components/AppBar/examples/AppBarModalPresentationExample.swift

// Copyright 2016-present the Material Components for iOS authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

import Foundation
import MaterialComponents.MaterialAppBar
import MaterialComponents.MaterialAppBar_ColorThemer

class AppBarModalPresentationSwiftExamplePresented: UITableViewController {

  let appBarViewController = MDCAppBarViewController()
  var colorScheme = MDCSemanticColorScheme()

  deinit {
    // Required for pre-iOS 11 devices because we've enabled observesTrackingScrollViewScrollEvents.
    appBarViewController.headerView.trackingScrollView = nil
  }

  init() {
    super.init(nibName: nil, bundle: nil)

    self.title = "Modal Presentation (Swift)"

    // Behavioral flags.
    appBarViewController.inferTopSafeAreaInsetFromViewController = true
    appBarViewController.headerView.minMaxHeightIncludesSafeArea = false

    self.addChildViewController(appBarViewController)
    self.modalPresentationStyle = .formSheet
    self.modalTransitionStyle = .coverVertical
  }

  required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
  }

  override func viewDidLoad() {
    super.viewDidLoad()

    MDCAppBarColorThemer.applyColorScheme(colorScheme, to: appBarViewController)

    // Allows us to avoid forwarding events, but means we can't enable shift behaviors.
    appBarViewController.headerView.observesTrackingScrollViewScrollEvents = true

    appBarViewController.headerView.trackingScrollView = self.tableView

    view.addSubview(appBarViewController.view)
    #if swift(>=4.2)
    appBarViewController.didMove(toParent: self)
    #else
    appBarViewController.didMove(toParentViewController: self)
    #endif

    self.navigationItem.rightBarButtonItem =
      UIBarButtonItem(title: "Touch", style: .done, target: nil, action: nil)

    self.navigationItem.leftBarButtonItem =
      UIBarButtonItem(title: "Dismiss", style: .done, target: self, action: #selector(dismissSelf))
  }

  override var childViewControllerForStatusBarHidden: UIViewController? {
    return appBarViewController
  }

  override var childViewControllerForStatusBarStyle: UIViewController? {
    return appBarViewController
  }

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

    self.navigationController?.setNavigationBarHidden(true, animated: animated)
  }

  override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 50
  }

  override func tableView(
    _ tableView: UITableView,
    cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    var cell = self.tableView.dequeueReusableCell(withIdentifier: "cell")
    if cell == nil {
      cell = UITableViewCell(style: .default, reuseIdentifier: "cell")
    }
    cell!.layoutMargins = UIEdgeInsets.zero
    return cell!
  }

  @objc func dismissSelf() {
    self.dismiss(animated: true, completion: nil)
  }
}

class AppBarModalPresentationSwiftExample: UITableViewController {

  let appBarViewController = MDCAppBarViewController()
  var colorScheme = MDCSemanticColorScheme()

  init() {
    super.init(nibName: nil, bundle: nil)

    self.title = "Modal Presentation (Swift)"

    self.addChildViewController(appBarViewController)
  }

  required init?(coder aDecoder: NSCoder) {
    super.init(coder: aDecoder)
  }

  override func viewDidLoad() {
    super.viewDidLoad()

    MDCAppBarColorThemer.applyColorScheme(colorScheme, to: appBarViewController)

    appBarViewController.headerView.trackingScrollView = self.tableView
    self.tableView.delegate = appBarViewController

    view.addSubview(appBarViewController.view)
    #if swift(>=4.2)
    appBarViewController.didMove(toParent: self)
    #else
    appBarViewController.didMove(toParentViewController: self)
    #endif

    self.navigationItem.rightBarButtonItem =
      UIBarButtonItem(title: "Detail", style: .done, target: self, action: #selector(presentModal))
  }

  override var childViewControllerForStatusBarHidden: UIViewController? {
    return appBarViewController
  }

  override var childViewControllerForStatusBarStyle: UIViewController? {
    return appBarViewController
  }

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

    self.navigationController?.setNavigationBarHidden(true, animated: animated)
  }

  @objc func presentModal() {
    let modalVC = AppBarModalPresentationSwiftExamplePresented()
    self.present(modalVC, animated: true, completion: nil)
  }
}

// MARK: Catalog by convention
extension AppBarModalPresentationSwiftExample {

  class func catalogMetadata() -> [String: Any] {
    return [
      "breadcrumbs": ["App Bar", "Modal Presentation (Swift)"],
      "primaryDemo": false,
      "presentable": false,
    ]
  }

  func catalogShouldHideNavigation() -> Bool {
    return true
  }
}

// MARK: - Typical application code (not Material-specific)

// MARK: UITableViewDataSource
extension AppBarModalPresentationSwiftExample {

  override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 50
  }

  override func tableView(
    _ tableView: UITableView,
    cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    var cell = self.tableView.dequeueReusableCell(withIdentifier: "cell")
    if cell == nil {
      cell = UITableViewCell(style: .default, reuseIdentifier: "cell")
    }
    cell!.layoutMargins = UIEdgeInsets.zero
    return cell!
  }

}