Convenience extension for SwiftUI previews.

PreviewExt.swift

//
// PreviewExt.swift
//  
//
// Created by Marius Felkner on 2021-11-15.
//
// The MIT License (MIT)
//
// Copyright (c) 2021 Marius Felkner (https://twitter.com/mflknr)
//
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//
// *****WARNING*****
// SINCE THE INTRODUCTION OF MACROS AND THE NEW PREVIEW CONTEXT
// THIS BECAME HEAVILY OUTDATED. USE WITH CAUTION OR JUST AS INSPIRATION
// *****WARNING*****

import SwiftUI

extension View {
    func withColorSchemes() -> some View {
        _PreviewColorScheme(content: self)
    }

    @available(iOS 15.0, *)
    func withInterfaceOrientations() -> some View {
        _PreviewInterfaceOrientations(content: self)
    }

    func asComponent() -> some View {
        _PreviewComponent(content: self)
    }

    func onDevices(devices: [PreviewDevices] = [.iPhone6s, .iPhone13ProMax]) -> some View {
        _PreviewDevices(content: self, devices: devices)
    }

    @available(iOS 15.0, *)
    func withDynamicTypeSizes() -> some View {
        _PreviewSizeCategory(content: self)
    }
}

// MARK: - Prievew Wrapper

struct _PreviewColorScheme<Content: View>: View {

    // MARK: - Properties

    var content: Content

    // MARK: - Body

    var body: some View {
        Group {
            self.content
                .preferredColorScheme(.light)

            self.content
                .preferredColorScheme(.dark)
        }
    }
}

@available(iOS 15.0, *)
struct _PreviewInterfaceOrientations<Content: View>: View {

    // MARK: - Properties

    var content: Content

    // MARK: - Body

    var body: some View {
        Group {
            self.content
                .previewInterfaceOrientation(.portrait)

            self.content
                .previewInterfaceOrientation(.landscapeRight)
        }
    }
}

struct _PreviewComponent<Content: View>: View {

    // MARK: - Properties

    var content: Content

    // MARK: - Body

    var body: some View {
        Group {
            self.content
                .previewLayout(.sizeThatFits)
        }
    }
}

struct _PreviewDevices<Content: View>: View {

    // MARK: - Properties

    var content: Content
    var devices: [PreviewDevices]

    // MARK: - Body

    var body: some View {
        Group {
            ForEach(devices, id: \.self) { device in
                self.content
                    .previewDevice(PreviewDevice.init(rawValue: device.rawValue))
                    .previewDisplayName(device.rawValue)
            }
        }
    }
}

@available(iOS 15.0, *)
struct _PreviewSizeCategory<Content: View>: View {

    // MARK: - Properties

    var content: Content

    private let dynamicTypeSizes: [DynamicTypeSize] = [
        DynamicTypeSize.allCases.first ?? DynamicTypeSize.xSmall,
        DynamicTypeSize.allCases.last ?? DynamicTypeSize.accessibility5
    ]

    // MARK: - Body

    var body: some View {
        Group {
            self.content
                .previewDisplayName("Default")
            
            ForEach(dynamicTypeSizes, id: \.self) {
                self.content
                    .environment(\.dynamicTypeSize, $0)
                    .previewDisplayName("\($0)")
            }
        }
    }
}

// MARK: - Preview Devices | iPhone and iPad devices from `xcrun simctl list devicetypes` on 2021-11-15

enum PreviewDevices: String, Hashable {
    case iPhone4s = "iPhone 4s"
    case iPhone5 = "iPhone 5"
    case iPhone5s = "iPhone 5s"
    case iPhone6Plus = "iPhone 6 Plus"
    case iPhone6 = "iPhone 6"
    case iPhone6s = "iPhone 6s"
    case iPhone6sPlus = "iPhone 6s Plus"
    case iPhoneSE_1stGen = "iPhone SE (1st Gen)"
    case iPhone7 = "iPhone 7"
    case iPhone7Plus = "iPhone 7 Plus"
    case iPhone8 = "iPhone 8"
    case iPhone8Plus = "iPhone 8 Plus"
    case iPhoneX = "iPhone X"
    case iPhoneXs = "iPhone Xs"
    case iPhoneXsMax = "iPhone Xs Max"
    case iPhoneXʀ = "iPhone Xʀ"
    case iPhone11 = "iPhone 11"
    case iPhone11Pro = "iPhone 11 Pro"
    case iPhone11ProMax = "iPhone 11 Pro Max"
    case iPhoneS_2ndGen = "iPhone SE (2nd Gen)"
    case iPhone12mini = "iPhone 12 mini"
    case iPhone12 = "iPhone 12"
    case iPhone12Pro = "iPhone 12 Pro"
    case iPhone12ProMax = "iPhone 12 Pro Max"
    case iPhone13Pro = "iPhone 13 Pro"
    case iPhone13ProMax = "iPhone 13 Pro Max"
    case iPhone13mini = "iPhone 13 mini"
    case iPhone13 = "iPhone 13"
    case iPad2 = "iPad 2"
    case iPadRetina = "iPad Retina"
    case iPadAir = "iPad Air"
    case iPadmini2 = "iPad mini 2"
    case iPadmini3 = "iPad mini 3"
    case iPadmini4 = "iPad mini 4"
    case iPadAir2 = "iPad Air 2"
    case iPadPro_9_7 = "iPad Pro (9.7-inch)"
    case iPadPro_12_9_1stGen = "iPad Pro (12.9-inch) (1st generation)"
    case iPad_5thGen = "iPad (5th generation)"
    case iPadPro_12_9_2ndGen = "iPad Pro (12.9-inch) (2nd generation)"
    case iPadPro_10_5 = "iPad Pro (10.5-inch)"
    case iPad_6thGen = "iPad (6th generation)"
    case iPad_7thGen = "iPad (7th generation)"
    case iPadPro_11_1stGen = "iPad Pro (11-inch) (1st generation)"
    case iPadPro_12_9_3rdGen = "iPad Pro (12.9-inch) (3rd generation)"
    case iPadPro_11_2ndGen = "iPad Pro (11-inch) (2nd generation)"
    case iPadPro_12_9_4thGen = "iPad Pro (12.9-inch) (4th generation)"
    case iPadmini_5thGen = "iPad mini (5th generation)"
    case iPadAir_3rdGen = "iPad Air (3rd generation)"
    case iPad_8thGen = "iPad (8th generation)"
    case iPad_9thGen = "iPad (9th generation)"
    case iPadAir_4thGen = "iPad Air (4th generation)"
    case iPadPro_11_3rdGen = "iPad Pro (11-inch) (3rd generation)"
    case iPadPro_12_9_5thGen = "iPad Pro (12.9-inch) (5th generation)"
    case iPadmini_6thGen = "iPad mini (6th generation)"
}