Add highlighter extension

This commit adds a highlighting extension for web pages. This works on
Safari, and can be used by selecting a text on a page and hitting the
share button at the bottom of the Safari UI

To make this possible, some refactoring was necessary:
1. Several sources were included in the extension bundle to provide access to DamusState, PostView, and the postbox
2. UIApplication.shared was replaced with `this_app`, which routes to UIApplication.shared on the main app bundle,
   and routes to a bogus UIApplication() in the extension. This is needed because UIApplication.shared cannot be used on an extension.
3. Some items were moved to different files to facilitate the transition.

The extension itself uses PostView, and implements views for several edge cases, and tries to handle the note publishing process gracefully.

Changelog-Added: Add highlighter for web pages
Signed-off-by: Daniel D’Aquino <daniel@daquino.me>

damus.xcodeproj/xcshareddata/xcschemes/HighlighterActionExtension.xcscheme

@@ -0,0 +1,101 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1540"
+   wasCreatedForAppExtension = "YES"
+   version = "2.0">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES"
+      buildArchitectures = "Automatic">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "D703D7162C66E47100A400EA"
+               BuildableName = "HighlighterActionExtension.appex"
+               BlueprintName = "HighlighterActionExtension"
+               ReferencedContainer = "container:damus.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "4CE6DEE227F7A08100C66700"
+               BuildableName = "damus.app"
+               BlueprintName = "damus"
+               ReferencedContainer = "container:damus.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      shouldAutocreateTestPlan = "YES">
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = ""
+      selectedLauncherIdentifier = "Xcode.IDEFoundation.Launcher.PosixSpawn"
+      launchStyle = "0"
+      askForAppToLaunch = "Yes"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES"
+      launchAutomaticallySubstyle = "2">
+      <RemoteRunnable
+         runnableDebuggingMode = "1"
+         BundleIdentifier = "com.apple.mobilesafari"
+         RemotePath = "/Library/Developer/CoreSimulator/Volumes/iOS_21F79/Library/Developer/CoreSimulator/Profiles/Runtimes/iOS 17.5.simruntime/Contents/Resources/RuntimeRoot/Applications/MobileSafari.app">
+      </RemoteRunnable>
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "4CE6DEE227F7A08100C66700"
+            BuildableName = "damus.app"
+            BlueprintName = "damus"
+            ReferencedContainer = "container:damus.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES"
+      askForAppToLaunch = "Yes"
+      launchAutomaticallySubstyle = "2">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "4CE6DEE227F7A08100C66700"
+            BuildableName = "damus.app"
+            BlueprintName = "damus"
+            ReferencedContainer = "container:damus.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

damus/Components/InvoiceView.swift

@@ -94,8 +94,8 @@ enum OpenWalletError: Error {
 }
 
 func open_with_wallet(wallet: Wallet.Model, invoice: String) throws {
-    if let url = URL(string: "\(wallet.link)\(invoice)"), UIApplication.shared.canOpenURL(url) {
+    if let url = URL(string: "\(wallet.link)\(invoice)"), this_app.canOpenURL(url) {
-        UIApplication.shared.open(url)
+        this_app.open(url)
     } else {
         guard let store_link = wallet.appStoreLink else {
             throw OpenWalletError.no_wallet_to_open
@@ -105,11 +105,11 @@ func open_with_wallet(wallet: Wallet.Model, invoice: String) throws {
             throw OpenWalletError.store_link_invalid
         }
         
-        guard UIApplication.shared.canOpenURL(url) else {
+        guard this_app.canOpenURL(url) else {
             throw OpenWalletError.system_cannot_open_store_link
         }
         
