doctor_app_flutter/ios/Runner/VCEmbeder.swift

//
//  VCEmbeder.swift
//  Runner
//
//  Created by Zohaib Iqbal Kambrani on 08/06/2021.
//  Copyright © 2021 The Chromium Authors. All rights reserved.
//

import Foundation

extension UIView {
    func fill(to parent: UIView) {
        topAnchor.constraint(equalTo: parent.topAnchor).isActive = true
        leadingAnchor.constraint(equalTo: parent.leadingAnchor).isActive = true
        bottomAnchor.constraint(equalTo: parent.bottomAnchor).isActive = true
        trailingAnchor.constraint(equalTo: parent.trailingAnchor).isActive = true
    }
    
    func fillToParent() {
        if let parent = self.superview{
            topAnchor.constraint(equalTo: parent.topAnchor).isActive = true
            leadingAnchor.constraint(equalTo: parent.leadingAnchor).isActive = true
            bottomAnchor.constraint(equalTo: parent.bottomAnchor).isActive = true
            trailingAnchor.constraint(equalTo: parent.trailingAnchor).isActive = true
        }
    }
    
    func fillTo(view:UIView) {
        view.addSubview(self)
        fill(to: view)
    }
}

class ViewEmbedder {
    class func embed(
        parent:UIViewController,
        container:UIView,
        child:UIViewController,
        previous:UIViewController?){

        if let previous = previous {
            removeFromParent(vc: previous)
        }
        child.willMove(toParent: parent)
        parent.addChild(child)
        container.addSubview(child.view)
        child.didMove(toParent: parent)
        let w = container.frame.size.width;
        let h = container.frame.size.height;
        child.view.frame = CGRect(x: 0, y: 0, width: w, height: h)
        
        child.view.fill(to: container)
    }

    class func removeFromParent(vc:UIViewController){
        vc.willMove(toParent: nil)
        vc.view.removeFromSuperview()
        vc.removeFromParent()
    }

    class func embed(withIdentifier id:String, parent:UIViewController, container:UIView, completion:((UIViewController)->Void)? = nil){
        let vc = parent.storyboard!.instantiateViewController(withIdentifier: id)
        embed(
            parent: parent,
            container: container,
            child: vc,
            previous: parent.children.first
        )
        completion?(vc)
    }
}