fix: ttsSetVoice now works on both platforms

Author: ddfreiling

flutter_readium/android/src/main/kotlin/dk/nota/flutter_readium/PublicationChannel.kt

@@ -1,3 +1,5 @@
+@file:OptIn(ExperimentalReadiumApi::class)
+
 package dk.nota.flutter_readium
 
 import android.app.Application
@@ -29,19 +31,16 @@ import org.readium.r2.shared.util.resource.filename
 import org.readium.navigator.media.tts.android.AndroidTtsPreferences
 import org.readium.r2.shared.ExperimentalReadiumApi
 import org.readium.r2.shared.publication.Locator
+import org.readium.r2.shared.publication.services.content.DefaultContentService
+import org.readium.r2.shared.publication.services.content.contentServiceFactory
+import org.readium.r2.shared.publication.services.content.iterators.HtmlResourceContentIterator
+import org.readium.r2.shared.publication.services.search.StringSearchService
+import org.readium.r2.shared.publication.services.search.searchServiceFactory
 
 private const val TAG = "PublicationChannel"
 
 internal const val publicationChannelName = "dk.nota.flutter_readium/main"
-
-private var readium: Readium? = null
-
-// TODO: Do we still want to use this?
-private var publication: Publication? = null
-internal fun publicationFromHandle(): Publication? {
-  return publication
-}
-
+internal var readium: Readium? = null
 internal var currentReadiumReaderView: ReadiumReaderView? = null
 
 // Collection of publications init to empty
@@ -67,6 +66,13 @@ private suspend fun assetToPublication(
         container = TransformingContainer(container) { _: Url, resource: Resource ->
           resource.injectScriptsAndStyles()
         }
+        // TODO: Temporary fix for missing service factories for WebPubs with HTML content.
+        servicesBuilder.contentServiceFactory = DefaultContentService.createFactory(
+          resourceContentIteratorFactories = listOf(
+            HtmlResourceContentIterator.Factory()
+          )
+        )
+        servicesBuilder.searchServiceFactory = StringSearchService.createDefaultFactory()
       })
         .getOrElse { err: OpenError ->
           Log.e(TAG, "Error opening publication: $err")
@@ -97,7 +103,6 @@ private suspend fun openPublication(
     }
     Log.d(TAG, "Opened publication = ${pub.metadata.identifier}")
     publications[pub.metadata.identifier ?: pubUrl.toString()] = pub
-    publication = pub
     // Manifest must now be manually turned into JSON
     val pubJsonManifest = pub.manifest.toJSON().toString().replace("\\/", "/")
     CoroutineScope(Dispatchers.Main).launch {
@@ -156,9 +161,21 @@ internal class PublicationMethodCallHandler(private val context: Context) :
           val args = call.arguments as Map<String, Any>?
           val ttsPrefs = if (args != null) androidTtsPreferencesFromMap(args) else AndroidTtsPreferences()
 
-          ttsViewModel = TTSViewModel(pluginAppContext as Application, publication!!, currentReadiumReaderView!!, ttsPrefs)
-          ttsViewModel?.initNavigator()
-          result.success(null)
+          val pubId = currentReadiumReaderView?.currentPublicationIdentifier
+          if (pubId == null || !publications.contains(pubId)) {
+            Log.e(TAG, "ttsEnable: Cannot enable TTS for un-opened publication. PubId=$pubId")
+          }
+          val publication = publicationFromIdentifier(pubId!!)
+
+
+          try {
+            ttsViewModel = TTSViewModel(pluginAppContext as Application, publication!!, ttsPrefs)
+            ttsViewModel?.initNavigator()
+            result.success(null)
+          } catch (e: Exception) {
+            Log.e(TAG, "ttsEnable: Failed to create TTSViewModel (likely navigator). PubId=$pubId")
+            result.error("ttsEnable", "Failed to create TTSModel", e.message)
+          }
         }
 
         "ttsSetPreferences" -> {
@@ -240,34 +257,26 @@ internal class PublicationMethodCallHandler(private val context: Context) :
           result.success(null)
         }
 
