enhance preview swiping and page loading

Author: raluaces

Django Files/Django_FilesApp.swift

@@ -177,7 +177,7 @@ struct Django_FilesApp: App {
                         showingPreview: $previewStateManager.showingDeepLinkPreview,
                         showFileInfo: $showFileInfo,
                         fileListDelegate: nil,
-                        allFiles: [file],
+                        allFiles: .constant([file]),
                         currentIndex: 0,
                         onNavigate: { _ in }
                     )

Django Files/Utils/ImageCache.swift

@@ -11,6 +11,7 @@ import Foundation
 class ImageCache {
     static let shared = ImageCache()
     private let cache = NSCache<NSString, UIImage>()
+    private let contentCache = NSCache<NSString, NSData>()
 
     private init() {
         // Cache is unlimited
@@ -23,6 +24,14 @@ class ImageCache {
     func get(for key: String) -> UIImage? {
         return cache.object(forKey: key as NSString)
     }
+    
+    func setContent(_ data: Data, for key: String) {
+        contentCache.setObject(data as NSData, forKey: key as NSString)
+    }
+    
+    func getContent(for key: String) -> Data? {
+        return contentCache.object(forKey: key as NSString) as Data?
+    }
 }
 
 struct CachedAsyncImage<Content: View, Placeholder: View>: View {
@@ -98,3 +107,20 @@ struct CachedAsyncImage<Content: View, Placeholder: View>: View {
         }
     }
 }
+
+// Add a new generic content loader
+struct CachedContentLoader {
+    static func loadContent(from url: URL) async throws -> Data {
+        let urlString = url.absoluteString
+        
+        // Check cache first
+        if let cachedData = ImageCache.shared.getContent(for: urlString) {
+            return cachedData
+        }
+        
+        // Download and cache if not found
+        let (data, _) = try await URLSession.shared.data(from: url)
+        ImageCache.shared.setContent(data, for: urlString)
+        return data
+    }
+}

Django Files/Views/Lists/FileList.swift

@@ -369,18 +369,26 @@ struct FileListView: View {
             }
         }
         .fullScreenCover(isPresented: $showingPreview) {
-            if let index = files.firstIndex(where: { $0.id == selectedFile?.id }) {
+            if let index = fileListManager.files.firstIndex(where: { $0.id == selectedFile?.id }) {
                 FilePreviewView(
                     file: $fileListManager.files[index],
                     server: server,
                     showingPreview: $showingPreview,
                     showFileInfo: $showFileInfo,
                     fileListDelegate: fileListManager,
-                    allFiles: files,
+                    allFiles: Binding(
+                        get: { fileListManager.files },
+                        set: { fileListManager.files = $0 }
+                    ),
                     currentIndex: index,
                     onNavigate: { newIndex in
-                        if newIndex >= 0 && newIndex < files.count {
-                            selectedFile = files[newIndex]
+                        if newIndex >= 0 && newIndex < fileListManager.files.count {
+                            selectedFile = fileListManager.files[newIndex]
+                        }
+                    },
+                    onLoadMore: {
+                        if hasNextPage && !isLoading {
+                            await loadNextPage()
                         }
                     }
                 )
@@ -711,7 +719,11 @@ struct FileListView: View {
 
         if let filesResponse = await api.getFiles(page: page, album: albumID, selectedServer: serverInstance, filterUserID: filterUserID) {
             if append {
-                files.append(contentsOf: filesResponse.files)
+                // Only append new files that aren't already in the list
+                let newFiles = filesResponse.files.filter { newFile in
+                    !files.contains { $0.id == newFile.id }
+                }
+                files.append(contentsOf: newFiles)
             } else {
                 files = filesResponse.files
             }

Django Files/Views/Preview/Image.swift

@@ -30,20 +30,21 @@ struct ImageScrollView: UIViewRepresentable {
         doubleTapGesture.numberOfTapsRequired = 2
         scrollView.addGestureRecognizer(doubleTapGesture)
 
-        // Calculate initial zoom scale
         let widthScale = UIScreen.main.bounds.width / image.size.width
         let heightScale = UIScreen.main.bounds.height / image.size.height
         let minScale = min(widthScale, heightScale)
 
         scrollView.minimumZoomScale = minScale
         scrollView.maximumZoomScale = 5.0
 
-        // Set content size to image size
         scrollView.contentSize = image.size
 
-        // Set initial zoom scale
         scrollView.zoomScale = minScale
 
+        scrollView.decelerationRate = .fast
+        scrollView.showsHorizontalScrollIndicator = false
+        scrollView.showsVerticalScrollIndicator = false
+        
         return scrollView
     }
 
@@ -65,39 +66,39 @@ struct ImageScrollView: UIViewRepresentable {
             return imageView
         }
 
-       func updateZoomScaleForSize(_ size: CGSize) {
-           guard let imageView = imageView,
-               let image = imageView.image,
-               let scrollView = scrollView,
-               size.width > 0,
-               size.height > 0,
-               image.size.width > 0,
-               image.size.height > 0 else { return }
-           
-           let widthScale = size.width / image.size.width
-           let heightScale = size.height / image.size.height
-           let minScale = min(widthScale, heightScale)
+        func updateZoomScaleForSize(_ size: CGSize) {
+            guard let imageView = imageView,
+                  let image = imageView.image,
+                  let scrollView = scrollView,
+                  size.width > 0,
+                  size.height > 0,
+                  image.size.width > 0,
+                  image.size.height > 0 else { return }
+            
+            let widthScale = size.width / image.size.width
+            let heightScale = size.height / image.size.height
+            let minScale = min(widthScale, heightScale)
 
-           scrollView.minimumZoomScale = minScale
-           scrollView.maximumZoomScale = max(minScale * 5, 5.0)
+            scrollView.minimumZoomScale = minScale
+            scrollView.maximumZoomScale = max(minScale * 5, 5.0)
+        }
+        
+        @objc func handleDoubleTap(_ gesture: UITapGestureRecognizer) {
+            guard let scrollView = gesture.view as? UIScrollView else { return }
+            
+            if scrollView.zoomScale > scrollView.minimumZoomScale {
+                scrollView.setZoomScale(scrollView.minimumZoomScale, animated: true)
+            } else {
+                let point = gesture.location(in: imageView)
+                let size = scrollView.bounds.size
+                let w = size.width / (scrollView.maximumZoomScale / 5)
+                let h = size.height / (scrollView.maximumZoomScale / 5)
+                let x = point.x - (w / 2.0)
+                let y = point.y - (h / 2.0)
+                let rect = CGRect(x: x, y: y, width: w, height: h)
+                scrollView.zoom(to: rect, animated: true)
+            }
         }
-       
-       @objc func handleDoubleTap(_ gesture: UITapGestureRecognizer) {
-           guard let scrollView = gesture.view as? UIScrollView else { return }
-           
-           if scrollView.zoomScale > scrollView.minimumZoomScale {
-               scrollView.setZoomScale(scrollView.minimumZoomScale, animated: true)
-           } else {
-               let point = gesture.location(in: imageView)
-               let size = scrollView.bounds.size
-               let w = size.width / (scrollView.maximumZoomScale / 5)
-               let h = size.height / (scrollView.maximumZoomScale / 5)
-               let x = point.x - (w / 2.0)
-               let y = point.y - (h / 2.0)
-               let rect = CGRect(x: x, y: y, width: w, height: h)
-               scrollView.zoom(to: rect, animated: true)
-           }
-       }
 
         func scrollViewDidZoom(_ scrollView: UIScrollView) {
             guard let imageView = imageView else { return }