A Simple FlashLight Application.

Here is a simple Application on how to use flashlight in android.

package com.coderzheaven.pack;

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;
import android.widget.Toast;

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;
		}
		try{
			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;
	
					}
	
				}
			});
		}catch(Exception e){
			Toast.makeText(this, "Your device doesnot have FlashLight capability", Toast.LENGTH_LONG).show();
		}

	}
}

Now the layout file 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>

AndroiManifest.xml file contents.

Make sure to add the permissions.

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

    <uses-sdk android:minSdkVersion="5" />

    <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>

Download the android java source code from here.

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