spiegel-keyman/ios/keyman/Keyman/SWKeyboard/KeyboardViewController.swift

//
//  KeyboardViewController.swift
//  Keyman
//
//  Created by Gabriel Wong on 2017-09-04.
//  Copyright © 2017 SIL International. All rights reserved.
//

import KeymanEngine
import UIKit
import Sentry

class KeyboardViewController: InputViewController {
  var topBarImageSource: ImageBannerViewController!

  // The entrypoint for the app-extension.
  override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
    // Only true if it's the first init of the class under app-extension mode.
    if !SentryManager.hasStarted {
      // Sentry can send errors from app extensions when "Allow Full Access"
      // is enabled.  They seem to get blocked otherwise, except in the Simulator.
      SentryManager.start(sendingEnabled: true)
    }
    _ = log
    _ = KeymanEngine.log

    Manager.applicationGroupIdentifier = "group.KM4I"

    let bundle = Bundle(for: KeyboardViewController.self)
    topBarImageSource = ImageBannerViewController(nibName: "ImageBanner", bundle: bundle)

    super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
  }

  required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
  }

  override func updateViewConstraints() {
    super.updateViewConstraints()

    if view.frame.size.width == 0 || self.view.frame.size.height == 0 {
      return
    }

    setupTopBarImage(size: view.frame.size)
  }

  override func viewDidLoad() {
    super.viewDidLoad()
    setupTopBarImage(size: view.frame.size)
  }

  override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
    super.viewWillTransition(to: size, with: coordinator)
    setupTopBarImage(size: size)
  }

  func getTopBarImage(size: CGSize) -> String? {
    return topBarImageSource.renderAsBase64(size: CGSize(width: size.width, height: self.activeTopBarHeight))
  }

  func setupTopBarImage(size: CGSize) {
    let imgPath = getTopBarImage(size: size)
    guard let path = imgPath else {
      SentryManager.captureAndLog("No image specified for the image banner!")
      return
    }

    self.setBannerImage(to: path)
  }

  override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
    super.traitCollectionDidChange(previousTraitCollection)
    guard let previousTraitCollection = previousTraitCollection else {return}
    if #available(iOS 13.0, *) {
      if previousTraitCollection.hasDifferentColorAppearance(comparedTo: traitCollection) {
        /* Ensure that the keyboard banner image transitions!  Noting that the backing view isn't in the view hierarchy,
         * and that manipulating said hierarchy is key for triggering the appearance change
         * (see https://developer.apple.com/documentation/uikit/uiappearance)...
         *
         * We have to reload the banner's backing view to trigger the change.  Thanks, Apple.
         * The only other alternative - creating a new instance of the view & its controller.
         *
         * With loadView, at least we can reuse the old instance, which would serve far better
         * for engine API calls if we decide to let the base InputViewController perform UIView
         * render functionality (as a KMEI offering) instead of having it only in our app.
         * That said, note https://developer.apple.com/documentation/uikit/uiviewcontroller/1621454-loadview:
         *
         * > You should never call this method directly.
         *
         * Well... I wouldn't, if it weren't the only way to trigger this without requiring a new instance.
         * We should be fine since we never place the banner's backing view into the actual hierarchy.
         */
        topBarImageSource.loadView()
        setupTopBarImage(size: view.frame.size)
      }
    }
  }
}