-        "get" -> {
+        "getLinkContent" -> {
           try {
             val args = call.arguments as List<Any?>
-            val isLink = args[0] as Boolean
-            val linkData = args[1] as String
-            val asString = args[2] as Boolean
-            val link: Link
-            if (isLink) {
-              link = Link.fromJSON(JSONObject(linkData))!!
-            } else {
-              val url = Url.fromEpubHref(linkData) ?: run {
-                Log.e(TAG, "get: invalid EPUB href $linkData")
-                throw Exception("get: invalid EPUB href $linkData")
-              }
-              link = Link(url)
+            val pubId = args[0] as String
+            val linkStr = args[1] as String
+            val asString = args[2] as? Boolean ?: true
+            val link = Link.fromJSON(JSONObject(linkStr))
+            val publication = publications[pubId]
+
+            if (publication == null || link == null) {
+              throw Exception("getLinkContent: failed to get resource. Missing pub or link: $publication, $link")
             }
+
             Log.d(TAG, "Use publication = $publication")
-            // TODO Debug why the next line crashed with a NullPointerException one time. Probably
-            // somehow related to the server being re-indexed. Was an invalid publication somehow
-            // created, or was a valid publication disposed and then used?
 
-            val resource = publication!!.get(link) ?: run {
-              Log.e(TAG, "get: failed to get resource via link $link")
-              throw Exception("failed to get resource via link $link")
+            val resource = publication.get(link) ?: run {
+              throw Exception("getLinkContent: failed to find pub resource via link: pubId=${publication.metadata.identifier},link=$link")
             }
             val resourceBytes = resource.read().getOrElse {
-              Log.e(TAG, "get: invalid EPUB href $linkData")
-              throw Exception("get: invalid EPUB href $linkData")
+              throw Exception("getLinkContent: failed to read resource. ${it.message}")
             }
 
             CoroutineScope(Dispatchers.Main).launch {

flutter_readium/android/src/main/kotlin/dk/nota/flutter_readium/Readium.kt

@@ -7,24 +7,13 @@
 package dk.nota.flutter_readium
 
 import android.content.Context
-import android.util.Log
+import org.readium.r2.shared.ExperimentalReadiumApi
 // import org.readium.adapter.pdfium.document.PdfiumDocumentFactory
 // import org.readium.r2.lcp.LcpError
 // import org.readium.r2.lcp.LcpService
 // import org.readium.r2.lcp.auth.LcpDialogAuthentication
-import org.readium.r2.shared.publication.Publication
-import org.readium.r2.shared.publication.presentation.presentation
-import org.readium.r2.shared.publication.services.content.contentServiceFactory
-import org.readium.r2.shared.util.Try
-import org.readium.r2.shared.util.Url
-//import org.readium.r2.shared.util.DebugError
-//import org.readium.r2.shared.util.Try
 import org.readium.r2.shared.util.asset.AssetRetriever
 import org.readium.r2.shared.util.http.DefaultHttpClient
-import org.readium.r2.shared.util.resource.Resource
-import org.readium.r2.shared.util.resource.TransformingContainer
-import org.readium.r2.shared.util.resource.TransformingResource
-import org.readium.r2.shared.util.resource.filename
 import org.readium.r2.streamer.PublicationOpener
 import org.readium.r2.streamer.parser.DefaultPublicationParser
 

flutter_readium/android/src/main/kotlin/dk/nota/flutter_readium/ReadiumReaderView.kt

@@ -40,9 +40,7 @@ internal class ReadiumReaderView(
   private var userPreferences = EpubPreferences()
   private var initialLocations: Locator.Locations?
 
-  // Create a CoroutineScope using the Main (UI) dispatcher
-  // TODO: What was/is this used for?
-  private var scope = CoroutineScope(Dispatchers.Main)
+  val currentPublicationIdentifier: String
 
   override fun getView(): View {
     //Log.d(TAG, "::getView")
@@ -82,6 +80,7 @@ internal class ReadiumReaderView(
     val initialPreferences =
       if (initPrefsMap == null) null else epubPreferencesFromMap(initPrefsMap, null)
     Log.d(TAG, "publication = $publication")
+    currentPublicationIdentifier = pubIdentifier
 
     initialLocations = initialLocator?.locations?.let { if (canScroll(it)) it else null }
     readiumView = EpubNavigatorView(context, publication, initialLocator, initialPreferences, this)
@@ -315,6 +314,7 @@ internal class ReadiumReaderView(
         }
         "dispose" -> {
           readiumView.removeAllViews()
+          currentReadiumReaderView = null
           initialLocations = null
           eventSink = null
           eventChannel.setStreamHandler(null)

