Get Started
In this guide you will learn step-by-step how to add MatrixScan to your application.
The general steps are:
- Include the ScanditBarcodeCapture library and its dependencies to your project, if any.
- Create a new data capture context, initialized with your license key.
- Create a barcode tracking settings instance where you enable the barcode symbologies you want to read in your application.
- Create a new barcode tracking object and initialize it with the settings created above.
- Obtain a camera instance and set it as the frame source on the data capture context previously created.
- Create a new data capture view and add a basic overlay instance to it for visual feedback.
- Register an overlay listener and implement BrushForTrackedBarcode(), which is called whenever a new tracked barcode appears.
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.
You can retrieve your Scandit Data Capture SDK license key by signing in to your Scandit account.
Internal dependencies
Some of the Scandit Data Capture SDK modules depend on others to work:
Module | Dependencies | Optional Dependencies |
---|---|---|
ScanditCaptureCore | None | None |
ScanditBarcodeCapture | ScanditCaptureCore | None |
ScanditParser | None | None |
ScanditLabelCapture | ScanditCaptureCore ScanditBarcodeCapture | ScanditLabelCaptureText ScanditPriceLabel |
ScanditIdCapture | ScanditCaptureCore | ScanditIdCaptureBackend ScanditIdEuropeDrivingLicense ScanditIdAamvaBarcodeVerification ScanditIdVoidedDetection |
When using ID Capture or Label Capture, consult the respective module's getting started guides to identify the optional dependencies required for your use case. The modules you need to include will vary based on the features you intend to use.
Please be aware that your license may only cover a subset of Barcode and/or ID Capture features. If you require additional features, contact us.
Create the Data Capture Context
The first step to add capture capabilities to your application is to create a new data capture context. The context expects a valid Scandit Data Capture SDK license key during construction.
const context = Scandit.DataCaptureContext.forLicenseKey(
'-- ENTER YOUR SCANDIT LICENSE KEY HERE --'
);
Configure the Barcode Batch Mode
The main entry point for the Barcode Batch Mode is the BarcodeBatch object. It is configured through BarcodeBatchSettings 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 BarcodeBatchListener, instead you will add a BarcodeBatchBasicOverlay and implement a BarcodeBatchBasicOverlayListener.
For this tutorial, we will setup Barcode Batch for tracking QR codes.
const settings = new Scandit.BarcodeBatchSettings();
settings.enableSymbology(Scandit.Symbology.QR, true);
Next, create a BarcodeBatch instance with the data capture context and the settings initialized in the previous steps:
const barcodeBatch = Scandit.BarcodeBatch.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.
In iOS, the user must explicitly grant permission for each app to access cameras. Your app needs to provide static messages to display to the user when the system asks for camera permission. To do that include the NSCameraUsageDescription key in your app’s Info.plist file.
In Android, the user must explicitly grant permission for each app to access cameras. Your app needs to declare the use of the Camera permission in the AndroidManifest.xml file and request it at runtime so the user can grant or deny the permission. To do that follow the guidelines from Request app permissions to request the android.permission.CAMERA permission.
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 cameraSettings = Scandit.BarcodeBatch.recommendedCameraSettings;
// Depending on the use case further camera settings adjustments can be made here.
const camera = Scandit.Camera.default;
if (camera != null) {
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():
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:
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 = Scandit.DataCaptureView.forContext(context);
view.connectToElement(htmlElement);
To visualize the results of Barcode Batch, first you need to add the following overlay:
const overlay = Scandit.BarcodeBatchBasicOverlay.withBarcodeBatchForView(
barcodeBatch,
view
);
Once the overlay has been added, you should implement the BarcodeBatchBasicOverlayListener interface. The method BarcodeBatchBasicOverlayListener.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 BarcodeBatchBasicOverlayListener.didTapTrackedBarcode() method.
overlay.listener = {
didTapTrackedBarcode: (overlay, trackedBarcode) => {
// A tracked barcode was tapped.
},
};
Get Barcode Batch Feedback
Barcode Batch, unlike Barcode Capture, doesn’t emit feedback (sound or vibration) when a new barcode is recognized. However, you may implement a BarcodeBatchListener 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.
const feedback = Scandit.Feedback.defaultFeedback;
Next, use this feedback in a BarcodeBatchListener:
const feedbackListener = {
didUpdateSession: (barcodeBatch, session) => {
if (session.addedTrackedBarcodes.length > 0) {
feedback.emit();
}
},
};
BarcodeBatchListener.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 BarcodeBatch instance.
barcodeBatch.addListener(feedbackListener);
Disabling Barcode Batch
To disable barcode tracking set BarcodeBatch.isEnabled to false. The effect is immediate: 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.