In this tutorial, we show you how to turn on/off the phone camera led or flashlight in Android. See code snippets :

1. Turn on


	camera = Camera.open();
	Parameters p = camera.getParameters();
	p.setFlashMode(Parameters.FLASH_MODE_TORCH);
	camera.setParameters(p);
	camera.startPreview();	

2. Turn off


	camera = Camera.open();
	Parameters p = camera.getParameters();
	p.setFlashMode(Parameters.FLASH_MODE_OFF);
	camera.setParameters(p);
	camera.stopPreview();

And, put following permission on AndroidManifest.xml.


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

P.S This project is developed in Eclipse 3.7, and tested with Samsung Galaxy S2 (Android 2.3.3).

1. Android Layout

A button only.

File : res/layout/main.xml


<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/relativeLayout1"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <Button
        android:id="@+id/buttonFlashlight"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
       	android:layout_centerVertical="true"
       	android:layout_centerHorizontal="true"
        android:text="Torch" />

</RelativeLayout>

2. Activity

Read the code, a button to turn on / off the flashlight, it should be self-explanatory.


package com.mkyong.android;

import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class FlashLightActivity extends Activity {

	//flag to detect flash is on or off
	private boolean isLighOn = false;

	private Camera camera;

	private Button button;

	@Override
	protected void onStop() {
		super.onStop();

		if (camera != null) {
			camera.release();
		}
	}

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		button = (Button) findViewById(R.id.buttonFlashlight);

		Context context = this;
		PackageManager pm = context.getPackageManager();

		// if device support camera?
		if (!pm.hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
			Log.e("err", "Device has no camera!");
			return;
		}

		camera = Camera.open();
		final Parameters p = camera.getParameters();

		button.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View arg0) {

				if (isLighOn) {

					Log.i("info", "torch is turn off!");

					p.setFlashMode(Parameters.FLASH_MODE_OFF);
					camera.setParameters(p);
					camera.stopPreview();
					isLighOn = false;

				} else {

					Log.i("info", "torch is turn on!");

					p.setFlashMode(Parameters.FLASH_MODE_TORCH);

					camera.setParameters(p);
					camera.startPreview();
					isLighOn = true;

				}

			}
		});

	}
}

3. Android Permission

Assign CAMERA permission.

File : AndroidManifest.xml


<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.mkyong.android"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="10" />

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

    <application
        android:debuggable="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:label="@string/app_name"
            android:name=".FlashLightActivity" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

4. Demo

None, until i have 2nd hand phone to capture the current flashlight on my phone :)

Download Source Code

Download it – Android-LED-FlashLight-Example.zip (16 KB)

References

  1. Android Camera Javadoc
  2. Android camera Parameters Javadoc