Develop Reference

Application skipping 600 frames

so im building this service for a application locker. it runs fine for the most part.but when i try to run the service to lock my own application(ie the app locker itself) there's a lag for like 4-5 seconds and then the lock activity launches. The logcat displays that it has skipped 600 frames and is doing too much work on the main thread. can anyone tell him how do i fix this or optimize this code
the AppActivities contains the name of activities that are to be ignored from launching the locker again when they are on top of the stack.eg the lockscreen activity to be shown to the user. The allowedapp is the last app verified by the user
public class LockerService extends Service {
String LockedApps[];
String allowedapp = null;
DataBaseHandler handler;
Intent pwdIntent = null;
ActivityManager am;
String[] AppActivities = { "com.packagename.Locker",
"com.packagename.Compare_Pattern",
"com.packagename.Captcha_Verfication",
"com.haibison.android.lockpattern.LockPatternActivity" };
private final static Handler servicehandler = new Handler() {
#Override
public void handleMessage(Message msg) {
}
};
#Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();
handler = new DataBaseHandler(this);
am = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
pwdIntent = new Intent(LockerService.this, Locker.class);
pwdIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
}
#Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
private Runnable checkforeground = new Runnable() {
public void run() {
handler.open();
LockedApps = handler.getPackages();
handler.close();
String packname = am.getRunningTasks(1).get(0).topActivity
.getPackageName();
String activityname = am.getRunningTasks(1).get(0).topActivity
.getClassName();
SharedPreferences sp = PreferenceManager
.getDefaultSharedPreferences(LockerService.this);
allowedapp = sp.getString("allowedapp", "anon");
// check if top application is mylocker application
if ((packname.equals("com.packagename"))
&& (allowedapp.equals("com.packagename"))) {
// do nothing
}
// check if top application is mylocker application and prevent relaunching the lockeractivity every 1.5 seconds
else if ((packname.equals("com.packagename"))
&& !(Arrays.asList(AppActivities).contains(activityname))) {
try {
Editor edit = sp.edit();
edit.putString("current_app", packname);
edit.commit();
startActivity(pwdIntent);
Thread.sleep(10000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} else if ((Arrays.asList(LockedApps).contains(packname))
&& (allowedapp.equals(packname))) {
// do nothing
} else if ((Arrays.asList(LockedApps).contains(packname))) {
Editor edit = sp.edit();
edit.putString("current_app", packname);
edit.commit();
startActivity(pwdIntent);
}
servicehandler.postDelayed(this, 1500); // 1.5 seconds
}
};
#Override
public void onStart(Intent intent, int startId) {
servicehandler.removeCallbacks(checkforeground);
servicehandler.postDelayed(checkforeground, 1500);// 1.5 second
}
#Override
public void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
servicehandler.removeCallbacks(checkforeground);
stopSelf();
}
}

first of all as Gabe mentioned, a runnable runs on the main Thread.To solve the frames issue You'll need to create another new thread to run your code in the background.
Try this initialize executorService and LcThread and a boolean running_statusin your service.
The running_status variable is used to break the while loop of your thread so that stops looping in the back
#Override
public void onStart(Intent intent, int startId) {
running_status = true;
executorService = Executors.newSingleThreadExecutor();
servicehandler.removeCallbacks(LcThread);
LcThread = new LockerThread();
executorService.submit(LcThread);
}
create the following class
class LockerThread implements Runnable {
#Override
public void run() {
while(running_status){
//copy code from your old Runnable run method here
}
}
}
next modify the onDestroy method
#Override
public void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
if (executorService != null) {
executorService.shutdown();
}
running_status = false;
servicehandler.removeCallbacks(LcThread);
stopSelf();
}
hope this solves your problem

A runnable still happens on the main thread. Services do not have their own thread by default, they run on the UI thread. If you want to do heavy processing in a service, you need to use a Thread or AsyncTask, so the processing does not occur on the UI thread.

Viewpager swip delay

I'm using viewpager to show music and on swip left/right changing music according to that.When i swip viewpager it takes few sec in swip(it doesnot swip smoothly).
Code:
#Override
public void onPageSelected(int arg0) {
// TODO Auto-generated method stub
if (mCurrentPage > arg0) {
try {
Constant.position--;
musicService = new Intent(getApplicationContext(),
MusicService.class);
musicService.putExtra(Constant.NEXT, Constant.PREVIOUS);
startService(musicService);
musicService = null;
} catch (Exception e) {
e.printStackTrace();
}
} else {
try {
Constant.position++;
musicService = new Intent(getApplicationContext(),
MusicService.class);
musicService.putExtra(Constant.NEXT, Constant.NEXT);
startService(musicService);
musicService = null;
} catch (Exception e) {
e.printStackTrace();
}
}
mCurrentPage = arg0;
}
whenever I remove this code from onPageSelected, it swip smoothly. I had also putted this code inside handler but no befinits same issue.
Suggest me where I'm doing wrong and how to resolver this.
Update:
#Override
public int onStartCommand(final Intent intent, int flags, int startId) {
// TODO Auto-generated method stub
mThread = new Thread(new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
sPosition = Constant.position;
if (intent != null) {
try {
mPrevious = (String) intent.getExtras().get(
Constant.NEXT);
System.out.println("value of previous=" + mPrevious);
if (mPrevious.equalsIgnoreCase(Constant.PLAY)) {
if (mediaPlayer.isPlaying()) {
mediaPlayer.pause();
cancelNotification();
} else {
mediaPlayer.start();
buildNotification(title, album);
}
} else if (mPrevious
.equalsIgnoreCase(Constant.PREVIOUS)) {
playPrevious();
} else if (mPrevious.equalsIgnoreCase(Constant.NEXT)) {
playNext();
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
});
mThread.start();
return START_NOT_STICKY;
}

