4.5. The camera scanner

enioka Scan can still be used to manage barcodes scanned using the Android camera, through com.enioka.scanner.sdk.camera, (check library dependencies and compatibility matrix). For that, it exposes the CameraBarcodeScanView and a series of helper classes to handle compatiblity with both Camera 1 and Camera 2 hardware APIs.

This page regroups all information needed to control this special scanner at a deeper level.

4.5.1. The `CameraBarcodeScanView` class

This is the base Android FrameLayout used by the activity to display the camera. This view wraps the API-specific CameraBarcodeScanViewBase implementation and handles the API selection based on the device’s properties.

For most users, this is the class they will interact with if they need to interact with the Camera hardware and not just the Scanner instance.

setReaderMode(CameraReader readerMode) → void

Change the library used to read barcodes from the camera feed.

Parameters:: readerMode (CameraReader) – The library to use, between CameraReader.ZBAR and CameraReader.ZXing

addSymbology(BarcodeType barcodeType) → void

Add a symbology to detect. By default, only CODE_128 is used.

Parameters:: barcodeType (BarcodeType) – The symbology to add.

setResultHandler(ResultHandler handler) → void

Change the callback used when a barcode is read.

Used by CameraBarcodeScanViewScanner to register itself with the view and correctly propagate barcodes read by the camera as any regular scanner reads.

Parameters:: handler (ResultHandler) – the ResultHandler implementation

setTorch(boolean value) → void

Switch the camera’s torch on or off.

Parameters:: value (boolean) – Indicate if the torch should be turned on (true) or off (false)

getSupportTorch() → boolean

Returns:: true if the camera supports torch activation. false otherwise.

getTorchOn() → boolean

Returns:: true if the camera’s torch is on, false otherwise.

cleanUp() → void: Unhooks all camera callbacks and closes it. After this method is called, the camera becomes unusable and the view needs to be reinitialized.

pauseCamera() → void: Pauses the camera’s capture.

resumeCamera() → void: Resumes the camera’s capture.

getLatestSuccessfulScanJpeg() → byte[]

Returns:: The JPEG data of the image used in the latest successful scan, or null if there is no previous scan data.

4.5.2. Use `CameraBarcodeScanView` in your custom layout

To use this view in your own layout, you can add the following block to its XML definition and adapt the attributes to your needs:

<com.enioka.scanner.camera.CameraBarcodeScanView
    android:id="@+id/camera_scan_view"
    android:layout_width="0dp"
    android:layout_height="0dp"
    app:forceCameraApiVersion="Auto"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintLeft_toLeftOf="parent"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:maxDistortionRatio="0.3"
    app:minResolutionY="720"
    app:maxResolutionY="1080"
    app:previewRatioMode="fillAvailableSpace"
    app:readerMode="Auto"
    app:storePreferredResolution="false"
    app:targetColorActive="@color/colorRed"
    app:targetColorPaused="@color/defaultItemColor"
    app:targetIsFixed="false"
    app:targetStrokeWidth="5"
    app:useAdaptiveResolution="true" 
/>

The main XML attributes are as follow:

app:forceCameraApiVersion: “1” for the old camera API, “2” for the Camera2 API, any other value to let the library detect the appropriate camera API for this device.

app:useAdaptiveResolution: If true, the resolution of the camera preview may be decreased if performances are deemed too low by the frame analyzer.

app:minResolutionY: The minimum vertical resolution of the camera preview, after which resolution can no longer be decreased by adaptive resolution when trying to improve performance.

app:maxResolutionY: The maximum vertical resolution of the camera preview, useful to limit performance costs.

app:readerMode: “1” for ZXING, any other value for ZBAR.

app:storePreferredResolution: If true, the app will persists the most used preview resolution to the application’s preference.

app:targetColorActive: The default color of the “target” indicating where barcodes are expected to be.

app:targetColorPaused: The color of the “target” indicating where barcodes are expected to be, used whenever the scanning is paused.

app:targetIsFixed: If true, the target cannot be moved by the user. If false, the user can drag the target up and down on the preview.

app:targetStrokeWidth: The thickness of the target’s lines.

4.5. The camera scanner

4.5.1. The CameraBarcodeScanView class

4.5.2. Use CameraBarcodeScanView in your custom layout

4.5.1. The `CameraBarcodeScanView` class

4.5.2. Use `CameraBarcodeScanView` in your custom layout