Initial commit

Examples/Example-iOS/InsertionSortViewController.swift

@@ -0,0 +1,172 @@
+import UIKit
+import DiffableDataSources
+
+final class InsertionSortViewController: UIViewController {
+    final class Section: Hashable {
+        var id = UUID()
+        var nodes: [Node]
+        private(set) var isSorted = false
+        private var currentIndex = 1
+
+        init(count: Int) {
+            nodes = (0..<count).map { Node(value: $0, maxValue: count) }.shuffled()
+        }
+
+        func hash(into hasher: inout Hasher) {
+            hasher.combine(id)
+        }
+
+        func sortNext() {
+            guard !isSorted, nodes.count > 1 else {
+                return isSorted = true
+            }
+
+            var index = currentIndex
+            let currentNode = nodes[index]
+            index -= 1
+
+            while index >= 0 && currentNode.value < nodes[index].value {
+                let node = nodes[index]
+                nodes[index] = currentNode
+                nodes[index + 1] = node
+                index -= 1
+            }
+
+            currentIndex += 1
+
+            if currentIndex >= nodes.count {
+                isSorted = true
+            }
+        }
+
+        static func == (lhs: Section, rhs: Section) -> Bool {
+            return lhs.id == rhs.id
+        }
+    }
+
+    struct Node: Hashable {
+        var id = UUID()
+        var value: Int
+        var color: UIColor
+
+        init(value: Int, maxValue: Int) {
+            let hue = CGFloat(value) / CGFloat(maxValue)
+            self.value = value
+            color = UIColor(hue: hue, saturation: 1, brightness: 1, alpha: 1)
+            id = UUID()
+        }
+
+        func hash(into hasher: inout Hasher) {
+            hasher.combine(id)
+        }
+
+        static func == (lhs: Node, rhs: Node) -> Bool {
+            return lhs.id == rhs.id
+        }
+    }
+
+    @IBOutlet private var collectionView: UICollectionView!
+    private var isSorting = false
+
+    let nodeSize = CGSize(width: 16, height: 34)
+
+    private lazy var dataSource = CollectionViewDiffableDataSource<Section, Node>(collectionView: collectionView) { collectionView, indexPath, node in
+        let cell = collectionView.dequeueReusableCell(withReuseIdentifier: UICollectionViewCell.name, for: indexPath)
+        cell.backgroundColor = node.color
+        return cell
+    }
+
+    override func viewDidLoad() {
+        super.viewDidLoad()
+
+        title = "Insertion Sort"
+
+        collectionView.delegate = self
+        collectionView.register(UICollectionViewCell.self, forCellWithReuseIdentifier: UICollectionViewCell.name)
+        navigationItem.rightBarButtonItem = UIBarButtonItem(title: nil, style: .plain, target: self, action: #selector(toggleSort))
+
+        updateSortButtonTitle()
+    }
+
+    override func viewDidLayoutSubviews() {
+        super.viewDidLayoutSubviews()
+        randmize(animated: false)
+    }
+
+    @objc func toggleSort() {
+        isSorting.toggle()
+        updateSortButtonTitle()
+
+        if isSorting {
+            startInsertionSort()
+        }
+    }
+
+    func updateSortButtonTitle() {
+        navigationItem.rightBarButtonItem?.title = isSorting ? "Stop" : "Sort"
+    }
+
+    func randmize(animated: Bool) {
+        let snapshot = DiffableDataSourceSnapshot<Section, Node>()
+        let rows = Int(collectionView.bounds.height / nodeSize.height) - 1
+        let columns = Int(collectionView.bounds.width / nodeSize.width)
+
+        for _ in 0..<rows {
+            let section = Section(count: columns)
+            snapshot.appendSections([section])
+            snapshot.appendItems(section.nodes)
+        }
+
+        dataSource.apply(snapshot, animatingDifferences: animated)
+    }
+
+    func startInsertionSort() {
+        guard isSorting else {
+            return
+        }
+
+        var isNextSortRequired = false
+        let snapshot = dataSource.snapshot()
+
+        for section in snapshot.sectionIdentifiers where !section.isSorted {
+            section.sortNext()
+            let items = section.nodes
+            snapshot.deleteItems(items)
+            snapshot.appendItems(items, toSection: section)
+            isNextSortRequired = true
+        }
+
+        if isNextSortRequired {
+            dataSource.apply(snapshot)
+        }
+
+        DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(isNextSortRequired ? 150 : 1000)) { [weak self] in
+            guard let self = self else {
+                return
+            }
+
+            if !isNextSortRequired {
+                self.randmize(animated: false)
+            }
+            self.startInsertionSort()
+        }
+    }
+}
+
+extension InsertionSortViewController: UICollectionViewDelegateFlowLayout {
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
+        return 0
+    }
+
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
+        return 0
+    }
+
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, insetForSectionAt section: Int) -> UIEdgeInsets {
+        return .zero
+    }
+
+    func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
+        return nodeSize
+    }
+}