At onCreate, I run a task that repeats every minute. Here how I do it:
myTimer = new Timer();
int delay = 30000; // delay for 30 sec.
int period = 600000; // repeat every 60 sec.
doThis = new TimerTask() {
public void run() {
Log.v("TImer","repeated");
wv.reload();
}
};
myTimer.scheduleAtFixedRate(doThis, delay, period);
All that code is in onCreate. So, when the app goes off from the screen, I can see in logcat that timer steel runs, and will not stop unless the app will be destroyed. So, in onPause of activity I call myTimer.cancel(); but it didnt help. I still can see updates in logcat, even when the app is not on the screen. So, how to stop timerTask?
Here is your code put into my file, with the values delay and period tweaked so I don't have to wait so long. I run the app. I see the messages in LogCat. I press the home button on my Galaxy S3. Then the messages stop in LogCat.
public class MainActivity extends Activity {
Timer myTimer;
TimerTask doThis;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myTimer = new Timer();
int delay = 0; // delay for 30 sec.
int period = 1000; // repeat every 60 sec.
doThis = new TimerTask() {
public void run() {
Log.v("TImer","repeated");
}
};
myTimer.scheduleAtFixedRate(doThis, delay, period);
}
#Override
protected void onPause() {
myTimer.cancel();
super.onPause();
}
}
It could be that since the thread has already been sent out, it runs one last time. In the onLoad set a variable to true, then in the onPause set it to false. Then in your timer task only run your code if the variable is true.
Write to the log outside of the new if statement though. If it is indeed running it just one last time, then that might be your solution. But if it is still running it over and over multiple times after the onPause then don't take my solution.
The actual answer is: The onPause method needs to be defined correctly.
The whole story:
The questioner defined the onPause method wrong. That was the reason for asking this question.
I'm writing this because I spent too much time reading question, answers, code and comments. The real answer was hidden in the last comment.
Related
My project is a radio app and I want to add a sleep timer so that the user can set it to close the app after a specified time.
Please use startTimer(long ms) to start countdown timer and cancel timer to stop. And use wakelock to continue timer after screen off.
CountDownTimer cTimer = null;
void startTimer(long time) {
if(!wakeLock.isHeld()) {
PowerManager mgr = (PowerManager) getApplicationContext().getSystemService(Context.POWER_SERVICE);
wakeLock = mgr.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "SonaHeartLock");
wakeLock.acquire();
}
cTimer = new CountDownTimer(time, 1000) {
public void onTick(long millisUntilFinished) {
timerSync = millisUntilFinished;
}
public void onFinish() {
timerSync = 0;
System.exit(0);
}
};
cTimer.start();
}
//cancel timer
void cancelTimer() {
if (cTimer != null) {
timerSync = 0;
cTimer.cancel();
cTimer=null;
if(wakeLock!=null && wakeLock.isHeld())
wakeLock.release();
}
}
Thread.sleep(2000);
will pause for 2 seconds (i.e 2000 ms). In an Android app I wrote several years ago I actually had:
Thread.currentThread().sleep(2000);
but I'm pretty sure the .currentThread() was not needed. I was just learning Java at the time.
See Oracle's doc.
In more detail, what I actually had was a separate task:
class TimerUpdater extends AsyncTask<String, String, Void>{
}
That periodically checked the time (pausing using Thread.sleep()) and displayed a countdown, and at zero set a flag that the main task periodically checked and ended the game when it saw it was set.
My app was terrible code, but I was learning both Java and Android at the same time as fast as I could, to make an app to help my kid in math class.
Android has changed a lot since then, though.
You can get the time from user and after that you can create one background process which count time everytime and check with user time. If both will match then immediately close your app
I'm trying to reproduce the beep.wav sound each second from 3 to 1 , for example, reproduce 3 , 2, and 1 the beep sound, and then when finish reproduce the beependsound.
