strongly recommended by Apple that use system colours to provide better UX and also to make sure the consistency across apps but using the asset you can define you colour choices. Once you define iOS will take care everything for you.

How to define Image for each mode?

Using the Assets you can specify which image you want to use for dark VS any other mode and just define the image and let iOS take care for you. 

How to detect dark mode programmatically?

On Load Detection? We can use overrideUserInterfaceStyle to check which mode is currently running on user device (Just make sure, this property only available on iOS 13 and above)

Runtime Detection? Can use traitCollectionDidChange to observe the changes, It is important to remember that trait-collection may be called for other trait changes (such as device rotation)

Set Dark Mode for Specific Screen? Yes you can, this property overrideUserInterfaceStyle is available for you to use (only iOS 13 and above)

Swift 5 ABI Stability why matters?

Swift is fast, safe and expressive language to code with great full stack potential and community support. According to Apple, it’s 2.6 times faster than Objective C (As a Swift Developer I agree on this too 🙌). It’s 6th most loved language on StackOverflow.

ABI Background
As a developer, I hope sometimes you also felt that Swift is not mature enough as every year major changes are being introduced. One of the key problems articulated by a lot of developers is “Lack of backward compatibility” and you have to choose one Swift version for your Xcode projects (Version lock). Resulting in with a new Swift release you have to make changes in your existing code.

What is ABI?
ABI stands for Application Binary Interface. During runtime, Swift program interacts with other libraries through ABI (low-level set of protocols for memory representation, function calls, and access).
So when I say ABI not stable it means that each binary is building its own version of Swift Dynamic Library inside it. Now the Swift 5 is ABI Stable which means if I build two apps, one using Swift 5.0 and another using Swift 5.2, both will use Swift ABI embedded in the iOS Operating System.

Why ABI Stability matters a lot?

  1. Compatibility: which means new compilers can compile your old Swift code which means no more migration pain.
  2. Bundle Size: It will reduce the build size because of no Swift standard Library in your Framework folder.
  3. Binary framework and runtime compatibility which enables the framework distribution as a binary which will work across multiple Swift versions.

Conclusion: Swift is the future for Apple ecosystem and now it’s ABI stable which means, in other words, it is like write once and use everywhere.

Reference:
https://swift.org/about/
https://github.com/apple/swift/blob/master/docs/ABIStabilityManifesto.md

Error: WKWebView before iOS 11.0 (NSCoding Support was broken in the previous version)

Important
Starting in iOS 8.0 and OS X 10.10, use WKWebView to add web content to your app. Do not use UIWebView or WebView.

WebKit was introduced in iOS 8 but it was released with an error which caused in a runtime crash, If you are using Xcode 9/10, your project configuration support less than iOS 11 and if you are trying to add WKWebView using interface builder. Xcode immediately shows a compile-time error.

WKWebView before iOS 11.0 (NSCoding Support was broken in the previous version)

Although WKWebView was introduced in iOS 8, there was a bug in –[WKWebView initWithCoder:] that was only fixed in iOS 11.

Resolution is you must add WKWebView through code (Only if you are supporting below iOS 11). That actually sounds strange.

Another solution is to change the Interface Builder Document Builds for the option to iOS 11 and later (If you’re migrating from older target to iOS 11 and still getting the same error).

Why use WKWebView, To use native Safari Javascript optimization. Means it loads web page much faster than UIWebView with less memory usage. 

What is the difference between setNeedsLayout, layoutIfNeeded and layoutSubviews? Quick Notes.

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When the user taps an on App icon, iOS creates an instance of UIApplication which runs on the main thread. This main thread processes all UI events such as touch, location updates etc.

After app launched successfully, it becomes available for the user to do interactions with it and every single interaction which known as an event is processed in a FIFO manner.

Now while events are being processed there may come some UI update requests which aren’t get fulfilled immediately. Instead, the system waits until the existing process finishes and the next redraw cycle comes. There is a periodic interval between the event processing and UI layout handling. The setLayoutNeeded() and layoutIfNeeded are two UIView’s methods here to ask the system for updating the view with new changes.

The setNeedsLayout() tells the system that you want the view and all it’s subviews to be redrawn in the update cycle.

Here is What Apple’s doc says on this, “Call this method on your application main thread when you want to adjust the layout of a view’s subviews. Note that it returns immediately (Async call) because it does not force an update, it waits for the next update cycle”.

Whereas layoutIfNeeded() is an async call which tells the system that you want the view and it’s subviews to be redrawn immediately without waiting for the next update cycle.

UIView have one more method named layoutSubviews() which you can use for your own implementation to set the frame of your view directly by overriding it. And since it’s default implementation uses the constraints you have given to determine it’s size and positions to get the frame, you should override it unless autoresizing and constraint behavior is not working for you as expected.

