Builduing a Simple Flashlight App in Android Studio

 In this post, you will learn how to create a simple flashlight app to enable or disable the phone's flashlight in android stuido using Java.

    For building the app, first, create a new project and add the power icon from vector assets in your drawable folder. Now, create two new drawable resource files that will be the background for our switch on and switch off button. Add the following code to the files:

Code for switch on button:

	<?xml version="1.0" encoding="utf-8"?>
	<shape xmlns:android="http://schemas.android.com/apk/res/android"
	android:shape="rectangle">
	<solid android:color="@android:color/holo_blue_bright"/>
	<corners android:radius="100dp"/>
	</shape>

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Code for switch off button:

	<?xml version="1.0" encoding="utf-8"?>
	<shape xmlns:android="http://schemas.android.com/apk/res/android"
	android:shape="rectangle">
	<solid android:color="@android:color/darker_gray"/>
	<corners android:radius="100dp"/>
	</shape>

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Once this is done, in the activity_main.xml file, create the layout for the app screen. Add the following code:

	<?xml version="1.0" encoding="utf-8"?>
	<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
	xmlns:app="http://schemas.android.com/apk/res-auto"
	xmlns:tools="http://schemas.android.com/tools"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	tools:context=".MainActivity"
	android:background="#4527A0">
	<ImageButton
	android:id="@+id/switch_on"
	android:layout_width="100dp"
	android:layout_height="100dp"
	android:layout_centerInParent="true"
	android:background="@drawable/green_round"
	android:src="@drawable/ic_power" />
	<ImageButton
	android:id="@+id/switch_off"
	android:layout_width="100dp"
	android:layout_height="100dp"
	android:src="@drawable/ic_power"
	android:layout_centerInParent="true"
	android:background="@drawable/gray_round"/>
	</RelativeLayout>

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The background of the image buttons are the switch_on and switch_off drawable files that we created earlier.

Now, in the MainActivity.java class , add the following code:

	public class MainActivity extends AppCompatActivity {
	ImageButton switch_on,switch_off;
	Camera camera;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_main);
	switch_on = findViewById(R.id.switch_on);
	switch_off = findViewById(R.id.switch_off);
	camera = Camera.open();
	final Camera.Parameters parameters = camera.getParameters();
	switch_on.setOnClickListener(new View.OnClickListener() {
	@Override
	public void onClick(View view) {
	switch_off.setVisibility(View.VISIBLE);
	switch_on.setVisibility(View.GONE);
	parameters.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
	camera.setParameters(parameters);
	camera.stopPreview();
	}
	});
	switch_off.setOnClickListener(new View.OnClickListener() {
	@Override
	public void onClick(View view) {
	switch_off.setVisibility(View.GONE);
	switch_on.setVisibility(View.VISIBLE);
	parameters.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
	camera.setParameters(parameters);
	camera.startPreview();
	}
	});
	}
	}

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Here the Camera used is Camera (android.hardware) and not the graphics one.

Now finally, in the AndroidManifest.xml file, add the permissions to allow access to the device's camera.

<uses-permission android:name="android.permission.CAMERA"/>

<uses-permission android:name="android.hardware.camera"/>

And that's it. You have successfully built your flashlight app...

Output:

Flashlight OFF

Flashlight ON