Adds ConfettiMode

Author: simonbs

Example/Example/ViewController.swift

@@ -11,36 +11,64 @@ import UIKit
 class ViewController: UIViewController {
     private let emojiLabel: UILabel = {
         let this = UILabel()
-        this.translatesAutoresizingMaskIntoConstraints = false
         this.font = .systemFont(ofSize: 64)
         this.text = "🎉"
         return this
     }()
-    private let confettiView: ConfettiView = {
-        let images = (1 ... 7).compactMap { UIImage(named: "confetti\($0)") }
-        let this = ConfettiView(images: images)
+    private var confettiView: ConfettiView?
+    private let segmentedControl: UISegmentedControl = {
+        let this = UISegmentedControl()
         this.translatesAutoresizingMaskIntoConstraints = false
+        this.insertSegment(withTitle: "Top to Bottom", at: 0, animated: false)
+        this.insertSegment(withTitle: "Center to Left", at: 1, animated: false)
+        this.selectedSegmentIndex = 0
         return this
     }()
 
     override func viewDidLoad() {
         super.viewDidLoad()
         view.backgroundColor = .systemBackground
         view.addSubview(emojiLabel)
-        view.addSubview(confettiView)
-        NSLayoutConstraint.activate([
-            emojiLabel.centerXAnchor.constraint(equalTo: view.centerXAnchor),
-            emojiLabel.centerYAnchor.constraint(equalTo: view.centerYAnchor),
+        view.addSubview(segmentedControl)
+        segmentedControl.addTarget(self, action: #selector(segmentedControlValueChanged), for: .valueChanged)
+        setupConfettiView(with: .topToBottom)
+    }
 
-            confettiView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
-            confettiView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
-            confettiView.topAnchor.constraint(equalTo: view.topAnchor),
-            confettiView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
-        ])
+    override func viewDidLayoutSubviews() {
+        super.viewDidLayoutSubviews()
+        let emojiLabelSize = emojiLabel.intrinsicContentSize
+        let emojiLabelOrigin = CGPoint(x: (view.frame.width - emojiLabelSize.width) / 2, y: (view.frame.height - emojiLabelSize.height) / 2)
+        emojiLabel.frame = CGRect(origin: emojiLabelOrigin, size: emojiLabelSize)
+        confettiView?.frame = view.bounds
+        let segmentedControlSize = segmentedControl.intrinsicContentSize
+        let segmentedControlOriginX = (view.frame.width - segmentedControlSize.width) / 2
+        let segmentedControlOriginY = view.frame.height - view.safeAreaInsets.bottom - segmentedControlSize.height - 30
+        let segmentedControlOrigin = CGPoint(x: segmentedControlOriginX, y: segmentedControlOriginY)
+        segmentedControl.frame = CGRect(origin: segmentedControlOrigin, size: segmentedControlSize)
     }
 
     override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
         super.touchesEnded(touches, with: event)
-        confettiView.shoot()
+        confettiView?.shoot()
+    }
+}
+
+private extension ViewController {
+    private func setupConfettiView(with mode: ConfettiMode) {
+        confettiView?.removeFromSuperview()
+        let images = (1 ... 7).compactMap { UIImage(named: "confetti\($0)") }
+        let confettiView = ConfettiView(mode: mode, images: images)
+        confettiView.isUserInteractionEnabled = false
+        view.addSubview(confettiView)
+        self.confettiView = confettiView
+        view.setNeedsLayout()
+    }
+
+    @objc private func segmentedControlValueChanged() {
+        if segmentedControl.selectedSegmentIndex == 0 {
+            setupConfettiView(with: .topToBottom)
+        } else if segmentedControl.selectedSegmentIndex == 1{
+            setupConfettiView(with: .centerToLeft)
+        }
     }
 }

Package.swift

@@ -1,11 +1,11 @@
-// swift-tools-version: 5.6
+// swift-tools-version: 5.7
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription
 
 let package = Package(
     name: "ConfettiKit",
-    platforms: [.iOS(.v15)],
+    platforms: [.iOS(.v15), .macCatalyst(.v15)],
     products: [
         .library(name: "ConfettiKit", targets: ["ConfettiKit"]),
     ],

Sources/ConfettiKit/ConfettiLayerView.swift

@@ -1,6 +1,7 @@
 import UIKit
 
 final class ConfettiLayerView: UIView {
+    private let mode: ConfettiMode
     private let emitterLayer: CAEmitterLayer = {
         var behaviors: [NSObject] = []
         if let behavior = EmitterBehavior.makeHorizontalWaveBehavior() {
@@ -10,7 +11,6 @@ final class ConfettiLayerView: UIView {
             behaviors.append(behavior)
         }
         let this = CAEmitterLayer()
-        this.emitterShape = .line
         this.birthRate = 0
         this.lifetime = 0
         if !behaviors.isEmpty {
@@ -25,13 +25,15 @@ final class ConfettiLayerView: UIView {
     private let scaleRange: CGFloat
     private let speed: Float
 
