Blog by Jeevan

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Showing posts from June, 2025

Quick look on abbreviations in SE (Software Engineering)

Here's a quick reference list with some common abbreviations that I have came across in my Engineering journey : 1. PR – Pull Request A request submitted by a developer to merge their code changes from one branch to another, typically for review and collaboration before integration. 2. MR – Merge Request Similar to a Pull Request, a Merge Request is used in GitLab to request code merging. It includes review, discussion, and approval before finalizing changes. 3. CR – Change Request A formal proposal to modify a system or product, often triggered by stakeholder feedback, bug reports, or evolving requirements. 4. LADR – Lightweight Architectural Decision Record A brief document that captures an important architectural decision made during a project. 5. BRD – Business Requirement Document Outlines the high-level business needs, objectives, and expectations of a project. It's used as a reference for aligning technical development with business goals. 6. LLD – Low-Level Desi...

Sorting Algorithms – Quick Reference for Interviews

Sorting is a fundamental operation in computer science and Understanding the basic sorting algorithms is essential for both interviews and real-world programming tasks. I am sharing the notes that I have taken in my learning curve. 1. Selection Sort Selection Sort repeatedly finds the minimum element from the unsorted part and puts it at the beginning. Steps: Loop through the array. For each index, find the smallest element in the rest of the array. Swap it with the current index. Time Complexity: O(n²) Example: [29, 10, 14, 37, 13] → [10, 29, 14, 37, 13] → [10, 13, 14, 37, 29] → [10, 13, 14, 37, 29] → [10, 13, 14, 29, 37] 2. Insertion Sort Insertion Sort builds the sorted array one element at a time by inserting each element into its correct position. Steps: Start from index 1. Compare current element with the left-side elements. Shift elements to the right and insert at the correct position. Time Complexity: O(n²) Example: [8, 4, 1, 3] → [4, 8, 1, 3] → [1, 4, 8, 3] → [1, 3, 4, 8] 3. ...

WWDC 2025 Sessions Summary: What's new in SwiftUI ?

This summary covers key updates from WWDC 2025 sessions to build a SwiftUI app with the new design. 1. Liquid Glass Liquid Glass is a new adaptive material inspired by glass and liquid, dynamically changing based on the content underneath. This SwiftUI’s new design system brings a fluid, glassy look across platforms, with tab bars, toolbars, and navigation views adopting Liquid Glass automatically. UI elements like sliders, toggles, and pickers animate fluidly with the new material, enhancing interactivity. 2. Background Extension Effect The NavigationSplitView now features a floating Liquid Glass sidebar and allows for safe-area background extension using backgroundExtensionEffect . 3. Tabbar Minimize Behavior A new tab bar behavior enables it to float above contents and minimize on scroll with tabBarMinimizeBehavior , keeping content in focus. Developers can add bottom accessory views to the tab bar using tabViewBottomAccessory , which adapts to collapse states. 4. Sheets b...

Animating label text update - choosing a better way

Recently I published a countdown app . At one point of development - I have to show a timer on a UILabel which ticks on each seconds. As usual I started setting text to a label object - self .timerLabel.text = someString Easy piece of cake right !? But wait ... it won't take much user attention when timer ticks on every seconds. So I decided to make use of a simple animation while label gets text update. I found there are dozens of ways to animate a label. In this short article, I listed 3 best way you can animate text on a label. ( Spoiler Alert 👀- I decided to go with 3rd option) 1. Fade In - Fade out animation : CATransition class has got transition type `fade`. With timing function of CATransition - I was able to see the below result. let animation: CATransition = CATransition () animation.timingFunction = CAMediaTimingFunction (name: CAMediaTimingFunctionName .easeInEaseOut) animation.type = CATransitionType .fade animation.subtype = C...

Prevent Navigationbar or Tabbar overlapping Subview - solved for Card view

Recently, I started with a Card view added as a subview of UIView in a view-controller. When a view controller created along subviews, it tends to use entire screen bounds and also slips behind Tab bar or Navigation bar. In my current situation, it's second case. Casually new iOS developers will write a patch by additional value for coordinate y and subtracting bar height from its size. A lot of them posted in SO threads too : How to prevent UINavigationBar from covering top of view? View got hidden below UINavigationBar iOS 7 Navigation Bar covers some part of view at Top So, how I got solved ? self.edgesForExtendedLayout = [] This will avoid all subviews in a view controller get behind any bars. Read full apple documentation on here. Full Source code below : //Simple view controller where its view layed-out as a card. class WidgetCardViewController : UIViewController { var containerView = UIView () //MARK:- View Controller Life Cyc...

UICollectionViewCell shows with wrong size on First time - Solved

We commonly use Collection view where its cell size calculated run time. The flow layout delegate is responsible to return individual cell sizes. BUT in most of the cases, delegate method `collectionView: layout sizeForItem:` expects cell size too early. Before generating actual cell size. extension YourViewController : UICollectionViewDelegateFlowLayout { func collectionView ( _ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize { return CGSize (width: externalWidth, height: externalHeight) } } For instance, if a cell size depends on external view and its frame is not yet ready - results with wrong (or outdated) cell size. Typically happens for the first time view controller laid out all views. You can find similar queries in StackOverflow community : Collection view sizeForItemNotWorking UICollectionViewCell content wrong size on first load How to refresh UICollec...

Implementing autocompletion OTP field in iOS

Long waiting is over. !! iOS 12 brings Autofill for OTP text field which is close to Android provided a decade back. Previously in iOS we used to toggle between OTP text screen and message inbox. Which was hard to remember and time consuming resulting a bad user experience. Personally, I have been asked from the client/customer couple of times to implement autocompletion for OTP field and took me a lot of time to convey that it is not possible in iOS. Why Autofill was not possible previously? We all know that Apple gives at most care for user privacy. When we see iOS architecture, each individual app is like a separate island. There is no inter-app bridge between apps (exception for Keychain and URLSchemes APIs which gives very limited scope). Thus we cannot read message content from inbox. Where to start Autofilling? First of all, the target SMS need to have the OTP Code with prefix string "Code" or "Passcode"on its message content. Beware of OTP c...

Static variable vs Class variable in Swift

How Static properties differs to usual properties ? Used to create type properties with either let or var. These are shared between all objects of a class. During class loading time, a single memory location allocated for the property if we declared as static. Static property belongs to a class (or struct) Type rather than Instance of class (or struct). Hence it also called Type Properties What if we declare "static var" ? Since it's a variable, we can change it in future even after initialised. When we change the value of the static variable property, that property is now changed in all future instances. What if we declare "static let" ? static let instance : Singleton = Singleton() Since it's constant, we cannot change once initialised. Its value will remain same even if we share among all the instance or object of a class or struct. Useful to adopt singleton pattern. How class variables differ static variables ? It dif...