DodoDistrib.swift

//
// Dodo
//
// A message bar for iOS.
//
// https://github.com/marketplacer/Dodo
//
// This file was automatically generated by combining multiple Swift source files.
//


// ----------------------------
//
// DodoAnimation.swift
//
// ----------------------------

import UIKit

/// A closure that is called for animation of the bar when it is being shown or hidden.
public typealias DodoAnimation = (UIView, _ duration: TimeInterval?,
  _ locationTop: Bool, _ completed: @escaping DodoAnimationCompleted)->()

/// A closure that is called by the animator when animation has finished.
public typealias DodoAnimationCompleted = ()->()


// ----------------------------
//
// DodoAnimations.swift
//
// ----------------------------

import UIKit

/// Collection of animation effects use for showing and hiding the notification bar.
public enum DodoAnimations: String {
  /// Animation that fades the bar in/out.
  case fade = "Fade"
  
  /// Used for showing notification without animation.
  case noAnimation = "No animation"
  
  /// Animation that rotates the bar around X axis in perspective with spring effect.
  case rotate = "Rotate"
  
  /// Animation that swipes the bar to/from the left with fade effect.
  case slideLeft = "Slide left"
  
  /// Animation that swipes the bar to/from the right with fade effect.
  case slideRight = "Slide right"
  
  /// Animation that slides the bar in/out vertically.
  case slideVertically = "Slide vertically"
  
  /**
  
  Get animation function that can be used for showing notification bar.
  
  - returns: Animation function.
  
  */
  public var show: DodoAnimation {
    switch self {
    case .fade:
      return DodoAnimationsShow.fade
      
    case .noAnimation:
      return DodoAnimations.doNoAnimation
      
    case .rotate:
      return DodoAnimationsShow.rotate
      
    case .slideLeft:
      return DodoAnimationsShow.slideLeft
      
    case .slideRight:
      return DodoAnimationsShow.slideRight
      
    case .slideVertically:
      return DodoAnimationsShow.slideVertically
    }
  }
  
  /**
  
  Get animation function that can be used for hiding notification bar.
  
  - returns: Animation function.
  
  */
  public var hide: DodoAnimation {
    switch self {
    case .fade:
      return DodoAnimationsHide.fade
      
    case .noAnimation:
      return DodoAnimations.doNoAnimation
      
    case .rotate:
      return DodoAnimationsHide.rotate
      
    case .slideLeft:
      return DodoAnimationsHide.slideLeft
      
    case .slideRight:
      return DodoAnimationsHide.slideRight
      
    case .slideVertically:
      return DodoAnimationsHide.slideVertically
    }
  }
  
  /**

  A empty animator which is used when no animation is supplied.
  It simply calls the completion closure.
  
  - parameter view: View supplied for animation.
  - parameter completed: A closure to be called after animation completes.

  */
  static func doNoAnimation(_ view: UIView, duration: TimeInterval?, locationTop: Bool,
    completed: DodoAnimationCompleted) {
      
    completed()
  }
  
  /// Helper function for fading the view in and out.
  static func doFade(_ duration: TimeInterval?, showView: Bool, view: UIView,
    completed: @escaping DodoAnimationCompleted) {
      
    let actualDuration = duration ?? 0.5
    let startAlpha: CGFloat = showView ? 0 : 1
    let endAlpha: CGFloat = showView ? 1 : 0

    view.alpha = startAlpha
    
    UIView.animate(withDuration: actualDuration,
      animations: {
        view.alpha = endAlpha
      },
      completion: { finished in
        completed()
      }
    )
  }
  
  /// Helper function for sliding the view vertically
  static func doSlideVertically(_ duration: TimeInterval?, showView: Bool, view: UIView,
    locationTop: Bool, completed: @escaping DodoAnimationCompleted) {
    
    let actualDuration = duration ?? 0.5
    view.layoutIfNeeded()
    
    var distance: CGFloat = 0
      
    if locationTop {
      distance = view.frame.height + view.frame.origin.y
    } else {
      distance = UIScreen.main.bounds.height - view.frame.origin.y
    }
            
    let transform = CGAffineTransform(translationX: 0, y: locationTop ? -distance : distance)
      
    let start: CGAffineTransform = showView ? transform : CGAffineTransform.identity
    let end: CGAffineTransform = showView ? CGAffineTransform.identity : transform
    
    view.transform = start
    
    UIView.animate(withDuration: actualDuration,
      delay: 0,
      usingSpringWithDamping: 1,
      initialSpringVelocity: 1,
      options: [],
      animations: {
        view.transform = end
      },
      completion: { finished in
        completed()
      }
    )
  }
  
  static weak var timer: MoaTimer?
  
  /// Animation that rotates the bar around X axis in perspective with spring effect.
  static func doRotate(_ duration: TimeInterval?, showView: Bool, view: UIView, completed: @escaping DodoAnimationCompleted) {
    
    let actualDuration = duration ?? 2.0
    let start: Double = showView ? Double(M_PI / 2) : 0
    let end: Double = showView ? 0 : Double(M_PI / 2)
    let damping = showView ? 0.85 : 3
    
    let myCALayer = view.layer
    
    var transform = CATransform3DIdentity
    transform.m34 = -1.0/200.0
    myCALayer.transform = CATransform3DRotate(transform, CGFloat(end), 1, 0, 0)
    myCALayer.zPosition = 300
    
    SpringAnimationCALayer.animate(myCALayer,
      keypath: "transform.rotation.x",
      duration: actualDuration,
      usingSpringWithDamping: damping,
      initialSpringVelocity: 1,
      fromValue: start,
      toValue: end,
      onFinished: showView ? completed : nil)
    
    // Hide the bar prematurely for better looks
    timer?.cancel()
    if !showView {
      timer = MoaTimer.runAfter(0.3) { timer in
        completed()
      }
    }
  }
  
  /// Animation that swipes the bar to the right with fade-out effect.
  static func doSlide(_ duration: TimeInterval?, right: Bool, showView: Bool,
    view: UIView, completed: @escaping DodoAnimationCompleted) {
      
    let actualDuration = duration ?? 0.4
    let distance = UIScreen.main.bounds.width
    let transform = CGAffineTransform(translationX: right ? distance : -distance, y: 0)
    
    let start: CGAffineTransform = showView ? transform : CGAffineTransform.identity
    let end: CGAffineTransform = showView ? CGAffineTransform.identity : transform
    
    let alphaStart: CGFloat = showView ? 0.2 : 1
    let alphaEnd: CGFloat = showView ? 1 : 0.2

    view.transform = start
    view.alpha = alphaStart
      
    UIView.animate(withDuration: actualDuration,
      delay: 0,
      options: UIViewAnimationOptions.curveEaseOut,
      animations: {
        view.transform = end
        view.alpha = alphaEnd
      },
      completion: { finished in
        completed()
      }
    )
  }
}


// ----------------------------
//
// DodoAnimationsHide.swift
//
// ----------------------------

import UIKit

/// Collection of animation effects use for hiding the notification bar.
struct DodoAnimationsHide {
  /**
  
  Animation that rotates the bar around X axis in perspective with spring effect.
  
  - parameter view: View supplied for animation.
  - parameter completed: A closure to be called after animation completes.
  
  */
  static func rotate(_ view: UIView, duration: TimeInterval?, locationTop: Bool,
    completed: @escaping DodoAnimationCompleted) {
      
    DodoAnimations.doRotate(duration, showView: false, view: view, completed: completed)
  }
  
  /**
  
  Animation that swipes the bar from to the left with fade-in effect.
  
  - parameter view: View supplied for animation.
  - parameter completed: A closure to be called after animation completes.
  
  */
  static func slideLeft(_ view: UIView, duration: TimeInterval?, locationTop: Bool,
    completed: @escaping DodoAnimationCompleted) {
      
    DodoAnimations.doSlide(duration, right: false, showView: false, view: view, completed: completed)
  }
  
  /**
  
  Animation that swipes the bar to the right with fade-out effect.
  
  - parameter view: View supplied for animation.
  - parameter completed: A closure to be called after animation completes.
  
  */
  static func slideRight(_ view: UIView, duration: TimeInterval?, locationTop: Bool,
    completed: @escaping DodoAnimationCompleted) {
      
    DodoAnimations.doSlide(duration, right: true, showView: false, view: view, completed: completed)
  }
  
  /**
  
  Animation that fades the bar out.
  
  - parameter view: View supplied for animation.
  - parameter completed: A closure to be called after animation completes.
  
  */
  static func fade(_ view: UIView, duration: TimeInterval?, locationTop: Bool,
    completed: @escaping DodoAnimationCompleted) {
      
    DodoAnimations.doFade(duration, showView: false, view: view, completed: completed)
  }
  
  /**
  
  Animation that slides the bar vertically out of view.
  
  - parameter view: View supplied for animation.
  - parameter completed: A closure to be called after animation completes.
  
  */
  static func slideVertically(_ view: UIView, duration: TimeInterval?, locationTop: Bool,
    completed: @escaping DodoAnimationCompleted) {
      
      DodoAnimations.doSlideVertically(duration, showView: false, view: view,
        locationTop: locationTop, completed: completed)
  }
}


// ----------------------------
//
// DodoAnimationsShow.swift
//
// ----------------------------

import UIKit

/// Collection of animation effects use for showing the notification bar.
struct DodoAnimationsShow {
  /**
  
  Animation that rotates the bar around X axis in perspective with spring effect.
  
  - parameter view: View supplied for animation.
  - parameter completed: A closure to be called after animation completes.
  
  */
  static func rotate(_ view: UIView, duration: TimeInterval?,
    locationTop: Bool, completed: @escaping DodoAnimationCompleted) {
      
    DodoAnimations.doRotate(duration, showView: true, view: view, completed: completed)
  }
  
  /**
  
  Animation that swipes the bar from the left with fade-in effect.
  
