MacBook Air M1 Zhuyin Keyboard written with SwiftUI ~=300 LOC, < 4hrs

VirtualKeyboard.swift

//
//  VirtualKeyboard.swift
//  MacBook Air M1 Zhuyin Keyboard
//  Written with SwiftUI ~=300 LOC, < 4hrs
//  Created by Ethan Huang on 2021/1/13.
//  Twitter: @ethanhuang13

import SwiftUI

struct VirtualKeyboard: View {
    var body: some View {
        VStack(spacing: .zero) {
            HStack(spacing: .zero) {
                speaker
                keyboard
                    .padding(.horizontal, 15)
                speaker
            }
            .padding(.horizontal, 15)
            .padding(.vertical, 15)

            trackPad
        }
        .padding(.vertical)
        .background(Color(white: 0.6))
        .clipShape(RoundedRectangle(cornerRadius: 20, style: .continuous))
    }

    private var speaker: some View {
        Color(white: 0.5)
            .frame(width: defaultWidth * 0.6)
            .padding(.vertical)
    }

    private var trackPad: some View {
        HStack { // Touchpad
            Color(white: 0.5)
                .clipShape(RoundedRectangle(cornerRadius: 20, style: .continuous))
                .frame(width: defaultWidth * 8.8, height: defaultHeight * 5)
        }
    }

    private var keyboard: some View {
        VStack(spacing: defaultWidth / 10) {
            let allKeys: [[KeyCap.Config]] = [
                [.esc,
                 .fn(top: "􀆫", bottom: "F1"),
                 .fn(top: "􀆭", bottom: "F2"),
                 .fn(top: "􀇴", bottom: "F3"),
                 .fn(top: "􀊫", bottom: "F4"),
                 .fn(top: "􀊰", bottom: "F5"),
                 .fn(top: "􀆹", bottom: "F6"),
                 .fn(top: "􀊉", bottom: "F7"),
                 .fn(top: "􀊇", bottom: "F8"),
                 .fn(top: "􀊋", bottom: "F9"),
                 .fn(top: "􀊠", bottom: "F10"),
                 .fn(top: "􀊤", bottom: "F11"),
                 .fn(top: "􀊨", bottom: "F12"),
                 .touchId],
                [.topBottom(top: "~", bottom: "."),
                 .grid(["!", "1", "ㄅ", ""]),
                 .grid(["@", "2", "ㄉ", ""]),
                 .grid(["#", "3", "ˇ", ""]),
                 .grid(["$", "4", "ˋ", ""]),
                 .grid(["%", "5", "ㄓ", ""]),
                 .grid(["^", "6", "ˊ", ""]),
                 .grid(["&", "7", "˙", ""]),
                 .grid(["*", "8", "ㄚ", ""]),
                 .grid(["(", "9", "ㄞ", ""]),
                 .grid([")", "0", "ㄢ", ""]),
                 .grid(["_", "-", "ㄦ", ""]),
                 .topBottom(top: "+", bottom: "="),
                 .backspace],
                [.tab,
                 .grid(["", "Q", "ㄆ", ""]),
                 .grid(["", "W", "ㄊ", ""]),
                 .grid(["", "E", "ㄍ", ""]),
                 .grid(["", "R", "ㄐ", ""]),
                 .grid(["", "T", "ㄔ", ""]),
                 .grid(["", "Y", "ㄗ", ""]),
                 .grid(["", "U", "ㄧ", ""]),
                 .grid(["", "I", "ㄛ", ""]),
                 .grid(["", "O", "ㄟ", ""]),
                 .grid(["", "P", "ㄣ", ""]),
                 .grid(["『", "{", "「", "["]),
                 .grid(["』", "}", "」", "]"]),
                 .grid(["", "|", "、", "\\"])],
                [.capsLock,
                 .grid(["", "A", "ㄇ", ""]),
                 .grid(["", "S", "ㄋ", ""]),
                 .grid(["", "D", "ㄎ", ""]),
                 .grid(["", "F", "ㄑ", ""]),
                 .grid(["", "G", "ㄕ", ""]),
                 .grid(["", "H", "ㄘ", ""]),
                 .grid(["", "J", "ㄨ", ""]),
                 .grid(["", "K", "ㄜ", ""]),
                 .grid(["", "L", "ㄠ", ""]),
                 .grid(["", ":", "ㄤ", ";"]),
                 .topBottom(top: "\"", bottom: "'"),
                 .return],
                [.leftShift,
                 .grid(["", "Z", "ㄈ", ""]),
                 .grid(["", "X", "ㄌ", ""]),
                 .grid(["", "C", "ㄏ", ""]),
                 .grid(["", "V", "ㄒ", ""]),
                 .grid(["", "B", "ㄖ", ""]),
                 .grid(["", "N", "ㄙ", ""]),
                 .grid(["", "M", "ㄩ", ""]),
                 .grid(["，", "<", "ㄝ", ","]),
                 .grid(["。", ">", "ㄡ", "."]),
                 .grid(["?", "", "ㄥ", "/"]),
                 .rightShift],
                [.globe,
                 .control,
                 .leftOption,
                 .leftCommand,
                 .space,
                 .rightCommand,
                 .rightOption,
                 .directions]
            ]
            ForEach(0 ..< allKeys.count) { index in
                let keys = allKeys[index]
                HStack {
                    ForEach(keys.map { AnyIdentifiable($0) }) {
                        KeyCap($0.value)
                    }
                }
            }
        }
        .padding(10)
        .background(Color(white: 0.5))
        .clipShape(RoundedRectangle(cornerRadius: 20, style: .continuous))
    }
}