In short use setNeedsLayout(), if you are okay with the system to update it in the next upcoming update cycle and use layoutIfNeeded() if you want it to be updated immediately.

Thanks for reading.

Swift | Open source projects for learning and developers to follow on twitter

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Announced in 2014, the Swift programming language has quickly become one of the fastest growing languages in history. Swift makes it easy to write software that is incredibly fast and safe by design.

Blog for developers to highlight, top 10 trending open source to learn.

  1. MessageViewController A SlackViewController replacement written in Swift, compatible with iPhone X, iOS12. Created by Ryan Nystrom
  2. Swift interpreter for Pascal language (Inspired from Ruslan’s Blog). Created by Igor Kulman
  3. CollectionViewSlantedLayout subclass of the UICollectionViewLayout allowing the display of slanted cells in a UICollectionView.Created by Yassir Barchi
  4. Mint Package manager that installs and runs Swift command line tools, created by Yonas Kolb
  5. CryptoSwift Collection of standard and secure cryptographic algorithms implemented in Swift. Created by Marcin Krzyzanowski
  6. CocoaDebug Debugger tools for iOS supports Swift and Objective C, created by CocoaDebug
  7. iOS-Depth-Sampler Examples of Depth APIs in iOS, created by Shuichi Tsutsumi
  8. Universal Link Testing  It fetches and parses apple-app-site-association file for you to quickly check whether Universal Links are working. created by Ethan Huang
  9. Swift Syntax Set of Swift bindings for the libSyntax library. It allows for Swift tools to parse, inspect, generate, and transform Swift source code. Created by Apple
  10. WhatsNewKit Showcase your awesome new app features, Created by Sven Tiigi

 

Thanks for reading!

The table of two values, Behaviour and Structure!

The table of two values, Behaviour and Structure!

Is it more important for the software system to work or is it more important to be easy to change? If you ask the business managers they will say work is more important, some developers also go along with this attitude but that’s the wrong attitude.

Why the wrong attitude?

  1. If you give me a program that works perfectly but impossible to change, it means it won’t work when the requirements change.
  2. If you give me a program that does not work but easy to change, it means I can make the change to make it work.

If you’re a programmer with the attitude (1.) then one day your system will reach to the point where the change will be impractical (cost of change will be unaffordably high).

Eisenhower Matrix

Eisenhower said, I have two kinds of problems, the urgent and the important, where the urgent are not important and the important is never urgent.

when it comes to software, The first value of software is behavior, is urgent but not always important. The second value is architecture, is important but never urgent. Of course, some things are not urgent and not important.

  1. Urgent and important
  2. Not urgent and important
  3. Urgent and not important
  4. Not urgent and not important.

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Mistakes that business managers and developer make is to elevate items in position 3 to 1. It means they always fail to separate those features that are urgent but not important from those features that are really urgent and important and this failure leads to ignoring the important architecture of the system in favor of the unimportant features of the system.

So if you are a software developer, you are hired to maintain the quality and structure of the system and only you know the importance of the architecture.

Thanks for reading it, if you want to read in more detail, buy “Clean Architecture by Robert C. Martin”

 

What are the Design and Architecture?

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What are the Design and Architecture?

The design is more often seems to when it comes to structures and low-level decisions whereas Architecture is often used in the context of something at the high level where we can see how components are connected with each other. But for starters, there is no different at all.

What is the GOAL of good software design?

The goal of software architecture is to minimize the Human Resources required to build and maintain the required system (By Uncle Bob Martin)

Basic fundamentals measure the design?

The measure of design quality is simply the measure of the effort required to meet the needs of the customer if the effort is low and stays same through the lifetime, System design is good else it’s bad.

The Signature of a system design mess?

  • Developer point of view
    The graph says developers started with nearly 100% of productivity but with each release, their productivity going down

Screen Shot 2018-09-23 at 8.00.44 PM.png

  • Executive point of view?
    Release 1 was delivered with a few hundred thousand payrolls and by the time of 5 release, it’s going to touch $500,000.

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What is going wrong?

The moral of the story says everything in one line: “Slow and steady wins the race”. Yes, it all because of overconfidence. Everyone wants to hit the market first or release the app asap with the statement “We can clean it up later” and they can’t go back for cleaning the things up because now we have the new feature, new release so maybe next time, next time and next time.

The only way to go fast is to go well.

To take the software architecture seriously we have to think and need to know what good software architecture is, compare the different architecture with the requirements.

Thanks for reading it, if you want to read in more detail, buy “Clean Architecture by Robert C. Martin”