Features/imageviewer transition

Example/Demo.xcodeproj/project.pbxproj

@@ -19,6 +19,7 @@
 		A6BC0BE023913C66004A4E46 /* GalleryViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = A6BC0BDF23913C66004A4E46 /* GalleryViewController.swift */; };
 		A6BC0BE223914239004A4E46 /* ThumbCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = A6BC0BE123914239004A4E46 /* ThumbCell.swift */; };
 		A6BC0BE823915420004A4E46 /* Data.swift in Sources */ = {isa = PBXBuildFile; fileRef = A6BC0BE723915420004A4E46 /* Data.swift */; };
+		A6FE4B4624EDDBAE00E9C754 /* README.md in Resources */ = {isa = PBXBuildFile; fileRef = A6FE4B4524EDDBAE00E9C754 /* README.md */; };
 		D303414D23CA5F17FEDDCF7B /* Pods_Demo.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 10710A5B07A80798DED8269E /* Pods_Demo.framework */; };
 /* End PBXBuildFile section */
 
@@ -39,6 +40,7 @@
 		A6BC0BDF23913C66004A4E46 /* GalleryViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = GalleryViewController.swift; sourceTree = "<group>"; };
 		A6BC0BE123914239004A4E46 /* ThumbCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ThumbCell.swift; sourceTree = "<group>"; };
 		A6BC0BE723915420004A4E46 /* Data.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Data.swift; sourceTree = "<group>"; };
+		A6FE4B4524EDDBAE00E9C754 /* README.md */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = net.daringfireball.markdown; name = README.md; path = ../../README.md; sourceTree = "<group>"; };
 		D023B1BBDAD100A2962FDC7E /* Pods-Demo.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-Demo.debug.xcconfig"; path = "Target Support Files/Pods-Demo/Pods-Demo.debug.xcconfig"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -83,6 +85,7 @@
 		A6BC0BC6239139F8004A4E46 /* Demo */ = {
 			isa = PBXGroup;
 			children = (
+				A6FE4B4524EDDBAE00E9C754 /* README.md */,
 				A6BC0BC7239139F8004A4E46 /* AppDelegate.swift */,
 				A6BC0BD0239139F9004A4E46 /* Assets.xcassets */,
 				A6BC0BD2239139F9004A4E46 /* LaunchScreen.storyboard */,
@@ -169,6 +172,7 @@
 			isa = PBXResourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				A6FE4B4624EDDBAE00E9C754 /* README.md in Resources */,
 				A6BC0BD4239139F9004A4E46 /* LaunchScreen.storyboard in Resources */,
 				A6BC0BD1239139F9004A4E46 /* Assets.xcassets in Resources */,
 			);

