Develop Reference

take photo from camera in service

How can Take picture from front camera in service without showing camera on screen.
I have service class
public class PhotoTakingService extends Service {
//Camera variables
//a surface holder
private SurfaceHolder sHolder;
//a variable to control the camera
private Camera mCamera;
//the camera parameters
private Parameters parameters;
boolean mPreviewRunning = false;
/**
* Called when the activity is first created.
*/
#Override
public void onCreate() {
super.onCreate();
}
#Override
public void onStart(Intent intent,int startId) {
// TODO Auto-generated method stub
super.onStart(intent,startId);
mCamera = Camera.open();
SurfaceView sv = new SurfaceView(getBaseContext());
try {
Camera.Parameters p = mCamera.getParameters();
mCamera.setParameters(p);
mCamera.startPreview();
mCamera.takePicture(null,null,mPictureCallback);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//Get a surface
sHolder = sv.getHolder();
//tells Android that this surface will have its data constantly replaced
sHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
Camera.PictureCallback mPictureCallback = new Camera.PictureCallback() {
public void onPictureTaken(byte[] imageData,Camera c) {
Log.e("Callback TAG","Here in jpeg Callback");
if (imageData != null) {
FileOutputStream outputStream = null;
try {
outputStream = new FileOutputStream("/sdcard/car_final/Image.jpg");
outputStream.write(imageData);
// Removed the finish call you had here
} catch (Exception e) {
e.printStackTrace();
} finally {
if (outputStream != null) try {
outputStream.close();
} catch (IOException ex) {
// TODO Auto-generated catch block
ex.printStackTrace();
}
}
}
}
};
#Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
}
and main activity. I want to call from main activity.
public class MainActivity extends Activity implements SurfaceHolder.Callback {
private static final String TAG = MainActivity.class.getSimpleName();
public static SurfaceView mSurfaceView;
public static SurfaceHolder mSurfaceHolder;
public static Camera mCamera;
public static boolean mPreviewRunning;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSurfaceView = (SurfaceView) findViewById(R.id.surfaceView);
mSurfaceHolder = mSurfaceView.getHolder();
mSurfaceHolder.addCallback(this);
mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
Button btnStart = (Button) findViewById(R.id.button1);
btnStart.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
Intent intent = new Intent(MainActivity.this, PhotoTakingService.class);
//intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startService(intent);
}
});
/* Button btnStop = (Button) findViewById(R.id.StopService);
btnStop.setOnClickListener(new View.OnClickListener()
{
public void onClick(View v)
{
stopService(new Intent(CameraRecorder.this, RecorderService.class));
}
});*/
}
#Override
public void surfaceCreated(SurfaceHolder holder) {
}
#Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
#Override
public void surfaceDestroyed(SurfaceHolder holder) {
}
}

When you are in background thread such as service use SurfaceTexture instead of SurfaceHolder. If you are looking for implementation here is a opensource app where I have implemented background video stream and UI video stream both.

Android Camera: Turn on/off camera flash - Application crash when rotate device

I have a simple application with a button to turn on/off camera flash:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button = (Button)findViewById(R.id.btnFlash);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if(!isLight)
{
switchON();
}
else
{
switchOFF();
}
}
});
}
If the flash was off, it will turn on and else, turn off. Yes, it works well.
The problem is:
- Firstly, I pressed the button to turn on, after that, I rotate my device and then pressing again to turn off -> Application crash.
Fatal Exception: main - Runtime Exception: Fail to connect to camera
service
These are 2 functions to turn on/off
public void switchON()
{
camera = Camera.open();
Parameters p = camera.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_TORCH);
camera.setParameters(p);
camera.startPreview();
isLight = true;
}
public void switchOFF()
{
Parameters p = camera.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_OFF);
camera.setParameters(p);
camera.stopPreview();
camera.release();
isLight = false;
}

Try This (I re-wrote the code):
public class YourClass extends Activity {
private Button button;
private Camera camera;
private boolean isLight=false;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
button = (Button)findViewById(R.id.btnFlash);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if(!isLight)
{
switchON();
}
else
{
switchOFF();
}
}
});
}
#Override
protected void onResume() {
super.onResume();
try{
camera = Camera.open();
} catch( Exception e ){
e.printStackTrace();
}
}
#Override
protected void onPause() {
if( camera != null ){
camera.release();
camera = null;
}
super.onPause();
}
private void switchOFF(){
if( mCamera != null ){
Parameters p = camera.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_OFF);
camera.setParameters(p);
isLight = false;
}
}
private void switchON(){
if( mCamera != null ){
Parameters p = camera.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_TORCH);
camera.setParameters(p);
isLight=true;
}
}
}

Try:
public void switchOFF()
{
if(camera == null)
{
camera = Camera.open();
}
Parameters p = camera.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_OFF);
camera.setParameters(p);
camera.stopPreview();
camera.release();
isLight = false;
}

Refresh Activity using onResume()

