/*

See LICENSE folder for this sample’s licensing information.

Abstract:

View controller demonstrating an accessible, custom NSView subclass that shows a hidden view on mouse over.

*/

import Cocoa

class TransientUIViewController: NSViewController {

    static let PageCount = 10

    var page = 0

    @IBOutlet var pageTextField: NSTextField!

    @IBOutlet var nextPageButton: NSButton!

    @IBOutlet var previousPageButton: NSButton!

    // MARK: - View Controller Lifecycle

    override func viewDidLoad() {

        super.viewDidLoad()

        updatePageTextView()

    }

    fileprivate func updateButtons() {

        let nextButtonEnabled = page < TransientUIViewController.PageCount - 1

        nextPageButton.isEnabled = nextButtonEnabled

        previousPageButton.isEnabled = page > 0

        if !nextButtonEnabled {

            let currentWindow = previousPageButton.window

            currentWindow?.makeFirstResponder(previousPageButton)

        }

    }

    fileprivate func updatePageTextView() {

        let formatter = NSLocalizedString("PageCountFormatter", comment: "page count formatter")

        let pageNumber = NumberFormatter.localizedString(from: NSNumber(value: page + 1),

                                                         number: NumberFormatter.Style.decimal)

        let pageCount = NumberFormatter.localizedString(from: NSNumber(value: TransientUIViewController.PageCount),

                                                        number: NumberFormatter.Style.decimal)

        pageTextField.stringValue = String(format: formatter, pageNumber, pageCount)

        updateButtons()

    }

    @IBAction func pressNextPageButton(_ sender: Any) {

        if page < TransientUIViewController.PageCount {

            page += 1

        }

        updatePageTextView()

    }

    @IBAction func pressPreviousPageButton(_ sender: Any) {

        if page > 0 {

            page -= 1

        }

        updatePageTextView()

    }

}