  - parameter view: View supplied for animation.
  - parameter completed: A closure to be called after animation completes.
  
  */
  static func slideLeft(_ view: UIView, duration: TimeInterval?, locationTop: Bool,
    completed: @escaping DodoAnimationCompleted) {
      
    DodoAnimations.doSlide(duration, right: false, showView: true, view: view, completed: completed)
  }
  
  /**
  
  Animation that swipes the bar from the right with fade-in effect.
  
  - parameter view: View supplied for animation.
  - parameter completed: A closure to be called after animation completes.
  
  */
  static func slideRight(_ view: UIView, duration: TimeInterval?, locationTop: Bool,
    completed: @escaping DodoAnimationCompleted) {
      
    DodoAnimations.doSlide(duration, right: true, showView: true, view: view, completed: completed)
  }
  
  /**
  
  Animation that fades the bar in.
  
  - parameter view: View supplied for animation.
  - parameter completed: A closure to be called after animation completes.
  
  */
  static func fade(_ view: UIView, duration: TimeInterval?, locationTop: Bool,
    completed: @escaping DodoAnimationCompleted) {
      
    DodoAnimations.doFade(duration, showView: true, view: view, completed: completed)
  }
  
  /**
  
  Animation that slides the bar in/out vertically.
  
  - parameter view: View supplied for animation.
  - parameter completed: A closure to be called after animation completes.
  
  */
  static func slideVertically(_ view: UIView, duration: TimeInterval?, locationTop: Bool,
    completed: @escaping DodoAnimationCompleted) {
      
    DodoAnimations.doSlideVertically(duration, showView: true, view: view,
      locationTop: locationTop,completed: completed)
  }
}


// ----------------------------
//
// DodoButtonOnTap.swift
//
// ----------------------------

/// A closure that is called when a bar button is tapped
public typealias DodoButtonOnTap = ()->()


// ----------------------------
//
// DodoButtonView.swift
//
// ----------------------------


import UIKit

class DodoButtonView: UIImageView {
  private let style: DodoButtonStyle
  weak var delegate: DodoButtonViewDelegate?
  var onTap: OnTap?
  
  init(style: DodoButtonStyle) {
    self.style = style
    
    super.init(frame: CGRect())
  }

  required init(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
  }
  
  // Create button views for given button styles.
  static func createMany(_ styles: [DodoButtonStyle]) -> [DodoButtonView] {
      
    if !haveButtons(styles) { return [] }
    
    return styles.map { style in
      let view = DodoButtonView(style: style)
      view.setup()
      return view
    }
  }
  
  static func haveButtons(_ styles: [DodoButtonStyle]) -> Bool {
    let hasImages = styles.filter({ $0.image != nil }).count > 0
    let hasIcons = styles.filter({ $0.icon != nil }).count > 0

    return hasImages || hasIcons
  }
  
  func doLayout(onLeftSide: Bool) {
    precondition(delegate != nil, "Button view delegate can not be nil")
    translatesAutoresizingMaskIntoConstraints = false
    
    // Set button's size
    TegAutolayoutConstraints.width(self, value: style.size.width)
    TegAutolayoutConstraints.height(self, value: style.size.height)
    
    if let superview = superview {
      let alignAttribute = onLeftSide ? NSLayoutAttribute.left : NSLayoutAttribute.right
      
      let marginHorizontal = onLeftSide ? style.horizontalMarginToBar : -style.horizontalMarginToBar
      
      // Align the button to the left/right of the view
      TegAutolayoutConstraints.alignSameAttributes(self, toItem: superview,
        constraintContainer: superview,
        attribute: alignAttribute, margin: marginHorizontal)
      
      // Center the button verticaly
      TegAutolayoutConstraints.centerY(self, viewTwo: superview, constraintContainer: superview)
    }
  }
  
  func setup() {
    if let image = DodoButtonView.image(style) { applyStyle(image) }
    setupTap()
  }
  
  /// Increase the hitsize of the image view if it's less than 44px for easier tapping.
  override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
    let oprimizedBounds = DodoTouchTarget.optimize(bounds)
    return oprimizedBounds.contains(point)
  }
  
  /// Returns the image supplied by user or create one from the icon
  class func image(_ style: DodoButtonStyle) -> UIImage? {
    if style.image != nil {
      return style.image
    }
    
    if let icon = style.icon {
      let bundle = Bundle(for: self)
      let imageName = icon.rawValue
      
      return UIImage(named: imageName, in: bundle, compatibleWith: nil)
    }
    
    return nil
  }
  
  private func applyStyle(_ imageIn: UIImage) {
    var imageToShow = imageIn
    if let tintColorToShow = style.tintColor {
      // Replace image colors with the specified tint color
      imageToShow = imageToShow.withRenderingMode(UIImageRenderingMode.alwaysTemplate)
      tintColor = tintColorToShow
    }
    
    layer.minificationFilter = kCAFilterTrilinear // make the image crisp
    image = imageToShow
    contentMode = UIViewContentMode.scaleAspectFit
    
    // Make button accessible
    if let accessibilityLabelToShow = style.accessibilityLabel {
      isAccessibilityElement = true
      accessibilityLabel = accessibilityLabelToShow
      accessibilityTraits = UIAccessibilityTraitButton
    }
  }
  
  private func setupTap() {
    onTap = OnTap(view: self, gesture: UITapGestureRecognizer()) { [weak self] in
      self?.didTap()
    }
  }
  
  private func didTap() {
    self.delegate?.buttonDelegateDidTap(self.style)
    style.onTap?()
  }
}


// ----------------------------
//
// DodoButtonViewDelegate.swift
//
// ----------------------------

protocol DodoButtonViewDelegate: class {
  func buttonDelegateDidTap(_ buttonStyle: DodoButtonStyle)
}


// ----------------------------
//
// Dodo.swift
//
// ----------------------------

import UIKit

/**

Main class that coordinates the process of showing and hiding of the message bar.

Instance of this class is created automatically in the `dodo` property of any UIView instance.
It is not expected to be instantiated manually anywhere except unit tests.

For example:

    let view = UIView()
    view.dodo.info("Horses are blue?")

*/
final class Dodo: DodoInterface, DodoButtonViewDelegate {
  private weak var superview: UIView!
  private var hideTimer: MoaTimer?
  
  // Gesture handler that hides the bar when it is tapped
  var onTap: OnTap?
  
  /// Specify optional layout guide for positioning the bar view.
  var topLayoutGuide: UILayoutSupport?
  
  /// Specify optional layout guide for positioning the bar view.
  var bottomLayoutGuide: UILayoutSupport?
  
  /// Defines styles for the bar.
  var style = DodoStyle(parentStyle: DodoPresets.defaultPreset.style)

  /// Creates an instance of Dodo class
  init(superview: UIView) {
    self.superview = superview
    
    DodoKeyboardListener.startListening()
  }
  
  /// Changes the style preset for the bar widget.
  var preset: DodoPresets = DodoPresets.defaultPreset {
    didSet {
      if preset != oldValue  {
        style.parent = preset.style
      }
    }
  }
  
  /**
  
  Shows the message bar with *.success* preset. It can be used to indicate successful completion of an operation.
  
  - parameter message: The text message to be shown.
  
  */
  func success(_ message: String) {
    preset = .success
    show(message)
  }
  
  /**
  
  Shows the message bar with *.Info* preset. It can be used for showing information messages that have neutral emotional value.
  
  - parameter message: The text message to be shown.
  
  */
  func info(_ message: String) {
    preset = .info
    show(message)
  }
  
  /**
  
  Shows the message bar with *.warning* preset. It can be used for for showing warning messages.
  
  - parameter message: The text message to be shown.
  
  */
  func warning(_ message: String) {
    preset = .warning
    show(message)
  }
  
  /**
  
  Shows the message bar with *.warning* preset. It can be used for showing critical error messages
  
  - parameter message: The text message to be shown.
  
  */
  func error(_ message: String) {
    preset = .error
    show(message)
  }
  
  /**
    
  Shows the message bar. Set `preset` property to change the appearance of the message bar, or use the shortcut methods: `success`, `info`, `warning` and `error`.
    
  - parameter message: The text message to be shown.
    
  */
  func show(_ message: String) {
    removeExistingBars()
    setupHideTimer()

    let bar = DodoToolbar(witStyle: style)
    setupHideOnTap(bar)
    bar.layoutGuide = style.bar.locationTop ? topLayoutGuide : bottomLayoutGuide
    bar.buttonViewDelegate = self
    bar.show(inSuperview: superview, withMessage: message)
  }
  
  /// Hide the message bar if it's currently shown.
  func hide() {
    hideTimer?.cancel()
    
    toolbar?.hide({})
  }
  
  func listenForKeyboard() {
    
  }
  
  private var toolbar: DodoToolbar? {
    get {
      return superview.subviews.filter { $0 is DodoToolbar }.map { $0 as! DodoToolbar }.first
    }
  }
  
  private func removeExistingBars() {
    for view in superview.subviews {
      if let existingToolbar = view as? DodoToolbar {
        existingToolbar.removeFromSuperview()
      }
    }
  }
  
  // MARK: - Hiding after delay
  
  private func setupHideTimer() {
    hideTimer?.cancel()
    
    if style.bar.hideAfterDelaySeconds > 0 {
      hideTimer = MoaTimer.runAfter(style.bar.hideAfterDelaySeconds) { [weak self] timer in
        
        DispatchQueue.main.async {
          self?.hide()
        }
      }
    }
  }
  
  // MARK: - Reacting to tap
  
  private func setupHideOnTap(_ toolbar: UIView) {
    onTap = OnTap(view: toolbar, gesture: UITapGestureRecognizer()) { [weak self] in
      self?.didTapTheBar()
    }
  }
  
  /// The bar has been tapped
  private func didTapTheBar() {
    style.bar.onTap?()
    
    if style.bar.hideOnTap {
      hide()
    }
  }
  
  // MARK: - DodoButtonViewDelegate
  
  func buttonDelegateDidTap(_ buttonStyle: DodoButtonStyle) {
    if buttonStyle.hideOnTap {
      hide()
    }
  }
}


// ----------------------------
//
// DodoBarOnTap.swift
//
// ----------------------------

/// A closure that is called when a bar is tapped
public typealias DodoBarOnTap = ()->()


// ----------------------------
//
// DodoInterface.swift
//
// ----------------------------

import UIKit

/**

Coordinates the process of showing and hiding of the message bar.

