JNTU MCA III MOBILE APPLICATION DEVELOPMENT Previous Question Paper (October/ November - 2020 - R17)

To implement this, define the layout in activity_main.xml and handle the logic in MainActivity.java.

activity_main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/rootLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <Button android:id="@+id/btnRed" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="RED"/>
    <Button android:id="@+id/btnGreen" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="GREEN"/>
    <Button android:id="@+id/btnBlue" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="BLUE"/>
</LinearLayout>

MainActivity.java:

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final View root = findViewById(R.id.rootLayout);
        findViewById(R.id.btnRed).setOnClickListener(v -> root.setBackgroundColor(Color.RED));
        findViewById(R.id.btnGreen).setOnClickListener(v -> root.setBackgroundColor(Color.GREEN));
        findViewById(R.id.btnBlue).setOnClickListener(v -> root.setBackgroundColor(Color.BLUE));
    }
}

Android OS is a powerful, open-source platform built on the Linux kernel. Its key features include:

• Application Framework: Provides reusable components and services, allowing developers to leverage existing APIs for location, sensors, and notifications.
• Dalvik/ART Runtime: Android uses the Android Runtime (ART) to execute bytecode, optimized for low-memory environments.
• Integrated Browser: Based on the open-source WebKit engine for efficient web rendering.
• Optimized Graphics: Includes a custom 2D graphics library and 3D graphics based on the OpenGL ES specification.
• SQLite: A lightweight, relational database engine used for structured data storage within applications.
• Media Support: Native support for common audio, video, and image formats (e.g., H.264, MP3, JPEG).
• Multi-touch and Hardware Support: Native support for touchscreens, Bluetooth, Wi-Fi, camera, and GPS sensors.
• Inter-process Communication (IPC): Uses a Binder mechanism to allow different applications and services to communicate securely.