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Get Started

In this guide you will learn step-by-step how to add MatrixScan to your application.

The general steps are:

Prerequisites

Before starting with adding a capture mode, make sure that you have a valid Scandit Data Capture SDK license key and that you added the necessary dependencies. If you have not done that yet, check out this guide.

note

You can retrieve your Scandit Data Capture SDK license key, by signing in to your Scandit account.

Enable browser multithreading

You can achieve better performance by enabling multithreading in any browser that supports it. Check the Requirements Page to know the minimum versions that can take advantage of multithreading.

To enable multithreading you must set your site to be crossOriginIsolated. This will enable the SDK to use multithreading and significantly boost performance. If the environment supports it the sdk will automatically use multithreading. You can programmatically check for multithreading supports using BrowserHelper.checkMultithreadingSupport().

important

Multithreading is particularly critical for MatrixScan so be sure to configure it correctly following this tutorial. You can also check this guide to enable cross-origin isolation and safely reviving shared memory.

An example of how headers could be set:

Cross-Origin-Embedder-Policy: require-corp;
Cross-Origin-Opener-Policy: same-origin;
Cross-Origin-Resource-Policy: cross-origin allow-credentials; require-corp origin https://example.com
https://example.net;

Internal dependencies

Some of the Scandit Data Capture SDK modules depend on others to work:

ModuleDependencies
ScanditCaptureCoreNo dependencies
ScanditBarcodeCaptureScanditCaptureCore

Create the Data Capture Context

The first step to add capture capabilities to your application is to create a new data capture context.

// the license key used in configure() will be used
const context = await SDCCore.DataCaptureContext.create();

Configure the Barcode Tracking Mode

The main entry point for the Barcode Tracking Mode is the BarcodeTracking object. It is configured through BarcodeTrackingSettings and allows to register one or more listeners that will get informed whenever a new frame has been processed.

Most of the times, you will not need to implement a BarcodeTrackingListener, instead you will add a BarcodeTrackingBasicOverlay and implement a BarcodeTrackingBasicOverlayListener.

For this tutorial, we will setup Barcode Tracking for tracking QR codes.

Next, create a BarcodeTracking instance with the data capture context and the settings initialized in the previous steps:

const barcodeTracking = await SDCBarcode.BarcodeTracking.forContext(
context,
settings
);

Use the Built-in Camera

The data capture context supports using different frame sources to perform recognition on. Most applications will use the built-in camera of the device, e.g. the world-facing camera of a device. The remainder of this tutorial will assume that you use the built-in camera.

When using the built-in camera there are recommended settings for each capture mode. These should be used to achieve the best performance and user experience for the respective mode. The following couple of lines show how to get the recommended settings and create the camera from it:

const camera = SDCCore.Camera.default;

const cameraSettings = SDCBarcode.BarcodeTracking.recommendedCameraSettings;
await camera.applySettings(cameraSettings);

Because the frame source is configurable, the data capture context must be told which frame source to use. This is done with a call to DataCaptureContext.setFrameSource():

await context.setFrameSource(camera);

The camera is off by default and must be turned on. This is done by calling FrameSource.switchToDesiredState() with a value of FrameSourceState.On:

await camera.switchToDesiredState(Scandit.FrameSourceState.On);

Use a Capture View to Visualize the Scan Process

When using the built-in camera as frame source, you will typically want to display the camera preview on the screen together with UI elements that guide the user through the capturing process. To do that, add a DataCaptureView to your view hierarchy:

const view = await SDCCore.DataCaptureView.forContext(context);
view.connectToElement(htmlElement);

To visualize the results of Barcode Tracking, first you need to add the following overlay:

const overlay =
await SDCBarcode.BarcodeTrackingBasicOverlay.withBarcodeTrackingForView(
barcodeTracking,
view
);

Once the overlay has been added, you should implement the BarcodeTrackingBasicOverlayListener interface. The method BarcodeTrackingBasicOverlayListener.brushForTrackedBarcode() is invoked every time a new tracked barcode appears and it can be used to set a brush that will be used to highlight that specific barcode in the overlay.

overlay.listener = {
brushForTrackedBarcode: (overlay, trackedBarcode) => {
// Return a custom Brush based on the tracked barcode.
},
};

If you would like to make the highlights tappable, you need to implement the BarcodeTrackingBasicOverlayListener.didTapTrackedBarcode() method.

overlay.listener = {
didTapTrackedBarcode: (overlay, trackedBarcode) => {
// A tracked barcode was tapped.
},
};

Get Barcode Tracking Feedback

Barcode Tracking, unlike Barcode Capture, doesn’t emit feedback (sound or vibration) when a new barcode is recognized. However, you may implement a BarcodeTrackingListener to provide a similar experience. Below, we use the default Feedback, but you may configure it with your own sound or vibration if you want.

Next, use this feedback in a BarcodeTrackingListener:

const feedbackListener = {
didUpdateSession: (barcodeTracking, session) => {
if (session.addedTrackedBarcodes.length > 0) {
feedback.emit();
}
},
};

BarcodeTrackingListener.didUpdateSession() is invoked for every processed frame. The session parameter contains information about the currently tracked barcodes, in particular, the newly recognized ones. We check if there are any and if so, we emit the feedback.

As the last step, register the listener responsible for emitting the feedback with the BarcodeTracking instance.

barcodeTracking.addListener(feedbackListener);

Disabling Barcode Tracking

To disable barcode tracking call BarcodeTracking.setEnabled() passing false. No more frames will be processed after the change. However, if a frame is currently being processed, this frame will be completely processed and deliver any results/callbacks to the registered listeners.

Note that disabling the capture mode does not stop the camera, the camera continues to stream frames until it is turned off or put it in standby calling SwitchToDesiredState with a value of StandBy.

Limitations

MatrixScan does not support the following symbologies:

  • DotCode
  • MaxiCode
  • All postal codes (KIX, RM4SCC)
important

Barcode Tracking needs browser multithreading to run. Check the minimum browser support in the Requirements Page and how to enable it Enable Multithreading, above.