The instance is created automatically in the `dodo` property of any UIView instance.
It is not expected to be instantiated manually anywhere except unit tests.

For example:

let view = UIView()
view.dodo.info("Horses are blue?")

*/
public protocol DodoInterface: class {  
  /// Specify optional layout guide for positioning the bar view.
  var topLayoutGuide: UILayoutSupport? { get set }
  
  /// Specify optional layout guide for positioning the bar view.
  var bottomLayoutGuide: UILayoutSupport? { get set }
  
  /// Defines styles for the bar.
  var style: DodoStyle { get set }
  
  /// Changes the style preset for the bar widget.
  var preset: DodoPresets { get set }
  
  /**
  
  Shows the message bar with *.success* preset. It can be used to indicate successful completion of an operation.
  
  - parameter message: The text message to be shown.
  
  */
  func success(_ message: String)
  
  /**
  
  Shows the message bar with *.Info* preset. It can be used for showing information messages that have neutral emotional value.
  
  - parameter message: The text message to be shown.
  
  */
  func info(_ message: String)
  
  /**
  
  Shows the message bar with *.warning* preset. It can be used for for showing warning messages.
  
  - parameter message: The text message to be shown.
  
  */
  func warning(_ message: String)
  
  /**
  
  Shows the message bar with *.warning* preset. It can be used for showing critical error messages
  
  - parameter message: The text message to be shown.
  
  */
  func error(_ message: String)
  
  /**
  
  Shows the message bar. Set `preset` property to change the appearance of the message bar, or use the shortcut methods: `success`, `info`, `warning` and `error`.
  
  - parameter message: The text message to be shown.
  
  */
  func show(_ message: String)
  
  /// Hide the message bar if it's currently shown.
  func hide()
}


// ----------------------------
//
// DodoKeyboardListener.swift
//
// ----------------------------

/**

Start listening for keyboard events. Used for moving the message bar from under the keyboard when the bar is shown at the bottom of the screen.

*/
struct DodoKeyboardListener {
  static let underKeyboardLayoutConstraint = UnderKeyboardLayoutConstraint()
  
  static func startListening() {
    // Just access the static property to make it initialize itself lazily if it hasn't been already.
    underKeyboardLayoutConstraint.isAccessibilityElement = false
  }
}


// ----------------------------
//
// DodoToolbar.swift
//
// ----------------------------

import UIKit

class DodoToolbar: UIView {
  var layoutGuide: UILayoutSupport?
  var style: DodoStyle
  weak var buttonViewDelegate: DodoButtonViewDelegate?
  private var didCallHide = false
  
  convenience init(witStyle style: DodoStyle) {
    self.init(frame: CGRect())
    
    self.style = style
  }
  
  override init(frame: CGRect) {
    style = DodoStyle()
    
    super.init(frame: frame)
  }
  
  required init(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
  }
  
  func show(inSuperview parentView: UIView, withMessage message: String) {
      
    if superview != nil { return } // already being shown
  
    parentView.addSubview(self)
    applyStyle()
    layoutBarInSuperview()
      
    let buttons = createButtons()

    createLabel(message, withButtons: buttons)
    
    style.bar.animationShow(self, style.bar.animationShowDuration, style.bar.locationTop, {})
  }
  
  func hide(_ onAnimationCompleted: @escaping ()->()) {
    // Respond only to the first hide() call
    if didCallHide { return }
    didCallHide = true
    
    style.bar.animationHide(self, style.bar.animationHideDuration,
                            style.bar.locationTop, { [weak self] in
        
      self?.removeFromSuperview()
      onAnimationCompleted()
    })
  }
    
  // MARK: - Label
  
  private func createLabel(_ message: String, withButtons buttons: [UIView]) {
    let label = UILabel()
    
    label.font = style.label.font
    label.text = message
    label.textColor = style.label.color
    label.textAlignment = NSTextAlignment.center
    label.numberOfLines = style.label.numberOfLines
    
    if style.bar.debugMode {
      label.backgroundColor = UIColor.red
    }
    
    if let shadowColor = style.label.shadowColor {
      label.shadowColor = shadowColor
      label.shadowOffset = style.label.shadowOffset
    }
    
    addSubview(label)
    layoutLabel(label, withButtons: buttons)
  }
  
  private func layoutLabel(_ label: UILabel, withButtons buttons: [UIView]) {
    label.translatesAutoresizingMaskIntoConstraints = false
    
    // Stretch the label vertically
    TegAutolayoutConstraints.fillParent(label, parentView: self,
      margin: style.label.horizontalMargin, vertically: true)
    
    if buttons.count == 0 {
      if let superview = superview {
        // If there are no buttons - stretch the label to the entire width of the view
        TegAutolayoutConstraints.fillParent(label, parentView: superview,
          margin: style.label.horizontalMargin, vertically: false)
      }
    } else {
      layoutLabelWithButtons(label, withButtons: buttons)
    }
  }
  
  private func layoutLabelWithButtons(_ label: UILabel, withButtons buttons: [UIView]) {
    if buttons.count != 2 { return }
    
    let views = [buttons[0], label, buttons[1]]
    
    if let superview = superview {
      TegAutolayoutConstraints.viewsNextToEachOther(views,
        constraintContainer: superview, margin: style.label.horizontalMargin, vertically: false)
    }
  }
  
  // MARK: - Buttons
  
  private func createButtons() -> [DodoButtonView] {
    precondition(buttonViewDelegate != nil, "Button view delegate can not be nil")
    let buttonStyles = [style.leftButton, style.rightButton]
    
    let buttonViews = DodoButtonView.createMany(buttonStyles)
    
    for (index, button) in buttonViews.enumerated() {
      addSubview(button)
      button.delegate = buttonViewDelegate
      button.doLayout(onLeftSide: index == 0)

      if style.bar.debugMode {
        button.backgroundColor = UIColor.yellow
      }
    }
    
    return buttonViews
  }
  
  // MARK: - Style the bar
  
  private func applyStyle() {
    backgroundColor = style.bar.backgroundColor
    layer.cornerRadius = style.bar.cornerRadius
    layer.masksToBounds = true
    
    if let borderColor = style.bar.borderColor , style.bar.borderWidth > 0 {
      layer.borderColor = borderColor.cgColor
      layer.borderWidth = style.bar.borderWidth
    }
  }
  
  private func layoutBarInSuperview() {
    translatesAutoresizingMaskIntoConstraints = false
    
    if let superview = superview {
      // Stretch the toobar horizontally to the width if its superview
      TegAutolayoutConstraints.fillParent(self, parentView: superview,
        margin: style.bar.marginToSuperview.width, vertically: false)
      
      let vMargin = style.bar.marginToSuperview.height
      let verticalMargin = style.bar.locationTop ? -vMargin : vMargin
      
      var verticalConstraints = [NSLayoutConstraint]()
      
      if let layoutGuide = layoutGuide {
        
        // Align the top/bottom edge of the toolbar with the top/bottom layout guide
        // (a tab bar, for example)
        verticalConstraints = TegAutolayoutConstraints.alignVerticallyToLayoutGuide(self,
          onTop: style.bar.locationTop,
          layoutGuide: layoutGuide,
          constraintContainer: superview,
          margin: verticalMargin)
        
      } else {
        
        // Align the top/bottom of the toolbar with the top/bottom of its superview
        verticalConstraints = TegAutolayoutConstraints.alignSameAttributes(superview, toItem: self,
          constraintContainer: superview,
          attribute: style.bar.locationTop ? NSLayoutAttribute.top : NSLayoutAttribute.bottom,
          margin: verticalMargin)
      }
      
      setupKeyboardEvader(verticalConstraints)
    }
  }
  
  // Moves the message bar from under the keyboard
  private func setupKeyboardEvader(_ verticalConstraints: [NSLayoutConstraint]) {
    if let bottomConstraint = verticalConstraints.first,
      let superview = superview
      , !style.bar.locationTop {
      
      DodoKeyboardListener.underKeyboardLayoutConstraint.setup(bottomConstraint,
        view: superview, bottomLayoutGuide: layoutGuide)
    }
  }
}


// ----------------------------
//
// DodoTouchTarget.swift
//
// ----------------------------

import UIKit

/**

Helper function to make sure bounds are big enought to be used as touch target.
The function is used in pointInside(point: CGPoint, withEvent event: UIEvent?) of UIImageView.

*/
struct DodoTouchTarget {
  static func optimize(_ bounds: CGRect) -> CGRect {
    let recommendedHitSize: CGFloat = 44
    
    var hitWidthIncrease:CGFloat = recommendedHitSize - bounds.width
    var hitHeightIncrease:CGFloat = recommendedHitSize - bounds.height
    
    if hitWidthIncrease < 0 { hitWidthIncrease = 0 }
    if hitHeightIncrease < 0 { hitHeightIncrease = 0 }
    
    let extendedBounds: CGRect = bounds.insetBy(dx: -hitWidthIncrease / 2,
      dy: -hitHeightIncrease / 2)
    
    return extendedBounds
  }
}


// ----------------------------
//
// DodoIcons.swift
//
// ----------------------------

/**

Collection of icons included with Dodo library.

*/
public enum DodoIcons: String {
  /// Icon for closing the bar.
  case close = "Close"
  
  /// Icon for reloading.
  case reload = "Reload"
}


// ----------------------------
//
// DodoMock.swift
//
// ----------------------------

import UIKit

/**

This class is for testing the code that uses Dodo. It helps verifying the messages that were shown in the message bar without actually showing them.

