Barcode Detector – Simple example

1. Dependencies:

dependencies {
    compile 'com.android.support:appcompat-v7:23.0.1'
    compile 'com.google.android.gms:play-services:8.1.0'
}

2. Initialization code:

    private BarcodeDetector detector;
    ...
    private void initAndCheckDetector() {
        detector = new BarcodeDetector.Builder(getActivity().getApplicationContext())
                .setBarcodeFormats(Barcode.DATA_MATRIX | Barcode.QR_CODE | Barcode.EAN_13)
                .build();
        if (!detector.isOperational()) {
            Toast.makeText(getActivity().getApplicationContext(), "Could not set up the detector!", Toast.LENGTH_SHORT).show();
            detector = null;
        }
    }

Recognize Barcode:

    private void recognizeBarcode(Bitmap myBitmap ) {
        if (detector!= null) {
            Frame frame = new Frame.Builder().setBitmap(myBitmap).build();
            SparseArray<Barcode> barcodes = detector.detect(frame);
            Barcode code = barcodes.valueAt(0);
            String result = code.rawValue;
        }
    }

Barcode Detection with the Mobile Vision API

Software keyboard control

Add soft keyboard listener:

final View activityRootView = getWindow().getDecorView().findViewById(android.R.id.content);
        activityRootView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                int heightDiff = activityRootView.getRootView().getHeight() - activityRootView.getHeight();
                if (heightDiff > 100) { // 99% of the time the height diff will be due to a keyboard.
                    if (!isSoftKeyboardOpen) {
                        MyLogger.log(TAG, "Soft keyboard is visible");
                        isSoftKeyboardOpen = true;
                    }
                    isSoftKeyboardOpen = true;
                } else if (isSoftKeyboardOpen) {
                    MyLogger.log(TAG, "Soft keyboard invisible");
                    isSoftKeyboardOpen = false;
                    removeFocusAndSaveToDB();
                }
            }
        });

Opens soft keyboard when alert dialog shown:

alertDialog.getWindow()
    .setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_VISIBLE);

Oracle certification, Java SE 7 Programmer I (1Z0-803)

Useful information about this exam:

And this is how the Java SE 7 Programmer I certification looks like:

oca

GCM – Push notification code (php)

An example that I used for tests.

define( 'API_ACCESS_KEY', 'fill_here_your_api_access_key' ); 
$registrationIds = array("fill_here_registered_id_of_your _device"); 

$msg = array ( 
    'parameter1' =>; 'Some data that you want to send',
    'parameter2' =>; 'Some additional data...',
);

$fields = array
(
    'registration_ids'  =>; $registrationIds,
    'data'              =>; $msg
);

$headers = array
(
    'Authorization: key=' . API_ACCESS_KEY,
    'Content-Type: application/json'
);

$ch = curl_init();
curl_setopt( $ch,CURLOPT_URL, 'https://android.googleapis.com/gcm/send' );
curl_setopt( $ch,CURLOPT_POST, true );
curl_setopt( $ch,CURLOPT_HTTPHEADER, $headers );
curl_setopt( $ch,CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch,CURLOPT_SSL_VERIFYPEER, false );
curl_setopt( $ch,CURLOPT_POSTFIELDS, json_encode( $fields ) );
$result = curl_exec($ch );
curl_close( $ch );

echo $result;

 

Three useful android libraries

The most useful libraries for me lately is:

  • Picasso – A powerful image downloading and caching library for Android.
  • Butterknife – Field and method binding for Android views.
  • EventBus – Simplifies the communication between components and makes your code simple.