components/AppBar/examples/AppBarInterfaceBuilderExampleController.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_Theming
import MaterialComponents.MaterialContainerScheme

class AppBarInterfaceBuilderSwiftExample: UIViewController, UIScrollViewDelegate {
  @IBOutlet weak var scrollView: UIScrollView!
  let appBarViewController = MDCAppBarViewController()
  @objc var containerScheme: MDCContainerScheming = MDCContainerScheme()

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

  override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
    super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
    commonAppBarInterfaceBuilderSwiftExampleSetup()
  }

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

  override func awakeFromNib() {
    super.awakeFromNib()
    commonAppBarInterfaceBuilderSwiftExampleSetup()
  }

  func commonAppBarInterfaceBuilderSwiftExampleSetup() {
    // Behavioral flags.
    appBarViewController.inferTopSafeAreaInsetFromViewController = true
    appBarViewController.headerView.minMaxHeightIncludesSafeArea = false

    addChild(appBarViewController)
  }

  override func viewDidLoad() {
    super.viewDidLoad()

    appBarViewController.applyPrimaryTheme(withScheme: containerScheme)

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

    appBarViewController.headerView.trackingScrollView = scrollView

    view.addSubview(appBarViewController.view)
    appBarViewController.didMove(toParent: self)
  }

  override var preferredStatusBarStyle: UIStatusBarStyle {
    // Ensure that our status bar is white.
    return .lightContent
  }
}

// MARK: Catalog by convention
extension AppBarInterfaceBuilderSwiftExample {

  @objc class func catalogMetadata() -> [String: Any] {
    return [
      "breadcrumbs": ["App Bar", "Interface Builder (Swift)"],
      "primaryDemo": false,
      "presentable": false,
      "storyboardName": "AppBarInterfaceBuilderSwiftExampleController",
      "skip_snapshots": true, // Currently crashing with "'NSUnknownKeyException', reason: '[<UIViewController 0x7fa0ca13f510> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key scrollView.'"
    ]
  }

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