-        UIApplication.shared.open(url)
+        this_app.open(url)
     }
 }
 
@@ -122,8 +122,3 @@ struct InvoiceView_Previews: PreviewProvider {
             .frame(width: 300, height: 200)
     }
 }
-
-
-func present_sheet(_ sheet: Sheets) {
-    notify(.present_sheet(sheet))
-}

damus/ContentView.swift

@@ -57,6 +57,10 @@ enum Sheets: Identifiable {
     }
 }
 
+func present_sheet(_ sheet: Sheets) {
+    notify(.present_sheet(sheet))
+}
+
 struct ContentView: View {
     let keypair: Keypair
     let appDelegate: AppDelegate?
@@ -877,7 +881,7 @@ func update_filters_with_since(last_of_kind: [UInt32: NostrEvent], filters: [Nos
 
 
 func setup_notifications() {
-    UIApplication.shared.registerForRemoteNotifications()
+    this_app.registerForRemoteNotifications()
     let center = UNUserNotificationCenter.current()
     
     center.getNotificationSettings { settings in

damus/Models/Camera/CameraService.swift

@@ -151,7 +151,7 @@ public class CameraService: NSObject, Identifiable {
 
             DispatchQueue.main.async {
                 self.alertError = AlertError(title: "Camera Access", message: "Damus needs camera and microphone access. Enable in settings.", primaryButtonTitle: "Go to settings", secondaryButtonTitle: nil, primaryAction: {
-                        UIApplication.shared.open(URL(string: UIApplication.openSettingsURLString)!,
+                        this_app.open(URL(string: UIApplication.openSettingsURLString)!,
                                                   options: [:], completionHandler: nil)
 
                 }, secondaryAction: nil)

damus/Util/DamusAliases.swift

@@ -0,0 +1,11 @@
+//
+//  DamusAliases.swift
+//  damus
+//
+//  Created by Daniel D’Aquino on 2024-08-12.
+//
+
+import Foundation
+import UIKit
+
+let this_app: UIApplication = UIApplication.shared

damus/Util/InputDismissKeyboard.swift

@@ -30,7 +30,7 @@ public struct DismissKeyboardOnTap: ViewModifier {
 }
 
 public func end_editing() {
-    UIApplication.shared.connectedScenes
+    this_app.connectedScenes
       .filter {$0.activationState == .foregroundActive}
       .map {$0 as? UIWindowScene}
       .compactMap({$0})

damus/Util/Theme.swift

@@ -11,8 +11,7 @@ import UIKit
 class Theme {
     
     static var safeAreaInsets: UIEdgeInsets? {
-        return UIApplication
+        return this_app
-                .shared
                 .connectedScenes
                 .flatMap { ($0 as? UIWindowScene)?.windows ?? [] }
                 .first { $0.isKeyWindow }?.safeAreaInsets

damus/Views/AddRelayView.swift

@@ -116,7 +116,7 @@ struct AddRelayView: View {
                 }
                 new_relay = ""
 
-                UIApplication.shared.sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
+                this_app.sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
                 
                 dismiss()
             }) {

damus/Views/Muting/AddMuteItemView.swift

@@ -87,7 +87,7 @@ struct AddMuteItemView: View {
 
                 new_text = ""
 
-                UIApplication.shared.sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
+                this_app.sendAction(#selector(UIResponder.resignFirstResponder), to: nil, from: nil, for: nil)
 
                 dismiss()
             }) {

damus/Views/Notifications/DamusAppNotificationView.swift

@@ -96,7 +96,7 @@ struct DamusAppNotificationView: View {
         
         @MainActor
         func open_url(url: URL) {
-            UIApplication.shared.open(url)
+            this_app.open(url)
         }
         
         var body: some View {

damus/Views/Zaps/CustomizeZapView.swift

@@ -356,7 +356,7 @@ struct ZapSheetViewIfPossible: View {
 extension View {
     func hideKeyboard() {
         let resign = #selector(UIResponder.resignFirstResponder)
-        UIApplication.shared.sendAction(resign, to: nil, from: nil, for: nil)
+        this_app.sendAction(resign, to: nil, from: nil, for: nil)
     }
 }
 

