Khoa Pham
Khoa Pham

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My year in review 2020

Issue #715

I remember this time last year in December 2019, I spent almost every single bit of my free time on Puma because I want a Swift friendly version of fastlane that suits my need and leverages Swift 5 features.

Here’s my review of my …

How to convert NSEvent locationInWindow to window coordinate

Issue #822

Get active screen with mouse

func activeScreen() -> NSScreen? {
    let mouseLocation = NSEvent.mouseLocation
    let screens = NSScreen.screens
    let screenWithMouse = (screens.first { NSMouseInRect(mouseLocation, $0.frame, false) }) …

How to sync width for child views in SwiftUI

Issue #821

Suppose we have a 16:9 preview Image and we want the title Text to be the same width

First we need PreferenceKey to store and sync size

struct SizePreferenceKey: PreferenceKey {
    typealias Value = CGSize
    static var defaultValue: …

How to highlight link in Text in SwiftUI

Issue #820

Use NSDataDetector to detect links, and NSMutableAttributedString to mark link range. Then we enumerateAttributes and build our Text

Screenshot 2021-07-06 at 07 23 56
func attribute(string: String) -> Text {
    guard let detector = try? NSDataDetector(types: …

How to conform UIImage to Codable

Issue #819

Either use EasyStash or make a simple CodableImage

struct CodableImage: Codable {
    let image: UIImage?

    init(image: UIImage) {
        self.image = image
    }

    enum CodingKeys: CodingKey {
        case data
        case scale …

How to show custom context menu in SwiftUI

Issue #818

There’s a lot to do to imitate iOS ContextMenu look and feel

  • vibrancy blur background
  • haptics feedback
  • targeted view position
  • interaction dismiss gesture

For now here’s a rough implementation of a custom context menu where we …

How to declare View with ViewBuilder in SwiftUI

Issue #817

Thanks to resultBuilder and container type in Swift, the following are possible in SwiftUI

Local variable

struct ChartView {
    var body: some View {
        computation
    }

    @ViewBuilder
    var computation: some View {
        let …

How to make custom Menu in SwiftUI

Issue #816

SwiftUI supports Menu but the menu items only appear after the menu button is touched. We can initiate the look and feel of Menu with a custom implementation

Screenshot 2021-07-01 at 21 11 02
import SwiftUI

struct CustomMenu<Content: View>: View {
    @ViewBuilder …

How ObservableObject work in SwiftUI

Issue #815

When ever a property marked with @Published change, ObservableObject will emit objectWillChange.send hence telling the View that observes it to reinvalidate.

In WWDC 2021 session Discover concurrency in SwiftUI they mention how …

How to cancel vertical scrolling on paging TabView in SwiftUI

Issue #814

From iOS 14, TabView has the PageTabViewStyle that turns TabView into the equivalent UIPageViewController.

We can of course implement our own Pager but the simple DragGesture does not bring the true experience of a paging UIScrollView or …

How to make simple swipe vertically to dismiss in SwiftUI

Issue #813

Use simultaneousGesture to not collide with potential horizontal scrolling in carousel view, and check that we’ more accidentally swipe horizontally.

import SwiftUI

struct SwipeToDismissModifier: ViewModifier {
    var onDismiss: () …

How to make carousel pager view in SwiftUI

Issue #812

Use GeometryReader to set width and a DragGesture on LazyVStack

CarouselView(
    pageCount: images.count,
    currentIndex: $selectedImageIndex
) {
    ForEach(0 ..< images) { image in
        // AsyncImage
    }
}
struct CarouselView …

How to use SwiftFormat

Issue #811

Don’t add SwiftFormat as SPM package, instead use command line directly

if which swiftformat >/dev/null; then
  swiftformat .
else
  echo "warning: SwiftFormaat not installed, download from …

How to update Firestore value with KeyPath in Swift

Issue #810

struct User {
    var createdAt: Date
    var name: Sttring
    var locked: Bool
}
extension KeyPath where Root == User {
    var keyPathString: String {
        switch self {
        case \User.createdAt: return "createdAt" …

How to show context menu with custom preview in SwiftUI

Issue #809

Add a hidden overlay UIContextMenuInteraction. Provide preview in previewProvider and actions in actionProvider. Use @ViewBuilder to make declaring preview easy.

extension View {
    func contextMenuWithPreview<Content: View>( …

How to login with Apple in SwiftUI

Issue #808

Make SignInWithAppleButton

Wrap ASAuthorizationAppleIDButton inside UIViewRepresentable

import SwiftUI
import UIKit
import AuthenticationServices

struct SignInWithAppleButton: View {
    @Environment(\.colorScheme)
    private var …

How to use SwiftLint in SPM project

Issue #807

Don’t add SwiftLint via SPM, but just add a Run Script Build phrase

if which swiftlint >/dev/null; then
  swiftlint
else
  echo "warning: SwiftLint not installed, download from https://github.com/realm/SwiftLint"
fi …

How to show modal window in AppKit

Issue #806

Use runModal

https://developer.apple.com/documentation/appkit/nsapplication/1428590-runmodalsession

Blocks main queue

A loop that uses this method is similar in some ways to a modal event loop run with runModal(for:), except with this …

How to perform action during long press in SwiftUI

Issue #805

Use LongPressGesture to detect when long-press gesture has been recognized, and chain with DragGesture to check when pressing still occurs

Image(systemName: SFSymbol.deleteLeft.rawValue)
    .imageScale(.medium)
    .onTapGesture { …

How to fallback img in React

Issue #804

<img 
    src={user.avatarUrl} 
    onError={(e) => {
        e.target.onerror = null; 
        e.target.src = "/images/default.png"
    }}
/>

Extract to React Component

interface Props {
    src: string
    className: …

How to use videojs in React

Issue #803

import React from 'react';
import videojs from 'video.js'
import 'video.js/dist/video-js.css';

export default class VideoPlayer extends React.Component {
    createPlayer() {
        // instantiate Video.js …

Khoa Pham

Hello, I’m Khoa

I’m a thinker and storyteller with a passion for exploring the intersection of creativity and technology

🧑‍💻 I love crafting high quality and useful apps
🔥 I love open source. My GitHub open source has 2.3k followers with packages that are integrated by 45k+ apps and over 3.4m+ downloads on CocoaPods.
✍️ I write here on my blog and on Medium, which has over 2.7k+ followers with tons of articles and 90k+ monthly views.
🖥 Follow me for sharings about Swift, SwiftUI, iOS and macOS development.
Hei