Sidemenu: Missing ability to provide custom overlay

[vkolosovsky]

New Issue Checklist

I have read the guidelines for contributing and I understand:

• [x] My issue is happening in the latest version of SideMenu.
• [x] My issue was not solved in the README.
• [x] My issue can not be answered on stackoverflow.com.
• [x] My issue is not a request for new functionality that I am unwilling to build and contribute with a pull request.
• [x] My issue is reproducible in the demo project.

Issue Description

Is there a way to display custom overlay, like it was done in previous version using

        transition.overlayBlock = {[weak self] () -> UIView? in
            guard let strongSelf = self else { return nil }
            return strongSelf.activeDelegate?.sideMenuOverlay?(menu: strongSelf)
        }

[jonkykong]

Hi @vkolosovsky,

Currently, that's not explicitly supported although it's easy to incorporate. Two options:

1. In your SideMenuNavigationController instance, override the viewWillAppear, etc. events to show your overlay.
2. Create your own SideMenuPresentationStyle that shows your overlay during display.

Hope this helps.

[otusweb]

For those coming here looking for the solution, here is the code I used:

class subClass: SideMenuNavigationController {
    var overlayView:UIView!

    override func viewDidLoad() {
        super.viewDidLoad()

        //overlay creation
        overlayView = UIView()
        overlayView.backgroundColor = .shade1
        overlayView.alpha = 0.3
        overlayView.translatesAutoresizingMaskIntoConstraints = false
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        if let viewToInsertIn = presentingViewController?.view
        {
            viewToInsertIn.insertSubview(overlayView, at: viewToInsertIn.subviews.count)
            overlayView.leadingAnchor.constraint(equalTo: viewToInsertIn.leadingAnchor).isActive = true
            overlayView.trailingAnchor.constraint(equalTo: viewToInsertIn.trailingAnchor).isActive = true
            overlayView.topAnchor.constraint(equalTo: viewToInsertIn.topAnchor).isActive = true
            overlayView.bottomAnchor.constraint(equalTo: viewToInsertIn.bottomAnchor).isActive = true
        }

    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)

        overlayView.removeFromSuperview()
    }
}

[sukhrobkhakimov]

@otusweb Your solution doesn't take presenting and dismissing animations into account. Here is a better solution:

import SideMenu
import UIKit

class MenuViewController: SideMenuNavigationController {
    private lazy var overlayView: UIView = {
        let view = UIView()
        view.translatesAutoresizingMaskIntoConstraints = false
        view.backgroundColor = .gray
        view.alpha = 0.0

        return view
    }()

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        showOverlayView()
    }

    override func viewWillDisappear(_ animated: Bool) {
        hideOverlayView()

        super.viewWillDisappear(animated)
    }
}

extension MenuViewController {
    private func showOverlayView() {
        addOverlayView()

        UIView.animate(withDuration: presentDuration) {
            self.overlayView.alpha = 0.2
        }
    }

    private func hideOverlayView() {
        UIView.animate(withDuration: dismissDuration) {
            self.overlayView.alpha = 0.0
        } completion: { _ in
            self.removeOverlayView()
        }
    }

    private func addOverlayView() {
        guard let view = presentingViewController?.view else { return }
        view.addSubview(overlayView)

        NSLayoutConstraint.activate([
            overlayView.topAnchor.constraint(equalTo: view.topAnchor),
            overlayView.bottomAnchor.constraint(equalTo: view.bottomAnchor),
            overlayView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            overlayView.trailingAnchor.constraint(equalTo: view.trailingAnchor)
        ])
    }

    private func removeOverlayView() {
        overlayView.removeFromSuperview()
    }
}

[sukhrobkhakimov]

@jonkykong Thanks for the awesome library :clap: