[Feature] Add transition ability with remote images and make the tran…

Optik/Classes/AlbumViewController.swift

@@ -80,21 +80,23 @@ internal final class AlbumViewController: UIViewController {
     private var cachedRemoteImages: [URL: UIImage] = [:]
     private var viewDidAppear: Bool = false
 
-    private var transitionController: TransitionController = TransitionController()
+    private var transitionController: TransitionController
 
     // MARK: - Init/Deinit
 
     init(imageData: ImageData,
          initialImageDisplayIndex: Int,
          activityIndicatorColor: UIColor?,
          dismissButtonImage: UIImage?,
-         dismissButtonPosition: DismissButtonPosition) {
+         dismissButtonPosition: DismissButtonPosition,
+         transitionShadow: Bool) {
 
         self.imageData = imageData
         self.initialImageDisplayIndex = initialImageDisplayIndex
         self.activityIndicatorColor = activityIndicatorColor
         self.dismissButtonImage = dismissButtonImage
         self.dismissButtonPosition = dismissButtonPosition
+        self.transitionController = TransitionController(transitionShadow: transitionShadow)
 
         pageViewController = UIPageViewController(transitionStyle: .scroll,
                                                   navigationOrientation: .horizontal,

Optik/Classes/Optik.swift

@@ -18,20 +18,22 @@ import UIKit
  - parameter delegate:                      Image viewer delegate.
  - parameter dismissButtonImage:            Image for the dismiss button.
  - parameter dismissButtonPosition:         Dismiss button position.
+ - parameter transitionShadow               Whether to display a shadow to the image or not during transitions.
 
  - returns: The created view controller.
  */
 public func imageViewer(withImages images: [UIImage],
                                    initialImageDisplayIndex: Int = 0,
                                    delegate: ImageViewerDelegate? = nil,
                                    dismissButtonImage: UIImage? = nil,
-                                   dismissButtonPosition: DismissButtonPosition = .topLeading) -> UIViewController {
+                                   dismissButtonPosition: DismissButtonPosition = .topLeading,
+                                   transitionShadow: Bool = true) -> UIViewController {
     let albumViewController = imageViewer(withData: .local(images: images),
                                           initialImageDisplayIndex: initialImageDisplayIndex,
+                                          delegate: delegate,
                                           dismissButtonImage: dismissButtonImage,
-                                          dismissButtonPosition: dismissButtonPosition)
-    albumViewController.modalPresentationStyle = .custom
-    albumViewController.imageViewerDelegate = delegate
+                                          dismissButtonPosition: dismissButtonPosition,
+                                          transitionShadow: transitionShadow)
 
     return albumViewController
 }
@@ -45,38 +47,48 @@ public func imageViewer(withImages images: [UIImage],
  - parameter activityIndicatorColor:        Tint color of the activity indicator that is displayed while images are being downloaded.
  - parameter dismissButtonImage:            Image for the dismiss button.
  - parameter dismissButtonPosition:         Dismiss button position.
+ - parameter transitionShadow               Whether to display a shadow to the image or not during transitions.
 
  - returns: The created view controller.
  */
 public func imageViewer(withURLs urls: [URL],
                                  initialImageDisplayIndex: Int = 0,
+                                 delegate: ImageViewerDelegate? = nil,
                                  imageDownloader: ImageDownloader,
                                  activityIndicatorColor: UIColor = .white,
                                  dismissButtonImage: UIImage? = nil,
-                                 dismissButtonPosition: DismissButtonPosition = .topLeading) -> UIViewController {
+                                 dismissButtonPosition: DismissButtonPosition = .topLeading,
+                                 transitionShadow: Bool = true) -> UIViewController {
     return imageViewer(withData: .remote(urls: urls, imageDownloader: imageDownloader),
                        initialImageDisplayIndex: initialImageDisplayIndex,
+                       delegate: delegate,
                        activityIndicatorColor: activityIndicatorColor,
                        dismissButtonImage: dismissButtonImage,
-                       dismissButtonPosition: dismissButtonPosition)
+                       dismissButtonPosition: dismissButtonPosition,
+                       transitionShadow: transitionShadow)
 }
 