Here is how to use it in your unit test.

1. Create an instance of DodoMock.
2. Set it to the `view.dodo` property of the view.
3. Run the code that you are testing.
4. Finally, verify which messages were shown in the message bar.

Example:

    // Supply mock to the view
    let dodoMock = DodoMock()
    view.dodo = dodoMock

    // Run the code from the app
    runSomeAppCode()

    // Verify the message is visible
    XCTAssert(dodoMock.results.visible)

    // Check total number of messages shown
    XCTAssertEqual(1, dodoMock.results.total)

    // Verify the text of the success message
    XCTAssertEqual("To be prepared is half the victory.", dodoMock.results.success[0])

*/
public class DodoMock: DodoInterface {
  /// This property is used in unit tests to verify which messages were displayed in the message bar.
  public var results = DodoMockResults()
  
  /// Specify optional layout guide for positioning the bar view.
  public var topLayoutGuide: UILayoutSupport?
  
  /// Specify optional layout guide for positioning the bar view.
  public var bottomLayoutGuide: UILayoutSupport?
  
  /// Defines styles for the bar.
  public var style = DodoStyle(parentStyle: DodoPresets.defaultPreset.style)
  
  /// Creates an instance of DodoMock class
  public init() { }
  
  /// Changes the style preset for the bar widget.
  public var preset: DodoPresets = DodoPresets.defaultPreset {
    didSet {
      if preset != oldValue  {
        style.parent = preset.style
      }
    }
  }
  
  /**
   
   Shows the message bar with *.success* preset. It can be used to indicate successful completion of an operation.
   
   - parameter message: The text message to be shown.
   
   */
  public func success(_ message: String) {
    preset = .success
    show(message)
  }
  
  /**
   
   Shows the message bar with *.Info* preset. It can be used for showing information messages that have neutral emotional value.
   
   - parameter message: The text message to be shown.
   
   */
  public func info(_ message: String) {
    preset = .info
    show(message)
  }
  
  /**
   
   Shows the message bar with *.warning* preset. It can be used for for showing warning messages.
   
   - parameter message: The text message to be shown.
   
   */
  public func warning(_ message: String) {
    preset = .warning
    show(message)
  }
  
  /**
   
   Shows the message bar with *.warning* preset. It can be used for showing critical error messages
   
   - parameter message: The text message to be shown.
   
   */
  public func error(_ message: String) {
    preset = .error
    show(message)
  }
  
  /**
   
   Shows the message bar. Set `preset` property to change the appearance of the message bar, or use the shortcut methods: `success`, `info`, `warning` and `error`.
   
   - parameter message: The text message to be shown.
   
   */
  public func show(_ message: String) {
    let mockMessage = DodoMockMessage(preset: preset, message: message)
    results.messages.append(mockMessage)
    results.visible = true
  }
  
  /// Hide the message bar if it's currently shown.
  public func hide() {
    results.visible = false
  }
}


// ----------------------------
//
// DodoMockMessage.swift
//
// ----------------------------

/**

Contains information about the message that was displayed in message bar. Used in unit tests.

*/
struct DodoMockMessage {
  let preset: DodoPresets
  let message: String
}


// ----------------------------
//
// DodoMockResults.swift
//
// ----------------------------

/**

Used in unit tests to verify the messages that were shown in the message bar.

*/
public struct DodoMockResults {
  /// An array of success messages displayed in the message bar.
  public var success: [String] {
    return messages.filter({ $0.preset == DodoPresets.success }).map({ $0.message })
  }
  
  /// An array of information messages displayed in the message bar.
  public var info: [String] {
    return messages.filter({ $0.preset == DodoPresets.info }).map({ $0.message })
  }
  
  /// An array of warning messages displayed in the message bar.
  public var warning: [String] {
    return messages.filter({ $0.preset == DodoPresets.warning }).map({ $0.message })
  }
  
  /// An array of error messages displayed in the message bar.
  public var errors: [String] {
    return messages.filter({ $0.preset == DodoPresets.error }).map({ $0.message })
  }
  
  /// Total number of messages shown.
  public var total: Int {
    return messages.count
  }
  
  /// Indicates whether the message is visible
  public var visible = false
  
  var messages = [DodoMockMessage]()
}


// ----------------------------
//
// DodoBarDefaultStyles.swift
//
// ----------------------------

import UIKit

/**

Default styles for the bar view.
Default styles are used when individual element styles are not set.

*/
public struct DodoBarDefaultStyles {
  
  /// Revert the property values to their defaults
  public static func resetToDefaults() {
    animationHide = _animationHide
    animationHideDuration = _animationHideDuration
    animationShow = _animationShow
    animationShowDuration = _animationShowDuration
    backgroundColor = _backgroundColor
    borderColor = _borderColor
    borderWidth = _borderWidth
    cornerRadius = _cornerRadius
    debugMode = _debugMode
    hideAfterDelaySeconds = _hideAfterDelaySeconds
    hideOnTap = _hideOnTap
    locationTop = _locationTop
    marginToSuperview = _marginToSuperview
    onTap = _onTap
  }
  
  // ---------------------------
  
  
  private static let _animationHide: DodoAnimation = DodoAnimationsHide.rotate
  
  /// Specify a function for animating the bar when it is hidden.
  public static var animationHide: DodoAnimation = _animationHide
  
  
  // ---------------------------
  
  
  private static let _animationHideDuration: TimeInterval? = nil
  
  /// Duration of hide animation. When nil it uses default duration for selected animation function.
  public static var animationHideDuration: TimeInterval? = _animationHideDuration
  
  
  // ---------------------------
  
  
  private static let _animationShow: DodoAnimation = DodoAnimationsShow.rotate
  
  /// Specify a function for animating the bar when it is shown.
  public static var animationShow: DodoAnimation = _animationShow
  
  
  // ---------------------------
  
  
  private static let _animationShowDuration: TimeInterval? = nil
  
  /// Duration of show animation. When nil it uses default duration for selected animation function.
  public static var animationShowDuration: TimeInterval? = _animationShowDuration
  
  
  // ---------------------------
  
  
  private static let _backgroundColor: UIColor? = nil
  
  /// Background color of the bar.
  public static var backgroundColor = _backgroundColor
  
  
  // ---------------------------
  
  
  private static let _borderColor: UIColor? = nil
  
  /// Color of the bar's border.
  public static var borderColor = _borderColor
  
  
  // ---------------------------
  
  
  private static let _borderWidth: CGFloat  = 1 / UIScreen.main.scale
  
  /// Border width of the bar.
  public static var borderWidth = _borderWidth
  
  
  // ---------------------------
  
  
  private static let _cornerRadius: CGFloat = 20
  
  /// Corner radius of the bar view.
  public static var cornerRadius = _cornerRadius
  
  
  // ---------------------------
  
  
  private static let _debugMode = false
  
  /// When true it highlights the view background for spotting layout issues.
  public static var debugMode = _debugMode
  
  
  // ---------------------------
  
  
  private static let _hideAfterDelaySeconds: TimeInterval = 0
  
  /**
  
  Hides the bar automatically after the specified number of seconds.
  The bar is kept on screen indefinitely if the value is zero.
  
  */
  public static var hideAfterDelaySeconds = _hideAfterDelaySeconds
  
  
  // ---------------------------
  
  
  private static let _hideOnTap = false
  
  /// When true the bar is hidden when user taps on it.
  public static var hideOnTap = _hideOnTap
  
  
  // ---------------------------

  
  private static let _locationTop = true
  
  /// Position of the bar. When true the bar is shown on top of the screen.
  public static var locationTop = _locationTop
  

  // ---------------------------
  
  
  private static let _marginToSuperview = CGSize(width: 5, height: 5)
  
  /// Margin between the bar edge and its superview.
  public static var marginToSuperview = _marginToSuperview
  

  // ---------------------------
  
  
  private static let _onTap: DodoBarOnTap? = nil
  
  /// Supply a function that will be called when user taps the bar.
  public static var onTap = _onTap
  
  // ---------------------------
}


// ----------------------------
//
// DodoBarStyle.swift
//
// ----------------------------

import UIKit

/// Defines styles related to the bar view in general.
public class DodoBarStyle {
  
  /// The parent style is used to get the property value if the object is missing one.
  var parent: DodoBarStyle?
  
  init(parentStyle: DodoBarStyle? = nil) {
    self.parent = parentStyle
  }
  
  /// Clears the styles for all properties for this style object. The styles will be taken from parent and default properties.
  public func clear() {
    _animationHide = nil
    _animationHideDuration = nil
    _animationShow = nil
    _animationShowDuration = nil
    _backgroundColor = nil
    _borderColor = nil
    _borderWidth = nil
    _cornerRadius = nil
    _debugMode = nil
    _hideAfterDelaySeconds = nil
    _hideOnTap = nil
    _locationTop = nil
    _marginToSuperview = nil
    _onTap = nil
  }
  
  // -----------------------------
  
  private var _animationHide: DodoAnimation?
  
  /// Specify a function for animating the bar when it is hidden.
  public var animationHide: DodoAnimation {
    get {
      return (_animationHide ?? parent?.animationHide) ?? DodoBarDefaultStyles.animationHide
    }
    
    set {
      _animationHide = newValue
    }
  }
  
  // ---------------------------
  
  private var _animationHideDuration: TimeInterval?
  
  /// Duration of hide animation. When nil it uses default duration for selected animation function.
  public var animationHideDuration: TimeInterval? {
    get {
      return (_animationHideDuration ?? parent?.animationHideDuration) ??
        DodoBarDefaultStyles.animationHideDuration
    }
    
    set {
      _animationHideDuration = newValue
    }
  }
  
  // ---------------------------
  
  private var _animationShow: DodoAnimation?
  
