components/BottomNavigation/examples/BottomNavigationSelectedIconExample.swift

/*
 Copyright 2018-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

// Example to show different icons for selected and unselected states
class BottomNavigationSelectedIconExample: UIViewController {
  var colorScheme = MDCSemanticColorScheme()
  var typographyScheme = MDCTypographyScheme()

  let bottomNavBar = MDCBottomNavigationBar()

  override func viewDidLoad() {
    colorScheme.backgroundColor = .white
    view.backgroundColor = colorScheme.backgroundColor

    let tabBarItem1 = UITabBarItem(title: "Home", image: UIImage(named: "Home"), tag: 0)
    let tabBarItem2 = UITabBarItem(title: "Messages", image: UIImage(named: "Email"), tag: 1)
    tabBarItem2.selectedImage = nil
    let tabBarItem3 = UITabBarItem(title: "Favorites", image: UIImage(named: "Cake"), tag: 2)
    tabBarItem3.selectedImage = UIImage(named: "Favorite")
    bottomNavBar.items = [ tabBarItem1, tabBarItem2, tabBarItem3 ]
    bottomNavBar.selectedItem = tabBarItem1
    view.addSubview(bottomNavBar)

    MDCBottomNavigationBarColorThemer.applySemanticColorScheme(colorScheme,
                                                               toBottomNavigation: bottomNavBar)
  }

  func layoutBottomNavBar() {
    let size = bottomNavBar.sizeThatFits(view.bounds.size)
    let bottomNavBarFrame = CGRect(x: 0,
                                   y: view.bounds.height - size.height,
                                   width: size.width,
                                   height: size.height)
    bottomNavBar.frame = bottomNavBarFrame
  }

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

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


// MARK: - Catalog by Conventions
extension BottomNavigationSelectedIconExample {
  class func catalogBreadcrumbs() -> [String] {
    return ["Bottom Navigation", "Bottom Navigation Selected"]
  }

  class func catalogIsPrimaryDemo() -> Bool {
    return false
  }
}