Replace PencilKit brush stroke view with CALayer-based

Modules/Legacy/Editing/Sources/Editing View/Workspace/PhotoEditingPathBrushStrokeView.swift

@@ -0,0 +1,136 @@
+//  Created by Geoff Pado on 10/31/24.
+//  Copyright © 2024 Cocoatype, LLC. All rights reserved.
+
+final class PhotoEditingPathBrushStrokeView: UIControl, PhotoEditingBrushStrokeView {
+    var color = UIColor.black {
+        didSet { pathLayer?.strokeColor = color.cgColor }
+    }
+    private(set) var currentPath: UIBezierPath?
+
+    init() {
+        super.init(frame: .zero)
+        backgroundColor = .clear
+        isOpaque = false
+        translatesAutoresizingMaskIntoConstraints = false
+    }
+
+    override class var layerClass: AnyClass { PathLayer.self }
+    private var pathLayer: PathLayer? { layer as? PathLayer }
+
+    private static var standardLineWidth = 10.0
+    private var lineWidth = PhotoEditingPathBrushStrokeView.standardLineWidth {
+        didSet { pathLayer?.lineWidth = lineWidth }
+    }
+    func updateTool(currentZoomScale: CGFloat) {
+        lineWidth = Self.standardLineWidth * pow(currentZoomScale, -1.0)
+    }
+
+    // MARK: Touch Handling
+
+    private var previousPoint: CGPoint?
+    private var previousEndPoint: CGPoint?
+
+    private func newPath() -> UIBezierPath {
+        let newPath = UIBezierPath()
+        newPath.lineCapStyle = .butt
+        newPath.lineJoinStyle = .bevel
+        newPath.lineWidth = lineWidth
+        return newPath
+    }
+
+    private func clearPath() {
+        currentPath = nil
+        previousPoint = nil
+        previousEndPoint = nil
+        pathLayer?.path = nil
+    }
+
+    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
+        super.touchesBegan(touches, with: event)
+        guard let touch = touches.first else { return }
+
+        let location = touch.location(in: self)
+        currentPath = newPath()
+        currentPath?.move(to: location)
+        previousPoint = location
+
+        pathLayer?.path = currentPath?.cgPath
+    }
+
+    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
+        super.touchesMoved(touches, with: event)
+        guard let touch = touches.first,
+              let path = currentPath,
+              let previousPoint = previousPoint else { return }
+
+        let currentPoint = touch.location(in: self)
+
+        // Smooth the line by using quadratic curves
+        let midPoint = CGPoint(
+            x: (previousPoint.x + currentPoint.x) / 2,
+            y: (previousPoint.y + currentPoint.y) / 2
+        )
+
+        if previousEndPoint != nil {
+            path.addQuadCurve(to: midPoint, controlPoint: previousPoint)
+        } else {
+            path.addLine(to: midPoint)
+        }
+
+        previousEndPoint = midPoint
+        self.previousPoint = currentPoint
+
+        // Update shape layer with the new path
+        CATransaction.begin()
+        CATransaction.setDisableActions(true)
+        pathLayer?.path = path.cgPath
+        CATransaction.commit()
+    }
+
+    override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) {
+        super.touchesCancelled(touches, with: event)
+        clearPath()
+    }
+
+    override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
+        super.touchesEnded(touches, with: event)
+        guard let touch = touches.first,
+              let path = currentPath else { return }
+
+        let location = touch.location(in: self)
+        path.addLine(to: location)
+        pathLayer?.path = path.cgPath
+
+        sendActions(for: .touchUpInside)
+        clearPath()
+    }
+
+    // MARK: Boilerplate
+
+    @available(*, unavailable)
+    required init(coder: NSCoder) {
+        let typeName = NSStringFromClass(type(of: self))
+        fatalError("\(typeName) does not implement init(coder:)")
+    }
+
+    private class PathLayer: CAShapeLayer {
+        override init() {
+            super.init()
+            fillColor = nil
+            strokeColor = UIColor.black.cgColor
+            lineCap = .butt
+            lineJoin = .bevel
+            lineWidth = PhotoEditingPathBrushStrokeView.standardLineWidth
+        }
+
+        override init(layer: Any) {
+            super.init(layer: layer)
+        }
+
+        @available(*, unavailable)
+        required init(coder: NSCoder) {
+            let typeName = NSStringFromClass(type(of: self))
+            fatalError("\(typeName) does not implement init(coder:)")
+        }
+    }
+}

Modules/Legacy/Editing/Sources/Editing View/Workspace/PhotoEditingWorkspaceView.swift

@@ -250,7 +250,7 @@ class PhotoEditingWorkspaceView: UIControl, UIGestureRecognizerDelegate {
     private let visualizationView = PhotoEditingObservationVisualizationView()
     private let debugView = PhotoEditingObservationDebugView()
     private let redactionView = PhotoEditingRedactionView()
-    private let brushStrokeView: (UIControl & PhotoEditingBrushStrokeView) = PhotoEditingCanvasBrushStrokeView()
+    private let brushStrokeView: (UIControl & PhotoEditingBrushStrokeView) = PhotoEditingPathBrushStrokeView()
     private let pencilDelegate = PhotoEditingWorkspacePencilDelegate()
 
     @available(*, unavailable)