fix regression related to scrollPos

.gitignore

@@ -3,3 +3,4 @@
 .DS_Store
 buildServer.json
 .swiftlint.yml
+/ImageViewer.xcodeproj/xcuserdata

ImageViewer/ViewController.swift

@@ -1,7 +1,9 @@
-//TODO: Implement support for bonus chapters
-//TODO: Implement Anilist support?
+//TODO: Support for bonus chapters
+//TODO: Anilist support?
 //TODO: Properly avoid swallowing of input from UICollectionView used for scrolling
 //TODO: Convert between state for normal and scrolling page turn
+//TODO: Support reading with scrolling and landscape mode
+//FIXME: Update comicCollectionView when switching between landscape and portrait mode
 
 import UIKit
 
@@ -82,6 +84,8 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
     var currentChapter: Int! = nil
     var currentPath: URL!
 
+    var changedOrientation = false
+
     var leftTap: UITapGestureRecognizer!
     var rightTap: UITapGestureRecognizer!
     var topTap: UITapGestureRecognizer!
@@ -247,13 +251,18 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
 
     func saveLocalState() {
         let color = readerView.backgroundColor ?? .black
+        let screenSize = UIScreen.main.bounds.size
+        var scrollOffset = scrollingCollectionView.contentOffset
+        if screenSize.width > screenSize.height {
+            scrollOffset.y *= (screenSize.height / screenSize.width)
+        }
         let progress: ReadProgress =
             switch self.mode {
             case .leftToRight:
-                ReadProgress.leftToRight(chapter: self.currentChapter, page: self.currentPage)
+                ReadProgress.leftToRight(chapter: currentChapter, page: currentPage)
             case .rightToLeft:
-                ReadProgress.rightToLeft(chapter: self.currentChapter, page: self.currentPage)
-            case .scroll: ReadProgress.scroll(scrollingCollectionView.contentOffset)
+                ReadProgress.rightToLeft(chapter: currentChapter, page: currentPage)
+            case .scroll: ReadProgress.scroll(scrollOffset)
             }
         queue.async {
             do {
@@ -278,27 +287,27 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
             let local = try JSONDecoder().decode(LocalState.self, from: json)
             switch local.progress {
             case .leftToRight(let chapter, let page):
-                self.currentChapter = chapter
-                self.currentPage = page
-                self.mode = .leftToRight
+                currentChapter = chapter
+                currentPage = page
+                mode = .leftToRight
             case .rightToLeft(let chapter, let page):
-                self.currentChapter = chapter
-                self.currentPage = page
-                self.mode = .rightToLeft
+                currentChapter = chapter
+                currentPage = page
+                mode = .rightToLeft
             case .scroll(let point):
-                if self.scrollPos == nil {
-                    self.scrollPos = point
-                    let centerPoint = CGPoint(
-                        x: scrollingCollectionView.bounds.midX
-                            + scrollingCollectionView.contentOffset.x,
-                        y: scrollingCollectionView.bounds.midY
-                            + scrollingCollectionView.contentOffset.y)
-
-                    if let indexPath = scrollingCollectionView.indexPathForItem(at: centerPoint) {
+                if scrollPos == nil {
+                    scrollPos = point
+                    let screenSize = UIScreen.main.bounds.size
+                    var scrollOffset = point
+                    if screenSize.width > screenSize.height {
+                        scrollOffset.y *= (screenSize.width / screenSize.height)
+                    }
+                    if let indexPath = scrollingCollectionView.indexPathForItem(at: scrollOffset) {
                         let (chapter, page) = chapterAndPages[indexPath.item]
                         currentChapter = chapter
                         currentPage = page
                     }
+
                 }
                 self.mode = .scroll
             }
@@ -338,11 +347,25 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
 
     override func viewDidLayoutSubviews() {
         super.viewDidLayoutSubviews()
-        if scrollingCollectionView.isHidden == false && mode == .scroll
-            && !hasSetContentOffset
+        if scrollingCollectionView.isHidden == true || mode != .scroll
+            || scrollingCollectionView.contentSize == .zero
         {
-            scrollingCollectionView.setContentOffset(scrollPos, animated: false)
+            return
+        }
+        if !hasSetContentOffset && scrollPos != nil {
+            let screenSize = UIScreen.main.bounds.size
+            var offset = scrollPos!
+            if screenSize.width > screenSize.height {
+                offset.y *= (screenSize.width / screenSize.height)
+            }
+            scrollingCollectionView.setContentOffset(offset, animated: false)
             hasSetContentOffset = true
+        } else if changedOrientation {
+            changedOrientation = false
+            let screenSize = UIScreen.main.bounds.size
+            var offset = scrollingCollectionView.contentOffset
+            offset.y *= (screenSize.width / screenSize.height)
+            scrollingCollectionView.setContentOffset(offset, animated: false)
         }
     }
 
@@ -972,7 +995,10 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
     }
 
     func setImages(path: URL, metadata: Metadata) {
-        let scaling = UIView.ContentMode.scaleAspectFit
+        let scaling: UIView.ContentMode =
+            if mode == .scroll {
+                .scaleAspectFill
+            } else { .scaleAspectFit }
         var directories: [URL] = []
         if currentPage != nil && currentChapter != nil {
             var vol = Int(metadata.chapters[currentChapter - 1].volume)
@@ -1051,16 +1077,20 @@ class ViewController: UIViewController, UIGestureRecognizerDelegate {
         to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator
     ) {
         super.viewWillTransition(to: size, with: coordinator)
-
-        self.imageLoader.loadImage(
-            at: self.getImagePath(
-                chapter: self.currentChapter,
-                volume: Int(self.metadata.chapters[self.currentChapter - 1].volume),
-                page: self.currentPage,
-                path: self.currentPath),
-            scaling: .scaleAspectFit
-        ) { image in
-            self.imageView.image = image
+        if mode != .scroll {
+            self.imageLoader.loadImage(
+                at: self.getImagePath(
+                    chapter: self.currentChapter,
+                    volume: Int(self.metadata.chapters[self.currentChapter - 1].volume),
+                    page: self.currentPage,
+                    path: self.currentPath),
+                scaling: .scaleAspectFit
+            ) { image in
+                self.imageView.image = image
+            }
+        } else {
+            scrollingCollectionView.reloadData()
+            changedOrientation = true
         }
     }
 }
@@ -1328,7 +1358,9 @@ class ImageLoader {
                 let vScaleImage = resizeImage(image, to: vScaledSize)
                 guard let cost = imageByteSize(vScaleImage) else { return }
                 self.cache.setObject(vScaleImage, forKey: path.path as NSString, cost: cost)
-                image = vScaleImage
+                if rotation == .vertical {
+                    image = vScaleImage
+                }
             }
 
             if completion == nil || rotation == .horizontal {
@@ -1340,7 +1372,9 @@ class ImageLoader {
                 let hScaleImage = resizeImage(image, to: hScaledSize)
                 guard let cost = imageByteSize(hScaleImage) else { return }
                 self.horCache.setObject(hScaleImage, forKey: path.path as NSString, cost: cost)
-                image = hScaleImage
+                if rotation == .horizontal {
+                    image = hScaleImage
+                }
             }
 
             DispatchQueue.main.async {