ImageViewerTransitionPresentationManager.swift

@@ -0,0 +1,205 @@
+//
+//  ImageViewerTransitionPresentationManager.swift
+//  ImageViewer.swift
+//
+//  Created by Michael Henry Pantaleon on 2020/08/19.
+//
+
+import Foundation
+import UIKit
+
+protocol ImageViewerTransitionViewControllerConvertible {
+
+    // The source view
+    var sourceView: UIImageView? { get }
+
+    // The final view
+    var targetView: UIImageView? { get }
+}
+
+final class ImageViewerTransitionPresentationAnimator:NSObject {
+
+    let isPresenting: Bool
+
+    init(isPresenting: Bool) {
+        self.isPresenting = isPresenting
+        super.init()
+    }
+}
+
+// MARK: - UIViewControllerAnimatedTransitioning
+extension ImageViewerTransitionPresentationAnimator: UIViewControllerAnimatedTransitioning {
+
+    func transitionDuration(using transitionContext: UIViewControllerContextTransitioning?)
+        -> TimeInterval {
+            return 0.3
+    }
+
+    func animateTransition(using transitionContext: UIViewControllerContextTransitioning) {
+        let key: UITransitionContextViewControllerKey = isPresenting ? .to : .from
+        guard let controller = transitionContext.viewController(forKey: key)
+            else { return }
+
+        let animationDuration = transitionDuration(using: transitionContext)
+
+        if isPresenting {
+            presentAnimation(
+                transitionView: transitionContext.containerView,
+                controller: controller,
+                duration: animationDuration) { finished in
+                    transitionContext.completeTransition(finished)
+            }
+
+        } else {
+            dismissAnimation(
+                transitionView: transitionContext.containerView,
+                controller: controller,
+                duration: animationDuration) { finished in
+                    transitionContext.completeTransition(finished)
+            }
+        }
+    }
+
+    private func createDummyImageView(frame: CGRect, image:UIImage? = nil)
+        -> UIImageView {
+            let dummyImageView:UIImageView = UIImageView(frame: frame)
+            dummyImageView.clipsToBounds = true
+            dummyImageView.contentMode = .scaleAspectFill
+            dummyImageView.alpha = 1.0
+            dummyImageView.image = image
+            return dummyImageView
+    }
+
+    private func presentAnimation(
+        transitionView:UIView,
+        controller: UIViewController,
+        duration: TimeInterval,
+        completed: @escaping((Bool) -> Void)) {
+
+        guard
+            let transitionVC = controller as? ImageViewerTransitionViewControllerConvertible
+        else { return }
+
+        let sourceView = transitionVC.sourceView
+
+        let dummyImageView = createDummyImageView(
+            frame: sourceView?.frameRelativeToWindow() ?? .zero,
+            image: sourceView?.image)
+        transitionView.addSubview(dummyImageView)
+
+        sourceView?.alpha = 0.0
+
+        transitionView.addSubview(controller.view)
+        controller.view.alpha = 0.0
+
+        UIView.animate(withDuration: duration, animations: {
+            dummyImageView.contentMode = .scaleAspectFit
+            dummyImageView.frame = UIScreen.main.bounds
+            controller.view.alpha = 1.0
+        }) { finished in
+            dummyImageView.removeFromSuperview()
+            completed(finished)
+        }
+    }
+
+    private func dismissAnimation(
+        transitionView:UIView,
+        controller: UIViewController,
+        duration:TimeInterval,
+        completed: @escaping((Bool) -> Void)) {
+
+        guard
+            let transitionVC = controller as? ImageViewerTransitionViewControllerConvertible
+        else { return }
+
+        let sourceView = transitionVC.sourceView
+        let targetView = transitionVC.targetView
+
+        let dummyImageView = createDummyImageView(
+            frame: targetView?.frameRelativeToWindow() ?? UIScreen.main.bounds,
+            image: targetView?.image)
+        transitionView.addSubview(dummyImageView)
+        targetView?.isHidden = true
+
+        controller.view.alpha = 1.0
+        UIView.animate(withDuration: duration, animations: {
+            if let sourceView = sourceView {
+                // return to original position
+                dummyImageView.frame = sourceView.frameRelativeToWindow()
+            } else {
+                // just disappear
+                dummyImageView.alpha = 0.0
+            }
+            controller.view.alpha = 0.0
+        }) { finished in
+            sourceView?.alpha = 1.0
+            controller.view.removeFromSuperview()
+            completed(finished)
+        }
+    }
+}
+
+final class ImageViewerTransitionPresentationController: UIPresentationController {
+
+    override var frameOfPresentedViewInContainerView: CGRect {
+        var frame: CGRect = .zero
+        frame.size = size(forChildContentContainer: presentedViewController,
+                          withParentContainerSize: containerView!.bounds.size)
+        return frame
+    }
+
+    override func containerViewWillLayoutSubviews() {
+        presentedView?.frame = frameOfPresentedViewInContainerView
+    }
+}
+
+final class ImageViewerTransitionPresentationManager: NSObject {
+
+}
+
+// MARK: - UIViewControllerTransitioningDelegate
+extension ImageViewerTransitionPresentationManager: UIViewControllerTransitioningDelegate {
+    func presentationController(
+        forPresented presented: UIViewController,
+        presenting: UIViewController?,
+        source: UIViewController
+    ) -> UIPresentationController? {
+        let presentationController = ImageViewerTransitionPresentationController(
+            presentedViewController: presented,
+            presenting: presenting)
+        return presentationController
+    }
+
+    func animationController(
+        forPresented presented: UIViewController,
+        presenting: UIViewController,
+        source: UIViewController
+    ) -> UIViewControllerAnimatedTransitioning? {
+
+        return ImageViewerTransitionPresentationAnimator(isPresenting: true)
+    }
+
+    func animationController(
+        forDismissed dismissed: UIViewController
+    ) -> UIViewControllerAnimatedTransitioning? {
+        return ImageViewerTransitionPresentationAnimator(isPresenting: false)
+    }
+}
+
+// MARK: - UIAdaptivePresentationControllerDelegate
+extension ImageViewerTransitionPresentationManager: UIAdaptivePresentationControllerDelegate {
+
+    func adaptivePresentationStyle(
+        for controller: UIPresentationController,
+        traitCollection: UITraitCollection
+    ) -> UIModalPresentationStyle {
+        return .none
+    }
+
+    func presentationController(
+        _ controller: UIPresentationController,
+        viewControllerForAdaptivePresentationStyle style: UIModalPresentationStyle
+    ) -> UIViewController? {
+        return nil
+    }
+}