Existing Code moved from private project repo

.github/workflows/test.yml

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+name: Build & Test
+
+on:
+  push:
+    branches: [ void ]
+  pull_request:
+    branches: [ void ]
+
+jobs:
+  build:
+
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build for macOS
+      run: swift build -v
+    - name: Run tests for macOS
+      run: swift test -v
+    - name: Build for iOS
+      run: xcodebuild build -sdk iphoneos -scheme 'WrappingStack'
+    - name: Run tests for iOS
+      run: xcodebuild test -destination 'name=iPhone 8' -scheme "WrappingStack"

Package.swift

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+// swift-tools-version:5.3
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "WrappingStack",
+    platforms: [
+        .iOS(.v9),
+        .watchOS(.v6),
+        .tvOS(.v13),
+        .macOS(.v10_10)
+    ],
+    products: [
+        .library(
+            name: "WrappingStack",
+            targets: ["WrappingStack"]),
+    ],
+    targets: [
+        .target(
+            name: "WrappingStack",
+            dependencies: []),
+        .testTarget(
+            name: "WrappingStackTests",
+            dependencies: ["WrappingStack"]),
+    ]
+)

Readme.md

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+# Swiftui WrappingStack
+
+![Swift 5.3](https://img.shields.io/badge/Swift-5.3-FA5B2C) ![Xcode 12.5](https://img.shields.io/badge/Xcode-12-44B3F6) ![iOS 9.0](https://img.shields.io/badge/iOS-8.0-178DF6) ![iPadOS 9.0](https://img.shields.io/badge/iPadOS-8.0-178DF6) ![MacOS 10.10](https://img.shields.io/badge/MacOS-10.10-178DF6) [![Build & Test](https://github.com/diniska/swiftui-wrapping-stack/actions/workflows/test.yml/badge.svg)](https://github.com/diniska/swiftui-wrapping-stack/actions/workflows/test.yml)
+
+A SwiftUI Views for wrapping HStack elements into multiple lines.
+
+`WrappingHStack` - provides `HStack` that supports line wrapping

Sources/WrappingStack/Helpers/SizeReader.swift

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+#if canImport(SwiftUI) && canImport(Combine)
+
+import SwiftUI
+
+@available(iOS 14, macOS 11, *)
+extension View {
+    func onSizeChange(perform action: @escaping (CGSize) -> ()) -> some View {
+        modifier(SizeReader(onChange: action))
+    }
+}
+
+@available(iOS 14, macOS 11, *)
+private struct SizeReader: ViewModifier {
+    var onChange: (CGSize) -> ()
+
+    func body(content: Content) -> some View {
+        content
+            .background(
+                GeometryReader { geometry in
+                    Color.clear
+                        .preference(key: SizePreferenceKey.self, value: geometry.size)
+                }
+            )
+            .onPreferenceChange(SizePreferenceKey.self, perform: onChange)
+    }
+}
+
+@available(iOS 14, macOS 11, *)
+private struct SizePreferenceKey: PreferenceKey {
+    static var defaultValue: CGSize = .zero
+    static func reduce(value: inout CGSize, nextValue: () -> CGSize) {}
+}
+
+#endif

Sources/WrappingStack/Helpers/TightHeightGeometryReader.swift

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+#if canImport(SwiftUI) && canImport(Combine)
+
+import SwiftUI
+
+@available(iOS 14, macOS 11, *)
+struct TightHeightGeometryReader<Content: View>: View {
+    @State private var height: CGFloat = 0
+
+    var content: (GeometryProxy) -> Content
+
+    init(@ViewBuilder content: @escaping (GeometryProxy) -> Content) {
+        self.content = content
+    }
+
+    var body: some View {
+        GeometryReader { geometry in
+            content(geometry)
+                .onSizeChange { size in
+                    if self.height != size.height {
+                        self.height = size.height
+                    }
+                }
+        }
+        .frame(height: height)
+    }
+}
+
+#endif

