Add support for torch and make beta APIs non beta.

[mebjas]

Version 2.2.5

Added support for turning torch On and Off in Html5QrcodeScanner. On supported devices + browsers.

This new feature will implement the feature request - Issue#129 and add support for torch (also called flash) on supported devices and browsers.

So far I have confirmed functionality on Samsung Flip 4 Chrome and Internet (Samsung's default browser).

This is only supported on Html5QrcodeScanner and can be enabled using the config like this.

let html5QrcodeScanner = new Html5QrcodeScanner(
    "reader",
    {
        fps: 10,
        qrbox: qrboxFunction,
        // Important notice: this is experimental feature, use it at your
        // own risk. See documentation in
        // mebjas@/html5-qrcode/src/experimental-features.ts
        experimentalFeatures: {
            useBarCodeDetectorIfSupported: true
        },
        rememberLastUsedCamera: true,
        aspectRatio: 1.7777778,
        showTorchButtonIfSupported: true
    });

The showTorchButtonIfSupported: true part is the crucial one. It's off by default for now as I don't like the UI very much.

Added support for getRunningTrackSettings().

Added a new API to get settings (type: MediaTrackSettings) for running video streams while QR code is being scanned.

/**
 * Returns the supported settings of the running video track.
 *
 * @returns the supported settings of the running video track.
 * @throws error if the scanning is not in running state.
 */
public getRunningTrackSettings(): MediaTrackSettings {}

This API can be used to check the currently applied settings on the running video stream like weather torch is on or not.

getRunningTrackCapabilities(..) and applyVideoConstraints(..) out of beta.

Both Html5Qrcode and Html5QrcodeScanner classes had support for following APIs.

/**
 * Returns the capabilities of the running video track.
 *
 * Note: Should only be called if {@code Html5QrcodeScanner#getState()}
 *   returns {@code Html5QrcodeScannerState#SCANNING} or
 *   {@code Html5QrcodeScannerState#PAUSED}.
 *
 * @returns the capabilities of a running video track.
 * @throws error if the scanning is not in running state.
 */
public getRunningTrackCapabilities(): MediaTrackCapabilities {}

 /**
 * Apply a video constraints on running video track from camera.
 *
 * Note: Should only be called if {@code Html5QrcodeScanner#getState()}
 *   returns {@code Html5QrcodeScannerState#SCANNING} or
 *   {@code Html5QrcodeScannerState#PAUSED}.
 *
 * @param {MediaTrackConstraints} specifies a variety of video or camera
 *  controls as defined in
 *  https://developer.mozilla.org/en-US/docs/Web/API/MediaTrackConstraints
 * @returns a Promise which succeeds if the passed constraints are applied,
 *  fails otherwise.
 * @throws error if the scanning is not in running state.
 */
public applyVideoConstraints(videoConstaints: MediaTrackConstraints)
    : Promise<any> {}

These have now been taken out of beta and publicly documented. More blog articles to be published for these.