Barcode and QR code reading

Remarks#

Using QRCodeReaderView (based on Zxing)

QRCodeReaderView implements an Android view which show camera and notify when there’s a QR code inside the preview.

It uses the zxing open-source, multi-format 1D/2D barcode image processing library.

Adding the library to your project

Add QRCodeReaderView dependency to your build.gradle

dependencies{
    compile 'com.dlazaro66.qrcodereaderview:qrcodereaderview:2.0.0'
}

First use

Add to your layout a QRCodeReaderView

<com.dlazaro66.qrcodereaderview.QRCodeReaderView android:id=”@+id/qrdecoderview” android:layout_width=“match_parent” android:layout_height=“match_parent” />
Create an Activity which implements onQRCodeReadListener, and use it as a listener of the QrCodeReaderView.
Make sure you have camera permissions in order to use the library. (https://developer.android.com/training/permissions/requesting.html)

Then in your Activity, you can use it as follows:

    public class DecoderActivity extends Activity implements OnQRCodeReadListener {

    private TextView resultTextView;
    private QRCodeReaderView qrCodeReaderView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_decoder);

        qrCodeReaderView = (QRCodeReaderView) findViewById(R.id.qrdecoderview);
        qrCodeReaderView.setOnQRCodeReadListener(this);

        // Use this function to enable/disable decoding
        qrCodeReaderView.setQRDecodingEnabled(true);

        // Use this function to change the autofocus interval (default is 5 secs)
        qrCodeReaderView.setAutofocusInterval(2000L);

        // Use this function to enable/disable Torch
        qrCodeReaderView.setTorchEnabled(true);

        // Use this function to set front camera preview
        qrCodeReaderView.setFrontCamera();

        // Use this function to set back camera preview
        qrCodeReaderView.setBackCamera();
    }

    // Called when a QR is decoded
    // "text" : the text encoded in QR
    // "points" : points where QR control points are placed in View
    @Override
    public void onQRCodeRead(String text, PointF[] points) {
        resultTextView.setText(text);
    }

    @Override
    protected void onResume() {
        super.onResume();
        qrCodeReaderView.startCamera();
    }

    @Override
    protected void onPause() {
        super.onPause();
        qrCodeReaderView.stopCamera();
    }
}