 // MARK: - Private functions
 
 private func imageViewer(withData imageData: ImageData,
                                   initialImageDisplayIndex: Int,
+                                  delegate: ImageViewerDelegate? = nil,
                                   activityIndicatorColor: UIColor? = nil,
                                   dismissButtonImage: UIImage?,
-                                  dismissButtonPosition: DismissButtonPosition) -> AlbumViewController {
+                                  dismissButtonPosition: DismissButtonPosition,
+                                  transitionShadow: Bool) -> AlbumViewController {
     let bundle = Bundle(for: AlbumViewController.self)
     let defaultDismissButtonImage = UIImage(named: "DismissIcon", in: bundle, compatibleWith: nil)
 
     let albumViewController = AlbumViewController(imageData: imageData,
                                                   initialImageDisplayIndex: initialImageDisplayIndex,
                                                   activityIndicatorColor: activityIndicatorColor,
                                                   dismissButtonImage: dismissButtonImage ?? defaultDismissButtonImage,
-                                                  dismissButtonPosition: dismissButtonPosition)
+                                                  dismissButtonPosition: dismissButtonPosition,
+                                                  transitionShadow: transitionShadow)
     albumViewController.modalPresentationCapturesStatusBarAppearance = true
+    albumViewController.modalPresentationStyle = .custom
+    albumViewController.imageViewerDelegate = delegate
 
     return albumViewController
 }

Optik/Classes/TransitionAnimator.swift

@@ -37,6 +37,8 @@ internal final class TransitionAnimator: NSObject {
     private weak var toImageView: UIImageView?
     private weak var animationView: UIImageView?
 
+    private var transitionShadow: Bool
+
     fileprivate weak var fromViewController: UIViewController?
     fileprivate weak var toViewController: UIViewController?
 
@@ -45,10 +47,11 @@ internal final class TransitionAnimator: NSObject {
 
     // MARK: - Init/deinit
 
-    init(transitionType: TransitionType, fromImageView: UIImageView, toImageView: UIImageView) {
+    init(transitionType: TransitionType, fromImageView: UIImageView, toImageView: UIImageView, transitionShadow: Bool) {
         self.transitionType = transitionType
         self.fromImageView = fromImageView
         self.toImageView = toImageView
+        self.transitionShadow = transitionShadow
 
         super.init()
     }
@@ -202,10 +205,12 @@ internal final class TransitionAnimator: NSObject {
         self.animationView = animationView
 
         animationView.frame = fromSuperView.convert(fromImageView.frame, to: transitionContainerView)
-        animationView.layer.shadowColor = Constants.animationViewShadowColor
-        animationView.layer.shadowOffset = Constants.animationViewShadowOffset
-        animationView.layer.shadowRadius = Constants.animationViewShadowRadius
-        animationView.layer.shadowOpacity = Constants.animationViewShadowOpacity
+        if (transitionShadow) {
+            animationView.layer.shadowColor = Constants.animationViewShadowColor
+            animationView.layer.shadowOffset = Constants.animationViewShadowOffset
+            animationView.layer.shadowRadius = Constants.animationViewShadowRadius
+            animationView.layer.shadowOpacity = Constants.animationViewShadowOpacity
+        }
 
         fromImageView.isHidden = true
         toImageView.isHidden = true

Optik/Classes/TransitionController.swift

@@ -31,8 +31,16 @@ internal final class TransitionController: NSObject {
     fileprivate var dismissTransitionAnimator: TransitionAnimator?
     fileprivate var shouldDismissInteractively: Bool = false
 
+    fileprivate var transitionShadow: Bool
+
     private var lastPanTranslation: CGPoint?
 
+    // MARK: - Initializers
+
+    init(transitionShadow: Bool) {
+        self.transitionShadow = transitionShadow
+    }
+
     // MARK: - Instance functions
 
     /**
@@ -119,7 +127,10 @@ extension TransitionController: UIViewControllerTransitioningDelegate {
                     return nil
             }
 
-            return TransitionAnimator(transitionType: .present, fromImageView: fromImageView, toImageView: toImageView)
+            return TransitionAnimator(transitionType: .present,
+                                      fromImageView: fromImageView,
+                                      toImageView: toImageView,
+                                      transitionShadow: transitionShadow)
     }
 
     func animationController(forDismissed dismissed: UIViewController)
@@ -132,7 +143,8 @@ extension TransitionController: UIViewControllerTransitioningDelegate {
 
             dismissTransitionAnimator = TransitionAnimator(transitionType: .dismiss,
                                                            fromImageView: fromImageView,
-                                                           toImageView: toImageView)
+                                                           toImageView: toImageView,
+                                                           transitionShadow: transitionShadow)
             return dismissTransitionAnimator
     }