feat: locale support fix #13

.gitignore

@@ -5,3 +5,4 @@
 .pub/
 
 build/
+example/.flutter-plugins-dependencies

.vscode/launch.json

@@ -0,0 +1,14 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Flutter",
+            "request": "launch",
+            "type": "dart",
+            "program": "example/lib/port.dart"
+        }
+    ]
+}

CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## 0.7.0
+
+### New
+
+  * locales method returns the list of available languages for speech
+  * new optional localeId parameter on listen method supports choosing the comprehension language separately from the current system locale. 
+
 ## 0.6.3
 
 ### Fix

README.md

@@ -6,6 +6,10 @@ This plugin contains a set of classes that make it easy to use the speech recogn
 capabilities of the mobile device in Flutter. It supports both Android and iOS. 
 
 ## Recent Updates
+The 0.7.0 version adds the ability to select the recognition language using the `localeId`
+parameter on the `listen` method. It also has a new `locales` method that returns a list 
+of supported locales for speech on the device. 
+
 The 0.6.0 version added a Duration parameter to the listen method to set a maximum time 
 to listen before automatically cancelling. 
 

android/src/main/kotlin/com/csdcorp/speech_to_text/SpeechToTextPlugin.kt

@@ -21,6 +21,10 @@ import io.flutter.plugin.common.MethodChannel.Result
 import io.flutter.plugin.common.PluginRegistry
 import io.flutter.plugin.common.PluginRegistry.Registrar
 import org.json.JSONObject
+import android.content.Context
+import android.content.BroadcastReceiver
+import java.util.*
+
 
 enum class SpeechToTextErrors {
   multipleRequests,
@@ -46,13 +50,15 @@ class SpeechToTextPlugin(activity: Activity, channel: MethodChannel ):
   private val pluginActivity: Activity = activity
   private val channel: MethodChannel = channel
   private val application: Application = activity.application
-  private val minSdkForSpeechSupport = 8
+  private val minSdkForSpeechSupport = 21
   private val speechToTextPermissionCode = 78521
   private var activeResult: Result? = null
   private var initializedSuccessfully: Boolean = false
   private var permissionToRecordAudio: Boolean = false
   private var speechRecognizer: SpeechRecognizer? = null
   private var recognizerIntent: Intent? = null
+  private var previousRecognizerLang: String? = null
+  private val defaultLanguageTag: String = Locale.getDefault().toLanguageTag()
 
   companion object {
     @JvmStatic
@@ -67,9 +73,17 @@ class SpeechToTextPlugin(activity: Activity, channel: MethodChannel ):
   override fun onMethodCall(call: MethodCall, result: Result) {
     when (call.method) {
       "initialize" ->  initialize( result )
-      "listen" ->  startListening( result )
+      "listen" -> {
+        if (null != call.arguments && call.arguments is String) {
+          val localeId = call.arguments as String
+          startListening( result, localeId )
+        } else {
+          startListening( result, defaultLanguageTag )
+        }
+      }
       "stop" -> stopListening( result )
       "cancel" ->  cancelListening( result )
+      "locales" -> locales( result )
       else -> result.notImplemented()
     }
   }
@@ -87,31 +101,32 @@ class SpeechToTextPlugin(activity: Activity, channel: MethodChannel ):
     initializeIfPermitted( application )
    }
 
-  fun sdkVersionTooLow(result: Result): Boolean {
+  private fun sdkVersionTooLow(result: Result): Boolean {
     if ( Build.VERSION.SDK_INT < minSdkForSpeechSupport ) {
       result.success(false)
       return true;
     }
     return false;
   }
 
-  fun isNotInitialized(result: Result): Boolean {
+  private fun isNotInitialized(result: Result): Boolean {
     if ( !initializedSuccessfully ) {
       result.success(false)
     }
     return !initializedSuccessfully
   }
 
-  fun startListening(result: Result) {
+  private fun startListening(result: Result, languageTag: String ) {
     if ( sdkVersionTooLow( result ) || isNotInitialized( result )) {
       return
     }
+    setupRecognizerIntent(languageTag)
     speechRecognizer?.startListening(recognizerIntent)
     notifyListening(isRecording = true)
     result.success(true)
   }
 
-  fun stopListening(result: Result) {
+  private fun stopListening(result: Result) {
     if ( sdkVersionTooLow( result ) || isNotInitialized( result )) {
       return
     }
@@ -120,7 +135,7 @@ class SpeechToTextPlugin(activity: Activity, channel: MethodChannel ):
     result.success(true)
   }
 
-  fun cancelListening(result: Result) {
+  private fun cancelListening(result: Result) {
     if ( sdkVersionTooLow( result ) || isNotInitialized( result )) {
       return
     }
@@ -129,6 +144,17 @@ class SpeechToTextPlugin(activity: Activity, channel: MethodChannel ):
     result.success(true)
   }
 
