UIKit_UIViewPreviewProvider

ReadMe.md

PreviewProvider in UIKit UIView

We can preview the drawing of coding via SwiftUI.

This part will demonstrate the code of encapsulating SWiftUI PreviewProvider and how it can be used in UIKit.UIView.

ViewProvider

The init function is encapsulated with ViewProvider the view and @ViewBuilder Or specified Size. The type of ViewProvider.viewController is AnyView, which means it will act like a previewer for Preview Provider.

ViewRepresentable.

ViewRepresentable is a struct complies with Protocol "UIViewRepresentable"

file: ViewPreviewProvider

You can cache the data that UIView holds and use them when you need to preview your code.

If you are interesting to know more about relative information, please check out PreviewProvider in UIKit UIViewController

KitProviderLayout.swift

//
//  KitProviderLayout.swift
//
//  Created by Woody on 2022/2/11.
//

import UIKit

#if canImport(SwiftUI) && DEBUG
class ViewLayout {
    typealias Size = CGSize
}

extension ViewLayout.Size {
    
    typealias Length = CGFloat
    
    static func Square(_ length: Length)-> Self {
        return Self.init(width: length, height: length)
    }
    
    static func Rectangle(width: Length, heightMultiplier m: Length)-> Self {
        return Self.init(width: width, height: width * m)
    }
}

extension ViewLayout.Size.Length {
    
    static var ScreenWidth: Self {
        return UIScreen.main.bounds.width
    }
    
    static var ScreenHeight: Self {
        return UIScreen.main.bounds.height
    }
}

#endif

ViewPreviewProvider.swift

//
//  ViewPreviewProvider.swift
//
//  Created by Woody on 2022/2/10.
//

import Foundation

#if canImport(SwiftUI) && DEBUG
import SwiftUI

extension ViewProvider {
    ///  current preview
    static var display: ViewProvider {
        return .default
    }
    
    

    
}


struct UIView_Preview: PreviewProvider {
    static var previews: some View {
        return ViewProvider.display
    }
}

#endif

ViewProvider.swift

//
//  ViewProvider.swift
//
//  Created by Woody on 2022/2/11.
//

import Foundation

#if canImport(SwiftUI) && DEBUG
import SwiftUI

public struct ViewProvider: View {
    public let view: AnyView
    public var body: some View {
        return view
    }
    
    init<Content>(_ view: UIView, @ViewBuilder content: (ViewRepresentable)-> Content) where Content: View {
        let vr = ViewRepresentable(view: view)
        self.view = AnyView(content(vr))
    }
    
    init(_ view: UIView) {
        let vr = ViewRepresentable(view: view)
        self.view = AnyView(vr)
    }
    
    init(_ view: UIView, size: ViewLayout.Size) {
        let vr = ViewRepresentable(view: view)
        self.view = AnyView(vr.frame(width: size.width, height: size.height, alignment: .center))
    }
    /// sample
    public static let `default`: ViewProvider = .init(UIView(), content: { $0.overlay(Color.red)})
    
}

#endif

ViewRepresentable.swift

//
//  ViewRepresentable.swift
//
//  Created by Woody on 2022/2/11.
//

import Foundation

#if canImport(SwiftUI) && DEBUG
import SwiftUI

@frozen public struct ViewRepresentable: UIViewRepresentable {
    let view: UIView
    public func makeUIView(context: Context) -> some UIView {
        return view
    }
    public func updateUIView(_ uiView: UIViewType, context: Context) {}
}

#endif