I am trying to use countdowntimer in Android, following is a small testcode to understand its behaviour
new CountDownTimer(30000, 1000) {
public void onTick(long millisUntilFinished) {
System.out.println("tick");
}
public void onFinish() {
System.out.println("finish");
}
}.start();
System.out.println("done");
If I place this snippet in MainActivity of my project it runs fine, but not in a standalone class. Why ?
Also, does countdown timer run on main thread itself, or it spawns another thread ?
Your code includes 2 parts:
CountDownTimer cdt = new CountDownTimer(30000, 1000) {
public void onTick(long millisUntilFinished) {
System.out.println("tick");
}
public void onFinish() {
System.out.println("finish");
}
};
The first part is instantiating a CountDownTimer object, you can place this code any where, on any thread, because only object was created, it does nothing.
The second part is:
cdt.start();
You should notice that CountDownTimer must be start from Main Thread (call it from onCreate or onResume... of an Activity). So if you place your code in another Class, it is not the problem, you must sure that start() function called on Main Thread.
//Update:
You know, the onTick and onFinish function of CountDownTimer always is called on Main Thread. CountDownTimer will not run any thread.
It's its code:
public synchronized final CountDownTimer start() {
mCancelled = false;
if (mMillisInFuture <= 0) {
onFinish();
return this;
}
mStopTimeInFuture = SystemClock.elapsedRealtime() + mMillisInFuture;
mHandler.sendMessage(mHandler.obtainMessage(MSG));
return this;
}
Very simply, CountDownTimer will send a message by a Handler.
And this is Handler:
// handles counting down
private Handler mHandler = new Handler() {
#Override
public void handleMessage(Message msg) {
synchronized (CountDownTimer.this) {
if (mCancelled) {
return;
}
final long millisLeft = mStopTimeInFuture - SystemClock.elapsedRealtime();
if (millisLeft <= 0) {
onFinish();
} else if (millisLeft < mCountdownInterval) {
// no tick, just delay until done
sendMessageDelayed(obtainMessage(MSG), millisLeft);
} else {
long lastTickStart = SystemClock.elapsedRealtime();
onTick(millisLeft);
// take into account user's onTick taking time to execute
long delay = lastTickStart + mCountdownInterval - SystemClock.elapsedRealtime();
// special case: user's onTick took more than interval to
// complete, skip to next interval
while (delay < 0) delay += mCountdownInterval;
sendMessageDelayed(obtainMessage(MSG), delay);
}
}
}
};
The Handler will send a delay message for calling next onTick() or onFinish(). So it must use Main Thread (or Main Looper). If you want it run in a custom thread, reimplement it in your way :D
I want to create a CountDownTimer passing its remaining time through all activities and show it in TextViews. I tried using intent.putExtra but when i start the new Activity the Timer restarts.
This is what I need:
-ActivityA starts with a 60 seconds timer, so its TextView shows 59...58...57...etc...
-ActivityB starts after 6 seconds so its TextView shows 54...53...52...etc...
The Countdown simply have to go on from first to last activity.
Hope I was clear enough.
Thank you for solutions and sorry for my Ital-English.
use a static variable (maybe create a new class for "better" code).
public static int time;
Or you can declare it in your ActivityA, count the variable down and use it in ActivityB
textView.setText("" + ActivityA.time);
EDIT:
public class MyTimer {
private static int time = 60;
public MyTimer() {
if(time >= 60) {
countDown(); //let countDown only run once
}
}
private void countDown() {
//insert a thread here, which counts your time down
}
public int getTime() {
return this.time;
}
}
And then, in your acitivities:
MyTimer mTimer = new MyTimer();
textview.setText(mTimer.getTime() + "");
I am looking for simplest way to close opened activity after x minutes. Does android provide countdown class or do I have to made one by my self ?
I've tried this code but its not working
Thread isOnDisplayThread = new Thread(new Runnable() {
#Override
public void run() {
Timer mTimer = new Timer();
mTimer.schedule(new TimerTask() {
#Override
public void run() {
Log.d(TAG, (isApplicationOnDisplay) ? "Application on display" : "APPLICATION ON BACKGROUND");
if (!isApplicationOnDisplay) {
notOnDisplayTime++;
if (notOnDisplayTime >= 10) {
Process.killProcess(Process.myPid());
}
} else {
notOnDisplayTime = 0;
}
}
}, 0, 1000);
}
});
isOnDisplayThread.run();
Handler handler = new Handler();
Runnable r=new Runnable() {
#Override
public void run() {
finish();
}
};
handler.postDelayed(r, 2000);
Never ever ever ever ever* call the run() method of a Java Thread. Call its start() method, which causes Java to call its run() method for you within the new thread.