-    init(images: [UIImage], birthRate: Float = 100, scale: CGFloat = 1, scaleRange: CGFloat = 0, speed: Float = 1) {
+    init(mode: ConfettiMode, images: [UIImage], birthRate: Float = 100, scale: CGFloat = 1, scaleRange: CGFloat = 0, speed: Float = 1) {
+        self.mode = mode
         self.images = images
         self.birthRate = birthRate
         self.scale = scale
         self.scaleRange = scaleRange
         self.speed = speed
         super.init(frame: .zero)
+        emitterLayer.emitterShape = mode.emitterShape
         layer.addSublayer(emitterLayer)
     }
 
@@ -42,7 +44,7 @@ final class ConfettiLayerView: UIView {
     override func layoutSubviews() {
         super.layoutSubviews()
         emitterLayer.emitterSize = CGSize(width: bounds.width, height: 0)
-        emitterLayer.emitterPosition = CGPoint(x: bounds.midX, y: -10)
+        emitterLayer.emitterPosition = mode.emitterPosition(in: bounds)
         emitterLayer.frame = bounds
         updateAttractorBehavior()
     }
@@ -139,12 +141,23 @@ private extension ConfettiLayerView {
     private func addGravityAnimation() {
         let animation = CAKeyframeAnimation()
         animation.duration = 6
-        animation.keyTimes = [0.05, 0.1, 0.5, 1]
-        animation.values = [0, 300, 750, 1000]
+        switch mode {
+        case .topToBottom:
+            animation.keyTimes = [0.05, 0.1, 0.5, 1]
+            animation.values = [0, 300, 750, 1000]
+        case .centerToLeft:
+            animation.keyTimes = [0, 0.1, 0.5, 1]
+            animation.values = [-1000, -750, -100, 0]
+        }
         let cells = emitterLayer.emitterCells ?? []
         for cell in cells {
             if let name = cell.name {
-                emitterLayer.add(animation, forKey: "emitterCells.\(name).yAcceleration")
+                switch mode {
+                case .topToBottom:
+                    emitterLayer.add(animation, forKey: "emitterCells.\(name).yAcceleration")
+                case .centerToLeft:
+                    emitterLayer.add(animation, forKey: "emitterCells.\(name).xAcceleration")
+                }
             }
         }
     }
@@ -155,3 +168,23 @@ private extension ConfettiLayerView {
         return radians.value
     }
 }
+
+private extension ConfettiMode {
+    var emitterShape: CAEmitterLayerEmitterShape {
+        switch self {
+        case .topToBottom:
+            return .line
+        case .centerToLeft:
+            return .point
+        }
+    }
+
+    func emitterPosition(in rect: CGRect) -> CGPoint {
+        switch self {
+        case .topToBottom:
+            return CGPoint(x: rect.midX, y: -10)
+        case .centerToLeft:
+            return CGPoint(x: rect.midX, y: rect.midY)
+        }
+    }
+}

Sources/ConfettiKit/ConfettiMode.swift

@@ -0,0 +1,4 @@
+public enum ConfettiMode {
+    case topToBottom
+    case centerToLeft
+}

Sources/ConfettiKit/ConfettiShotView.swift

@@ -4,9 +4,9 @@ final class ConfettiShotView: UIView {
     private let backgroundLayerView: ConfettiLayerView
     private let foregroundLayerView: ConfettiLayerView
 
-    init(images: [UIImage]) {
-        backgroundLayerView = ConfettiLayerView(images: images, birthRate: 20, scale: 0.6, speed: 0.95)
-        foregroundLayerView = ConfettiLayerView(images: images, birthRate: 48, scale: 0.8, scaleRange: 0.1)
+    init(mode: ConfettiMode, images: [UIImage], birthRate1: Float, birthRate2: Float) {
+        backgroundLayerView = ConfettiLayerView(mode: mode, images: images, birthRate: birthRate1, scale: 0.6, speed: 0.95)
+        foregroundLayerView = ConfettiLayerView(mode: mode, images: images, birthRate: birthRate2, scale: 0.8, scaleRange: 0.1)
         backgroundLayerView.alpha = 0.5
         super.init(frame: .zero)
         addSubview(backgroundLayerView)

Sources/ConfettiKit/ConfettiView.swift

@@ -1,10 +1,15 @@
 import UIKit
 
 public final class ConfettiView: UIView {
+    public var birthRate1: Float = 48
+    public var birthRate2: Float = 20
+
+    private let mode: ConfettiMode
     private let images: [UIImage]
     private var shootings: [Shooting] = []
 
-    public init(images: [UIImage]) {
+    public init(mode: ConfettiMode = .topToBottom, images: [UIImage]) {
+        self.mode = mode
         self.images = images
         super.init(frame: .zero)
         clipsToBounds = true
@@ -22,7 +27,7 @@ public final class ConfettiView: UIView {
     }
 
     public func shoot() {
-        let view = ConfettiShotView(images: images)
+        let view = ConfettiShotView(mode: mode, images: images, birthRate1: birthRate1, birthRate2: birthRate2)
         view.frame = bounds
         addSubview(view)
         let shooting = Shooting(view: view)