+  private fun locales(result: Result) {
+    if ( sdkVersionTooLow( result ) || isNotInitialized( result )) {
+      return
+    }
+    val detailsIntent = RecognizerIntent.getVoiceDetailsIntent(pluginActivity)
+//    val detailsIntent = Intent(RecognizerIntent.ACTION_GET_LANGUAGE_DETAILS)
+    pluginActivity.sendOrderedBroadcast(
+            detailsIntent, null, LanguageDetailsChecker( result, pluginActivity ),
+            null, Activity.RESULT_OK, null, null)
+  }
+
   private fun notifyListening(isRecording: Boolean) {
     val status = when (isRecording) {
       true -> SpeechToTextStatus.listening.name
@@ -167,16 +193,27 @@ class SpeechToTextPlugin(activity: Activity, channel: MethodChannel ):
         setRecognitionListener(this@SpeechToTextPlugin)
       }
 
+      setupRecognizerIntent( defaultLanguageTag )
+    }
+
+    initializedSuccessfully = permissionToRecordAudio
+    activeResult?.success(permissionToRecordAudio)
+    activeResult = null
+  }
+
+  private fun setupRecognizerIntent( languageTag: String ) {
+    if ( previousRecognizerLang == null || previousRecognizerLang != languageTag ) {
+      previousRecognizerLang = languageTag;
       recognizerIntent = Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH).apply {
         putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_FREE_FORM)
         putExtra(RecognizerIntent.EXTRA_CALLING_PACKAGE, application.packageName)
         putExtra(RecognizerIntent.EXTRA_PARTIAL_RESULTS, true)
+        if ( languageTag != Locale.getDefault().toLanguageTag()) {
+          putExtra(RecognizerIntent.EXTRA_LANGUAGE, languageTag );
+        }
       }
-    }
 
-    initializedSuccessfully = permissionToRecordAudio
-    activeResult?.success(permissionToRecordAudio)
-    activeResult = null
+    }
   }
 
   override fun onRequestPermissionsResult( requestCode: Int, permissions: Array<out String>?,
@@ -224,3 +261,42 @@ class SpeechToTextPlugin(activity: Activity, channel: MethodChannel ):
   override fun onEvent(p0: Int, p1: Bundle?) {}
   override fun onBeginningOfSpeech() {}
 }
+
+  // See https://stackoverflow.com/questions/10538791/how-to-set-the-language-in-speech-recognition-on-android/10548680#10548680
+class LanguageDetailsChecker(flutterResult: Result, pluginActivity: Activity) : BroadcastReceiver() {
+  private val pluginActivity: Activity = pluginActivity
+  private val result: Result = flutterResult
+  private var supportedLanguages: List<String>? = null
+
+  private var languagePreference: String? = null
+
+  override fun onReceive(context: Context, intent: Intent) {
+    val results = getResultExtras(true)
+    if (results.containsKey(RecognizerIntent.EXTRA_LANGUAGE_PREFERENCE)) {
+      languagePreference = results.getString(RecognizerIntent.EXTRA_LANGUAGE_PREFERENCE)
+    }
+    if (results.containsKey(RecognizerIntent.EXTRA_SUPPORTED_LANGUAGES)) {
+      supportedLanguages = results.getStringArrayList(
+              RecognizerIntent.EXTRA_SUPPORTED_LANGUAGES)
+      createResponse( supportedLanguages )
+    }
+  }
+    private fun createResponse( supportedLanguages: List<String>? ) {
+      val currentLocale = Locale.getDefault()
+      val localeNames = ArrayList<String>()
+      localeNames.add( buildIdNameForLocale(currentLocale))
+      if ( null != supportedLanguages ) {
+        for ( lang in supportedLanguages) {
+          val locale = Locale.forLanguageTag(lang)
+         localeNames.add( buildIdNameForLocale(locale))
+        }
+      }
+      pluginActivity.runOnUiThread { result.success(localeNames) }
+
+    }
+
+    private fun buildIdNameForLocale( locale: Locale ): String {
+      val name = locale.displayName.replace(':', ' ')
+      return "${locale.language}_${locale.country}:$name"
+    }
+}

example/ios/Flutter/Flutter.podspec

@@ -0,0 +1,18 @@
+#
+# NOTE: This podspec is NOT to be published. It is only used as a local source!
+#
+
+Pod::Spec.new do |s|
+  s.name             = 'Flutter'
+  s.version          = '1.0.0'
+  s.summary          = 'High-performance, high-fidelity mobile apps.'
+  s.description      = <<-DESC
+Flutter provides an easy and productive way to build and deploy high-performance mobile apps for Android and iOS.
+                       DESC
+  s.homepage         = 'https://flutter.io'
+  s.license          = { :type => 'MIT' }
+  s.author           = { 'Flutter Dev Team' => 'flutter-dev@googlegroups.com' }
+  s.source           = { :git => 'https://github.com/flutter/engine', :tag => s.version.to_s }
+  s.ios.deployment_target = '8.0'
+  s.vendored_frameworks = 'Flutter.framework'
+end