Added DialogController

Sources/iOS/DialogController.swift

+/*
+ * Copyright (C) 2018, Daniel Dahan and CosmicMind, Inc. <http://cosmicmind.com>.
+ * All rights reserved.
+ *
+ * Original Inspiration & Author
+ * Copyright (C) 2018 Orkhan Alikhanov <orkhan.alikhanov@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *  * Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ *  * Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ *  * Neither the name of CosmicMind nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+import UIKit
+
+/// A UIViewController managing DialogView.
+open class DialogController<T: DialogView>: UIViewController {
+  /// A reference to dialogView.
+  public let dialogView = T()
+  
+  /// A boolean indicating cancelability of dialog when user taps on background.
+  open var isCancelable = false
+  
+  /// A reference to did-cancel handler.
+  open var didCancelHandler: (() -> Void)?
+  
+  /**
+   A reference to should-dismiss handler which takes dialogView
+   and tapped button and returns Boolean indicating if dialog should be dismissed.
+   */
+  open var shouldDismissHandler: ((T, Button?) -> Bool)?
+  
+  /// A reference to handler for when positiveButton is tapped.
+  open var didTapPositiveButtonHandler: (() -> Void)?
+  
+  /// A reference to handler for when negativeButton is tapped.
+  open var didTapNegativeButtonHandler: (() -> Void)?
+  
+  /// A reference to handler for when neutralButton is tapped.
+  open var didTapNeutralButtonHandler: (() -> Void)?
+  
+  public override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
+    super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
+    prepare()
+  }
+  
+  required public init?(coder aDecoder: NSCoder) {
+    super.init(coder: aDecoder)
+    prepare()
+  }
+  
+  /// Prepares controller for presentation.
+  open func prepare() {
+    isMotionEnabled = true
+    motionTransitionType = .fade
+    modalPresentationStyle = .overFullScreen
+  }
+  
+  open override func viewDidLoad() {
+    super.viewDidLoad()
+    prepareView()
+    prepareDialogView()
+  }
+  
+  open override func viewWillLayoutSubviews() {
+    super.viewWillLayoutSubviews()
+    dialogView.maxSize = CGSize(width: Screen.width * 0.8, height: Screen.height * 0.9)
+  }
+  
+  /**
+   Dismisses dialog.
+   - Parameter isAnimated: A boolean.
+   */
+  open func dismiss(isAnimated: Bool = true) {
+    dismiss(isTriggeredByUserInteraction: false, isAnimated: isAnimated)
+  }
+  
+  /// Handler for when background scrim is tapped.
+  @objc
+  private func didTapBackgroundView() {
+    guard isCancelable else {
+      return
+    }
+    
+    dismiss(isTriggeredByUserInteraction: true, isAnimated: true)
+    didCancelHandler?()
+  }
+  
+  /// Handler for when one of 3 dialog buttons is tapped.
+  @objc
+  private func didTapButton(_ sender: Button) {
+    switch sender {
+    case dialogView.positiveButton:
+      didTapPositiveButtonHandler?()
+      
+    case dialogView.negativeButton:
+      didTapNegativeButtonHandler?()
+      
+    case dialogView.neutralButton:
+      didTapNeutralButtonHandler?()
+      
+    default:
+      break
+    }
+    
+    dismiss(isTriggeredByUserInteraction: true, isAnimated: true, using: sender)
+  }
+}
+
+private extension DialogController {
+  /// Prepares view.
+  func prepareView() {
+    let v = UIControl()
+    v.backgroundColor = Color.black.withAlphaComponent(0.33)
+    v.addTarget(self, action: #selector(didTapBackgroundView), for: .touchUpInside)
+    view = v
+  }
+  
+  /// Prepares dialogView.
+  func prepareDialogView() {
+    view.layout(dialogView).center()
+    dialogView.buttonArea.subviews.forEach {
+      ($0 as? Button)?.addTarget(self, action: #selector(didTapButton), for: .touchUpInside)
+    }
+  }
+}
+
+private extension DialogController {
+  /**
+   Dismisses dialog.
+   - Parameter isTriggeredByUserInteraction: A boolean indicating whether the action is
+   triggered by a user interaction
+   - Parameter isAnimated: A boolean indicating if the dismissal should be animated.
+   - Parameter using button: A button triggering the dismissal.
+  */
+  func dismiss(isTriggeredByUserInteraction: Bool, isAnimated: Bool, using button: Button? = nil) {
+    if isTriggeredByUserInteraction {
+      guard shouldDismissHandler?(dialogView, button) ?? true else {
+        return
+      }
+    }
+    
+    presentingViewController?.dismiss(animated: isAnimated, completion: nil)
+  }
+}