For some reason only the beependsound is playing but when reaching second 3 it seems the ui freezes for a sec and then the numbers decrease fast to 0
private void stopPlaying(){
if(mp!=null){
try {
mp.reset();
mp.prepareAsync();
mp.stop();
mp.release();
mp=null;
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
private void startCountDown() {
aCounter = new CountDownTimer(10000, 100) {
public void onTick(long millisUntilFinished) {
if (Math.round((float) millisUntilFinished / 1000.0f) != secondsLeft) {
countDownTxt.setTextColor(getResources().getColor(R.color.white));
secondsLeft = Math.round((float) millisUntilFinished / 1000.0f);
countDownTxt.setText(String.valueOf(secondsLeft));
}
if (secondsLeft <= 3) {
countDownTxt.setTextColor(getResources().getColor(R.color.colorAccent));
stopPlaying();
mp = MediaPlayer.create(MainActivity.this, R.raw.beep);
mp.start();
}
}
public void onFinish() {
secondsLeft = 0;
stopPlaying();
mp = MediaPlayer.create(MainActivity.this, R.raw.beepend);
mp.start();
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
aCounter.cancel();
startCountDown();
}
}, 1000);
}
};
aCounter.start();
}
I spect this to work as described above, any hint ?
MediaPlayer.create() can be a fairly expensive call. Consider what happens if it takes approximately 100ms (or even more):
The timer calls onTick().
onTick() blocks for about 100ms inside MediaPlayer.create().
mp starts playing, and onTick() returns. (So far, so good!)
Immediately, the timer realizes another onTick() call is due! The last one started over 100ms ago!
onTick() is called again, almost immediately. Very quickly, it reaches the stopPlaying() call. But you only started playing about 1ms ago!
This leads to a situation where your timer spends all its time in MediaPlayer.create(), and almost no time actually playing the sound.
Note that, with the code as written, it will attempt to play the sound approximately 30 times in the last 3 seconds of the countdown (since the ticks are ideally 100ms apart). If your intent was to play the sound only 3 times, you may want to move your second if block to inside the first. That way, you only attempt play when secondsLeft actually changes. This will actually ameliorate the original problem, and you may not need any further changes.
But if you want to optimize further, note that you can prepare mp in advance -- say, when the app starts up -- and simply reuse it: Instead of release()-ing it each time, just stop() it, and prepare() it (and don't reset() it). That'll leave it ready for the next play. You could even create a separate MediaPlayer just for beepend, and you could prepare them both during app initialization.
I am trying to make simple maths game. Aim of the game is to answer so many questions right in a certain time limit.
I have a timer which counts down and calls my final screen to set your highscore. Problem is, when testing the app if the back button is pressed before timer is done, it seems to continue in the background and my highScore screen randomly appears. How can I make this stop?
Here is the code for my timer:
/**
* timer method
*/
public void timer() {
new CountDownTimer(10000, 1000) {
public void onTick(long millisUntilFinished) {
}
public void onFinish() {
Intent i = new Intent(MainActivity.this, HighScoreScreen.class);
i.putExtra("Score", score);
startActivity(i);
resetScore();
finish();
}
}.start();
}
One solution to this very particular problem would be to override onBackPressed and cancel your timer there. On the other hand, if you want to cancel the timer when there is any interruption (e.g. user receives a call while using your app), you could perhaps place the cancel call in a lifecycle method like onStop.
I am creating application which works with SMS service and FTP networking.
If user does not establish connectivity, it will try to reconnect again in 30 seconds.
I am using CountDownTimer with TextView to inform user about time left to reconnnect.
Either it will be successful or it will start counting again.
My problem is, that if counter restarts while activity is in background or the screen is locked, TextView keeps showing number "1" (it won't update) until the timer restarts again in foreground (but updating numbers without timer restart works fine in backround or lock, I am using wakelock in my foreground service).
After counter restarts again (so it won't stop counting) while application is in foreground, everything comes back to normal, TextView updates from freezed "1" to "30" and starts counting down to "1".
I think problem will be somewhere in communication between counter thread and background activity with UI, but I don't know nothing more about it.
I tried several things like:
creating setter and getter for miliseconds and update them in each
tick, then try to update textview from onReume(), didn't work.
create local variable for TextView inside timer, initialize it inside onTick() and
try to update text from there, also didn't work.
Thanks everyone for help, I will appriciate any advices.