Bad idea:
Process.killProcess(Process.myPid());
You should call finish() function in UI thread. For example, use runOnUiThread(): link
It is not working because you are calling the run method. It will not start the thread.
So you need to call the start method to invoke the thread
isOnDisplayThread.start();
Also to finish off the thread you need to call the
finish() ///method of the Activity class
If the code is with in the Activity class then just call the finish() method
if (notOnDisplayTime >= 10) {
finish();
}
private final long startTime = 200000;
private final long interval = 1000;
countDownTimer = new MalibuCountDownTimer(startTime, interval);
countDownTimer.start();
public class MalibuCountDownTimer extends CountDownTimer{
public MalibuCountDownTimer(long startTime, long interval){
super(startTime, interval);
}
#Override
public void onFinish(){
txttimer.setText("Time's up!");
//timeElapsedView.setText("Time Elapsed: " + String.valueOf(startTime));
}
#Override
public void onTick(long millisUntilFinished) {
//text.setText("Time remain:" + millisUntilFinished);
//timeElapsed = startTime - millisUntilFinished;
String format = String.format("%%0%dd",2);
String seconds = String.format(format, millisUntilFinished/1000 % 60);
String minutes = String.format(format, (millisUntilFinished /(1000*60))%60);
String hours = String.format(format, (millisUntilFinished /(1000*60*60))%24);
String time = hours + ":" + minutes + ":" + seconds;
txttimer.setText("Time Remaining:" + time);
TimeUnit.MILLISECONDS.toMinutes(timeElapsed) - TimeUnit.HOURS.toMinutes(TimeUnit.MILLISECONDS.toHours(timeElapsed)),
TimeUnit.MILLISECONDS.toSeconds(millis) - TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes(timeElapsed)));
System.out.println(hms);
//text.setText("Time remain:" + h+":"+m+":"+s);
//timeElapsedView.setText("Time Elapsed: " + String.valueOf(timeElapsed));
}
}
Declare the Timer and Call finish(). It will close your activity after certain time.
//Declare the timer
Timer t = new Timer();
//Set the schedule function and rate
t.schedule(new TimerTask() {
#Override
public void run() {
finish();
}
},
//Set how long before to start calling the TimerTask (in milliseconds)
0,
//Set the amount of time between each execution (in milliseconds)
1000);
Simply use Handler.postDelayed method.
I want to make an Android app that starts counting down from 10 mins and when it reaches 0, it should execute a command to send data via internet.
After that it should start all over again from 10 mins. It should keep sending data every 10 mins until I manually stop it.
(I have already created command to send data via internet and it works perfectly, but I don't know how to make the count down timer.)
Thanks in advance!
public class MyCounter extends CountDownTimer
{
public MyCounter(long millisInFuture, long countDownInterval)
{
super(millisInFuture, countDownInterval);
}
#Override
public void onFinish()
{
System.out.println("Timer Completed.");
}
#Override
public void onTick(long millisUntilFinished)
{
//Your function here..
}
}
Before oncreate,
final MyCounter timer = new MyCounter(Long.MAX_VALUE,600000);
In oncreate,
timer.start();
You can use the concept of multi threading in java, make a thread and make it sleep for minutes as it wakes call the code/method in, you can start thread
class SampleThread extends Thread {
#Override
public void run() {
try {
Thread.sleep(600000);
callYourmethodHere();
}
catch (InterruptedException e) {
}
}
SampleThread t = new SampleThread();
t.start();
start the timer when ever required
Code:
public class SMH extends Activity {
public void onCreate(Bundle b) {
super.onCreate(b);
setContentView(R.layout.main);
TextView tv = (TextView) findViewById(R.id.tv);
new CountDownTimer(10000, 2000) {
public void onTick(long m) {
long sec = m/1000+1;
tv.append(sec+" seconds remain\n");
}
public void onFinish() {
tv.append("Done!");
}
}.start();
}
Output:
10 seconds remain
8 seconds remain
6 seconds remain
4 seconds remain
Done!
