/*

    Copyright (C) 2016 Apple Inc. All Rights Reserved.

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    Provides a stack layout in the z axis.

*/

import CoreGraphics

/// A layout that renders content on top of each other in the z dimension.

struct ZStackLayout<Child: Layout>: Layout {

    typealias Content = Child.Content

    var children: [Child]

    mutating func layout(in rect: CGRect) {

        for index in children.indices {

            /*

                The same rect is used for each layout——the important part for the

                `ZStackLayout` is that it returns its child's contents in the correct

                order.

            */

            children[index].layout(in: rect)

        }

    }

    var contents: [Content] {

        return children.flatMap { $0.contents }

    }

}