flutter_readium/android/src/main/kotlin/dk/nota/flutter_readium/TTSViewModel.kt

@@ -39,7 +39,6 @@ private const val TTS_DECORATION_ID_CURRENT_RANGE = "tts-range"
 internal class TTSViewModel(
   private val appContext: Context,
   private val publication: Publication,
-  private val reader: ReadiumReaderView,
   private var preferences: AndroidTtsPreferences = AndroidTtsPreferences()
 ) {
   private val jobs = mutableListOf<Job>()
@@ -65,7 +64,7 @@ internal class TTSViewModel(
       }
     }
     CoroutineScope(Dispatchers.Main).async {
-      val firstVisibleLocator = this@TTSViewModel.reader.getFirstVisibleLocator()
+      val firstVisibleLocator = currentReadiumReaderView?.getFirstVisibleLocator()
 
       val ttsNavigator = factory.createNavigator(listener, firstVisibleLocator, preferences).getOrElse {
         Log.e(TAG, "ttsEnable: failed to create navigator: $it")
@@ -106,10 +105,14 @@ internal class TTSViewModel(
   }
 
   fun setPreferredVoice(voiceId: String, lang: String?) {
+    // Modify existing map of voice overrides, in case user sets multiple preferred voices.
+    val voices = this.preferences.voices?.toMutableMap() ?: mutableMapOf()
     // If no lang provided, assume client wants to override currently spoken language.
     val language = if (lang != null) Language(lang) else this.ttsNavigator?.settings?.value?.language
-    val voices = if (language != null) mapOf(language to AndroidTtsEngine.Voice.Id(voiceId)) else emptyMap()
-    this.updatePreferences(AndroidTtsPreferences(voices = voices))
+    if (language != null) {
+      voices[language] = AndroidTtsEngine.Voice.Id(voiceId)
+      this.updatePreferences(AndroidTtsPreferences(voices = voices))
+    }
   }
 
   val voices: Set<AndroidTtsEngine.Voice>
@@ -155,7 +158,7 @@ internal class TTSViewModel(
           )
         }
         CoroutineScope(Dispatchers.Main).launch {
-          this@TTSViewModel.reader.applyDecorations(decorations, group = "tts")
+          currentReadiumReaderView?.applyDecorations(decorations, group = "tts")
         }
       }
       .launchIn(CoroutineScope(Dispatchers.IO))
@@ -167,7 +170,7 @@ internal class TTSViewModel(
       .map { it.tokenLocator ?: it.utteranceLocator }
       .distinctUntilChanged()
       .onEach { locator ->
-        this@TTSViewModel.reader.justGoToLocator(locator, animated = true)
+        currentReadiumReaderView?.justGoToLocator(locator, animated = true)
       }
       .launchIn(CoroutineScope(Dispatchers.Main))
       .let { jobs.add(it) }

flutter_readium/example/lib/state/player_controls_bloc.dart

@@ -117,7 +117,7 @@ class PlayerControlsBloc extends Bloc<PlayerControlsEvent, PlayerControlsState>
       // Change to first voice matching "da-DK" language.
       final daVoice = voices.firstWhereOrNull((l) => l.language == "da-DK");
       if (daVoice != null) {
-        await instance.ttsSetVoice(daVoice.identifier);
+        await instance.ttsSetVoice(daVoice.identifier, null);
       }
     });
   }

flutter_readium/ios/flutter_readium/Sources/flutter_readium/FlutterReadiumPlugin.swift

