Create a Powerful Flutter Speech to Text App

Create a Powerful Flutter Speech to Text App

Table of Contents:

1. Introduction
2. Setting up the Application 2.1 Adding the Speech Recognition Library 2.2 Setting Permissions 2.3 Importing the Library into Main Dart File 2.4 Initializing the State and Fields 2.5 Setting up Callback Functions 2.6 Activating the Speech Recognition
3. Building the User Interface 3.1 Creating the Scaffold 3.2 Adding the Floating Action Buttons 3.3 Styling the Buttons
4. Adding Logic to the Buttons 4.1 Starting the Speech Recognition 4.2 Stopping the Speech Recognition 4.3 Cancelling the Speech Recognition
5. Configuring the Emulator
6. Conclusion

Building a Speech-to-Text Recognizer Application in Flutter

In this tutorial, we will learn how to build a speech-to-text recognizer application in Flutter. The application will allow users to speak into their device's microphone, and convert their speech into written text. This can be useful for various tasks such as creating to-do lists, taking notes, or even sending text via email. We will be using the speech recognition library for this project, specifically version 0.3.0+1.

1. Introduction

Speech-to-text recognition technology has become increasingly popular in recent years, with applications ranging from virtual assistants to transcription services. In this tutorial, we will explore how to develop a speech-to-text application using Flutter, a flexible and user-friendly framework for building cross-platform mobile applications.

2. Setting up the Application 2.1 Adding the Speech Recognition Library To begin, we need to add the speech recognition library to our Flutter project. We will be using version 0.3.0+1 of the library. Open your project's pubspec.yaml file and add the following dependency:

dependencies:
  speech_recognition: ^0.3.0+1

Save the file and run the flutter packages get command to fetch the library.

2.2 Setting Permissions For our application to access the device's microphone, we need to add the necessary permissions. If you are using Android, open the AndroidManifest.xml file located in android/app/src/main and add the following permission:

<uses-permission android:name="android.permission.RECORD_AUDIO" />

If You are targeting iOS, open the Info.plist file located in ios/Runner and add the following keys and strings:

<key>NSMicrophoneUsageDescription</key>
<string>We need microphone access to convert speech to text.</string>
<key>NSSpeechRecognitionUsageDescription</key>
<string>We need speech recognition access to convert speech to text.</string>

2.3 Importing the Library into Main Dart File Next, we need to import the speech recognition library into our main.dart file. Add the following import statement at the beginning of the file:

import 'Package:speech_recognition/speech_recognition.dart';

2.4 Initializing the State and Fields To keep track of the speech recognition process, we will need to maintain certain fields within our stateful widget. Let's define these fields by adding the following code inside our SpeechToTextWidgetState class:

SpeechRecognition _speechRecognition;
bool _isAvailable = false;
bool _isListening = false;
String _resultText = '';

Here, we have created an instance of the SpeechRecognition class and defined three boolean variables: _isAvailable, _isListening, and a STRING variable _resultText.

2.5 Setting up Callback Functions To handle various events related to speech recognition, we need to set up callback functions. Add the following code inside the initState method of our stateful widget:

void _initSpeechRecognizer() {
  _speechRecognition.setAvailabilityHandler((bool result) {
    setState(() {
      _isAvailable = result;
    });
  });

  _speechRecognition.setRecognitionStartedHandler(() {
    setState(() {
      _isListening = true;
    });
  });

  _speechRecognition.setRecognitionResultHandler((String speech) {
    setState(() {
      _resultText = speech;
    });
  });

  _speechRecognition.setRecognitionCompleteHandler(() {
    setState(() {
      _isListening = false;
    });
  });

  _speechRecognition.activate().then((result) {
    setState(() {
      _isAvailable = result;
    });
  });
}

In this code, We Are setting up callback functions for availability, recognition start, recognition result, and recognition complete events. These functions update the respective fields using the setState method.

2.6 Activating the Speech Recognition Finally, we need to call the _initSpeechRecognizer function inside the initState method of our stateful widget. This will activate the speech recognition and set up the necessary handlers.

3. Building the User Interface 3.1 Creating the Scaffold To create the user interface, we will utilize a scaffold widget. Add the following code inside the build method of our stateful widget:

return Scaffold(
  appBar: AppBar(
    title: Text('Speech-to-Text Recognizer'),
  ),
  body: Container(
    padding: EdgeInsets.all(16.0),
    child: Column(
      mainAxisAlignment: MainAxisAlignment.center,
      children: [
        // Add Floating Action Buttons and Text Container here
      ],
    ),
  ),
);