Develop Reference

How can i keep the job service running when the app is closed from recent task list by user

I am using Job Scheduler API in my app to schedule a job for me after specific time interval. It runs fine when the app is running. But whenever the user closes the app or clears it from the recent task list the app stops and the scheduled job never executes afterwards until you open the app and it is rescheduled again from the time it is opened.
Now i want someone to help me to keep the jobs on executing even if the app is closed or cleared from the recent task list.
If there is any alternative solution please tell me.
i am looking for the solution from the past 3 days. Tried everything said by developers on StackOverFlow and other sites and none of them worked for me.
This is where is schedule the job!
ComponentName componentName = new
ComponentName(getActivity().getBaseContext(),WallpaperJobService.class);
JobInfo jobInfo = new JobInfo.Builder(777,componentName)
.setRequiresCharging(sharedPreferences.getBoolean("Charging",false))
.setRequiredNetworkType(sharedPreferences.getBoolean("Wifi",false) ?
JobInfo.NETWORK_TYPE_UNMETERED : JobInfo.NETWORK_TYPE_ANY)
.setPeriodic(sharedPreferences.getInt("Duration",15) * 60 *
1000)
.setPersisted(true)
.build();
JobScheduler scheduler = (JobScheduler)
getContext().getSystemService(Context.JOB_SCHEDULER_SERVICE);
scheduler.schedule(jobInfo);
My Job Service Class:
public class WallpaperJobService extends JobService {
private boolean jobCancelled;
private SharedPreferences sharedPreferences;
private SharedPreferences.Editor editor;
#Override
public boolean onStartJob(JobParameters params) {
Log.i("WallpaperJobService", "Job started!");
changeWallpaper(params);
return true;
}
private void changeWallpaper(final JobParameters params) {
final ArrayList<Image> images = (ArrayList<Image>)
MainActivity.favoritesRoomDatabase.roomDao().getAllFavoriteWallpapers();
sharedPreferences = getSharedPreferences("GridSize", MODE_PRIVATE);
editor = sharedPreferences.edit();
if (images != null && images.size() != 0) {
if (sharedPreferences.getInt("Index", 0) == images.size()) {
editor.putInt("Index", 0);
editor.commit();
}
Picasso.get().load(Constants.domain +
images.get(sharedPreferences.getInt("Index", 0)).getImage_url()).into(new
Target() {
#Override
public void onBitmapLoaded(final Bitmap bitmap,
Picasso.LoadedFrom from) {
new Thread(new Runnable() {
#Override
public void run() {
if (jobCancelled) {
Log.i("WallpaperJobService","Returned");
return;
}
try {
//Doing some work here
} catch (IOException e) {
e.printStackTrace();
}
Log.i("WallpaperJobService", "Job finished!");
jobFinished(params, false);
}
}).start();
}
#Override
public void onBitmapFailed(Exception e, Drawable errorDrawable)
{
Log.i("WallpaperJobService", "Bitmap load failed " +
e.getMessage());
}
#Override
public void onPrepareLoad(Drawable placeHolderDrawable) {
}
});
} else {
Log.i("WallpaperJobService", "Favorite database is null!");
}
}
#Override
public boolean onStopJob(JobParameters params) {
Log.i("WallpaperJobService", "Job cancelled before completion!");
jobCancelled = true;
return true;
}
}

When doing stuff periodically in the background — JobScheduler, WorkManager, AlarmManager, FCM push messages, etc. — you have to take into account that your process might not be around when it is time for you to do your work. Android will fork a process for you, but it is "starting from scratch". Anything that your UI might have set up in memory, such as a database, would have been for some prior process and might not be set up in the new process.