highlighter action extension/ActionViewController.swift

@@ -0,0 +1,250 @@
+//
+//  ActionViewController.swift
+//  highlighter action extension
+//
+//  Created by Daniel D’Aquino on 2024-08-09.
+//
+
+import UIKit
+import MobileCoreServices
+import UniformTypeIdentifiers
+import SwiftUI
+
+struct ShareExtensionView: View {
+    @State var highlighter_state: HighlighterState = .loading
+    let extensionContext: NSExtensionContext
+    @State var state: DamusState? = nil
+    @State var signedEvent: String? = nil
+    
+    @State private var selectedText = ""
+    @State private var selectedTextHeight: CGFloat = .zero
+    @State private var selectedTextWidth: CGFloat = .zero
+    
+    var body: some View {
+        VStack(spacing: 15) {
+            if let state {
+                switch self.highlighter_state {
+                    case .loading:
+                        ProgressView()
+                    case .no_highlight_text:
+                        Group {
+                            Text("No text selected", comment: "Title indicating that a highlight cannot be posted because no text was selected.")
+                                .font(.largeTitle)
+                                .multilineTextAlignment(.center)
+                                .padding()
+                            Text("You cannot post a highlight because you have selected no text on the page! Please close this, select some text, and try again.", comment: "Label explaining a highlight cannot be made because there was no selected text, and some instructions on how to resolve the issue")
+                                .multilineTextAlignment(.center)
+                            Button(action: {
+                                self.done()
+                            }, label: {
+                                Text("Close", comment: "Button label giving the user the option to close the sheet from which they were trying to post a highlight")
+                            })
+                            .foregroundStyle(.secondary)
+                        }
+                    case .not_logged_in:
+                        Group {
+                            Text("Not logged in", comment: "Title indicating that a highlight cannot be posted because the user is not logged in.")
+                                .font(.largeTitle)
+                                .multilineTextAlignment(.center)
+                                .padding()
+                            Text("You cannot post a highlight because you are not logged in with a private key! Please close this, login with a private key (or nsec), and try again.", comment: "Label explaining a highlight cannot be made because the user is not logged in")
+                                .multilineTextAlignment(.center)
+                            Button(action: {
+                                self.done()
+                            }, label: {
+                                Text("Close", comment: "Button label giving the user the option to close the sheet from which they were trying to post a highlight")
+                            })
+                            .foregroundStyle(.secondary)
+                        }
+                    case .loaded(let highlighted_text, let source_url):
+                        PostView(
+                            action: .highlighting(HighlightContentDraft(selected_text: highlighted_text, source: .external_url(source_url))),
+                            damus_state: state
+                        )
+                    case .failed(let error):
+                        Group {
+                            Text("Error", comment: "Title indicating that an error has occurred.")
+                                .font(.largeTitle)
+                                .multilineTextAlignment(.center)
+                                .padding()
+                            Text("An unexpected error occurred. Please contact Damus support via [Nostr](damus:npub18m76awca3y37hkvuneavuw6pjj4525fw90necxmadrvjg0sdy6qsngq955) or [email](support@damus.io) with the error message below.", comment: "Label explaining there was an error, and suggesting next steps")
+                                .multilineTextAlignment(.center)
+                            Text("Error: \(error)")
+                            Button(action: {
+                                self.done()
+                            }, label: {
+                                Text("Close", comment: "Button label giving the user the option to close the sheet from which they were trying to post a highlight")
+                            })
+                            .foregroundStyle(.secondary)
+                        }
+                    case .posted(event: let event):
+                        Group {
+                            Image(systemName: "checkmark.circle.fill")
+                                .resizable()
+                                .frame(width: 60, height: 60)
+                            Text("Posted", comment: "Title indicating that the user has posted a highlight successfully")
+                                .font(.largeTitle)
+                                .multilineTextAlignment(.center)
+                                .padding(.bottom)
+                            
+                            Link(destination: URL(string: "damus:\(event.id.bech32)")!, label: {
+                                Text("Go to the app", comment: "Button label giving the user the option to go to the app after posting a highlight")
+                            })
+                            .buttonStyle(GradientButtonStyle())
+                            Button(action: {
+                                self.done()
+                            }, label: {
+                                Text("Close", comment: "Button label giving the user the option to close the sheet from which they posted a highlight")
+                            })
+                            .foregroundStyle(.secondary)
+                        }
+                    case .cancelled:
+                        Group {
+                            Text("Cancelled", comment: "Title indicating that the user has cancelled.")
+                                .font(.largeTitle)
+                                .padding()
+                            Button(action: {
+                                self.done()