Sources/WrappingStack/WrappingHStack.swift

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+#if canImport(SwiftUI) && canImport(Combine)
+
+import SwiftUI
+
+/// An HStack that grows vertically when single line overflows
+@available(iOS 14, macOS 11, *)
+public struct WrappingHStack<Data: RandomAccessCollection, ID: Hashable, Content: View>: View {
+
+    public let data: Data
+    public var content: (Data.Element) -> Content
+    public var id: KeyPath<Data.Element, ID>
+    public var alignment: Alignment
+    public var horizontalSpacing: CGFloat
+    public var verticalSpacing: CGFloat
+
+    @State private var sizes: [ID: CGSize] = [:]
+    @State private var calculatesSizesKeys: Set<ID> = []
+
+    private let idsForCalculatingSizes: Set<ID>
+    private var dataForCalculatingSizes: [Data.Element] {
+        var result: [Data.Element] = []
+        var idsToProcess: Set<ID> = idsForCalculatingSizes
+        idsToProcess.subtract(calculatesSizesKeys)
+
+        data.forEach { item in
+            let itemId = item[keyPath: id]
+            if idsToProcess.contains(itemId) {
+                idsToProcess.remove(itemId)
+                result.append(item)
+            }
+        }
+        return result
+    }
+
+    public init(
+        id: KeyPath<Data.Element, ID>,
+        alignment: Alignment = .center,
+        horizontalSpacing: CGFloat = 0,
+        verticalSpacing: CGFloat = 0,
+        @ViewBuilder content create: () -> ForEach<Data, ID, Content>
+    ){
+        let forEach = create()
+        data = forEach.data
+        content = forEach.content
+        idsForCalculatingSizes = Set(data.map { $0[keyPath: id] })
+        self.id = id
+        self.alignment = alignment
+        self.horizontalSpacing = horizontalSpacing
+        self.verticalSpacing = verticalSpacing
+    }
+
+    private func splitIntoLines(maxWidth: CGFloat) -> [Range<Data.Index>] {
+        var width: CGFloat = 0
+        var result: [Range<Data.Index>] = []
+        var lineStart = data.startIndex
+        var lineLength = 0
+
+        for element in data {
+            guard let elementWidth = sizes[element[keyPath: id]]?.width
+            else { break }
+            let newWidth = width + elementWidth
+            if newWidth < maxWidth || lineLength == 0 {
+                width = newWidth + horizontalSpacing
+                lineLength += 1
+            } else {
+                width = elementWidth
+                let lineEnd = data.index(lineStart, offsetBy:lineLength)
+                result.append(lineStart ..< lineEnd)
+                lineLength = 0
+                lineStart = lineEnd
+            }
+        }
+
+        if lineStart != data.endIndex {
+            result.append(lineStart ..< data.endIndex)
+        }
+        return result
+    }
+
+    public var body: some View {
+        if calculatesSizesKeys.isSuperset(of: idsForCalculatingSizes) {
+            TightHeightGeometryReader { geometry in
+                let splitted = splitIntoLines(maxWidth: geometry.size.width)
+
+                // All sizes are known
+                VStack(alignment: alignment.horizontal, spacing: verticalSpacing) {
+                    ForEach(Array(splitted.enumerated()), id: \.offset) { list in
+                        HStack(alignment: alignment.vertical, spacing: horizontalSpacing) {
+                            ForEach(data[list.element], id: id) {
+                                content($0)
+                            }
+                        }
+                    }
+                }
+            }
+        } else {
+            // Calculating sizes
+            VStack {
+                ForEach(dataForCalculatingSizes, id: id) { d in
+                    content(d)
+                        .onSizeChange { size in
+                            let key = d[keyPath: id]
+                            sizes[key] = size
+                            calculatesSizesKeys.insert(key)
+                        }
+                }
+            }
+        }
+    }
+}
+
+@available(iOS 14, macOS 11, *)
+extension WrappingHStack where ID == Data.Element.ID, Data.Element: Identifiable {
+    public init(@ViewBuilder content create: () -> ForEach<Data, ID, Content>) {
+        self.init(id: \.id, content: create)
+    }
+}
+
+#if DEBUG
+
+@available(iOS 14, macOS 11, *)
+struct WrappingHStack_Previews: PreviewProvider {
+    static var previews: some View {
+        WrappingHStack(id: \.self, alignment: .topLeading) {
+            ForEach(["Hello1", "world1", "Hello2", "world2", "Hello3", "world3", "Hello4", "world4       ", "Hello1"], id: \.self) { item in
+                Text(item)
+                    .padding()
+                    .background(Color(.systemGray))
+                    .cornerRadius(3)
+            }
+        }
+        .frame(width: 300)
+    }
+}
+
+#endif
+
+#endif

Tests/WrappingStackTests/WrappingStackTests.swift

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+import XCTest
+@testable import WrappingStack
+
+final class WrappingStackTests: XCTestCase {
+}