Enabling Camera Flash While Recording Video

I need a way to control the camera flash on an Android device while it is recording video. I'm making a strobe light app, and taking videos with a flashing strobe light would result in the ability to record objects that are moving at high speeds, like a fan blade.
The flash can only be enabled by starting a video preview and setting FLASH_MODE_TORCH in the camera's parameters. That would look like this:
Camera c = Camera.open();
Camera.Parameters p = c.getParameters();
p.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
c.setParameters(p);
c.startPreview();
Once the preview has started, I can flip that parameter back and forth to turn the light on and off. This works well until I try to record a video. The trouble is that in order to give the camera to the MediaRecorder, I first have to unlock it.
MediaRecorder m = new MediaRecorder();
c.unlock(); // the killer
m.setCamera(c);
After that unlock, I can no longer change the camera parameters and therefore have no way to change the flash state.
I do not know if it is actually possible to do this since I'm not the best at java-hacking, but here is what I do know:
Camera.unlock() is a native method, so I can't really see the mechanism behind the way it locks me out
Camera.Parameter has a HashMap that contains all of its parameters
Camera.setParameters(Parameters) takes the HashMap, converts it to a string, and passes it to a native method
I can eliminate all the parameters but TORCH-MODE from the HashMap and the Camera will still accept it
So, I can still access the Camera, but it won't listen to anything I tell it. (Which is kind of the purpose of Camera.unlock())
Edit:
After examining the native code, I can see that in CameraService.cpp my calls to Camera.setParameters(Parameters) get rejected because my Process ID does not match the Process ID the camera service has on record. So it would appear that that is my hurdle.
Edit2:
It would appear that the MediaPlayerService is the primary service that takes control of the camera when a video is recording. I do not know if it is possible, but if I could somehow start that service in my own process, I should be able to skip the Camera.unlock() call.
Edit3:
One last option would be if I could somehow get a pointer to the CameraHardwareInterface. From the looks of it, this is a device specific interface and probably does not include the PID checks. The main problem with this though is that the only place that I can find a pointer to it is in CameraService, and CameraService isn't talking.
Edit4: (several months later)
At this point, I don't think it is possible to do what I originally wanted. I don't want to delete the question on the off chance that someone does answer it, but I'm not actively seeking an answer. (Though, receiving a valid answer would be awesome.)

I encountered a similar issue. The user should be able to change the flash mode during recording to meet their needs depending on the light situation. After some investigative research i came to the following solution:
I assume, that you've already set up a proper SurfaceView and a SurfaceHolder with its necessary callbacks. The first thing i did was providing this code (not declared variables are globals):
public void surfaceCreated(SurfaceHolder holder) {
try {
camera = Camera.open();
parameters = camera.getParameters();
parameters.setFlashMode(Parameters.FLASH_MODE_OFF);
camera.setParameters(parameters);
camera.setPreviewDisplay(holder);
camera.startPreview();
recorder = new MediaRecorder();
} catch (IOException e) {
e.printStackTrace();
}
}
My next step was initializing and preparing the recorder:
private void initialize() {
camera.unlock();
recorder.setCamera(camera);
recorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
recorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
recorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
recorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
recorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
recorder.setVideoFrameRate(20);
recorder.setOutputFile(filePath);
try {
recorder.prepare();
} catch (IllegalStateException e) {
e.printStackTrace();
finish();
} catch (IOException e) {
e.printStackTrace();
finish();
}
}
It's important to note, that camera.unlock() has to be called BEFORE the whole initialization process of the media recorder. That said also be aware of the proper order of each set property, otherwise you'll get an IllegalStateException when calling prepare() or start(). When it comes to recording, i do this. This will usually be triggered by a view element:
public void record(View view) {
if (recording) {
recorder.stop();
//TODO: do stuff....
recording = false;
} else {
recording = true;
initialize();
recorder.start();
}
}
So now, i finally can record properly. But what's with that flash? Last but not least, here comes the magic behind the scenes:
public void flash(View view) {
if(!recording) {
camera.lock();
}
parameters.setFlashMode(parameters.getFlashMode().equals(Parameters.FLASH_MODE_TORCH) ? Parameters.FLASH_MODE_OFF : Parameters.FLASH_MODE_TORCH);
camera.setParameters(parameters);
if(!recording) {
camera.unlock();
}
}
Everytime i call that method via an onClick action i can change the flash mode, even during recording. Just take care of properly locking the camera. Once the lock is aquired by the media recorder during recording, you don't have to lock/unlock the camera again. It doesn't even work. This was tested on a Samsung Galaxy S3 with Android-Version 4.1.2. Hope this approach helps.