  /// Specify a function for animating the bar when it is shown.
  public var animationShow: DodoAnimation {
    get {
      return (_animationShow ?? parent?.animationShow) ?? DodoBarDefaultStyles.animationShow
    }
    
    set {
      _animationShow = newValue
    }
  }
  
  // ---------------------------
  
  private var _animationShowDuration: TimeInterval?
  
  /// Duration of show animation. When nil it uses default duration for selected animation function.
  public var animationShowDuration: TimeInterval? {
    get {
      return (_animationShowDuration ?? parent?.animationShowDuration) ??
        DodoBarDefaultStyles.animationShowDuration
    }
    
    set {
      _animationShowDuration = newValue
    }
  }
  
  // ---------------------------
  
  private var _backgroundColor: UIColor?
  
  /// Background color of the bar.
  public var backgroundColor: UIColor? {
    get {
      return _backgroundColor ?? parent?.backgroundColor ?? DodoBarDefaultStyles.backgroundColor
    }
    
    set {
      _backgroundColor = newValue
    }
  }
  
  // -----------------------------
  
  private var _borderColor: UIColor?
  
  /// Color of the bar's border.
  public var borderColor: UIColor? {
    get {
      return _borderColor ?? parent?.borderColor ?? DodoBarDefaultStyles.borderColor
    }
    
    set {
      _borderColor = newValue
    }
  }
  
  // -----------------------------
  
  private var _borderWidth: CGFloat?
  
  /// Border width of the bar.
  public var borderWidth: CGFloat {
    get {
      return _borderWidth ?? parent?.borderWidth ?? DodoBarDefaultStyles.borderWidth
    }
    
    set {
      _borderWidth = newValue
    }
  }
  
  // -----------------------------
  
  private var _cornerRadius: CGFloat?
  
  /// Corner radius of the bar view.
  public var cornerRadius: CGFloat {
    get {
      return _cornerRadius ?? parent?.cornerRadius ?? DodoBarDefaultStyles.cornerRadius
    }
    
    set {
      _cornerRadius = newValue
    }
  }
  
  // -----------------------------
  
  private var _debugMode: Bool?
  
  /// When true it highlights the view background for spotting layout issues.
  public var debugMode: Bool {
    get {
      return _debugMode ?? parent?.debugMode ?? DodoBarDefaultStyles.debugMode
    }
    
    set {
      _debugMode = newValue
    }
  }
  
  // ---------------------------
  
  private var _hideAfterDelaySeconds: TimeInterval?
  
  /**
  
  Hides the bar automatically after the specified number of seconds.
  If nil the bar is kept on screen.
  
  */
  public var hideAfterDelaySeconds: TimeInterval {
    get {
      return _hideAfterDelaySeconds ?? parent?.hideAfterDelaySeconds ??
        DodoBarDefaultStyles.hideAfterDelaySeconds
    }
    
    set {
      _hideAfterDelaySeconds = newValue
    }
  }
  
  // -----------------------------

  private var _hideOnTap: Bool?
  
  /// When true the bar is hidden when user taps on it.
  public var hideOnTap: Bool {
    get {
      return _hideOnTap ?? parent?.hideOnTap ??
        DodoBarDefaultStyles.hideOnTap
    }
    
    set {
      _hideOnTap = newValue
    }
  }
  
  // -----------------------------
  
  private var _locationTop: Bool?
  
  /// Position of the bar. When true the bar is shown on top of the screen.
  public var locationTop: Bool {
    get {
      return _locationTop ?? parent?.locationTop ?? DodoBarDefaultStyles.locationTop
    }
    
    set {
      _locationTop = newValue
    }
  }
  
  // -----------------------------
  
  private var _marginToSuperview: CGSize?

  /// Margin between the bar edge and its superview.
  public var marginToSuperview: CGSize {
    get {
      return _marginToSuperview ?? parent?.marginToSuperview ??
        DodoBarDefaultStyles.marginToSuperview
    }
    
    set {
      _marginToSuperview = newValue
    }
  }
  
  // ---------------------------
  
  private var _onTap: DodoBarOnTap?
  
  /// Supply a function that will be called when user taps the bar.
  public var onTap: DodoBarOnTap? {
    get {
      return _onTap ?? parent?.onTap ?? DodoBarDefaultStyles.onTap
    }
    
    set {
      _onTap = newValue
    }
  }
  
  // -----------------------------
}


// ----------------------------
//
// DodoButtonDefaultStyles.swift
//
// ----------------------------

import UIKit

/**

Default styles for the bar button.
Default styles are used when individual element styles are not set.

*/
public struct DodoButtonDefaultStyles {

  /// Revert the property values to their defaults
  public static func resetToDefaults() {
    accessibilityLabel = _accessibilityLabel
    hideOnTap = _hideOnTap
    horizontalMarginToBar = _horizontalMarginToBar
    icon = _icon
    image = _image
    onTap = _onTap
    size = _size
    tintColor = _tintColor
  }
  
  
  // ---------------------------
  
  
  private static let _accessibilityLabel: String? = nil
  
  /**
  
  This text is spoken by the device when it is in accessibility mode. It is recommended to always set the accessibility label for your button. The text can be a short localized description of the button function, for example: "Close the message", "Reload" etc.
  
  */
  public static var accessibilityLabel = _accessibilityLabel
  
  
  // ---------------------------
  
  
  private static let _hideOnTap = false
  
  /// When true it hides the bar when the button is tapped.
  public static var hideOnTap = _hideOnTap
  
  
  // ---------------------------
  
  
  private static let _horizontalMarginToBar: CGFloat = 10
  
  /// Margin between the bar edge and the button
  public static var horizontalMarginToBar = _horizontalMarginToBar
  
  
  // ---------------------------
  
  private static let _icon: DodoIcons? = nil
  
  /// When set it shows one of the default Dodo icons. Use `image` property to supply a custom image. The color of the image can be changed with `tintColor` property.
  public static var icon = _icon
  
  
  // ---------------------------
  
  
  private static let _image: UIImage? = nil
  
  /// Custom image for the button. One can also use the `icon` property to show one of the default Dodo icons. The color of the image can be changed with `tintColor` property.
  public static var image = _image
  
  
  // ---------------------------

  
  private static let _onTap: DodoButtonOnTap? = nil
  
  /// Supply a function that will be called when user taps the button.
  public static var onTap = _onTap
  
  
  // ---------------------------
  
  
  private static let _size = CGSize(width: 25, height: 25)
  
  /// Size of the button.
  public static var size = _size
  
  
  // ---------------------------

  
  private static let _tintColor: UIColor? = nil
  
  /// Replaces the color of the image or icon. The original colors are used when nil.
  public static var tintColor = _tintColor
  
  
  // ---------------------------
}


// ----------------------------
//
// DodoButtonStyle.swift
//
// ----------------------------

import UIKit

/// Defines styles for the bar button.
public class DodoButtonStyle {
  
  /// The parent style is used to get the property value if the object is missing one.
  var parent: DodoButtonStyle?
  
  init(parentStyle: DodoButtonStyle? = nil) {
    self.parent = parentStyle
  }
  
  /// Clears the styles for all properties for this style object. The styles will be taken from parent and default properties.
  public func clear() {
    _accessibilityLabel = nil
    _hideOnTap = nil
    _horizontalMarginToBar = nil
    _icon = nil
    _image = nil
    _onTap = nil
    _size = nil
    _tintColor = nil
  }
  
  // -----------------------------
  
  private var _accessibilityLabel: String?
  
  /**
  
  This text is spoken by the device when it is in accessibility mode. It is recommended to always set the accessibility label for your button. The text can be a short localized description of the button function, for example: "Close the message", "Reload" etc.
  
  */
  public var accessibilityLabel: String? {
    get {
      return _accessibilityLabel ?? parent?.accessibilityLabel ?? DodoButtonDefaultStyles.accessibilityLabel
    }
    
    set {
      _accessibilityLabel = newValue
    }
  }
  
  // -----------------------------
  
  private var _hideOnTap: Bool?
  
  /// When true it hides the bar when the button is tapped.
  public var hideOnTap: Bool {
    get {
      return _hideOnTap ?? parent?.hideOnTap ?? DodoButtonDefaultStyles.hideOnTap
    }
    
    set {
      _hideOnTap = newValue
    }
  }
  
  // -----------------------------
  
  private var _horizontalMarginToBar: CGFloat?
  
  /// Horizontal margin between the bar edge and the button.
  public var horizontalMarginToBar: CGFloat {
    get {
      return _horizontalMarginToBar ?? parent?.horizontalMarginToBar ??
        DodoButtonDefaultStyles.horizontalMarginToBar
    }
    
    set {
      _horizontalMarginToBar = newValue
    }
  }
  
  // -----------------------------
  
  private var _icon: DodoIcons?
  
  /// When set it shows one of the default Dodo icons. Use `image` property to supply a custom image. The color of the image can be changed with `tintColor` property.
  public var icon: DodoIcons? {
    get {
      return _icon ?? parent?.icon ?? DodoButtonDefaultStyles.icon
    }
    
    set {
      _icon = newValue
    }
  }
  
  // -----------------------------

  private var _image: UIImage?
  
  /// Custom image for the button. One can also use the `icon` property to show one of the default Dodo icons. The color of the image can be changed with `tintColor` property.
  public var image: UIImage? {
    get {
      return _image ?? parent?.image ?? DodoButtonDefaultStyles.image
    }
    
    set {
      _image = newValue
    }
  }
  
  // ---------------------------
  
  private var _onTap: DodoButtonOnTap?
  
  /// Supply a function that will be called when user taps the button.
  public var onTap: DodoButtonOnTap? {
    get {
      return _onTap ?? parent?.onTap ?? DodoButtonDefaultStyles.onTap
    }
    
    set {
      _onTap = newValue
    }
  }
  
  // -----------------------------
  
  private var _size: CGSize?
  
