Scan barcodes in Jetpack Compose using ML Kit and CameraX

Hey y’all, grab a cup of coffee ☕, and let’s see how to implement a barcode scanner in Jetpack Compose.

Dependencies

Open :app/build.gradle.kts and add the ML Kit, CameraX, and the Accompanist dependencies.

dependencies {
    // ML Kit
    implementation("com.google.mlkit:barcode-scanning:17.2.0")

    // CameraX
    val cameraxVersion = "1.4.0-alpha02"
    implementation("androidx.camera:camera-camera2:$cameraxVersion")
    implementation("androidx.camera:camera-lifecycle:$cameraxVersion")
    implementation("androidx.camera:camera-view:$cameraxVersion")

    // Permissions
    implementation("com.google.accompanist:accompanist-permissions:0.33.2-alpha")
}

Now go to AndroidManifest.xml and add this inside the application.

<meta-data
    android:name="com.google.mlkit.vision.DEPENDENCIES"
    android:value="barcode" />

I do like to keep the camera and its functions in a separate class called BarcodeCamera . Now let’s create the camera preview which is a Composable. This will have a callback that will return the scanned barcode.

class EanCamera {

    private var camera: Camera? = null

    @Composable
    fun CameraPreview(
        onBarcodeScanned: (Barcode?) -> Unit
    ) {
        //…