Part of code relative to question:
private CountDownTimer cdt = null;
private final TextView getTextView_ActivityMainMenu_Timer(){
return (TextView) findViewById(R.id.ActivityMainMenu_TextView_Timer);
}
private BroadcastReceiver broadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
if(intent.getBooleanExtra("KEY_FAILED", false)){
cdt = new CountDownTimer(30000, 1000) {
public void onTick(long millisUntilFinished) {
getTextView_ActivityMainMenu_Timer().setText("" + millisUntilFinished / 1000);
}
public void onFinish() {
;
}
}
.start();
}
else
{
if(cdt != null)
cdt.cancel();
}
}
};
Finally I found solution of this problem. I didn't realize that I am unregistering the receiver in onPause() method. So I had to change it and put registration of broadcast into onResume() and unregister it only in onDestroy() method.
I recently began working with Java and am exploring Android development. I was trying to port over one of the Java programs I made, but I am having some difficulty with getting the java Timer to function the same way in Android. I read through a number of posts and they, for the most part, indicated that it would be better to use the Handler class in android as opposed to Timer.
This was my timer in Java:
playTimer = new Timer(1000/model.getFPS(), new ActionListener() {
public void actionPerformed(ActionEvent evt) {
// do something
...
if( finished everything ) playTimer.stop();
}
});
And once a certain button was clicked, I would simply run "playTimer.start()" to start it.
As you can see, I had it set up so that the user could set the FPS they wanted (by simply setting the first parameter of the Timer class to 1000/model.getFPS()).
Now I've tried to do something similar in Android using handlers, but I am having some difficulty. It appears that the Handler ticks are not firing at the proper intervals. It seems that they are quite slow compared to what I need it to be. This is what I did in android so far:
public void startTimer() {
playHandler = new Handler();
startTime = System.currentTimeMillis();
playHandler.removeCallbacks(updateTimeTask);
playHandler.postDelayed(updateTimeTask, 0);
}
private Runnable updateTimeTask = new Runnable() {
public void run() {
// do something
...
if( finished everything ) playHander.cancel();
else {
playHandler.postDelayed(updateTimeTask, 1000/model.getFPS());
}
}
};
Excuse the semi-pseudocode. Can anyone shed any light? Thanks guys.
You can use a timer as below. The timer runs every second incrementing the counter. Displs the counter value in textview.
Timer runs on a different thread. SO you should set the text on the UI Thread.
The counter runs from 0 to 99. After 99 the timer is cancelled. Also cancel the timer when not required like in onPause().
public class MainActivity extends Activity {
TextView _tv,tv2;
Timer _t;
int _count=0;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
_tv = (TextView) findViewById( R.id.textView1 );
_t = new Timer();
_tv.setText(R.string.app_name);
_t.scheduleAtFixedRate( new TimerTask() {
#Override
public void run() {
_count++;
runOnUiThread(new Runnable() //run on ui thread
{
public void run()
{
_tv.setText(""+_count);
if(_count==99)
{
_t.cancel();
}
}
});
}
}, 1000, 1000 ); //change this value of 1000 to whatever you need.
}
#Override
protected void onPause() {
// TODO Auto-generated method stub
super.onPause();
_t.cancel();
}
}
If you decide not to use Timer (for whatever reason) you can just write a separate Thread that sleeps for x milliseconds and then wakes up and calls whatever Runnable you want it to call. That's going to be pretty precise. I have it working at the 10 millisecond level and it works quite nicely.
Just remember that it HAS to call a Runnable because a separate Thread can't have direct effect on anything on the main display thread.
public boolean keepPlayingAnimation = true
Handler h = new Handler()
Runnable updateDisplay = new Runnable(){
public void run(){
//do something in my display;
}
}
new Thread(){
public void run(){
while(keepPlayingAnimation){
try{
sleep(10);
}catch(Exception e){
}
h.post(updateDisplay);
}
}
}.start();
Just don't forget to set keepPlayingAnimation to false when you're done with this cause otherwise it will sit there running in the background for ever (or just about).
Take a look at Android Timer
It already has everything you need i guess. From ticking every 1 second to finish handly and so on.
Here is an example how to setup an TimerTask: setup
Not sure if you need such but i just remembered that i made this.