From the guide topic Services:
Caution: A services runs in the same process as the application in which it is declared and in the main thread of that application, by default. So, if your service performs intensive or blocking operations while the user interacts with an activity from the same application, the service will slow down activity performance. To avoid impacting application performance, you should start a new thread inside the service
Make sure your music service starts a thread to delegate work to.

Android Timed Async Task

Hi currently i have the following code which utilizes Asycn Task and Timer.
My async task is basically trying to send a HTTP GET method from a URL where the response from the server could varies depending on connection and load.
What i would like to do is to have a timed async task. Where, it will schedule an AsyncTask every X second BUT if there is currently an Async Task in progress i would have to kill it first. Then start a new one.
Here is the code that i have at the moment:
private static boolean running = false;
Timer myTimer;
protected void onCreate(Bundle savedInstanceState) {
/* REST OF CODE OMITTED */
MyTimerTask myTask = new MyTimerTask();
myTimer = new Timer();
myTimer.schedule(myTask, 0, 10000);
}
/* REST OF CODE OMITTED */
private class MyTimerTask extends TimerTask {
public void run() {
if(!running){
Log.i("TAG", "NEW TIMER STARTED.");
RetrieveChatMessage task = new RetrieveChatMessage();
task.execute();
running = true;
}else{
running = false;
}
}
}
private class RetrieveChatMessage extends AsyncTask<String, Void, ArrayList<Chat>> {
#Override
protected ArrayList<Chat> doInBackground(String... params) {
// TODO Auto-generated method stub
ArrayList<Chat> cList = null;
String jResult = null;
Log.i("TAG", "RETRIEVING CHAT MESSAGE");
try {
jResult = ((new HttpRetriever())).getChatList(mAccount.email, mAccount.passwd);
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
if(jResult != null){
Log.i("TAG", "JSON DATA: " + jResult);
cList = (new ChatHandlers()).getChatList(jResult);
}else{
cList = null;
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("TAG", "JSON Exception " + e.toString());
}
return cList;
}
#Override
protected void onPostExecute(final ArrayList<Chat> result) {
Log.i("TAG", "ON POST EXECUTE");
if(result != null){
// Do something here
}
}
}
To be honest the code above works with slight issues:
1. It seems to execute the Async randomly, instead of every 10 seconds.
2. When i go to another activity, somewhat it prevents other Async task from doing its job (Which is also trying to retrieve JSON response from server).
I am not too worried about the later problem (and that is not the question i am asking). I just would like to know how to have a proper timed Async Task. Can anyone point me to a direction.
Thank you.
EDIT #1:
after reading #thepoosh comment's i tried the following (i put it in onCreate):
scheduleTaskExecutor= Executors.newScheduledThreadPool(5);
scheduleTaskExecutor.scheduleAtFixedRate(new Runnable() {
public void run() {
// Parsing RSS feed:
// myFeedParser.doSomething();
Log.w("THUMBQOO", "NEW TASK STARTED");
retrieveChat();
}
}, 0, 15, TimeUnit.SECONDS);
Result: i have a consistent execution of Task. However, it seems that retrieveChat(); is never be called after the first execution.

Actually AsyncTask is not used for long operations .Check Here
You should use a Thread that uses a interface to notify UI or you can simply use a Handler which is the most Preffered way in android. Simply you can do a task repeatedly for every 10 seconds by
handler.postDelayed(new Runnable() {
#Override
public void run() {
// do work
handler.postDelayed(10000);
}
}, 10000);

Declare a Handler object to maintain future task executor...
private Handler mTimerHandler = new Handler();
Write a thread which will execute your future task...
private Runnable mTimerExecutor = new Runnable() {
#Override
public void run() {
//write your code what you want to do after the specified time elapsed
if(!running){
RetrieveChatMessage task = new RetrieveChatMessage();
task.execute();
running = true;
}else{
running = false;
}
}
};
Call your future tast executor with time using hanlder...
mTimerHandler.postDelayed(mTimerExecutor, 10000);
You can cancle your future task executor any time by this...
mTimerHandler.removeCallbacks(mTimerExecutor);