+                            }, label: {
+                                Text("Close", comment: "Button label giving the user the option to close the sheet from which they were trying to post a highlight")
+                            })
+                            .foregroundStyle(.secondary)
+                        }
+                    case .posting:
+                        Group {
+                            ProgressView()
+                                .frame(width: 20, height: 20)
+                            Text("Posting", comment: "Title indicating that the highlight post is being published to the network")
+                                .font(.largeTitle)
+                                .multilineTextAlignment(.center)
+                                .padding(.bottom)
+                            Text("Your highlight is being broadcasted to the network. Please wait.", comment: "Label explaining there their highlight publishing action is in progress")
+                                .multilineTextAlignment(.center)
+                                .padding()
+                        }
+                }
+            }
+        }
+        .onAppear(perform: {
+            self.loadSharedUrl()
+            guard let keypair = get_saved_keypair() else { return }
+            guard keypair.privkey != nil else {
+                self.highlighter_state = .not_logged_in
+                return
+            }
+            self.state = DamusState(keypair: keypair)
+        })
+        .onChange(of: self.highlighter_state) {
+            if case .cancelled = highlighter_state {
+                self.done()
+            }
+        }
+        .onReceive(handle_notify(.post)) { post_notification in
+            switch post_notification {
+                case .post(let post):
+                    self.post(post)
+                case .cancel:
+                    self.highlighter_state = .cancelled
+            }
+        }
+    }
+    
+    func loadSharedUrl() {
+        guard
+           let extensionItem = extensionContext.inputItems.first as? NSExtensionItem,
+           let itemProvider = extensionItem.attachments?.first else {
+            self.highlighter_state = .failed(error: "Can't get itemProvider")
+            return
+        }
+        
+        let propertyList = UTType.propertyList.identifier
+        if itemProvider.hasItemConformingToTypeIdentifier(propertyList) {
+            itemProvider.loadItem(forTypeIdentifier: propertyList, options: nil, completionHandler: { (item, error) -> Void in
+                guard let dictionary = item as? NSDictionary else { return }
+                if error != nil {
+                    self.highlighter_state = .failed(error: "Error loading plist item: \(error?.localizedDescription ?? "Unknown")")
+                    return
+                }
+                OperationQueue.main.addOperation {
+                    if let results = dictionary[NSExtensionJavaScriptPreprocessingResultsKey] as? NSDictionary,
+                       let urlString = results["URL"] as? String,
+                       let selection = results["selectedText"] as? String,
+                       let url = URL(string: urlString) {
+                        guard selection != "" else {
+                            self.highlighter_state = .no_highlight_text
+                            return
+                        }
+                        self.highlighter_state = .loaded(highlighted_text: selection, source_url: url)
+                    }
+                    else {
+                        self.highlighter_state = .failed(error: "Cannot load results")
+                    }
+                }
+            })
+        }
+        else {
+            self.highlighter_state = .failed(error: "No plist detected")
+        }
+    }
+    
+    func post(_ post: NostrPost) {
+        self.highlighter_state = .posting
+        guard let state else {
+            self.highlighter_state = .failed(error: "Damus state not initialized")
+            return
+        }
+        guard let full_keypair = state.keypair.to_full() else {
+            self.highlighter_state = .not_logged_in
+            return
+        }
+        guard let posted_event = post.to_event(keypair: full_keypair) else {
+            self.highlighter_state = .failed(error: "Cannot convert post data into a nostr event")
+            return
+        }
+        state.postbox.send(posted_event, on_flush: .once({ flushed_event in
+            if flushed_event.event.id == posted_event.id {
+                DispatchQueue.main.asyncAfter(deadline: .now() + 1, execute: {  // Offset labor perception bias
+                    self.highlighter_state = .posted(event: flushed_event.event)
+                })
+            }
+            else {
+                self.highlighter_state = .failed(error: "Flushed event is not the event we just tried to post.")
+            }
+        }))
+    }
+    
+    func done() {
+        self.extensionContext.completeRequest(returningItems: [], completionHandler: nil)
+    }
+    
+    enum HighlighterState: Equatable {
+        case loading
+        case no_highlight_text
+        case not_logged_in
+        case loaded(highlighted_text: String, source_url: URL)
+        case posting
+        case posted(event: NostrEvent)
+        case cancelled
+        case failed(error: String)
+    }
+}
+
+class ActionViewController: UIViewController {
+    override func viewDidLoad() {
+        super.viewDidLoad()
+        self.view.tintColor = UIColor(DamusColors.purple)
+        
+        DispatchQueue.main.async {
+            let contentView = UIHostingController(rootView: ShareExtensionView(extensionContext: self.extensionContext!))
+            self.addChild(contentView)
+            self.view.addSubview(contentView.view)
+            
+            // set up constraints
+            contentView.view.translatesAutoresizingMaskIntoConstraints = false
+            contentView.view.topAnchor.constraint(equalTo: self.view.topAnchor).isActive = true
+            contentView.view.bottomAnchor.constraint (equalTo: self.view.bottomAnchor).isActive = true
+            contentView.view.leftAnchor.constraint(equalTo: self.view.leftAnchor).isActive = true
+            contentView.view.rightAnchor.constraint (equalTo: self.view.rightAnchor).isActive = true
+        }
+    }
+}