@@ -120,6 +120,45 @@ public class FlutterReadiumPlugin: NSObject, FlutterPlugin, ReadiumShared.Warnin
             }
         }
       }
+    case "getLinkContent":
+      let args = call.arguments as! [Any?]
+      //let asString = args[2] as? Bool ?? true
+      let asString = true
+      guard let pubId = args[0] as? String,
+            let linkStr = args[1] as? String,
+            let publication = getPublicationByIdentifier(pubId),
+            let link = try? Link(fromJsonString: linkStr) else {
+        return result(FlutterError.init(
+          code: "getLinkContent",
+          message: "Failed to get link content",
+          details: nil))
+      }
+      Task.detached(priority: .background) {
+        let resource = publication.get(link)
+        do {
+          if (asString) {
+            let linkContent = try await resource?.readAsString(encoding: .utf8).get()
+            await MainActor.run {
+              result(linkContent)
+            }
+          } else {
+            let data = try await resource!.read().get()
+            await MainActor.run {
+              result(FlutterStandardTypedData(bytes: data))
+            }
+          }
+        } catch let err {
+          await MainActor.run {
+            print("\(TAG).getLinkContent exception: \(err)")
+            result(
+              FlutterError.init(
+                code: "getLinkContent",
+                message: err.localizedDescription,
+                details: "Something went wrong fetching link content."))
+          }
+        }
+      }
+      
     case "ttsEnable":
       Task.detached(priority: .high) {
         do {
@@ -176,7 +215,9 @@ public class FlutterReadiumPlugin: NSObject, FlutterPlugin, ReadiumShared.Warnin
       let availableVocies = self.ttsGetAvailableVoices()
       result(availableVocies.map { $0.jsonString } )
     case "ttsSetVoice":
-      let voiceIdentifier = call.arguments as! String
+      let args = call.arguments as! [Any?]
+      let voiceIdentifier = args[0] as! String
+      // TODO: language might be supplied as args[1], ignored on iOS for now.
       do {
         try self.ttsSetVoice(voiceIdentifier: voiceIdentifier)
         result(nil)

flutter_readium/ios/flutter_readium/Sources/flutter_readium/ReadiumExtensions.swift

@@ -8,16 +8,16 @@ func clamp<T>(_ value: T, minValue: T, maxValue: T) -> T where T : Comparable {
     return min(max(value, minValue), maxValue)
 }
 
-extension Resource {
-  var propertiesSync: ResourceProperties {
-    let semaphore = DispatchSemaphore(value: 0)
-    var props: ResourceProperties? = nil
-    Task {
-      props = await properties().getOrNil()
-      semaphore.signal()
+extension Link {
+  init(fromJsonString jsonString: String) throws {
+    do {
+      let jsonObj = try JSONSerialization.jsonObject(with: jsonString.data(using: .utf8)!)
+      try self.init(json: jsonObj)
+    } catch {
+        print("Invalid Link object: \(error)")
+        throw JSONError.parsing(Self.self)
     }
-    semaphore.wait()
-    return props ?? ResourceProperties()
+    
   }
 }
 

flutter_readium/test/flutter_readium_test.dart

@@ -110,7 +110,7 @@ class MockFlutterReadiumPlatform with MockPlatformInterfaceMixin implements Flut
   }
 
   @override
-  Future<void> ttsSetVoice(String voiceIdentifier) {
+  Future<void> ttsSetVoice(String voiceIdentifier, String? forLanguage) {
     // TODO: implement ttsSetVoice
     throw UnimplementedError();
   }

flutter_readium_platform_interface/lib/flutter_readium_platform_interface.dart

@@ -72,7 +72,7 @@ abstract class FlutterReadiumPlatform extends PlatformInterface {
   Future<void> ttsPrevious() => throw UnimplementedError('ttsPrevious() has not been implemented');
   Future<List<ReaderTTSVoice>> ttsGetAvailableVoices() =>
       throw UnimplementedError('ttsGetAvailableVoices() has not been implemented');
-  Future<void> ttsSetVoice(String voiceIdentifier) =>
+  Future<void> ttsSetVoice(String voiceIdentifier, String? forLanguage) =>
       throw UnimplementedError('ttsSetVoice() has not been implemented');
   Future<void> ttsSetDecorationStyle(
     ReaderDecorationStyle? utteranceDecoration,

flutter_readium_platform_interface/lib/method_channel_flutter_readium.dart

@@ -122,11 +122,15 @@ class MethodChannelFlutterReadium extends FlutterReadiumPlatform {
   }
 
   @override
-  Future<void> ttsSetVoice(String voiceIdentifier) async {
-    await methodChannel.invokeMethod('ttsSetVoice', voiceIdentifier);
+  Future<void> ttsSetVoice(String voiceIdentifier, String? forLanguage) async {
+    await methodChannel.invokeMethod('ttsSetVoice', [voiceIdentifier, forLanguage]);
   }
 
   @override
   Future<void> ttsSetPreferences(TTSPreferences preferences) =>
       methodChannel.invokeMethod('ttsSetPreferences', preferences.toMap());
+
+  @override
+  Future<String?> getLinkContent(final String pubIdentifier, final Link link) =>
+      methodChannel.invokeMethod<String>('getLinkContent', [pubIdentifier, jsonEncode(link.toJson())]);
 }