material-components_material-components-ios/components/BottomAppBar/examples/BottomAppBarTypicalUseExample.swift

// Copyright 2017-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 UIKit

import MaterialComponents.MaterialAppBar
import MaterialComponents.MaterialBottomAppBar
import MaterialComponents.MaterialBottomAppBar_ColorThemer
import MaterialComponents.MaterialButtons_ButtonThemer

class BottomAppBarTypicalUseSwiftExample: UIViewController {

  let appBarViewController = MDCAppBarViewController()
  let bottomBarView = MDCBottomAppBarView()
  var colorScheme = MDCSemanticColorScheme()
  var typographyScheme = MDCTypographyScheme()

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

    self.title = "Bottom App Bar (Swift)"
    self.addChildViewController(appBarViewController)

    let color = UIColor(white: 0.2, alpha:1)
    appBarViewController.headerView.backgroundColor = color
    appBarViewController.navigationBar.tintColor = .white
    appBarViewController.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName : UIColor.white]
    commonInitBottomAppBarTypicalUseSwiftExample()
  }

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

  override func viewDidLoad() {
    super.viewDidLoad()

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

  func commonInitBottomAppBarTypicalUseSwiftExample() {
    bottomBarView.autoresizingMask = [ .flexibleWidth, .flexibleTopMargin ]
    view.addSubview(bottomBarView)

    // Add touch handler to the floating button.
    bottomBarView.floatingButton.addTarget(self,
                                           action: #selector(didTapFloatingButton(_:)),
                                           for: .touchUpInside)

    // Set the image on the floating button.
    let addImage = UIImage(named:"Add")?.withRenderingMode(.alwaysTemplate)
    bottomBarView.floatingButton.setImage(addImage, for: .normal)

    // Set the position of the floating button.
    bottomBarView.floatingButtonPosition = .center

    // Theme the floating button.
    let buttonScheme = MDCButtonScheme()
    buttonScheme.colorScheme = colorScheme
    buttonScheme.typographyScheme = typographyScheme
    MDCFloatingActionButtonThemer.applyScheme(buttonScheme, to: bottomBarView.floatingButton)
    MDCBottomAppBarColorThemer.applySurfaceVariant(withSemanticColorScheme: colorScheme,
                                                   to: bottomBarView)

    // Configure the navigation buttons to be shown on the bottom app bar.
    let barButtonLeadingItem = UIBarButtonItem()
    let menuImage = UIImage(named:"Menu")?.withRenderingMode(.alwaysTemplate)
    barButtonLeadingItem.image = menuImage

    let barButtonTrailingItem = UIBarButtonItem()
    let searchImage = UIImage(named:"Search")?.withRenderingMode(.alwaysTemplate)
    barButtonTrailingItem.image = searchImage

    bottomBarView.leadingBarButtonItems = [ barButtonLeadingItem ]
    bottomBarView.trailingBarButtonItems = [ barButtonTrailingItem ]
  }

  @objc func didTapFloatingButton(_ sender : MDCFloatingButton) {

    // Example of how to animate position of the floating button.
    if (bottomBarView.floatingButtonPosition == .center) {
      bottomBarView.setFloatingButtonPosition(.trailing, animated: true)
    } else {
      bottomBarView.setFloatingButtonPosition(.center, animated: true)
    }
  }

  func layoutBottomAppBar() {
    let size = bottomBarView.sizeThatFits(view.bounds.size)
    let bottomBarViewFrame = CGRect(x: 0,
                                    y: view.bounds.size.height - size.height,
                                    width: size.width,
                                    height: size.height)
    bottomBarView.frame = bottomBarViewFrame
  }

  override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    self.view.backgroundColor = .white

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

  override func viewWillLayoutSubviews() {
    super.viewWillLayoutSubviews()
    layoutBottomAppBar()
  }

  #if swift(>=3.2)
  @available(iOS 11, *)
  override func viewSafeAreaInsetsDidChange() {
    super.viewSafeAreaInsetsDidChange()
    layoutBottomAppBar()
  }
  #endif

}

// MARK: Catalog by convention
extension BottomAppBarTypicalUseSwiftExample {

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

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