Vibrancy Effect for SwiftUI

VibrancyEffect.swift

//
//  VibrancyEffect.swift
//  MFileViewer
//
//  Created by yuki on 2025/02/07.
//

import SwiftUI

public struct VibrancyEffect<Content: View>: View {
    public var content: Content
    
    public var style: Style
    
    public var thickness: Thickness
    
    public var saturation: CGFloat
    
    public var vibrancy: Bool = true
    
    public enum Style {
        case light
        case dark
    }
    
    public enum Thickness {
        case ultraThin // 0.1
        case thin // 0.3
        case regular // 0.5
        case thick // 0.7
        case ultraThick // 0.9
        case custom(CGFloat)
    }
    
    public init(
        style: Style = .light,
        thickness: Thickness = Thickness.regular,
        saturation: CGFloat = 0.7,
        @ViewBuilder content: () -> Content
    ) {
        self.style = style
        self.thickness = thickness
        self.saturation = saturation
        self.content = content()
    }
    
    public func enableVibrancy(_ enable: Bool) -> Self {
        var copy = self
        copy.vibrancy = enable
        return copy
    }
    
    public var body: some View {
        ZStack {
            self.content
                .foregroundColor(self.overlayColor())
                .blendMode(.overlay)
                .opacity(self.vibrancy ? 1 : 0)
            
            self.content
                .foregroundColor(self.contentColor())
                .opacity(self.vibrancy ? self.opacityForThickness() : 1)
        }
    }
    
    private func opacityForThickness() -> Double {
        switch self.thickness {
        case .ultraThin: return 0.1
        case .thin: return 0.3
        case .regular: return 0.5
        case .thick: return 0.7
        case .ultraThick: return 0.9
        case .custom(let value): return Double(value)
        }
    }
    
    private func contentColor() -> Color {
        switch self.style {
        case .light: return Color.white
        case .dark: return Color.black
        }
    }
    
    private func overlayColor() -> Color {
        switch self.style {
        case .light: return Color(white: self.saturation)
        case .dark: return Color(white: 1.0 - self.saturation)
        }
    }
}