After preparing media recorder, use camera.lock(), and then set whatever parameters you want to set to camera.
But before starting recording you need to call camera.unlock(), and after you stop media recorder you need to call camera.lock() to start preview.
Enjoy!!!

Try this.. hopefully it will work.. :)
private static Torch torch;
public Torch() {
super();
torch = this;
}
public static Torch getTorch() {
return torch;
}
private void getCamera() {
if (mCamera == null) {
try {
mCamera = Camera.open();
} catch (RuntimeException e) {
Log.e(TAG, "Camera.open() failed: " + e.getMessage());
}
}
}
public void toggleLight(View view) {
toggleLight();
}
private void toggleLight() {
if (lightOn) {
turnLightOff();
} else {
turnLightOn();
}
}
private void turnLightOn() {
if (!eulaAgreed) {
return;
}
if (mCamera == null) {
Toast.makeText(this, "Camera not found", Toast.LENGTH_LONG);
button.setBackgroundColor(COLOR_WHITE);
return;
}
lightOn = true;
Parameters parameters = mCamera.getParameters();
if (parameters == null) {
button.setBackgroundColor(COLOR_WHITE);
return;
}
List<String> flashModes = parameters.getSupportedFlashModes();
if (flashModes == null) {
button.setBackgroundColor(COLOR_WHITE);
return;
}
String flashMode = parameters.getFlashMode();
Log.i(TAG, "Flash mode: " + flashMode);
Log.i(TAG, "Flash modes: " + flashModes);
if (!Parameters.FLASH_MODE_TORCH.equals(flashMode)) {
if (flashModes.contains(Parameters.FLASH_MODE_TORCH)) {
parameters.setFlashMode(Parameters.FLASH_MODE_TORCH);
mCamera.setParameters(parameters);
button.setBackgroundColor(COLOR_LIGHT);
startWakeLock();
} else {
Toast.makeText(this, "Flash mode (torch) not supported",
Toast.LENGTH_LONG);
button.setBackgroundColor(COLOR_WHITE);
Log.e(TAG, "FLASH_MODE_TORCH not supported");
}
}
}
private void turnLightOff() {
if (lightOn) {
button.setBackgroundColor(COLOR_DARK);
lightOn = false;
if (mCamera == null) {
return;
}
Parameters parameters = mCamera.getParameters();
if (parameters == null) {
return;
}
List<String> flashModes = parameters.getSupportedFlashModes();
String flashMode = parameters.getFlashMode();
if (flashModes == null) {
return;
}
Log.i(TAG, "Flash mode: " + flashMode);
Log.i(TAG, "Flash modes: " + flashModes);
if (!Parameters.FLASH_MODE_OFF.equals(flashMode)) {
if (flashModes.contains(Parameters.FLASH_MODE_OFF)) {
parameters.setFlashMode(Parameters.FLASH_MODE_OFF);
mCamera.setParameters(parameters);
stopWakeLock();
} else {
Log.e(TAG, "FLASH_MODE_OFF not supported");
}
}
}
}
private void startPreview() {
if (!previewOn && mCamera != null) {
mCamera.startPreview();
previewOn = true;
}
}
private void stopPreview() {
if (previewOn && mCamera != null) {
mCamera.stopPreview();
previewOn = false;
}
}
private void startWakeLock() {
if (wakeLock == null) {
Log.d(TAG, "wakeLock is null, getting a new WakeLock");
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
Log.d(TAG, "PowerManager acquired");
wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, WAKE_LOCK_TAG);
Log.d(TAG, "WakeLock set");
}
wakeLock.acquire();
Log.d(TAG, "WakeLock acquired");
}
private void stopWakeLock() {
if (wakeLock != null) {
wakeLock.release();
Log.d(TAG, "WakeLock released");
}
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (Eula.show(this)) {
eulaAgreed = true;
}
setContentView(R.layout.main);
button = findViewById(R.id.button);
surfaceView = (SurfaceView) this.findViewById(R.id.surfaceview);
surfaceHolder = surfaceView.getHolder();
surfaceHolder.addCallback(this);
surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
disablePhoneSleep();
Log.i(TAG, "onCreate");
}

