AirQr

Helps in detecting QR codes using Jetpack's CameraX and Google Vision.

Features

Covers permissions, viewfinder
Provides detected string from QR code
Option to signal the library to stop detection
Informs if flash hardware present, Option to toggle it on or off
Provides on error, exception, permission denied callbacks
Releases resources on pause, reclaims on resume, closes proxyImage when done, handles backpressure
Uses Jetpack's CameraX library and Google's ML Kit internally - so you're in safe hands!
Bonus:
- Option to detect QR code from Bitmap
- Option to get bitmap from project assets or device gallery on the fly
- Supports Jetpack Compose

Demo

InShot_20220408_161949510.mp4

Install

In project-level build.gradle

allprojects {
  repositories {
    maven { url 'https://jitpack.io' }
  }
}

In app-level build.gradle

android {
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = '1.8'
    }
    // if using compose
    buildFeatures {
        compose true
    }
    composeOptions {
        kotlinCompilerExtensionVersion compose_version
    }
}
dependencies {
    // airqr
    implementation "com.github.mumayank:airqr:AIR_QR_VERSION"
    // jetpack cameraX
    implementation "androidx.camera:camera-core:+"
    implementation "androidx.camera:camera-view:+"
    // jetpack compose
    implementation "androidx.compose.ui:ui:+"
    implementation "androidx.compose.ui:ui-tooling-preview:+"
    implementation "androidx.compose.material:material:+"
    implementation 'androidx.activity:activity-compose:+'
}

where AIR_QR_VERSION is

The Jetpack Compose Way

in onCreate define previewView:

val previewView = PreviewView(this)

in onCreate's setContent:

AndroidView(
	factory = { previewView }, 
	modifier = Modifier.fillMaxSize()
)
AirQr.Builder()
	.withContext(LocalContext.current)
	.withLifecycleOwner(LocalLifecycleOwner.current)
	.withPreviewView(previewView)
	.onError {
	    // can ignore as this means error only in processing the current frame
	}
	.onPermissionsNotGranted {
	    // cannot proceed, show some error
	}
	.onException {
	    // cannot proceed, show some error
	}
	.onQrCodeDetected { string, shouldStopScanning ->
	    if (string.isNotEmpty()) { 		// your logic to confirm this is the QR code you are interested in
		shouldStopScanning?.invoke() 	// call this method to inform the library to stop
						// your regular flow continues from here
	    }
	}
	.build()
	.startScan() // you could choose to stop at .build() and call airQr?.startScan() later too

The View Binding Way

Add PreviewView in your layout xml:

<androidx.camera.view.PreviewView
	android:id="@+id/previewView"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" />

In your activity:

Declare airQr at activity-level:

private var airQr: AirQr? = null

Define airQr inside onCreate:

airQr = AirQr.Builder()
	.withContext(this@BindingExampleActivity)
	.withLifecycleOwner(this@BindingExampleActivity)
	.withPreviewView(binding.previewView)
	// (rest of the builder functions same as above jetpack-way)

In activity, override:

override fun onRequestPermissionsResult(
	requestCode: Int,
	permissions: Array<String>,
	grantResults: IntArray
) {
	super.onRequestPermissionsResult(requestCode, permissions, grantResults)
	airQr?.onRequestPermissionsResult(this, requestCode)
}

Bonus

Analyze any bitmap for QR code:

AirQr.analyzeBitmap(
    bitmap,
    onDetection = { string ->
        // qr code is successfully detected containing string
    },
    onError = { errorString ->
        // show some error to the user
    }
)

Get bitmap from image file in project's assets folder:

BitmapHelper.getBitmapFromAsset(
    appCompatActivity,
    "image.png",  // image file name with extension
    onSuccess = { bitmap ->
        // use the bitmap in the above function to analyze it
    }, 
    onFailure = { errorString ->
        // show some error to the user
    }
)

Choose image from user's device (using explorer app/ other photos app installed on user's device)

BitmapHelper.getBitmapFromGallery(
    this,
    onSuccess = { bitmap ->
        // use the bitmap in the above airqr function to analyze it
    },
    onFailure = { errorString ->
        // show some error to the user
    }
)

That's all!

Checkout: Issues and Wiki too!

PRs are welcomed!