[ADD] iOS 13 compatible AsyncImage implementation with cache

AltStore/View Components/AppIconView.swift

@@ -7,6 +7,7 @@
 //
 
 import SwiftUI
+import AsyncImage
 
 struct AppIconView: View {
     let iconUrl: URL?
@@ -16,7 +17,7 @@ struct AppIconView: View {
     }
     
     var body: some View {
-        if let iconUrl, #available(iOS 15.0, *) {
+        if let iconUrl {
             AsyncImage(url: iconUrl) { image in
                 image
                     .resizable()
@@ -25,10 +26,6 @@ struct AppIconView: View {
             }
             .frame(width: size, height: size)
             .clipShape(RoundedRectangle(cornerRadius: cornerRadius, style: .continuous))
-        } else {
-            RoundedRectangle(cornerRadius: cornerRadius, style: .continuous)
-                .background(Color.secondary)
-                .frame(width: size, height: size)
         }
     }
 }

AltStore/Views/App Detail/AppDetailView.swift

@@ -8,6 +8,7 @@
 
 import SwiftUI
 import GridStack
+import AsyncImage
 import AltStoreCore
 
 struct AppDetailView: View {
@@ -39,7 +40,7 @@ struct AppDetailView: View {
     }
     
     var body: some View {
-        ObservableScrollView(scrollOffset: self.$scrollOffset) { proxy in
+        ObservableScrollView(scrollOffset: $scrollOffset) { proxy in
             LazyVStack {
                 headerView
                     .frame(height: headerViewHeight)
@@ -86,29 +87,35 @@ struct AppDetailView: View {
     }
     
     var contentView: some View {
-        VStack(alignment: .leading) {
+        VStack(alignment: .leading, spacing: 24) {
             if let subtitle = storeApp.subtitle {
                 Text(subtitle)
                     .multilineTextAlignment(.center)
                     .frame(maxWidth: .infinity)
-                    .padding()
+                    .padding(.horizontal)
             }
             
             if !storeApp.screenshotURLs.isEmpty {
-                screenshotsView
+                // Equatable: Only reload the view if the screenshots change.
+                // This prevents unnecessary redraws on scroll.
+                AppScreenshotsScrollView(urls: storeApp.screenshotURLs)
+                    .equatable()
             }
             
             Text(storeApp.localizedDescription)
                 .lineLimit(6)
-                .padding()
+                .padding(.horizontal)
             
             currentVersionView
+                .padding(.horizontal)
             
             permissionsView
+                .padding(.horizontal)
             
             // TODO: Add review view
             // Only let users rate the app if it is currently installed!
         }
+        .padding(.vertical)
         .background(
             RoundedRectangle(cornerRadius: contentCornerRadius)
                 .foregroundColor(Color(UIColor.systemBackground))
@@ -116,28 +123,6 @@ struct AppDetailView: View {
         )
     }
     
-    var screenshotsView: some View {
-        ScrollView(.horizontal, showsIndicators: false) {
-            HStack {
-                ForEach(storeApp.screenshotURLs) { url in
-                    if #available(iOS 15.0, *) {
-                        AsyncImage(url: url) { image in
-                            image.resizable()
-                        } placeholder: {
-                            Rectangle()
-                                .foregroundColor(.secondary)
-                        }
-                        .aspectRatio(9/16, contentMode: .fit)
-                        .cornerRadius(8)
-                    }
-                }
-            }
-            .padding(.horizontal)
-        }
-        .frame(height: 400)
-        .shadow(radius: 12)
-    }
-    
     var currentVersionView: some View {
         VStack(alignment: .leading, spacing: 8) {
             HStack(alignment: .bottom) {
@@ -169,7 +154,6 @@ struct AppDetailView: View {
                     .foregroundColor(.secondary)
             }
         }
-        .padding()
     }
     
     var permissionsView: some View {
@@ -199,12 +183,5 @@ struct AppDetailView: View {
             
             Spacer()
         }
-        .padding()
     }
 }
-
-//struct AppDetailView_Previews: PreviewProvider {
-//    static var previews: some View {
-//        AppDetailView()
-//    }
-//}