To access the device camera, you must declare the CAMERA permission in your Android Manifest. Also be sure to include the <uses-feature> manifest element to declare camera features used by your application. For example, if you use the camera and auto-focus feature, your Manifest should include the following:
<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
A sample that checks for torch support might look something like this:
//Create camera and parameter objects
private Camera mCamera;
private Camera.Parameters mParameters;
private boolean mbTorchEnabled = false;
//... later in a click handler or other location, assuming that the mCamera object has already been instantiated with Camera.open()
mParameters = mCamera.getParameters();
//Get supported flash modes
List flashModes = mParameters.getSupportedFlashModes ();
//Make sure that torch mode is supported
//EDIT - wrong and dangerous to check for torch support this way
//if(flashModes != null && flashModes.contains("torch")){
if(flashModes != null && flashModes.contains(Camera.Parameters.FLASH_MODE_TORCH)){
if(mbTorchEnabled){
//Set the flash parameter to off
mParameters.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
}
else{
//Set the flash parameter to use the torch
mParameters.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
}
//Commit the camera parameters
mCamera.setParameters(mParameters);
mbTorchEnabled = !mbTorchEnabled;
}
To turn the torch on, you simply set the camera parameter Camera.Parameters.FLASH_MODE_TORCH
Camera mCamera;
Camera.Parameters mParameters;
//Get a reference to the camera/parameters
mCamera = Camera.open();
mParameters = mCamera.getParameters();
//Set the torch parameter
mParameters.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
//Comit camera parameters
mCamera.setParameters(mParameters);
To turn the torch off, set Camera.Parameters.FLASH_MODE_OFF

Splash screen with background tasks

I am trying to make my application launcha splash screen for 5 seconds while initializing various web services in the background. Here is my code:
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
// Splash screen view
setContentView(R.layout.splashscreen);
final SplashScreen sPlashScreen = this;
// The thread to wait for splash screen events
mSplashThread = new Thread()
{
#Override
public void run()
{
try {
synchronized(this){
// Wait given period of time or exit on touch
wait(5000);
}
}
catch(InterruptedException ex)
{
}
finally
{
finish();
// Run next activity
Intent intent = new Intent();
intent.setClass(sPlashScreen, Splash_testActivity.class);
startActivity(intent);
stop();
}
}
};
mSplashThread.start();
for (int i=0;i<100;i++)
Log.d("splash test", "initialize web methods");
}
Now what I think should happen is that while the splash screen is displayed, the application should log "initialize web methods."
But what actually happens is that the log is added only after the slash screen disappears.
What am I doing wrong??

Try to do it this way. This tutorial is simple and flexible. This is what you need:
// You initialize _splashTime to any value
// thread for displaying the SplashScreen
Thread splashTread = new Thread() {
#Override
public void run() {
try {
int waited = 0;
while(waited < _splashTime)) {
sleep(100);
waited += 100;
}
}
} catch(InterruptedException e) {
// do nothing
} finally {
finish();
startActivity(new Intent("com.droidnova.android.splashscreen.MyApp"));
stop();
}
}
};
splashTread.start();
Note: This code is adopted from the above url.

Run your Thread Using Handler or AsyncTask.

How to manage Android MediaPlayer state, errors, and exceptions?

