// Copyright 2018, Ralf Ebert
// License   https://opensource.org/licenses/MIT
// License   https://creativecommons.org/publicdomain/zero/1.0/
// Source    https://www.ralfebert.de/ios-examples/uikit/choicepopover/

import UIKit

/**
 By default, when you use:
 
    ```
    controller.modalPresentationStyle = .popover
    ```

 in a horizontally compact environment (iPhone in portrait mode), this option behaves the same as fullScreen.
 You can make it to always show a popover by using:
 
    ```
    let presentationController = AlwaysPresentAsPopover.configurePresentation(forController: controller)
    ```
  */
class AlwaysPresentAsPopover : NSObject, UIPopoverPresentationControllerDelegate {
    
    // `sharedInstance` because the delegate property is weak - the delegate instance needs to be retained.
    private static let sharedInstance = AlwaysPresentAsPopover()
    
    private override init() {
        super.init()
    }
    
    func adaptivePresentationStyle(for controller: UIPresentationController) -> UIModalPresentationStyle {
        return .none
    }
    
    static func configurePresentation(forController controller : UIViewController) -> UIPopoverPresentationController {
        controller.modalPresentationStyle = .popover
        let presentationController = controller.presentationController as! UIPopoverPresentationController        
        presentationController.delegate = AlwaysPresentAsPopover.sharedInstance
        return presentationController
    }
    
}