highlighter action extension/HighlighterExtensionAliases.swift

@@ -0,0 +1,11 @@
+//
+//  HighlighterExtensionAliases.swift
+//  highlighter action extension
+//
+//  Created by Daniel D’Aquino on 2024-08-12.
+//
+
+import Foundation
+import UIKit
+
+let this_app: UIApplication = UIApplication()

highlighter action extension/Info.plist

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>NSExtension</key>
+	<dict>
+		<key>NSExtensionAttributes</key>
+		<dict>
+			<key>NSExtensionActivationRule</key>
+			<string>TRUEPREDICATE</string>
+			<key>NSExtensionJavaScriptPreprocessingFile</key>
+			<string>getSelection</string>
+			<key>NSExtensionServiceAllowsFinderPreviewItem</key>
+			<true/>
+			<key>NSExtensionServiceAllowsTouchBarItem</key>
+			<true/>
+			<key>NSExtensionServiceFinderPreviewIconName</key>
+			<string>NSActionTemplate</string>
+			<key>NSExtensionServiceTouchBarBezelColorName</key>
+			<string>TouchBarBezel</string>
+			<key>NSExtensionServiceTouchBarIconName</key>
+			<string>NSActionTemplate</string>
+		</dict>
+		<key>NSExtensionPointIdentifier</key>
+		<string>com.apple.ui-services</string>
+		<key>NSExtensionPrincipalClass</key>
+		<string>$(PRODUCT_MODULE_NAME).ActionViewController</string>
+	</dict>
+</dict>
+</plist>

highlighter action extension/Media.xcassets/AppIconExtension.appiconset/Contents.json

@@ -0,0 +1,14 @@
+{
+  "images" : [
+    {
+      "filename" : "highlighter.png",
+      "idiom" : "universal",
+      "platform" : "ios",
+      "size" : "1024x1024"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

highlighter action extension/Media.xcassets/Contents.json

@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

highlighter action extension/Media.xcassets/TouchBarBezel.colorset/Contents.json

@@ -0,0 +1,14 @@
+{
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  },
+  "colors" : [
+    {
+      "idiom" : "mac",
+      "color" : {
+        "reference" : "systemPurpleColor"
+      }
+    }
+  ]
+}

highlighter action extension/getSelection.js

@@ -0,0 +1,12 @@
+var Share = function() {};
+
+Share.prototype = {
+  run: function(arguments) {
+    arguments.completionFunction({"URL": document.URL, "selectedText": document.getSelection().toString()});
+  },
+  finalize: function(arguments) {
+    // alert shared!
+  }
+};
+
+var ExtensionPreprocessingJS = new Share

highlighter action extension/highlighter action extension.entitlements

@@ -0,0 +1,18 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>com.apple.security.app-sandbox</key>
+	<true/>
+	<key>com.apple.security.application-groups</key>
+	<array>
+		<string>group.com.damus</string>
+	</array>
+	<key>com.apple.security.network.client</key>
+	<true/>
+	<key>keychain-access-groups</key>
+	<array>
+		<string>$(AppIdentifierPrefix)com.jb55.damus2</string>
+	</array>
+</dict>
+</plist>