  /// Size of the button.
  public var size: CGSize {
    get {
      return _size ?? parent?.size ?? DodoButtonDefaultStyles.size
    }
    
    set {
      _size = newValue
    }
  }
  
  // -----------------------------
  
  private var _tintColor: UIColor?
  
  /// Replaces the color of the image or icon. The original colors are used when nil.
  public var tintColor: UIColor? {
    get {
      return _tintColor ?? parent?.tintColor ?? DodoButtonDefaultStyles.tintColor
    }
    
    set {
      _tintColor = newValue
    }
  }
  
  
  // -----------------------------
}


// ----------------------------
//
// DodoLabelDefaultStyles.swift
//
// ----------------------------

import UIKit

/**

Default styles for the text label.
Default styles are used when individual element styles are not set.

*/
public struct DodoLabelDefaultStyles {
  
  /// Revert the property values to their defaults
  public static func resetToDefaults() {
    color = _color
    font = _font
    horizontalMargin = _horizontalMargin
    numberOfLines = _numberOfLines
    shadowColor = _shadowColor
    shadowOffset = _shadowOffset
  }
  
  // ---------------------------
  
  
  private static let _color = UIColor.white
  
  /// Color of the label text.
  public static var color = _color
  
  
  // ---------------------------
  
  
  private static let _font = UIFont.preferredFont(forTextStyle: UIFontTextStyle.headline)
  
  /// Font of the label text.
  public static var font = _font
  
  
  // ---------------------------

  
  private static let _horizontalMargin: CGFloat = 10
  
  /// Margin between the bar/button edge and the label.
  public static var horizontalMargin = _horizontalMargin
  
  
  // ---------------------------
  
  
  private static let _numberOfLines: Int = 3
  
  /// The maximum number of lines in the label.
  public static var numberOfLines = _numberOfLines
  
  
  // ---------------------------
  
  
  private static let _shadowColor: UIColor? = nil
  
  /// Color of text shadow.
  public static var shadowColor = _shadowColor
  

  // ---------------------------

  
  private static let _shadowOffset = CGSize(width: 0, height: 1)
  
  /// Text shadow offset.
  public static var shadowOffset = _shadowOffset
  
  
  // ---------------------------
}


// ----------------------------
//
// DodoLabelStyle.swift
//
// ----------------------------

import UIKit

/// Defines styles related to the text label.
public class DodoLabelStyle {
  
  /// The parent style is used to get the property value if the object is missing one.
  var parent: DodoLabelStyle?
  
  init(parentStyle: DodoLabelStyle? = nil) {
    self.parent = parentStyle
  }
  
  /// Clears the styles for all properties for this style object. The styles will be taken from parent and default properties.
  public func clear() {
    _color = nil
    _font = nil
    _horizontalMargin = nil
    _numberOfLines = nil
    _shadowColor = nil
    _shadowOffset = nil
  }

  // -----------------------------
  
  private var _color: UIColor?
  
  /// Color of the label text.
  public var color: UIColor {
    get {
      return _color ?? parent?.color ?? DodoLabelDefaultStyles.color
    }
    
    set {
      _color = newValue
    }
  }
  
  // -----------------------------
  
  private var _font: UIFont?
  
  /// Color of the label text.
  public var font: UIFont {
    get {
      return _font ?? parent?.font ?? DodoLabelDefaultStyles.font
    }
    
    set {
      _font = newValue
    }
  }
  
  // -----------------------------
  
  private var _horizontalMargin: CGFloat?
  
  /// Margin between the bar/button edge and the label.
  public var horizontalMargin: CGFloat {
    get {
      return _horizontalMargin ?? parent?.horizontalMargin ??
        DodoLabelDefaultStyles.horizontalMargin
    }
    
    set {
      _horizontalMargin = newValue
    }
  }
  
  // -----------------------------
  
  private var _numberOfLines: Int?
  
  /// The maximum number of lines in the label.
  public var numberOfLines: Int {
    get {
      return _numberOfLines ?? parent?.numberOfLines ??
        DodoLabelDefaultStyles.numberOfLines
    }
    
    set {
      _numberOfLines = newValue
    }
  }
  
  // -----------------------------
  
  private var _shadowColor: UIColor?
  
  /// Color of text shadow.
  public var shadowColor: UIColor? {
    get {
      return _shadowColor ?? parent?.shadowColor ?? DodoLabelDefaultStyles.shadowColor
    }
    
    set {
      _shadowColor = newValue
    }
  }
  
  // -----------------------------
  
  private var _shadowOffset: CGSize?
  
  /// Text shadow offset.
  public var shadowOffset: CGSize {
    get {
      return _shadowOffset ?? parent?.shadowOffset ?? DodoLabelDefaultStyles.shadowOffset
    }
    
    set {
      _shadowOffset = newValue
    }
  }
  
  // -----------------------------
}


// ----------------------------
//
// DodoPresets.swift
//
// ----------------------------


/**

Defines the style presets for the bar.

*/
public enum DodoPresets {
  /// A styling preset used for indicating successful completion of an operation. Usually styled with green color.
  case success
  
  /// A styling preset for showing information messages, neutral in color.
  case info
  
  /// A styling preset for showing warning messages. Can be styled with yellow/orange colors.
  case warning
  
  /// A styling preset for showing critical error messages. Usually styled with red color.
  case error
  
  /// The preset is used by default for the bar if it's not set by the user.
  static let defaultPreset = DodoPresets.success
  
  /// The preset cache.
  private static var styles = [DodoPresets: DodoStyle]()
  
  /// Returns the style for the preset
  public var style: DodoStyle {
    var style = DodoPresets.styles[self]
    
    if style == nil {
      style = DodoPresets.makeStyle(forPreset: self)
      DodoPresets.styles[self] = style
    }
    
    precondition(style != nil, "Failed to create style")
    
    return style ?? DodoStyle()
  }
  
  /// Reset alls preset styles to their initial states.
  public static func resetAll() {
    styles = [:]
  }
  
  /// Reset the preset style to its initial state.
  public func reset() {
    DodoPresets.styles.removeValue(forKey: self)
  }
  
  private static func makeStyle(forPreset preset: DodoPresets) -> DodoStyle{
    
    let style = DodoStyle()
    
    switch preset {
    case .success:
      style.bar.backgroundColor = DodoColor.fromHexString("#00CC03C9")
      
    case .info:
      style.bar.backgroundColor = DodoColor.fromHexString("#0057FF96")
      
    case .warning:
      style.bar.backgroundColor = DodoColor.fromHexString("#CEC411DD")
      
    case .error:
      style.bar.backgroundColor = DodoColor.fromHexString("#FF0B0BCC")
    }
        
    return style
  }
}


// ----------------------------
//
// DodoStyle.swift
//
// ----------------------------

import UIKit

/// Combines various styles for the toolbar element.
public class DodoStyle {
  
  /// The parent style is used to get the property value if the object is missing one.
  var parent: DodoStyle? {
    didSet {
      changeParent()
    }
  }
  
  init(parentStyle: DodoStyle? = nil) {
    self.parent = parentStyle
  }
  
  private func changeParent() {
    bar.parent = parent?.bar
    label.parent = parent?.label
    leftButton.parent = parent?.leftButton
    rightButton.parent = parent?.rightButton
  }
  
  /**
  
  Reverts all the default styles to their initial values. Usually used in setUp() function in the unit tests.
  
  */
  public static func resetDefaultStyles() {
    DodoBarDefaultStyles.resetToDefaults()
    DodoLabelDefaultStyles.resetToDefaults()
    DodoButtonDefaultStyles.resetToDefaults()
  }
  
  
  /// Clears the styles for all properties for this style object. The styles will be taken from parent and default properties.
  public func clear() {
    bar.clear()
    label.clear()
    leftButton.clear()
    rightButton.clear()
  }
  
  /**

  Styles for the bar view.

  */
  public lazy var bar: DodoBarStyle = self.initBarStyle()
  
  private func initBarStyle() -> DodoBarStyle {
    return DodoBarStyle(parentStyle: parent?.bar)
  }
  

  /**

  Styles for the text label.

  */
  public lazy var label: DodoLabelStyle = self.initLabelStyle()
  
  private func initLabelStyle() -> DodoLabelStyle {
    return DodoLabelStyle(parentStyle: parent?.label)
  }
  
  /**

  Styles for the left button.

  */
  public lazy var leftButton: DodoButtonStyle = self.initLeftButtonStyle()
  
  private func initLeftButtonStyle() -> DodoButtonStyle {
    return DodoButtonStyle(parentStyle: parent?.leftButton)
  }
  
  /**

  Styles for the right button.

  */
  public lazy var rightButton: DodoButtonStyle = self.initRightButtonStyle()
  
  private func initRightButtonStyle() -> DodoButtonStyle {
    return DodoButtonStyle(parentStyle: parent?.rightButton)
  }
}


// ----------------------------
//
// UIView+SwiftAlertBar.swift
//
// ----------------------------

import UIKit

private var sabAssociationKey: UInt8 = 0

/**

UIView extension for showing a notification widget.

    let view = UIView()
    view.dodo.show("Hello World!")

*/
public extension UIView {
  /**
  
  Message bar extension.
  Call `dodo.show`, `dodo.success`, dodo.error` functions to show a notification widget in the view.
  
      let view = UIView()
      view.dodo.show("Hello World!")
  
  */
  public var dodo: DodoInterface {
    get {
      if let value = objc_getAssociatedObject(self, &sabAssociationKey) as? DodoInterface {
        return value
      } else {
        let dodo = Dodo(superview: self)
        
        objc_setAssociatedObject(self, &sabAssociationKey, dodo,
          objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN)
        
        return dodo
      }
    }
    
    set {
      objc_setAssociatedObject(self, &sabAssociationKey, newValue,
        objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN)
    }
  }
}


// ----------------------------
//
// DodoColor.swift
//
// ----------------------------

import UIKit

/**
  
Creates a UIColor object from a string.