I am trying to play a short sound byte after processing a scanned bar code. My code currently works fine for as many as twenty scans. However, eventually the MediaPlayer throws the following error repeatedly even after the app has been killed:
MediaPlayer: Error (-38, 0)
MediaPlayer: Attempt to perform seekTo in wrong state: mPlayer=0xXXXXXX, mCurrentState=0
--the X's representing a random 6 digit memory address--
I originally was playing the sound byte off of the UI thread. Since I've created a handler in an attempt to mitigate the issue. This is how I access the handler:
try {
mHandler.post(mScanFeedback);
} catch (IllegalStateException e) {
System.out.println("Media player state error");
e.printStackTrace();
}
Here is the code for the handler:
private Runnable mScanFeedback = new Runnable(){
public void run() {
if(getString(R.string.working).equals(mStatusHourly)) {
final MediaPlayer mediaPlayer = MediaPlayer.create(getBaseContext(), R.raw.bleep_working);
mediaPlayer.setOnErrorListener(new OnErrorListener() {
public boolean onError(MediaPlayer mp, int what, int extra) {
mediaPlayer.reset();
System.out.println("Media Player onError callback!");
return true;
}
});
mediaPlayer.start();
try {
Thread.sleep(150);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
mediaPlayer.release();
}
} else if(getString(R.string.not_working).equals(mStatusHourly)) {
final MediaPlayer mediaPlayer = MediaPlayer.create(getBaseContext(), R.raw.bleep_not_working);
mediaPlayer.setOnErrorListener(new OnErrorListener() {
public boolean onError(MediaPlayer mp, int what, int extra) {
mediaPlayer.reset();
System.out.println("Media Player onError callback!");
return true;
}
});
mediaPlayer.start();
try {
Thread.sleep(275);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
mediaPlayer.release();
}
} else {
System.out.println("Audio feedback failed as status was indeterminate.");
}
}
};
In the beginning I didn't call release() and adding it hasn't seemed to make it work any better or worse. The onError callback is never called when the problem occurs. I've tried to reset() the media player after each time it is played but that throws an error. Right now I resort to restarting the phone to keep my Logcat from being unusable by the onslaught of the same two error lines repeated continually.
I'm using zxing's bar code scanner and there is a short beep played within that activity as confirmation that the bar code has been captured. A small part of me wonders if their isn't a conflict there.
I'm still new to programming and this is my first question on stack overflow. Let me know if I should have provided any additional information or if I should try to keep it a little more lean.
Update:
I was unable to resolve the issue with the MediaPlayer. However, I was able to work around the issue by switching to a SoundPool implementation. The class below provides the needed functionality.
import java.util.HashMap;
import android.content.Context;
import android.media.AudioManager;
import android.media.SoundPool;
public class SoundManager {
private SoundPool mSoundPool;
private HashMap mSoundPoolMap;
private AudioManager mAudioManager;
private Context mContext;
public void initSounds(Context theContext) {
mContext = theContext;
mSoundPool = new SoundPool(4, AudioManager.STREAM_MUSIC, 0);
mSoundPoolMap = new HashMap();
mAudioManager = (AudioManager)mContext.getSystemService(Context.AUDIO_SERVICE);
}
public void addSound(int index, int SoundID) {
mSoundPoolMap.put(index, mSoundPool.load(mContext, SoundID, 1));
}
public void playSound(int index) {
float streamVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
streamVolume = streamVolume / mAudioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
mSoundPool.play(index, streamVolume, streamVolume, 1, 0, 1f);
}
public void playLoopedSound(int index) {
float streamVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
streamVolume = streamVolume / mAudioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
mSoundPool.play(index, streamVolume, streamVolume, 1, -1, 1f);
}
}
Which I then accessed from my Activity with:
mSoundManager = new SoundManager();
mSoundManager.initSounds(getBaseContext());
mSoundManager.addSound(1, R.raw.bleep_working);
mSoundManager.addSound(2, R.raw.bleep_not_working);
mSoundManager.playSound(1);
mSoundManager.playSound(2);

