SwiftUI View Extensions

ViewExtensions.swift

import SwiftUI

public extension View {
    func fillMaxSize(alignment: Alignment = .center) -> some View {
        frame(maxWidth: .infinity, maxHeight: .infinity, alignment: alignment)
    }

    func fillMaxWidth(alignment: Alignment = .center) -> some View {
        frame(maxWidth: .infinity, alignment: alignment)
    }

    func fillMaxHeight(alignment: Alignment = .center) -> some View {
        frame(maxHeight: .infinity, alignment: alignment)
    }

    func size(_ size: CGFloat, alignment: Alignment = .center) -> some View {
        frame(width: size, height: size, alignment: alignment)
    }

    func height(_ height: CGFloat) -> some View {
        frame(height: height)
    }

    func width(_ width: CGFloat) -> some View {
        frame(width: width)
    }

    func padding(paddings: Paddings) -> some View {
        padding(
            EdgeInsets(top: paddings.top, leading: paddings.leading, bottom: paddings.bottom, trailing: paddings.trailing)
        )
    }

    /// Returns the size of the view after drawing, so it can be stored in a @State variable and used to fit other views
    func readSize(onChange: @escaping (CGSize) -> Void) -> some View {
        background(
            GeometryReader { geometryProxy in
                Color.clear
                    .preference(key: SizePreferenceKey.self, value: geometryProxy.size)
            }
        )
        .onPreferenceChange(SizePreferenceKey.self, perform: onChange)
    }
}

private struct SizePreferenceKey: PreferenceKey {
    static var defaultValue: CGSize = .zero

    static func reduce(value _: inout CGSize, nextValue _: () -> CGSize) {}
}