Examples:

    DodoColor.fromHexString('#340f9a')

    // With alpha channel
    DodoColor.fromHexString('#f1a2b3a6')

*/
public class DodoColor {
  /**
  
  Creates a UIColor object from a string.
  
  - parameter rgba: a RGB/RGBA string representation of color. It can include optional alpha value. Example: "#cca213" or "#cca21312" (with alpha value).
  
  - returns: UIColor object.
  
  */
  public class func fromHexString(_ rgba: String) -> UIColor {
    var red: CGFloat   = 0.0
    var green: CGFloat = 0.0
    var blue: CGFloat  = 0.0
    var alpha: CGFloat = 1.0
    
    if !rgba.hasPrefix("#") {
      print("Warning: DodoColor.fromHexString, # character missing")
      return UIColor()
    }
    
    let index = rgba.characters.index(rgba.startIndex, offsetBy: 1)
    let hex = rgba.substring(from: index)
    let scanner = Scanner(string: hex)
    var hexValue: CUnsignedLongLong = 0
    
    if !scanner.scanHexInt64(&hexValue) {
      print("Warning: DodoColor.fromHexString, error scanning hex value")
      return UIColor()
    }

    if hex.characters.count == 6 {
      red   = CGFloat((hexValue & 0xFF0000) >> 16) / 255.0
      green = CGFloat((hexValue & 0x00FF00) >> 8)  / 255.0
      blue  = CGFloat(hexValue & 0x0000FF) / 255.0
    } else if hex.characters.count == 8 {
      red   = CGFloat((hexValue & 0xFF000000) >> 24) / 255.0
      green = CGFloat((hexValue & 0x00FF0000) >> 16) / 255.0
      blue  = CGFloat((hexValue & 0x0000FF00) >> 8)  / 255.0
      alpha = CGFloat(hexValue & 0x000000FF)         / 255.0
    } else {
      print("Warning: DodoColor.fromHexString, invalid rgb string, length should be 7 or 9")
      return UIColor()
    }
   
    return UIColor(red: red, green: green, blue: blue, alpha: alpha)
  }
}


// ----------------------------
//
// MoaTimer.swift
//
// ----------------------------

import UIKit

/**

Creates a timer that executes code after delay.

Usage

    var timer: MoaTimer.runAfter?
    ...

    func myFunc() {
       timer = MoaTimer.runAfter(0.010) { timer in
          ... code to run
       }
    }

Canceling the timer

Timer is Canceling automatically when it is deallocated. You can also cancel it manually:

    let timer = MoaTimer.runAfter(0.010) { timer in ... }
    timer.cancel()

*/
final class MoaTimer: NSObject {
  private let repeats: Bool
  private var timer: Timer?
  private var callback: ((MoaTimer)->())?
  
  private init(interval: TimeInterval, repeats: Bool = false, callback: @escaping (MoaTimer)->()) {
    self.repeats = repeats
    
    super.init()
    
    self.callback = callback
    timer = Timer.scheduledTimer(timeInterval: interval, target: self,
      selector: #selector(MoaTimer.timerFired(_:)), userInfo: nil, repeats: repeats)
  }
  
  /// Timer is cancelled automatically when it is deallocated.
  deinit {
    cancel()
  }
  
  /**
  
  Cancels the timer and prevents it from firing in the future.
  
  Note that timer is cancelled automatically whe it is deallocated.
  
  */
  func cancel() {
    timer?.invalidate()
    timer = nil
  }
  
  /**
  
  Runs the closure after specified time interval.
  
  - parameter interval: Time interval in milliseconds.
  :repeats: repeats When true, the code is run repeatedly.
  - returns: callback A closure to be run by the timer.
  
  */
  @discardableResult
  class func runAfter(_ interval: TimeInterval, repeats: Bool = false,
    callback: @escaping (MoaTimer)->()) -> MoaTimer {
      
    return MoaTimer(interval: interval, repeats: repeats, callback: callback)
  }
  
  func timerFired(_ timer: Timer) {
    self.callback?(self)
    if !repeats { cancel() }
  }
}


// ----------------------------
//
// OnTap.swift
//
// ----------------------------

import UIKit

/**

Calling tap with closure.

*/
class OnTap: NSObject {
  var closure: ()->()

  init(view: UIView, gesture: UIGestureRecognizer, closure: @escaping ()->()) {
    self.closure = closure
    super.init()
    view.addGestureRecognizer(gesture)
    view.isUserInteractionEnabled = true
    gesture.addTarget(self, action: #selector(OnTap.didTap(_:)))
  }

  func didTap(_ gesture: UIGestureRecognizer) {
    closure()
  }
}


// ----------------------------
//
// SpringAnimationCALayer.swift
//
// ----------------------------

import UIKit

/**

Animating CALayer with spring effect in iOS with Swift

https://github.com/evgenyneu/SpringAnimationCALayer

*/
class SpringAnimationCALayer {
  // Animates layer with spring effect.
  class func animate(_ layer: CALayer,
    keypath: String,
    duration: CFTimeInterval,
    usingSpringWithDamping: Double,
    initialSpringVelocity: Double,
    fromValue: Double,
    toValue: Double,
    onFinished: (()->())?) {
      
      CATransaction.begin()
      CATransaction.setCompletionBlock(onFinished)
      
      let animation = create(keypath, duration: duration,
        usingSpringWithDamping: usingSpringWithDamping,
        initialSpringVelocity: initialSpringVelocity,
        fromValue: fromValue, toValue: toValue)
      
      layer.add(animation, forKey: keypath + " spring animation")
      CATransaction.commit()
  }
  
  // Creates CAKeyframeAnimation object
  class func create(_ keypath: String,
    duration: CFTimeInterval,
    usingSpringWithDamping: Double,
    initialSpringVelocity: Double,
    fromValue: Double,
    toValue: Double) -> CAKeyframeAnimation {
      
      let dampingMultiplier = Double(10)
      let velocityMultiplier = Double(10)
      
      let values = animationValues(fromValue, toValue: toValue,
        usingSpringWithDamping: dampingMultiplier * usingSpringWithDamping,
        initialSpringVelocity: velocityMultiplier * initialSpringVelocity)
      
      let animation = CAKeyframeAnimation(keyPath: keypath)
      animation.values = values
      animation.duration = duration
      
      return animation
  }
  
  class func animationValues(_ fromValue: Double, toValue: Double,
    usingSpringWithDamping: Double, initialSpringVelocity: Double) -> [Double]{
      
      let numOfPoints = 1000
      var values = [Double](repeating: 0.0, count: numOfPoints)
      
      let distanceBetweenValues = toValue - fromValue
      
      for point in (0..<numOfPoints) {
        let x = Double(point) / Double(numOfPoints)
        let valueNormalized = animationValuesNormalized(x,
          usingSpringWithDamping: usingSpringWithDamping, initialSpringVelocity: initialSpringVelocity)
        
        let value = toValue - distanceBetweenValues * valueNormalized
        values[point] = value
      }
      
      return values
  }
  
  private class func animationValuesNormalized(_ x: Double, usingSpringWithDamping: Double,
    initialSpringVelocity: Double) -> Double {
      
      return pow(M_E, -usingSpringWithDamping * x) * cos(initialSpringVelocity * x)
  }
}


// ----------------------------
//
// TegAutolayoutConstraints.swift
//
// ----------------------------

//
//  TegAlign.swift
//
//  Collection of shortcuts to create autolayout constraints.
//

import UIKit

class TegAutolayoutConstraints {
  class func centerX(_ viewOne: UIView, viewTwo: UIView,
    constraintContainer: UIView) -> [NSLayoutConstraint] {
      
      return center(viewOne, viewTwo: viewTwo, constraintContainer: constraintContainer, vertically: false)
  }
  
  @discardableResult
  class func centerY(_ viewOne: UIView, viewTwo: UIView,
    constraintContainer: UIView) -> [NSLayoutConstraint] {
      
      return center(viewOne, viewTwo: viewTwo, constraintContainer: constraintContainer, vertically: true)
  }
  
  private class func center(_ viewOne: UIView, viewTwo: UIView,
    constraintContainer: UIView, vertically: Bool = false) -> [NSLayoutConstraint] {
      
      let attribute = vertically ? NSLayoutAttribute.centerY : NSLayoutAttribute.centerX
      
      let constraint = NSLayoutConstraint(
        item: viewOne,
        attribute: attribute,
        relatedBy: NSLayoutRelation.equal,
        toItem: viewTwo,
        attribute: attribute,
        multiplier: 1,
        constant: 0)
      
      constraintContainer.addConstraint(constraint)
      
      return [constraint]
  }
  
  @discardableResult
  class func alignSameAttributes(_ item: AnyObject, toItem: AnyObject,
    constraintContainer: UIView, attribute: NSLayoutAttribute, margin: CGFloat = 0) -> [NSLayoutConstraint] {
      
      let constraint = NSLayoutConstraint(
        item: item,
        attribute: attribute,
        relatedBy: NSLayoutRelation.equal,
        toItem: toItem,
        attribute: attribute,
        multiplier: 1,
        constant: margin)
      
      constraintContainer.addConstraint(constraint)
      
      return [constraint]
  }
  
  class func alignVerticallyToLayoutGuide(_ item: AnyObject, onTop: Bool,
    layoutGuide: UILayoutSupport, constraintContainer: UIView,
    margin: CGFloat = 0) -> [NSLayoutConstraint] {
      
    let constraint = NSLayoutConstraint(
      item: layoutGuide,
      attribute: onTop ? NSLayoutAttribute.bottom : NSLayoutAttribute.top,
      relatedBy: NSLayoutRelation.equal,
      toItem: item,
      attribute: onTop ? NSLayoutAttribute.top : NSLayoutAttribute.bottom,
      multiplier: 1,
      constant: margin)
    
    constraintContainer.addConstraint(constraint)
    
