Data Binding Library

Links the UI to actual data without having to use findViewById for every item.

In build.gradle, add 'dataBinding.enabled = true':
apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    buildToolsVersion "28.0.3"
    ...
    dataBinding.enabled = true;
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.2'
}

Create a plain old Java object to act as a placeholder for the data:
/**
 * BoardingPassInfo is a simple POJO that contains information about, you guessed it, a boarding
 * pass! Normally, it is best practice in Java to declare member variables as private and provide
 * getters, but we are leaving these fields public for ease of use.
 */
public class BoardingPassInfo {

    public String passengerName;
    public String flightCode;
    public String originCode;
    public String destCode;

    public Timestamp boardingTime;
    public Timestamp departureTime;
    public Timestamp arrivalTime;

    public String departureTerminal;
    public String departureGate;
    public String seatNumber;

    public int barCodeImageResource;

    public long getMinutesUntilBoarding() {
        long millisUntilBoarding = boardingTime.getTime() - System.currentTimeMillis();
        return TimeUnit.MILLISECONDS.toMinutes(millisUntilBoarding);
    }
}

Add layout as the root tag to the UI (in this case, activity_main.xml file). Android will automatically create a Binding class for any layout with these tags:
<?xml version="1.0" encoding="utf-8"?>
<layout>
<ScrollView xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/scroll"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <android.support.constraint.ConstraintLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <TextView
            android:text="@string/passenger_label"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content" />
            
            ...

    </android.support.constraint.ConstraintLayout>
</ScrollView>
</layout>

In your Activity, create a Binding instance, and point the instance to the correct content view using DatabindingUtil:
public class MainActivity extends AppCompatActivity {

    ActivityMainBinding mBinding; // ActivityMainBinding is automatically generated based on the activity_main.xml file name

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

        mBinding = DataBindingUtil.setContentView(this, R.layout.activity_main); // Passes in the Activity and sets the content view to the correct layout file
        BoardingPassInfo boardingPass = generateBoardingPassInfo(); // Whatever method to produce an instance of your placeholder class populated with data
        displayBoardingPassInfo(boardingPass); // Passes the placeholder instance to the method below
    }

    private void displayBoardingPassInfo(BoardingPassInfo info) {

        mBinding.textViewPassengerName.setText(info.passengerName);
        mBinding.textViewFlightCode.setText(info.flightCode);
        mBinding.textViewOriginAirport.setText(info.originCode);
        mBinding.textViewDestinationAirport.setText(info.destCode);
        mBinding.textViewTerminal.setText(info.departureTerminal);
        mBinding.textViewGate.setText(info.departureGate);
        mBinding.textViewSeat.setText(info.seatNumber);

        SimpleDateFormat formatter = new SimpleDateFormat("hh:mm a", Locale.getDefault());
        String boardingTime = formatter.format(info.boardingTime);
        mBinding.textViewBoardingTime.setText(boardingTime);
        String departureTime = formatter.format(info.departureTime);
        mBinding.textViewDepartureTime.setText(departureTime);
        String arrivalTime = formatter.format(info.arrivalTime);
        mBinding.textViewArrivalTime.setText(arrivalTime);

        long totalMinutesUntilBoarding = info.getMinutesUntilBoarding();
        long hoursUntilBoarding = TimeUnit.MINUTES.toHours(totalMinutesUntilBoarding);
        long minutesMinusHoursUntilBoarding = totalMinutesUntilBoarding - (hoursUntilBoarding*60);
        String hoursAndMinutesUntilBoarding = hoursUntilBoarding + ":" + minutesMinusHoursUntilBoarding;
        mBinding.textViewBoardingInCountdown.setText(hoursAndMinutesUntilBoarding);
    }
}

ud851-Exercises-student\Lesson11-Completeing-The-UI\T11.02