Voice Service Integration

 Objective

Integrate voice commands in your Android applications using the voice service of the Almer Arc.

  Interaction between your App and Service

The application and the service will communicate using broadcasts. In the following examples you will find the functionalities of the voice service alongside code samples to fully acknowledge how to integrate the voice commands in your app.

1. Registering voice commands

Voice commands can be registered by sending a list to the Voice Service using an intent:

kotlin

companion object {
    // Intention to add new voice commands
    private const val ACTION_OVERRIDE = "com.almer.voiceassistant.action.OVERRIDE_COMMANDS"

    // List of commands to be added
    private const val EXTRA_COMMANDS = "com.almer.voiceassistant.extra.COMMANDS"

    // Package name of the app that sends the voice commands
    private const val EXTRA_SOURCE = "com.almer.voiceassistant.extra.SOURCE_PACKAGE"
}

private fun sendCommands() {
    val voiceCommands = arrayOf(
        "Turn Camera on",
        "Turn Camera off"
    )

    val intent = Intent(ACTION_OVERRIDE)
    intent.putExtra(EXTRA_SOURCE, packageName)
    intent.putExtra(EXTRA_COMMANDS, voiceCommands)

    sendBroadcast(intent)
}

java

// Intention to add new voice commands
private final String ACTION_OVERRIDE = "com.almer.voiceassistant.action.OVERRIDE_COMMANDS";

// List of commands to be added
private final String EXTRA_COMMANDS = "com.almer.voiceassistant.extra.COMMANDS";

// Package name of the app that sends the voice commands
private final String EXTRA_SOURCE = "com.almer.voiceassistant.extra.SOURCE_PACKAGE";

private void sendCommands() {
    String[] voiceCommands = { "Turn Camera on", "Turn Camera off" };

    Intent intent = new Intent(ACTION_OVERRIDE);
    intent.putExtra(EXTRA_SOURCE, getPackageName());
    intent.putExtra(EXTRA_COMMANDS, voiceCommands);

    sendBroadcast(intent);
}

2. Reacting to voice command triggers

• Applications can listen for when the speech recognizer has detected a spoken voice command (e.g "Enter text <...>") by using a BroadcastReceiver:

kotlin

companion object {
    // Action for the broadcast receiver intent filter: voice service detected a command
    private const val ACTION_SPEECH_EVENT = "com.almer.voiceassistant.action.SPEECH_EVENT"

    // The detected voice command
    private const val EXTRA_COMMAND = "com.almer.voiceassistant.extra.COMMAND"
}

private val speechBroadcastReceiver = object : BroadcastReceiver() {
    override fun onReceive(context: Context?, intent: Intent?) {
        if (intent?.action == ACTION_SPEECH_EVENT) {
            val command = intent.getStringExtra(EXTRA_COMMAND)
        }
    }
}

java

// Action for the broadcast receiver intent filter: voice service detected a command
private final String ACTION_SPEECH_EVENT = "com.almer.voiceassistant.action.SPEECH_EVENT";

// The detected voice command
private final String EXTRA_COMMAND = "com.almer.voiceassistant.extra.COMMAND";

private final BroadcastReceiver speechBroadcastReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        if (intent != null && intent.getAction().equals(ACTION_SPEECH_EVENT)) {
            String command = intent.getStringExtra(EXTRA_COMMAND);
        }
    }
};

3. Restore normal services

When your application has finished with the speech recogniser it should send a message to restore default behaviour, using the RESTORE_COMMANDS intent.

kotlin

companion object {
    // Resets the voice service to default commands
    private const val ACTION_RESTORE = "com.almer.voiceassistant.action.RESTORE_COMMANDS"
}

private fun restoreVoiceCommands() {
    val intent = Intent(ACTION_RESTORE)
    sendBroadcast(intent)
}

java

// Resets the voice service to default commands
private final String ACTION_RESTORE = "com.almer.voiceassistant.action.RESTORE_COMMANDS";

private void restoreVoiceCommands() {
    Intent intent = new Intent(ACTION_RESTORE);
    sendBroadcast(intent);
}

4. API

Intent	Description
com.almer.voiceassistant.action.OVERRIDE_COMMANDS	Used to take control of the speech recogniser
com.almer.voiceassistant.action.RESTORE_COMMANDS	Used to reset the speech recogniser to its default behavior
com.almer.voiceassistant.action.SPEECH_EVENT	Sent from the Voice Service to identify spoken voice commands

Extra	Data Type	Description
com.almer.voiceassistant.extra.COMMANDS	String[]	Used to pass in a list of voice commands to the speech recogniser
com.almer.voiceassistant.extra.SOURCE_PACKAGE	String	Used to pass the application's package name to the speech recogniser
com.almer.voiceassistant.extra.COMMAND	String	Passed from the speech recogniser when a voice command is spoken. Identifies the command spoken by the user