Improve gallery expand animation

Use spring timing, slide in top/bottom controls

Tusker/Screens/Attachment Gallery/GalleryViewController.swift

@@ -27,6 +27,10 @@ class GalleryViewController: UIPageViewController, UIPageViewControllerDataSourc
     }
 
     var animationSourceView: UIImageView? { sourceViews[currentIndex] }
+    var largeImageController: LargeImageViewController? {
+        // use protocol because page controllers may be loading or non-loading VCs
+        (pages[currentIndex] as? LargeImageAnimatableViewController)?.largeImageController
+    }
     var animationImage: UIImage? {
         if let page = pages[currentIndex] as? LargeImageAnimatableViewController,
             let image = page.animationImage {
@@ -48,6 +52,9 @@ class GalleryViewController: UIPageViewController, UIPageViewControllerDataSourc
     override var prefersStatusBarHidden: Bool {
         return true
     }
+    override var preferredStatusBarUpdateAnimation: UIStatusBarAnimation {
+        return .none
+    }
     override var childForHomeIndicatorAutoHidden: UIViewController? {
         return viewControllers?.first
     }

Tusker/Screens/Large Image/LargeImageViewController.swift

@@ -13,6 +13,7 @@ class LargeImageViewController: UIViewController, UIScrollViewDelegate, LargeIma
     typealias ContentView = UIView & LargeImageContentView
 
     weak var animationSourceView: UIImageView?
+    var largeImageController: LargeImageViewController? { self }
     var animationImage: UIImage? { contentView.animationImage }
     var animationGifData: Data? { contentView.animationGifData }
     var dismissInteractionController: LargeImageInteractionController?
@@ -49,6 +50,9 @@ class LargeImageViewController: UIViewController, UIScrollViewDelegate, LargeIma
     override var prefersStatusBarHidden: Bool {
         return true
     }
+    override var preferredStatusBarUpdateAnimation: UIStatusBarAnimation {
+        return .none
+    }
     
     override var prefersHomeIndicatorAutoHidden: Bool {
         return !controlsVisible

Tusker/Screens/Large Image/LoadingLargeImageViewController.swift

@@ -36,6 +36,7 @@ class LoadingLargeImageViewController: UIViewController, LargeImageAnimatableVie
     var shrinkGestureEnabled = true
     
     weak var animationSourceView: UIImageView?
+    var largeImageController: LargeImageViewController? { largeImageVC }
     var animationImage: UIImage? { largeImageVC?.animationImage ?? animationSourceView?.image }
     var animationGifData: Data? { largeImageVC?.animationGifData }
     var dismissInteractionController: LargeImageInteractionController?
@@ -43,6 +44,9 @@ class LoadingLargeImageViewController: UIViewController, LargeImageAnimatableVie
     override var prefersStatusBarHidden: Bool {
         return true
     }
+    override var preferredStatusBarUpdateAnimation: UIStatusBarAnimation {
+        return .none
+    }
     override var childForHomeIndicatorAutoHidden: UIViewController? {
         return largeImageVC
     }

Tusker/Screens/Large Image/Transitions/LargeImageExpandAnimationController.swift

@@ -11,6 +11,7 @@ import Gifu
 
 protocol LargeImageAnimatableViewController: UIViewController {
     var animationSourceView: UIImageView? { get }
+    var largeImageController: LargeImageViewController? { get }
     var animationImage: UIImage? { get }
     var animationGifData: Data? { get }
     var dismissInteractionController: LargeImageInteractionController? { get }
@@ -37,7 +38,7 @@ extension LargeImageAnimatableViewController {
 class LargeImageExpandAnimationController: NSObject, UIViewControllerAnimatedTransitioning {
     
     func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?) -> TimeInterval {
-        return 0.2
+        return 0.5
     }
     
     func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
@@ -47,19 +48,22 @@ class LargeImageExpandAnimationController: NSObject, UIViewControllerAnimatedTra
         }
         
         let containerView = transitionContext.containerView
-        containerView.addSubview(toVC.view)
+        
 
         let finalVCFrame = transitionContext.finalFrame(for: toVC)
         guard let sourceView = toVC.animationSourceView,
-            let sourceFrame = toVC.sourceViewFrame(in: fromVC.view),
+              let sourceFrame = toVC.sourceViewFrame(in: fromVC.view),
-            let image = toVC.animationImage else {
+              let image = toVC.animationImage else {
                 toVC.view.frame = finalVCFrame
                 transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
                 return
         }
         
-        // use alpha, becaus isHidden makes stack views re-layout
+        // use alpha, because isHidden makes stack views re-layout
         sourceView.alpha = 0
+        toVC.view.alpha = 0
+        toVC.largeImageController?.contentView.isHidden = true
+        toVC.largeImageController?.setControlsVisible(false, animated: false)
 
         var finalFrameSize = finalVCFrame.inset(by: fromVC.view.safeAreaInsets).size
         let newWidth = finalFrameSize.width / image.size.width
@@ -81,21 +85,17 @@ class LargeImageExpandAnimationController: NSObject, UIViewControllerAnimatedTra
         imageView.layer.maskedCorners = sourceView.layer.maskedCorners
         imageView.layer.masksToBounds = true
         
-        let blackView = UIView(frame: finalVCFrame)
+        containerView.addSubview(toVC.view)
-        blackView.backgroundColor = .black
-        blackView.alpha = 0
-        
-        containerView.addSubview(blackView)
         containerView.addSubview(imageView)
         
-        toVC.view.isHidden = true
-        
         let duration = transitionDuration(using: transitionContext)
-        UIView.animate(withDuration: duration, animations: {
+        let velocity = 1 / CGFloat(duration)
+        UIView.animate(withDuration: duration, delay: 0, usingSpringWithDamping: 0.65, initialSpringVelocity: velocity, options: []) {
             imageView.frame = finalFrame
             imageView.layer.cornerRadius = 0
-            blackView.alpha = 1
+            toVC.view.alpha = 1
-        }, completion: { _ in
+            toVC.largeImageController?.setControlsVisible(true, animated: false)
+        } completion: { (_) in
             // This shouldn't be necessary. I believe it's a workaround for using a XIB
             // for the large image VC. Without this, the final frame of the large image VC
             // is not set to the propper rect (it uses the frame of the preview device
@@ -103,15 +103,14 @@ class LargeImageExpandAnimationController: NSObject, UIViewControllerAnimatedTra
             // (or UIKit does layout differently when loading the view) and this is not necessary.
             toVC.view.frame = finalVCFrame
             
-            toVC.view.isHidden = false
+            toVC.largeImageController?.contentView.isHidden = false
             fromVC.view.isHidden = false
-            blackView.removeFromSuperview()
             imageView.removeFromSuperview()
             
             sourceView.alpha = 1
 
             transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
-        })
+        }
     }
     
 }