Merge pull request #14 from seek-oss/feature/flow-layout-stack

Add new FlowLayoutStack

Author: shaun-seek

…ect.xcworkspace/contents.xcworkspacedata …age.xcworkspace/contents.xcworkspacedatastackable.xcodeproj/project.xcworkspace/contents.xcworkspacedata renamed to .swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata stackable.xcodeproj/project.xcworkspace/contents.xcworkspacedata renamed to .swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata

@@ -0,0 +1,26 @@
+// swift-tools-version: 5.9
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "Stackable",
+    platforms: [
+        .iOS(.v15)
+    ],
+    products: [
+        .library(
+            name: "Stackable",
+            targets: ["Stackable"]),
+    ],
+    dependencies: [],
+    targets: [
+        .target(
+            name: "Stackable"
+        ),
+        .testTarget(
+            name: "StackableTests",
+            dependencies: ["Stackable"]
+        )
+    ]
+)

Package.swift

@@ -0,0 +1,106 @@
+//  Copyright © 2024 SEEK. All rights reserved.
+//
+
+import UIKit
+
+open class FlowLayoutStack: HStack {
+    let lineSpacing: CGFloat
+    private var itemSpacing: CGFloat {
+        spacing
+    }
+    
+    public init(
+        itemSpacing: CGFloat = 0.0,
+        lineSpacing: CGFloat = 0.0,
+        width: CGFloat? = nil,
+        thingsToStack: [Stackable]
+    ) {
+        self.lineSpacing = lineSpacing
+        
+        super.init(
+            spacing: itemSpacing,
+            layoutMargins: .zero,
+            thingsToStack: thingsToStack,
+            width: width
+        )
+    }
+    
+    public convenience init(
+        itemSpacing: CGFloat = 0.0,
+        lineSpacing: CGFloat = 0.0,
+        width: CGFloat? = nil,
+        thingsToStack: () -> [Stackable]
+    ) {
+        self.init(
+            itemSpacing: itemSpacing,
+            lineSpacing: lineSpacing,
+            width: width,
+            thingsToStack: thingsToStack()
+        )
+    }
+    
+    open override func framesForLayout(_ width: CGFloat, origin: CGPoint) -> [CGRect] {
+        var frames: [CGRect] = []
+        var currentY = origin.y
+        var currentX = origin.x
+
+        func moveToNextRow() {
+            currentX = 0
+            currentY = frames.reduce(0) { result, rect in
+                max(
+                    result,
+                    rect.origin.y + rect.size.height
+                )
+            } + lineSpacing
+        }
+        
+        for stackable in self.visibleThingsToStack() {
+            let stackableWidth = getWidth(
+                for: stackable,
+                width: width
+            )
+                            
+            if currentX + stackableWidth > width {
+                moveToNextRow()
+            }
+            
+            if let stack = stackable as? Stack {
+                frames.append(
+                    contentsOf: stack.framesForLayout(
+                        (width - currentX),
+                        origin: .init(
+                            x: currentX,
+                            y: currentY
+                        )
+                    )
+                )
+            } else if let item = stackable as? StackableItem {
+                frames.append(
+                    .init(
+                        x: currentX,
+                        y: currentY,
+                        width: stackableWidth,
+                        height: item.heightForWidth(stackableWidth)
+                    )
+                )
+            }
+
+            currentX += stackableWidth + itemSpacing
+        }
+
+        return frames
+    }
+    
+    private func getWidth(for stackable: Stackable, width: CGFloat) -> CGFloat {
+        return if let stackableItem = stackable as? StackableItem {
+            min(
+                stackableItem.intrinsicContentSize.width,
+                width
+            )
+        } else if let fixedSizeStack = stackable as? Stack, let stackWidth = fixedSizeStack.width {
+            stackWidth
+        } else {
+           stackable.intrinsicContentSize.width
+        }
+    }
+}

Sources/FlowLayoutStack.swift

@@ -3,7 +3,7 @@
 
 import UIKit
 
-public protocol Stack: class, Stackable {
+public protocol Stack: AnyObject, Stackable {
     var thingsToStack: [Stackable] { get }
     var spacing: CGFloat { get }
     var layoutMargins: UIEdgeInsets { get }

Sources/Info.plist

@@ -2,8 +2,8 @@
 //
 
 import Foundation
-@testable import stackable
 import XCTest
+@testable import Stackable
 
 class FixedSizeStackableTests: XCTestCase {
     func test_view_should_return_expected() {