private let fnHeight: CGFloat = 25
private let defaultWidth: CGFloat = 50
private let defaultHeight: CGFloat = 50

struct AnyIdentifiable<T>: Identifiable {
    let id = UUID()
    let value: T
    init(_ value: T) {
        self.value = value
    }
}

struct KeyCap: View {
    enum Config {
        case esc
        case fn(top: String, bottom: String)
        case touchId
        case topBottom(top: String, bottom: String)
        case grid([String])
        case backspace
        case tab
        case capsLock, `return`
        case leftShift, rightShift
        case globe, control, leftOption, leftCommand, space, rightCommand, rightOption
        case directions
    }

    init(_ config: Config) {
        self.config = config
    }

    let config: Config

    var body: some View {
        if case Config.directions = config {
            key
        } else {
            key
                .padding(5)
                .background(Color.black)
                .clipShape(RoundedRectangle(cornerRadius: 8, style: .continuous))
        }
    }

    private struct Grid: View {
        let keys: [String]

        var body: some View {
            let columns = [GridItem(.fixed(defaultWidth / 2), spacing: 5),
                           GridItem(.fixed(defaultWidth / 2), spacing: 5)]
            LazyVGrid(columns: columns, spacing: 0, content: {
                ForEach(keys.map { AnyIdentifiable($0) }) {
                    Text($0.value)
                        .padding(0)
                }
            })
        }
    }

    private struct TopBottom: View {
        init(top: String, bottom: String, alignment: HorizontalAlignment = .center) {
            self.top = top
            self.bottom = bottom
            self.alignment = alignment
        }

        let top: String
        let bottom: String
        let alignment: HorizontalAlignment

        var body: some View {
            VStack(alignment: alignment, spacing: 5) {
                Text(top)
                    .padding(.horizontal, 3)
                Text(bottom)
                    .padding(.horizontal, 3)
            }
        }
    }

    private struct Arrow: View {
        let key: String

        var body: some View {
            Text(key)
                .font(.caption)
                .frame(width: defaultWidth * 1.15, height: defaultHeight / 1.7)
                .background(Color.black)
                .clipShape(RoundedRectangle(cornerRadius: 8, style: .continuous))
        }
    }

    @ViewBuilder
    var key: some View {
        switch config {
        case .esc:
            HStack {
                Text("esc")
                    .frame(width: defaultWidth, height: fnHeight, alignment: .leading)
            }
        case .fn(let top, let bottom):
            VStack {
                Text(top)
                Text(bottom)
                    .font(.caption2)
            }
            .frame(width: defaultWidth * 1.083, height: fnHeight)
        case .touchId:
            Text("")
                .frame(width: defaultWidth / 2, height: fnHeight)
        case .topBottom(let top, let bottom):
            TopBottom(top: top, bottom: bottom)
                .frame(width: defaultWidth, height: defaultHeight)
                .font(.title2)
                .frame(width: defaultWidth, height: defaultHeight)
        case .grid(let keys):
            Grid(keys: keys)
                .font(.title2)
                .frame(width: defaultWidth, height: defaultHeight)
        case .backspace:
            TopBottom(top: "", bottom: "􀆛")
                .frame(width: defaultWidth * 1.5, height: defaultHeight, alignment: .trailing)
        case .tab:
            TopBottom(top: "", bottom: "􀅆")
                .frame(width: defaultWidth * 1.5, height: defaultHeight, alignment: .leading)
        case .capsLock:
            TopBottom(top: "•", bottom: "中/英", alignment: .leading)
                .frame(width: defaultWidth * 2, height: defaultHeight, alignment: .leading)
        case .return:
            TopBottom(top: "", bottom: "􀅇")
                .frame(width: defaultWidth * 1.9, height: defaultHeight, alignment: .trailing)
        case .leftShift:
            TopBottom(top: "", bottom: "􀆝")
                .frame(width: defaultWidth * 2.6, height: defaultHeight, alignment: .leading)
        case .rightShift:
            TopBottom(top: "", bottom: "􀆝")
                .frame(width: defaultWidth * 2.6, height: defaultHeight, alignment: .trailing)
        case .globe:
            Grid(keys: ["", "fn", "􀆪", ""])
                .font(.title3)
                .frame(width: defaultWidth, height: defaultHeight)
        case .control:
            TopBottom(top: "􀆍", bottom: "control", alignment: .trailing)
                .frame(width: defaultWidth, height: defaultHeight, alignment: .trailing)
        case .leftOption:
            TopBottom(top: "􀆕", bottom: "option", alignment: .trailing)
                .frame(width: defaultWidth, height: defaultHeight, alignment: .trailing)
        case .leftCommand:
            TopBottom(top: "􀆔", bottom: "command", alignment: .trailing)
                .frame(width: defaultWidth * 1.35, height: defaultHeight, alignment: .trailing)
        case .space:
            Color.clear
                .frame(width: defaultWidth * 6.4, height: defaultHeight)
        case .rightCommand:
            TopBottom(top: "􀆔", bottom: "command", alignment: .trailing)
                .frame(width: defaultWidth * 1.35, height: defaultHeight, alignment: .leading)
        case .rightOption:
            TopBottom(top: "􀆕", bottom: "option", alignment: .trailing)
                .frame(width: defaultWidth, height: defaultHeight, alignment: .leading)
        case .directions:
            VStack(spacing: 0) {
                HStack {
                    Arrow(key: "􀄤")
                }
                HStack(spacing: 8) {
                    Arrow(key: "􀄦")
                    Arrow(key: "􀄥")
                    Arrow(key: "􀄧")
                }
            }
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        VirtualKeyboard()
    }
}

Announcement tweet: https://twitter.com/ethanhuang13/status/1349944306954473472?s=21