[ADD] News, Browse and Settings views ported to SwiftUI

This commit contains WIP SwiftUI versions of most of the views in SideStore.

AltStore/Views/Browse/SourcesView.swift

@@ -0,0 +1,188 @@
+//
+//  SourcesView.swift
+//  SideStore
+//
+//  Created by Fabian Thies on 20.11.22.
+//  Copyright © 2022 Fabian Thies. All rights reserved.
+//
+
+import SwiftUI
+import AltStoreCore
+import CoreData
+
+struct SourcesView: View {
+    
+    @Environment(\.managedObjectContext)
+    var managedObjectContext
+    
+    @SwiftUI.FetchRequest(sortDescriptors: [
+        NSSortDescriptor(keyPath: \Source.name, ascending: true),
+        NSSortDescriptor(keyPath: \Source.sourceURL, ascending: true),
+        NSSortDescriptor(keyPath: \Source.identifier, ascending: true)
+    ])
+    var installedSources: FetchedResults<Source>
+    
+    
+    @State var isShowingAddSourceAlert = false
+    @State var sourceToConfirm: FetchedSource?
+    
+    var body: some View {
+        ScrollView {
+            LazyVStack(alignment: .leading, spacing: 24) {
+                // Installed Sources
+                LazyVStack(alignment: .leading, spacing: 12) {
+                    Text("Sources control what apps are available to download through SideStore.")
+                        .font(.callout)
+                        .foregroundColor(.secondary)
+                    
+                    ForEach(installedSources, id: \.identifier) { source in
+                        
+                        VStack(alignment: .leading) {
+                            Text(source.name)
+                                .bold()
+                            
+                            Text(source.sourceURL.absoluteString)
+                                .font(.callout)
+                                .foregroundColor(.secondary)
+                        }
+                        .frame(maxWidth: .infinity, alignment: .leading)
+                        .padding()
+                        .background(Color.accentColor.opacity(0.5))
+                        .clipShape(RoundedRectangle(cornerRadius: 30, style: .circular))
+                        .if(source.identifier != Source.altStoreIdentifier) { view in
+                            view.contextMenu(ContextMenu(menuItems: {
+                                SwiftUI.Button {
+                                    self.removeSource(source)
+                                } label: {
+                                    Label("Remove", systemImage: "trash")
+                                }
+                            }))
+                        }
+                    }
+                }
+                
+                // Trusted Sources
+                LazyVStack(alignment: .leading) {
+                    Text("Trusted Sources")
+                        .font(.title3)
+                        .bold()
+                    
+                    Text("SideStore has reviewed these sources to make sure they meet our safety standards.")
+                        .font(.callout)
+                        .foregroundColor(.secondary)
+                    
+                    
+                }
+            }
+            .padding()
+        }
+        .navigationTitle("Sources")
+        .toolbar {
+            ToolbarItem(placement: .navigationBarLeading) {
+                SwiftUI.Button {
+                    self.isShowingAddSourceAlert = true
+                } label: {
+                    Image(systemName: "plus")
+                }
+                .sheet(isPresented: self.$isShowingAddSourceAlert) {
+                    NavigationView {
+                        AddSourceView(continueHandler: fetchSource(with:))
+                    }
+                }
+                .sheet(item: self.$sourceToConfirm) { source in
+                    if #available(iOS 16.0, *) {
+                        NavigationView {
+                            ConfirmAddSourceView(fetchedSource: source, confirmationHandler: addSource(_:)) {
+                                self.sourceToConfirm = nil
+                            }
+                        }
+                        .presentationDetents([.medium])
+                    }
+                }
+            }
+            
+            ToolbarItem(placement: .navigationBarTrailing) {
+                SwiftUI.Button {
+                    self.isShowingAddSourceAlert = false
+                } label: {
+                    Text("Done").bold()
+                }
+            }
+        }
+    }
+    
+    
+    func fetchSource(with urlText: String) {
+        self.isShowingAddSourceAlert = false
+        
+        guard let url = URL(string: urlText) else {
+            return
+        }
+        
+        AppManager.shared.fetchSource(sourceURL: url) { result in
+            
+            switch result {
+            case let .success(source):
+                self.sourceToConfirm = FetchedSource(source: source)
+            case let .failure(error):
+                print(error)
+            }
+        }
+    }
+    
+    func addSource(_ source: FetchedSource) {
+        source.context?.perform {
+            do {
+                try source.context?.save()
+            } catch {
+                print(error)
+            }
+        }
+        
+        self.sourceToConfirm = nil
+    }
+    
+    func removeSource(_ source: Source) {
+        DatabaseManager.shared.persistentContainer.performBackgroundTask { (context) in
+            let source = context.object(with: source.objectID) as! Source
+            context.delete(source)
+            
+            do {
+                try context.save()
+            } catch {
+                print(error)
+            }
+        }
+    }
+}
+
+struct SourcesListView_Previews: PreviewProvider {
+    static var previews: some View {
+        SourcesView()
+    }
+}
+
+
+extension Source: Identifiable {
+    public var id: String {
+        self.identifier
+    }
+}
+
+
+struct FetchedSource: Identifiable {
+    let source: Source
+    let context: NSManagedObjectContext?
+    
+    var id: String {
+        source.identifier
+    }
+    
+    init?(source: Source) {
+        guard let context = source.managedObjectContext else{
+            return nil
+        }
+        self.source = source
+        self.context = context
+    }
+}