rm19

q1.

 <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <ToggleButton
        android:id="@+id/toggleButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:checked="false"
        android:textOff="Turn Off"
        android:textOn="Turn On" />

    <ImageView
        android:id="@+id/bulbImageView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:src="@drawable/bulb_off"
        android:layout_below="@id/toggleButton"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="16dp"/>

</RelativeLayout>

 import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.CompoundButton;
import android.widget.ImageView;
import android.widget.ToggleButton;

public class MainActivity extends AppCompatActivity {
    private ToggleButton toggleButton;
    private ImageView bulbImageView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        toggleButton = findViewById(R.id.toggleButton);
        bulbImageView = findViewById(R.id.bulbImageView);

        toggleButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                if (isChecked) {
                    bulbImageView.setImageResource(R.drawable.bulb_on);
                } else {
                    bulbImageView.setImageResource(R.drawable.bulb_off);
                }
            }
        });
    }
}

add two png files bulb_on and bulb_off