feat: adding the max input length

Author: Mhp23

android/src/main/java/com/speech/SpeechModule.kt

@@ -29,6 +29,12 @@ class SpeechModule(reactContext: ReactApplicationContext) :
     return NAME
   }
 
+  override fun getTypedExportedConstants(): MutableMap<String, Any> {
+    return mutableMapOf(
+      "maxInputLength" to maxInputLength
+    )
+  }
+
   companion object {
     const val NAME = "Speech"
 
@@ -41,7 +47,7 @@ class SpeechModule(reactContext: ReactApplicationContext) :
     )
   }
   private val queueLock = Any()
-
+  private val maxInputLength = TextToSpeech.getMaxSpeechInputLength()
   private val isSupportedPausing = Build.VERSION.SDK_INT >= Build.VERSION_CODES.O
 
   private lateinit var synthesizer: TextToSpeech
@@ -480,6 +486,13 @@ class SpeechModule(reactContext: ReactApplicationContext) :
       promise.reject("speech_error", "Text cannot be null")
       return
     }
+    if (text.length > maxInputLength) {
+      promise.reject(
+        "speech_error",
+        "Text exceeds the maximum input length of $maxInputLength characters"
+      )
+      return
+    }
     ensureInitialized(promise) {
       isDucking = globalOptions["ducking"] as? Boolean ?: false
       activateDuckingSession()
@@ -501,8 +514,15 @@ class SpeechModule(reactContext: ReactApplicationContext) :
       promise.reject("speech_error", "Text cannot be null")
       return
     }
+    if (text.length > maxInputLength) {
+      promise.reject(
+        "speech_error",
+        "Text exceeds the maximum input length of $maxInputLength characters"
+      )
+      return
+    }
     ensureInitialized(promise) {
-      val validatedOptions = getValidatedOptions(options) 
+      val validatedOptions = getValidatedOptions(options)
       isDucking = validatedOptions["ducking"] as? Boolean ?: false
       activateDuckingSession()
       val utteranceId = getUniqueID()

docs/USAGE.md

@@ -5,6 +5,7 @@
     - [Bare React Native](#bare-react-native)
     - [Expo](#expo)
   - [API Overview](#api-overview)
+    - [Constants](#constants)
     - [Getting Available Voices](#getting-available-voices)
     - [Engine Management (Android)](#engine-management-android)
       - [Get Available Engines](#get-available-engines)
@@ -79,6 +80,18 @@ import Speech from '@mhpdev/react-native-speech';
 
 ---
 
+### Constants
+
+The `Speech` class static constants.
+
+**Values**
+
+`maxInputLength`
+
+The **maximum number of characters** allowed in a single call to the speak methods.
+
+Android enforces this limit, which is determined by `TextToSpeech.getMaxSpeechInputLength`. If your text exceeds this limit, you must manually split it into smaller utterances on the JavaScript side. (_iOS has no synthesis system limit, and by default, the speech class returns `Number.MAX_VALUE`_)
+
 ### Getting Available Voices
 
 Retrieve a list of all available voices on the device. Optionally, you can filter voices by providing a language code or tag ([IETF BCP 47 language tag](https://www.techonthenet.com/js/language_tags.php)).

ios/Speech.mm

@@ -14,6 +14,16 @@ + (BOOL)requiresMainQueueSetup {
   return NO;
 }
 
+- (NSDictionary<NSString *, id> *)constantsToExport
+{
+  return @{};
+}
+
+- (NSDictionary<NSString *, id> *)getConstants
+{
+  return [self constantsToExport];
+}
+
 - (instancetype)init {
   self = [super init];
 

src/NativeSpeech.ts

@@ -39,7 +39,7 @@ export interface VoiceOptions {
   /**
    * Determines how speech audio interacts with the device's silent (ringer) switch.
    * This option is ignored if `ducking` is `true`.
-   * @platform ios
+   * @platform iOS
    *
    * - `obey`: (Default) Does not change the app's audio session. Speech follows the system default.
    * - `respect`: Speech will be silenced by the ringer switch. Use for non-critical audio.
@@ -80,7 +80,18 @@ export interface EngineProps {
    */
   isDefault: boolean;
 }
+
+interface ConstantsProps {
+  /**
+   * The maximum number of characters allowed in a single call to `speak()` or `speakWithOptions()`.
+   * @platform Android
+   */
+  maxInputLength?: number;
+}
+
 export interface Spec extends TurboModule {
+  getConstants: () => ConstantsProps;
+  //Methods
   reset: () => void;
   stop: () => Promise<void>;
   pause: () => Promise<boolean>;
@@ -93,7 +104,7 @@ export interface Spec extends TurboModule {
   setEngine: (engineName: string) => Promise<void>;
   getAvailableVoices: (language: string) => Promise<VoiceProps[]>;
   speakWithOptions: (text: string, options: VoiceOptions) => Promise<void>;
-
+  //Listeners
   readonly onError: EventEmitter<EventProps>;
   readonly onStart: EventEmitter<EventProps>;
   readonly onFinish: EventEmitter<EventProps>;

src/Speech.ts

@@ -2,6 +2,16 @@ import TurboSpeech from './NativeSpeech';
 import type {VoiceProps, VoiceOptions, EngineProps} from './NativeSpeech';
 
 export default class Speech {
+  /**
+   * The *maximum number of characters allowed in a single call to the speak methods.
+   *
+   * On `Android`, this value is determined by `TextToSpeech.getMaxSpeechInputLength`.
+   * Text exceeding this length must be manually split into smaller utterances on the JavaScript side.
+   *
+   * On `iOS`, there is no synthesis system limit, and by default, the speech class returns `Number.MAX_VALUE`.
+   */
+  static readonly maxInputLength =
+    TurboSpeech.getConstants().maxInputLength ?? Number.MAX_VALUE;
   /**
    * Gets a list of all available voices on the device
    * @param language - Optional language code to filter voices (e.g., 'en', 'fr', 'en-US', 'fr-FR').
@@ -21,7 +31,7 @@ export default class Speech {
   /**
    * Gets a list of all available text-to-speech engines on the device
    * @returns Promise<EngineProps[]> Array of engine properties including name, label, and isDefault flag
-   * @platform android
+   * @platform Android
    * @example
    * const engines = await Speech.getEngines();
    * engines.forEach(engine => {
@@ -38,7 +48,7 @@ export default class Speech {
    * Sets the text-to-speech engine to use for speech synthesis
    * @param engineName - The name of the engine to use (obtained from getEngines())
    * @returns Promise<void> Resolves when engine is set
-   * @platform android
+   * @platform Android
    * @example
    * // First, get available engines
    * const engines = await Speech.getEngines();
@@ -54,7 +64,7 @@ export default class Speech {
    * Opens the system UI to install or update TTS voice data.
    * @returns Promise<void> Resolves when the installer activity has been launched.
    * @throws If the installer activity cannot be opened on the device.
-   * @platform android
+   * @platform Android
    */
   public static openVoiceDataInstaller(): Promise<void> {
     return TurboSpeech.openVoiceDataInstaller();