/*

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

    See LICENSE.txt for this sample’s licensing information

    Abstract:

    Demonstrates the implementation of the previewing delegate's "Peek" and "Pop" callbacks.

*/

import UIKit

extension MasterViewController: UIViewControllerPreviewingDelegate {

    // MARK: UIViewControllerPreviewingDelegate

    /// Create a previewing view controller to be shown at "Peek".

    func previewingContext(_ previewingContext: UIViewControllerPreviewing, viewControllerForLocation location: CGPoint) -> UIViewController? {

        // Obtain the index path and the cell that was pressed.

        guard let indexPath = tableView.indexPathForRow(at: location),

                  let cell = tableView.cellForRow(at: indexPath) else { return nil }

        // Create a detail view controller and set its properties.

        guard let detailViewController = storyboard?.instantiateViewController(withIdentifier: "DetailViewController") as? DetailViewController else { return nil }

        let previewDetail = sampleData[(indexPath as NSIndexPath).row]

        detailViewController.sampleTitle = previewDetail.title

        /*

            Set the height of the preview by setting the preferred content size of the detail view controller.

            Width should be zero, because it's not used in portrait.

        */

        detailViewController.preferredContentSize = CGSize(width: 0.0, height: previewDetail.preferredHeight)

        // Set the source rect to the cell frame, so surrounding elements are blurred.

        previewingContext.sourceRect = cell.frame

        return detailViewController

    }

    /// Present the view controller for the "Pop" action.

    func previewingContext(_ previewingContext: UIViewControllerPreviewing, commit viewControllerToCommit: UIViewController) {

        // Reuse the "Peek" view controller for presentation.

        show(viewControllerToCommit, sender: self)

    }

}