adireddy/device-capabilities

import js.Browser;
import js.html.SpeechRecognitionEvent;
import js.html.SpeechGrammarList;
import js.html.SpeechRecognition;

@:expose @:keep class Speech {

    public static var LANGUAGE:String = "en-GB";
    public static var MAX_ALTERNATIVES:Int = 1;
    public static var INTERIM_RESULTS:Bool = false;

    /**
    * Support check.
    *
    * @property isSupported
    * @type {Bool}
    */
    public var isSupported:Bool;

    public var recognition:SpeechRecognition;
    public var grammarList:SpeechGrammarList;

    /**
    * Class for speech recognition.
    *
    * @class Vibration
    * @constructor
    * @example
    *         var speech = new Speech();
    *         vibration.startRecognition(onResult);
    *
    *       function onResult(results) {
    *             trace(results[0][0].transcript);
    *       }
    */
    public function new() {
        if (Reflect.field(Browser.window, "SpeechRecognition") != null) {
            recognition = Type.createInstance(Reflect.field(Browser.window, "SpeechRecognition"), []);
        }
        else if (Reflect.field(Browser.window, "webkitSpeechRecognition") != null) {
            recognition = Type.createInstance(Reflect.field(Browser.window, "webkitSpeechRecognition"), []);
        }

        if (Reflect.field(Browser.window, "SpeechGrammarList") != null) {
            grammarList = Type.createInstance(Reflect.field(Browser.window, "SpeechGrammarList"), []);
        }
        else if (Reflect.field(Browser.window, "webkitSpeechGrammarList") != null) {
            grammarList = Type.createInstance(Reflect.field(Browser.window, "webkitSpeechGrammarList"), []);
        }

        isSupported = (recognition != null && grammarList != null);
    }

    /**
    * Function to add grammar string.
    *
    * @method addGrammar
    * @param {String} grammar
    */
    public function addGrammar(grammar:String) {
        grammarList.addFromString(grammar, 1);
    }

    /**
    * Function to start speech recognition.
    *
    * @method startRecognition
    * @param {Function} callback
    * @param {Function} [endCallback]
    * @param {Function} [noMatchCallback]
    * @param {Function} [errorCallback]
    */
    public function startRecognition(callback:Dynamic -> Void, ?endCallback:Void -> Void, ?noMatchCallback:Void -> Void, ?errorCallback:Void -> Void) {
        recognition.grammars = grammarList;
        recognition.lang = LANGUAGE;
        recognition.interimResults = INTERIM_RESULTS;
        recognition.maxAlternatives = MAX_ALTERNATIVES;
        recognition.start();
        recognition.onresult = function(event:SpeechRecognitionEvent) {
            callback(event.results);
        };
        recognition.onspeechend = function() {
            recognition.stop();
            if (endCallback != null) endCallback();
        };
        recognition.onnomatch = function(event) {
            if (noMatchCallback != null) noMatchCallback();
        };
        recognition.onerror = function(event) {
            if (errorCallback != null) errorCallback();
        };
    }
}