I am not sure if this is a very good way of accomplishing this (my answer here below) :
Use a Handler, create a HandlerThread and keep posting messages to this handler.
For the handlers "handleMessage" method, you can do your task and again send a message back to the MessageQueue.
HandlerThread thread = new HandlerThread(<name>);
thread.start();
Looper looper = thread.getLooper();
CustomHandler handler = new CustomHandler(looper);
// The CustomHandler class
class CustomHandler extends Handler {
public CustomHandler(Looper looper) {
super(looper);
}
#Override
public void handleMessage(Message msg) {
//Do your operation here
handler.sendEmptyMessageDelayed(msg, <delayTime>);
}
}

Android: How to change TextView periodically

I'm recently working on a ShoutCast radio project. By using streamscrapper library I'm able to get the current song name and the current artist. Here is the problem. Once I open the app, it gets the song name and the artist name, however since then it does not update it. I tried to do it with timer but couldn't figure out.
And here is the method which I get the current song id:
private void initializeMediaPlayer() {
player = new AACPlayer();
scraper = new ShoutCastScraper();
try {
streams = scraper.scrape(new URI("http://sunucu2.radyolarburada.com:5000/"));
String str = "asd";
for (Stream stream: streams) {
str = stream.getCurrentSong();
currPlayView.setText("Now Playing: " + str);
}
} catch (ScrapeException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (URISyntaxException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

Maybe something like a runnable:
private Handler handler = new Handler();
handler.postAtTime(timeTask, SystemClock.uptimeMillis() + 500);
private Runnable timeTask = new Runnable() {
public void run() {
//do stuff here
//do it again soon
handler.postAtTime(timeTask, SystemClock.uptimeMillis() + 500);
}
};
Before you leave make sure to stop the tasks:
handler.removeCallbacksAndMessages(null);

use a Handler to update it ,
Handler handler=new Handler();
int FREQ=5000; // the update frequency
handler.postDelayed(new Runnable()
{
public void run()
{
try
{
String currStr; // get your next song name
currPlayView.setText(currStr);
}
finally
{
handler.postDelayed(this, FREQ);
}
}
}, FREQ);

remove toast and also destroy or force stop thread

hi i am working on custom toast , and i am able to do that, but after when i move to next activity the thread is running or active of back activity , so what should i do for removing that thread or stop this thread.
my code is given below :
public void customToast(int x, int y, String str) {
if (Util.tipson == true) {
toast = new Toast(getApplicationContext());
toast.setDuration(Toast.LENGTH_SHORT);
toast.setGravity(Gravity.TOP, x, y);
LayoutInflater li = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
toastView = li.inflate(R.layout.toastlayout, null);
toast.setView(toastView);
TextView text = (TextView) toastView.findViewById(R.id.text);
text.setText(str);
// toast.show();
fireLongToast();
}
}
private void fireLongToast() {
t = new Thread() {
public void run() {
int count = 0;
try {
while (true && count < 40) {
try {
toast.show();
sleep(100);
count++;
} catch (Exception e) {
// TODO: handle exception
}
// do some logic that breaks out of the while loop
}
toast = null;
toastView = null;
} catch (Exception e) {
Log.e("LongToast", "", e);
}
}
};
t.start();
}

You Need to stop your thread by yourself. Since java doesn't allow you to use stop() function.
Write class for your Thread as this
public class YourThread extends Thread {
private volatile boolean stopped = false;
public void run() {
int count = 0;
try {
while (true && count < 40 && !stopped) {
try {
toast.show();
sleep(100);
count++;
} catch (Exception e) {
// TODO: handle exception
}
// do some logic that breaks out of the while loop
}
toast = null;
toastView = null;
} catch (Exception e) {
Log.e("LongToast", "", e);
}
}
public void stopThread() {
stopped = true;
}
}
Now when your Activity which has the Thread Finishes stop Your thread
#Override
protected void onDestroy() {
if(isFinishing())
yourThreadVariable.stopThread();
}

Dont know for sure, but you can call the function join of thread in onDestroy of your activity.

To stop the thread you can just use interrupt(). But for better solution I would say not to use Thread. Just create a Handler with Runnable and manage your Runnable using Handler, that would be a nice way as Android has given Handler for managing one or more Runnables.
Creating a Runnable
Runnable runnable = new Runnable() {
#Override
public void run() {
// put your code stuff here
}
};
To start Runnable use
handler.postDelayed(runnable, your_time_in_millis);
To stop Runnable use
handler.removeCallbacks(runnable);

Does finishing the activity have any effect?

I would like to suggest Lalit Poptani method too and implement this:
protected void onStop(){
handler.removeCallbacks(runnable);
super.onStop();
}
The documentation for the method:
onStop,Called when the activity is no longer visible to the user, because another activity has been resumed and is covering this one. This may happen either because a new activity is being started, an existing one is being brought in front of this one, or this one is being destroyed.
http://developer.android.com/reference/android/app/Activity.html