RocketChat/Rocket.Chat

/**
 * This class is used for stream manipulation.
 * @remarks
 * This class wraps up browser media stream and HTMLMedia element
 * and takes care of rendering the media on a given element.
 * This provides enough abstraction so that the higher level
 * classes do not need to know about the browser specificities for
 * media.
 * This will also provide stream related functionalities such as
 * mixing of 2 streams in to 2, adding/removing tracks, getting a track information
 * detecting voice energy etc. Which will be implemented as when needed
 */
export default class Stream {
    protected mediaStream: MediaStream | undefined;

    constructor(mediaStream: MediaStream) {
        this.mediaStream = mediaStream;
    }
    /**
     * Called for stopping the tracks in a given stream.
     * @remarks
     * All the tracks from a given stream will be stopped.
     */

    private stopTracks(): void {
        const tracks = this.mediaStream?.getTracks();
        if (tracks) {
            for (let i = 0; i < tracks?.length; i++) {
                tracks[i].stop();
            }
        }
    }

    /**
     * Called for setting the callback when the track gets added
     * @remarks
     */

    onTrackAdded(callBack: any): void {
        this.mediaStream?.onaddtrack?.(callBack);
    }

    /**
     * Called for setting the callback when the track gets removed
     * @remarks
     */

    onTrackRemoved(callBack: any): void {
        this.mediaStream?.onremovetrack?.(callBack);
    }

    /**
     * Called for clearing the streams and media element.
     * @remarks
     * This function stops the media element play, clears the srcObject
     * stops all the tracks in the stream and sets media stream to undefined.
     * This function ususally gets called when call ends or to clear the previous stream
     * when the stream is switched to another stream.
     */

    clear(): void {
        if (this.mediaStream) {
            this.stopTracks();
            this.mediaStream = undefined;
        }
    }
}