NSIntelligenceUIWashAnimationView.swift

import SwiftUI


struct NSIntelligenceUIWashAnimationView: NSViewRepresentable {
    let startColor: Color
    let endColor: Color
    var onFinish: () -> Void = {}
    
    func makeAnimationView() -> NSView {
        let UIWashAnimationView = NSClassFromString("AppKit._NSIntelligenceUIWashAnimationView") as! NSView.Type
        let view = UIWashAnimationView.init(frame: .zero)

        let selector = NSSelectorFromString("animateWithStartColor:endColor:completionHandler:")
        let method = class_getInstanceMethod(type(of: view), selector)
        let implementation = method_getImplementation(method!)
        typealias Function = @convention(c) (AnyObject, Selector, Any, Any, Any) -> Void
        let function = unsafeBitCast(implementation, to: Function.self)
        

        let completionBlock: @convention(block) () -> Void = {
            onFinish()
        }
        
        function(view, selector, NSColor(startColor), NSColor(endColor), completionBlock)
        
        return view
    }
    
    func makeNSView(context: Context) -> some NSView {
        return makeAnimationView()
    }
    
    func updateNSView(_ nsViewController: NSViewType, context: Context) {}
}



// MARK: -  DemoView.
struct NSIntelligenceUIWashAnimationDemoView: View {
    @State private var isAnimating: Bool = false
    
    var body: some View {
        Button {
            self.isAnimating = true
        } label: {
            ZStack {
                if isAnimating {
                    NSIntelligenceUIWashAnimationView(startColor: .indigo, endColor: .black) {
                        self.isAnimating = false
                    }
                    .frame(width: 100, height: 40)
                    .clipShape(RoundedRectangle(cornerRadius: 10))
                }
                
                Text("Animate")
                    .font(.callout.weight(.semibold))
                    .foregroundStyle(isAnimating ? Color.primary : Color.gray)
            }
            .frame(width: 100, height: 40)
            .overlay {
                RoundedRectangle(cornerRadius: 10)
                    .stroke(.quaternary, lineWidth: 1)
            }
        }
        .animation(.smooth, value: isAnimating)
        .buttonStyle(.plain)
        .onHover {
            $0 ? NSCursor.pointingHand.set() : NSCursor.pop()
        }
    }
}



// MARK: -  Helpers.
struct VisualEffectBlur: NSViewRepresentable {
    var material: NSVisualEffectView.Material
    var blendingMode: NSVisualEffectView.BlendingMode
    
    func makeNSView(context: Context) -> NSVisualEffectView {
        let view = NSVisualEffectView()
        view.material = material
        view.blendingMode = blendingMode
        view.state = .active
        return view
    }
    
    func updateNSView(_ nsView: NSVisualEffectView, context: Context) {
        nsView.material = material
        nsView.blendingMode = blendingMode
    }
}

@main
struct DemoApp: App {
    var body: some Scene {
        WindowGroup {
            ZStack {
                VisualEffectBlur(material: .hudWindow, blendingMode: .behindWindow)
                    .ignoresSafeArea()
                
                NSIntelligenceUIWashAnimationDemoView()
            }
            .frame(width: 275, height: 130, alignment: .center)
        }
        .windowResizability(.contentSize)
        .windowStyle(.hiddenTitleBar)
    }
}

Screen.Recording.2025-12-28.at.11.58.32.PM.mov