AltStore/Views/App Detail/AppScreenshotsScrollView.swift

@@ -0,0 +1,49 @@
+//
+//  AppScreenshotsScrollView.swift
+//  SideStore
+//
+//  Created by Fabian Thies on 27.11.22.
+//  Copyright © 2022 SideStore. All rights reserved.
+//
+
+import SwiftUI
+import AsyncImage
+
+
+/// Horizontal ScrollView with an asynchronously loaded image for each screenshot URL
+///
+/// The struct inherits the `Equatable` protocol and implements the respective comparisation function to prevent the view from being constantly re-rendered when a `@State` change in the parent view occurs.
+/// This way, the `AppScreenshotsScrollView` will only be reloaded when the parameters change.
+struct AppScreenshotsScrollView: View {
+    let urls: [URL]
+    var aspectRatio: CGFloat = 9/16
+    var height: CGFloat = 400
+    
+    var body: some View {
+        ScrollView(.horizontal, showsIndicators: false) {
+            HStack {
+                ForEach(urls) { url in
+                    AsyncImage(url: url) { image in
+                        image
+                            .resizable()
+                    } placeholder: {
+                        Rectangle()
+                            .foregroundColor(.secondary)
+                    }
+                    .aspectRatio(aspectRatio, contentMode: .fit)
+                    .cornerRadius(8)
+                }
+            }
+            .padding(.horizontal)
+        }
+        .frame(height: height)
+        .shadow(radius: 12)
+    }
+}
+
+extension AppScreenshotsScrollView: Equatable {
+    /// Prevent re-rendering of the view if the parameters didn't change
+    static func == (lhs: AppScreenshotsScrollView, rhs: AppScreenshotsScrollView) -> Bool {
+        lhs.urls == rhs.urls && lhs.aspectRatio == rhs.aspectRatio && lhs.height == rhs.height
+    }
+}

AltStore/Views/Browse/BrowseAppPreviewView.swift

@@ -7,6 +7,7 @@
 //
 
 import SwiftUI
+import AsyncImage
 import AltStoreCore
 
 struct BrowseAppPreviewView: View {
@@ -23,16 +24,15 @@ struct BrowseAppPreviewView: View {
             if !storeApp.screenshotURLs.isEmpty {
                 HStack {
                     ForEach(storeApp.screenshotURLs.prefix(2)) { url in
-                        if #available(iOS 15.0, *) {
-                            AsyncImage(url: url) { image in
-                                image
-                                    .resizable()
-                                    .aspectRatio(contentMode: .fit)
-                            } placeholder: {
-                                Color(UIColor.secondarySystemBackground)
-                            }
-                            .cornerRadius(8)
+                        AsyncImage(url: url) { image in
+                            image
+                                .resizable()
+                                .aspectRatio(contentMode: .fit)
+                        } placeholder: {
+                            Color(UIColor.secondarySystemBackground)
+                                .aspectRatio(9/16, contentMode: .fit)
                         }
+                        .cornerRadius(8)
                     }
                 }
                 .frame(height: 300)

AltStore/Views/News/NewsItemView.swift

@@ -7,6 +7,7 @@
 //
 
 import SwiftUI
+import AsyncImage
 import AltStoreCore
 
 struct NewsItemView: View {
@@ -53,17 +54,15 @@ struct NewsItemView: View {
             }
             .padding(24)
             
-            if let imageUrl = newsItem.imageURL, #available(iOS 15.0, *) {
-                AsyncImage(
-                    url: imageUrl,
-                    content: { image in
-                        if let image = image.image {
-                            image
-                                .resizable()
-                                .aspectRatio(contentMode: .fit)
-                        }
-                    }
-                )
+            if let imageUrl = newsItem.imageURL {
+                AsyncImage(url: imageUrl) { image in
+                    image
+                        .resizable()
+                        .aspectRatio(contentMode: .fit)
+                } placeholder: {
+                    Color.secondary
+                        .frame(maxWidth: .infinity, maxHeight: 100)
+                }
             }
         }
         .frame(

AltStore/Views/Settings/SettingsView.swift

@@ -7,6 +7,7 @@
 //
 
 import SwiftUI
+import AsyncImage
 import AltStoreCore
 import Intents
 
@@ -86,6 +87,9 @@ struct SettingsView: View {
                     Text("Switch to UIKit")
                 }
 
+                SwiftUI.Button(action: resetImageCache) {
+                    Text("Reset Image Cache")
+                }
             } header: {
                 Text("Debug")
             }
@@ -137,6 +141,19 @@ struct SettingsView: View {
         
         UIApplication.shared.keyWindow?.rootViewController = rootVC
     }
+    
+    func resetImageCache() {
+        do {
+            let url = try FileManager.default.url(
+                for: .cachesDirectory,
+                in: .userDomainMask,
+                appropriateFor: nil,
+                create: true)
+            try FileManager.default.removeItem(at: url.appendingPathComponent("com.zeu.cache", isDirectory: true))
+        } catch let error {
+            fatalError("\(error)")
+        }
+    }
 }
 
 struct SettingsView_Previews: PreviewProvider {
@@ -144,3 +161,5 @@ struct SettingsView_Previews: PreviewProvider {
         SettingsView()
     }
 }
+
+