Trouble with Android Camera

I have some code I have been experimenting with to see what I can do with the camera device. This following code works, but I have some issues with it that I cannot seem to solve.
The first call never works. The first time running the code the onPictureTaken callback is never called, so the file is never written. However the camera goes through all the other steps, including making the fake shutter noise.
I can't seem to set the picture size to something other than whatever it defaults to. If I try to set it to something else, the code stops working. Does the same as above, where the camera goes through all the motions, but the onPictureTaken callback is never called.
When the pictures are saved to the DCIM folder, the taken pictures do not show up in the default 'Photos' app on my phone, unless i reboot the phone.
Is there any way through code to disable the shutter noise?
Sorry, the code is a little messy because its an experiment.
Also, this code is executed in a BroadcastReceiver
#Override
public void onReceive(Context context, Intent intent) {
// TODO Auto-generated method stub
if(intent.getAction().equals(TAKE_PICTURE_INTENT))
{
Toast.makeText(context, "Test", Toast.LENGTH_LONG).show();
System.out.println("GOT THE INTENT");
try
{
Camera camera = Camera.open();
System.out.println("CAMERA OPENED");
Parameters params = camera.getParameters();
params.set("flash-mode", "off");
params.set("focus-mode", "infinity");
params.set("jpeg-quality", "100");
//params.setPictureSize(2592, 1952);
String str = params.get("picture-size" + "-values");
System.out.println(str);
String size = str.split(",")[0];
System.out.println(size);
//params.set("picture-size", size);
camera.setParameters(params);
System.out.println("CAMERA PARAMETERS SET");
camera.startPreview();
System.out.println("CAMERA PREVIEW STARTED");
camera.autoFocus(new AutoFocusCallBackImpl());
}
catch(Exception ex)
{
System.out.println("CAMERA FAIL, SKIP");
return ;
}
}//if
}//onreceive
private void TakePicture(Camera camera)
{
camera.takePicture(new Camera.ShutterCallback() {
#Override
public void onShutter() {
// TODO Auto-generated method stub
System.out.println("CAMERA SHUTTER CALLBACK");
}
}
, null,
new Camera.PictureCallback() {
public void onPictureTaken(byte[] imageData, Camera c) {
//c.release();
System.out.println("CAMERA CALLBACK");
FileOutputStream outStream = null;
try {
System.out.println("Start Callback");
File esd = Environment.getExternalStorageDirectory();
outStream = new FileOutputStream(esd.getAbsolutePath() + String.format(
"/DCIM/%d.jpg", System.currentTimeMillis()));
outStream.write(imageData);
outStream.close();
System.out.println( "onPictureTaken - wrote bytes: " + imageData.length);
} catch (FileNotFoundException e) {
e.printStackTrace();
System.out.println("File not found exception");
} catch (IOException e) {
e.printStackTrace();
System.out.println("IO exception");
} finally {
System.out.println("Finally");
c.release();
}
}
}
);
//camera.release();
}//TAKE PICTURE
private class AutoFocusCallBackImpl implements Camera.AutoFocusCallback {
#Override
public void onAutoFocus(boolean success, Camera camera) {
//bIsAutoFocused = success; //update the flag used in onKeyDown()
System.out.println("Inside autofocus callback. autofocused="+success);
//play the autofocus sound
//MediaPlayer.create(CameraActivity.this, R.raw.auto_focus).start();
if(success)
{
System.out.println("AUTO FOCUS SUCCEDED");
}
else
{
System.out.println("AUTO FOCUS FAILED");
}
TakePicture(camera);
System.out.println("CALLED TAKE PICTURE");
}
}//AUTOFOCUSCALLBACK

1.First of all put all camera logic out of BroadCast receiver & put it into seprate Activity.
2.
When the pictures are saved to the DCIM folder, the taken pictures do not show up in the default 'Photos' app on my phone, unless i reboot the phone.
because MediaScanner needs to be called to rescan images/changes once you take photo. When u reboot phone mediascanner scans media & finds new images. for this isuue you should check out MediaScanner.
3.Follow Android Camera Tutorial & Camera API
-Thanks