OSBarcodeLib

An Android library to scan barcodes, using ML Kit or ZXing for code detection. The UI is implemented with Jetpack Compose, and image analysis is setup with CameraX (https://developer.android.com/reference/androidx/camera/core/ImageAnalysis).

The library supports many popular encoding types of 1D and 2D barcodes, such as:

• 1D Barcodes
  • Codabar
  • Code 39
  • Code 93
  • Code 128
  • Databar (GS1) (only with ML Kit)
  • EAN-8
  • EAN-13
  • ITF
  • ISBN-10
  • ISBN-13
  • ISBN-13 Dual Barcode
  • RSSExpanded (only with ZXing)
  • UPC-A
  • UPC-E
• 2D Barcodes
  • Aztec Code
  • Data Matrix
  • MaxiCode (only with ZXing)
  • PDF 417
  • QR Code

The OSBARCController class provides the main feature of the library, which is the Barcode Scanner, to be detailed in the following sections. The OSBARCScanLibraryFactory provides a way to create a instance of OSBARCScanLibraryInterface, which has an implementation for ML Kit and another for ZXing.

Index

• Motivation
• Usage
• Methods
  • scanBarcode
  • handleActivityResult

Motivation

This library is to be used by the Barcode Plugin.

Usage

In your app-level gradle file, import the OSBarcodeLib library like so:

dependencies {
    implementation("com.github.outsystems:osbarcode-android:1.0.0@aar")
}

Methods

scanBarcode

fun scanCode(
    activity: Activity,
    parameters: OSBARCScanParameters
)

A method that triggers the barcode reader/scanner, opening a new activity with the scanning UI.

Parameters

• activity: The activity to be used to launch the activity with the scanning UI. When scanning ends, either because a code was detected or by being cancelled, the result will come in the onActivityResult() of this activity.
• parameters: OSBARCScanParameters object that contains all the barcode parameters to be used when scanning.
  • scanInstructions: A string that contains the scan instructions to be displayed in the screen.
  • cameraDirection: An integer indicating which camera to use - back or front.
  • scanOrientation: An integer indicating which scan orientation to use - portrait, landscape, or adaptive.
  • scanButton: A boolean that will display a scan button on the barcode reader. If true, scanning will only be triggered when pressing the button instead of automatically when framing the barcode. A second click on the button disables scannning.
  • scanText: A string that contains the text to be displayed on the scan button. It will only be shown if scanButton is set to true.
  • hint: An integer that holds a hint to what type of barcode to look for. This parameter isn't being used yet.
    • androidScanningLibrary: A string which determines what barcode library to use - ML Kit or ZXing.

Usage

var barcodeController = OSBARCController()
barcodeController.scanCode(activity, parameters)

handleActivityResult

fun handleActivityResult(
        requestCode: Int,
        resultCode: Int,
        intent: Intent?,
        onSuccess: (String) -> Unit,
        onError: (OSBARCError) -> Unit
    )

A method that can be used to handle the activitu result from scanning a barcode.

Parameters

• requestCode: The code identifying the request.
• resultCode: The code identifying the result of the request.
• intent: The resulting intent from the operation.
• onSuccess: The code to be executed if the operation was successful.
• onError: The code to be executed if the operation was not successful.

Usage

barcodeController.handleActivityResult(requestCode, resultCode, intent,
    { result ->
        // handle success, probably returning result
    },
    { error ->
        // handle error, probably returning it
    }
)

Errors

Code	Message
OS-PLUG-BARC-0004	Error while trying to scan code.
OS-PLUG-BARC-0006	Couldn't scan because the process was cancelled.
OS-PLUG-BARC-0007	Couldn't scan because camera access wasn’t provided. Check your camera permissions and try again.
OS-PLUG-BARC-0008	Scanning parameters are invalid.
OS-PLUG-BARC-0009	There was an error scanning the barcode with ZXing.
OS-PLUG-BARC-0010	There was an error scanning the barcode with ML Kit.

Credits

Third-party libraries: ZXing, ML Kit, licensed with Apache-2.0.