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!