    return [constraint]
  }
  
  class func aspectRatio(_ view: UIView, ratio: CGFloat) {
    let constraint = NSLayoutConstraint(
      item: view,
      attribute: NSLayoutAttribute.width,
      relatedBy: NSLayoutRelation.equal,
      toItem: view,
      attribute: NSLayoutAttribute.height,
      multiplier: ratio,
      constant: 0)
    
    view.addConstraint(constraint)
  }
  
  class func fillParent(_ view: UIView, parentView: UIView, margin: CGFloat = 0, vertically: Bool = false) {
    var marginFormat = ""
    
    if margin != 0 {
      marginFormat = "-\(margin)-"
    }
    
    var format = "|\(marginFormat)[view]\(marginFormat)|"
    
    if vertically {
      format = "V:" + format
    }
    
    let constraints = NSLayoutConstraint.constraints(withVisualFormat: format,
      options: [], metrics: nil,
      views: ["view": view])
    
    parentView.addConstraints(constraints)
  }
  
  @discardableResult
  class func viewsNextToEachOther(_ views: [UIView],
    constraintContainer: UIView, margin: CGFloat = 0,
    vertically: Bool = false) -> [NSLayoutConstraint] {
      
    if views.count < 2 { return []  }
      
    var constraints = [NSLayoutConstraint]()
      
    for (index, view) in views.enumerated() {
      if index >= views.count - 1 { break }
      
      let viewTwo = views[index + 1]
      
      constraints += twoViewsNextToEachOther(view, viewTwo: viewTwo,
        constraintContainer: constraintContainer, margin: margin, vertically: vertically)
    }
      
    return constraints
  }
  
  class func twoViewsNextToEachOther(_ viewOne: UIView, viewTwo: UIView,
    constraintContainer: UIView, margin: CGFloat = 0,
    vertically: Bool = false) -> [NSLayoutConstraint] {
      
    var marginFormat = ""
    
    if margin != 0 {
      marginFormat = "-\(margin)-"
    }
    
    var format = "[viewOne]\(marginFormat)[viewTwo]"
    
    if vertically {
      format = "V:" + format
    }
    
    let constraints = NSLayoutConstraint.constraints(withVisualFormat: format,
      options: [], metrics: nil,
      views: [ "viewOne": viewOne, "viewTwo": viewTwo ])
        
    constraintContainer.addConstraints(constraints)
    
    return constraints
  }
  
  class func equalWidth(_ viewOne: UIView, viewTwo: UIView,
    constraintContainer: UIView) -> [NSLayoutConstraint] {
      
    let constraints = NSLayoutConstraint.constraints(withVisualFormat: "[viewOne(==viewTwo)]",
        options: [], metrics: nil,
        views: ["viewOne": viewOne, "viewTwo": viewTwo])
          
          
    constraintContainer.addConstraints(constraints)
    
    return constraints
  }
  
  @discardableResult
  class func height(_ view: UIView, value: CGFloat) -> [NSLayoutConstraint] {
    return widthOrHeight(view, value: value, isWidth: false)
  }
  
  @discardableResult
  class func width(_ view: UIView, value: CGFloat) -> [NSLayoutConstraint] {
    return widthOrHeight(view, value: value, isWidth: true)
  }
  
  private class func widthOrHeight(_ view: UIView, value: CGFloat,
    isWidth: Bool) -> [NSLayoutConstraint] {
    
    let attribute = isWidth ? NSLayoutAttribute.width : NSLayoutAttribute.height
      
    let constraint = NSLayoutConstraint(
      item: view,
      attribute: attribute,
      relatedBy: NSLayoutRelation.equal,
      toItem: nil,
      attribute: NSLayoutAttribute.notAnAttribute,
      multiplier: 1,
      constant: value)
    
    view.addConstraint(constraint)
    
    return [constraint]
  }
}


// ----------------------------
//
// UnderKeyboardDistrib.swift
//
// ----------------------------

//
// An iOS libary for moving content from under the keyboard.
//
// https://github.com/marketplacer/UnderKeyboard
//
// This file was automatically generated by combining multiple Swift source files.
//


// ----------------------------
//
// UnderKeyboardLayoutConstraint.swift
//
// ----------------------------

import UIKit


/**
 Adjusts the length (constant value) of the bottom layout constraint when keyboard shows and hides.
 */
@objc public class UnderKeyboardLayoutConstraint: NSObject {
  private weak var bottomLayoutConstraint: NSLayoutConstraint?
  private weak var bottomLayoutGuide: UILayoutSupport?
  private var keyboardObserver = UnderKeyboardObserver()
  private var initialConstraintConstant: CGFloat = 0
  private var minMargin: CGFloat = 10
  
  private var viewToAnimate: UIView?
  
  /// Creates an instance of the class
  public override init() {
    super.init()
    
    keyboardObserver.willAnimateKeyboard = keyboardWillAnimate
    keyboardObserver.animateKeyboard = animateKeyboard
    keyboardObserver.start()
  }
  
  deinit {
    stop()
  }
  
  /// Stop listening for keyboard notifications.
  public func stop() {
    keyboardObserver.stop()
  }
  
  /**
   
   Supply a bottom Auto Layout constraint. Its constant value will be adjusted by the height of the keyboard when it appears and hides.
   
   - parameter bottomLayoutConstraint: Supply a bottom layout constraint. Its constant value will be adjusted when keyboard is shown and hidden.
   
   - parameter view: Supply a view that will be used to animate the constraint. It is usually the superview containing the view with the constraint.
   
   - parameter minMargin: Specify the minimum margin between the keyboard and the bottom of the view the constraint is attached to. Default: 10.
   
   - parameter bottomLayoutGuide: Supply an optional bottom layout guide (like a tab bar) that will be taken into account during height calculations.
   
   */
  public func setup(_ bottomLayoutConstraint: NSLayoutConstraint,
                    view: UIView, minMargin: CGFloat = 10,
                    bottomLayoutGuide: UILayoutSupport? = nil) {
    
    initialConstraintConstant = bottomLayoutConstraint.constant
    self.bottomLayoutConstraint = bottomLayoutConstraint
    self.minMargin = minMargin
    self.bottomLayoutGuide = bottomLayoutGuide
    self.viewToAnimate = view
    
    // Keyboard is already open when setup is called
    if let currentKeyboardHeight = keyboardObserver.currentKeyboardHeight
      , currentKeyboardHeight > 0 {
      
      keyboardWillAnimate(currentKeyboardHeight)
    }
  }
  
  func keyboardWillAnimate(_ height: CGFloat) {
    guard let bottomLayoutConstraint = bottomLayoutConstraint else { return }
    
    let layoutGuideHeight = bottomLayoutGuide?.length ?? 0
    let correctedHeight = height - layoutGuideHeight
    
    if height > 0 {
      let newConstantValue = correctedHeight + minMargin
      
      if newConstantValue > initialConstraintConstant {
        // Keyboard height is bigger than the initial constraint length.
        // Increase constraint length.
        bottomLayoutConstraint.constant = newConstantValue
      } else {
        // Keyboard height is NOT bigger than the initial constraint length.
        // Show the initial constraint length.
        bottomLayoutConstraint.constant = initialConstraintConstant
      }
      
    } else {
      bottomLayoutConstraint.constant = initialConstraintConstant
    }
  }
  
  func animateKeyboard(_ height: CGFloat) {
    viewToAnimate?.layoutIfNeeded()
  }
}


// ----------------------------
//
// UnderKeyboardObserver.swift
//
// ----------------------------

import UIKit

/**
 Detects appearance of software keyboard and calls the supplied closures that can be used for changing the layout and moving view from under the keyboard.
 */
public final class UnderKeyboardObserver: NSObject {
  public typealias AnimationCallback = (_ height: CGFloat) -> ()
  
  let notificationCenter: NotificationCenter
  
  /// Function that will be called before the keyboard is shown and before animation is started.
  public var willAnimateKeyboard: AnimationCallback?
  
  /// Function that will be called inside the animation block. This can be used to call `layoutIfNeeded` on the view.
  public var animateKeyboard: AnimationCallback?
  
  /// Current height of the keyboard. Has value `nil` if unknown.
  public var currentKeyboardHeight: CGFloat?
  
  /// Creates an instance of the class
  public override init() {
    notificationCenter = NotificationCenter.default
    super.init()
  }
  
  deinit {
    stop()
  }
  
  /// Start listening for keyboard notifications.
  public func start() {
    stop()
    
    notificationCenter.addObserver(self, selector: #selector(UnderKeyboardObserver.keyboardNotification(_:)), name:NSNotification.Name.UIKeyboardWillShow, object: nil);
    notificationCenter.addObserver(self, selector: #selector(UnderKeyboardObserver.keyboardNotification(_:)), name:NSNotification.Name.UIKeyboardWillHide, object: nil);
  }
  
  /// Stop listening for keyboard notifications.
  public func stop() {
    notificationCenter.removeObserver(self)
  }
  
  // MARK: - Notification
  
  func keyboardNotification(_ notification: Notification) {
    let isShowing = notification.name == NSNotification.Name.UIKeyboardWillShow
    
    if let userInfo = (notification as NSNotification).userInfo,
      let height = (userInfo[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue.height,
      let duration: TimeInterval = (userInfo[UIKeyboardAnimationDurationUserInfoKey] as? NSNumber)?.doubleValue,
      let animationCurveRawNSN = userInfo[UIKeyboardAnimationCurveUserInfoKey] as? NSNumber {
      
      let correctedHeight = isShowing ? height : 0
      willAnimateKeyboard?(correctedHeight)
      
      UIView.animate(withDuration: duration,
                     delay: TimeInterval(0),
                     options: UIViewAnimationOptions(rawValue: animationCurveRawNSN.uintValue),
                     animations: { [weak self] in
                      self?.animateKeyboard?(correctedHeight)
        },
                     completion: nil
      )
      
      currentKeyboardHeight = correctedHeight
    }
  }
}