I have a Flashlight Activity. Normally it works fine but When I go to any other activity, it stop working!
So I want to refresh the code when I back to the Flashlight Activity.
I think refreshing using onResume() would help me best, But how to do it?
public class FlashLightActivity extends Activity {
//flag to detect flash is on or off
private boolean isLighOn = false;
private Camera camera;
private Button next1, next2;
#Override
protected void onStop() {
super.onStop();
if (camera != null) {
camera.release();
}
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
next1 = (Button) findViewById(R.id.ebtn28_answer);
next1.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent myIntent = new Intent(view.getContext(), FullScreen.class);
startActivityForResult(myIntent, 0);
}
});
next2 = (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();
next2.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;
}
}
});
}
}

You need to override onPause and onResume. In onPause, you need to release the Camera. In onResume, you need to re-request it. Camera doesn't like it if you try to hold it when you aren't the active activity.
public void onPause(){
super.onPause();
if(camera != null){
camera.release();
camera = null;
}
}
public void onResume(){
super.onResume();
//Need to release if we already have one, or we won't get the camera
if(camera != null){
camera.release();
camera = null;
}
try {
camera = Camera.open();
}
catch (Exception e){
}
}

Changing two button into a toggle button

I have a Flashlight code that use two buttons (on_btn and off_btn) to turn on and turn off the Flashlight.
How can I associate them in a single button?
Very novice can you give elaborate suggestion please?
The code below is found from an answer: And it works for my mobile. But on the emulator it crashs while clicking on the button. Here is the cat-log https://dl.dropbox.com/u/15065300/logcat1.png
The line number 74 is: Parameters params = mCamera.getParameters();
Can anybody any suggestion please?
public class FlashLight extends Activity {
private final static String LOG_TAG = "FlashLight";
private Button mOnBtn;
private Camera mCamera;
private boolean isActive;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//this will be inside your onCreate...
mOnBtn = (Button) findViewById(R.id.on_btn);
mOnBtn.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
flipSwitch();
processClick();
}
});
}
//these will be outside your onCreate
public void flipSwitch() {
isActive = !isActive;
}
#Override
protected void onResume() {
super.onResume();
try{
mCamera = Camera.open();
mCamera.startPreview();
Toast.makeText(getApplicationContext(),"Camera is present", Toast.LENGTH_LONG).show();
} catch( Exception e ){
Log.e(LOG_TAG, "Impossible d'ouvrir la camera");
}
}
#Override
protected void onPause() {
if( mCamera != null ){
mCamera.release();
mCamera = null;
}
super.onPause();
}
public void processClick() {
if(isActive) {
Parameters params = mCamera.getParameters();
params.set("flash-mode", "torch");
mCamera.setParameters( params );
mCamera.startPreview();
}
else {
Parameters params = mCamera.getParameters();
params.set("flash-mode", "off");
mCamera.setParameters( params );
mCamera.stopPreview();
}
}
}

use the button to flip a boolean value, and change your flashlight to go on and off accordingly.
private boolean isActive;
//this will be inside your onCreate...
button.setOnClickListener(new View.onClickListener() {
public void onClick(View v) {
flipSwitch();
processClick();
}
}
//these will be outside your onCreate
public void flipSwitch() {
isActive = !isActive;
}
public void processClick() {
if(isActive) {
//button is clicked on
}
else {
//button is clicked off
}
}

You could always use the Toggle Button instead of two buttons. It's very "Android formal".
//Create a toggle button
ToggleButton tg = (ToggleButton) findviewbyId(R.id.togbut);
//Implement onClickListener
tg.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v){
//Flip on or off
}
});
In the onClick() method, you can do what you need to do according to what your app is suppose to do when the button is on or off.
In the xml layout, you say what the toggle button says when it's on and off.
<ToggleButton
android:id="#+id/togbut"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textOn="Button On"
android:textOff="Button Off"
android:checked="true" />
When you click the toggle button, it will automatically change the text and toggle.
Here's a good example: http://www.mkyong.com/android/android-togglebutton-example/
Hope that helps!

Make Strobe Light from LED light on button click

i have made a flashlight app and i want to try to make add-on to allow a strobe light feature.
I want to set it up on a different button thought, not the same one. i think i need to use a timer , but i have never used a timer because im new to java.
here is my code for the flashlight:
public class FlashLightActivity extends Activity {
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 (!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() {
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;
}
}
});
}
}

You could use a Handler
public class Strobe extends Activity {
private LinearLayout mLinearLayout;
private Handler mHander = new Handler();
private boolean mActive = false;
private boolean mSwap = true;
private final Runnable mRunnable = new Runnable() {
public void run() {
if (mActive) {
if (mSwap) {
mLinearLayout.setBackgroundColor(Color.WHITE);
mSwap = false;
mHander.postDelayed(mRunnable, 20);
} else {
mLinearLayout.setBackgroundColor(Color.BLACK);
mSwap = true;
mHander.postDelayed(mRunnable, 100);
}
}
}
};
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mLinearLayout = (LinearLayout) findViewById(R.id.strobe);
startStrobe();
}
private void startStrobe() {
mActive = true;
mHander.post(mRunnable);
}
}
Set a Theme to the Activity to make it full screen.
android:theme="#android:style/Theme.NoTitleBar.Fullscreen"