Problem:
How do I get it to show "2 seconds remain"? The time elapsed is indeed 10 seconds, but the last onTick() never happens. If I change the second parameter from 2000 to 1000, then this is the output:
10 seconds remain
9 seconds remain
8 seconds remain
7 seconds remain
6 seconds remain
5 seconds remain
4 seconds remain
3 seconds remain
2 seconds remain
Done!
So you see, it seems to be skipping that last onTick() call. And btw, the XML file is basically the default main.xml with the TextView assigned the id tv and the text set to "".
I checked the source code of CountDownTimer. The "missing tick" comes from a special feature of CountDownTimer that I have not yet seen being documented elsewhere:
At the start of every tick, before onTick() is called, the remaining time until the end of the countdown is calculated. If this time is smaller than the countdown time interval, onTick is not called anymore. Instead only the next tick (where the onFinish() method will be called) is scheduled.
Given the fact that hardware clocks are not always super precise, that there may be other processes in the background that delay the thread running CountDownTimer plus that Android itself will probably create a small delay when calling the message handler of CountDownTimer it is more than likely that the call for the last tick before the end of the count down will be at least one millisecond late and therefore onTick() will not be called.
For my application I solved this problem simply by making the tick intervals "slightly" smaller (500 ms)
myCountDownTimer = new CountDownTimer(countDownTime, intervalTime - 500) {
...
}
and I could leave my code just as it is. For applications where the length of the interval time is critical, the other solutions posted here are probably the best.
I don't know why the last tick is not working but you can create your own timer with Runable , for example.
class MyCountDownTimer {
private long millisInFuture;
private long countDownInterval;
public MyCountDownTimer(long pMillisInFuture, long pCountDownInterval) {
this.millisInFuture = pMillisInFuture;
this.countDownInterval = pCountDownInterval;
}
public void Start()
{
final Handler handler = new Handler();
Log.v("status", "starting");
final Runnable counter = new Runnable(){
public void run(){
if(millisInFuture <= 0) {
Log.v("status", "done");
} else {
long sec = millisInFuture/1000;
Log.v("status", Long.toString(sec) + " seconds remain");
millisInFuture -= countDownInterval;
handler.postDelayed(this, countDownInterval);
}
}
};
handler.postDelayed(counter, countDownInterval);
}
}
and to start it,
new MyCountDownTimer(10000, 2000).Start();
EDIT FOR GOOFY'S QUESTION
you should have a variable to hold counter status (boolean) . then you can write a Stop() method like Start().
EDIT-2 FOR GOOFY'S QUESTION
actually there is no bug on stopping counter but there is a bug on start again after stop(resume).
I'm writing a new updated full code that I had just tried and it's working. It's a basic counter that show time on screen with start and stop button.
class for counter
public class MyCountDownTimer {
private long millisInFuture;
private long countDownInterval;
private boolean status;
public MyCountDownTimer(long pMillisInFuture, long pCountDownInterval) {
this.millisInFuture = pMillisInFuture;
this.countDownInterval = pCountDownInterval;
status = false;
Initialize();
}
public void Stop() {
status = false;
}
public long getCurrentTime() {
return millisInFuture;
}
public void Start() {
status = true;
}
public void Initialize()
{
final Handler handler = new Handler();
Log.v("status", "starting");
final Runnable counter = new Runnable(){
public void run(){
long sec = millisInFuture/1000;
if(status) {
if(millisInFuture <= 0) {
Log.v("status", "done");
} else {
Log.v("status", Long.toString(sec) + " seconds remain");
millisInFuture -= countDownInterval;
handler.postDelayed(this, countDownInterval);
}
} else {
Log.v("status", Long.toString(sec) + " seconds remain and timer has stopped!");
handler.postDelayed(this, countDownInterval);
}
}
};
handler.postDelayed(counter, countDownInterval);
}
}
activity class
public class CounterActivity extends Activity {
/** Called when the activity is first created. */
TextView timeText;
Button startBut;
Button stopBut;
MyCountDownTimer mycounter;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
timeText = (TextView) findViewById(R.id.time);
startBut = (Button) findViewById(R.id.start);
stopBut = (Button) findViewById(R.id.stop);
mycounter = new MyCountDownTimer(20000, 1000);
RefreshTimer();
}
public void StartTimer(View v) {
Log.v("startbutton", "saymaya basladi");
mycounter.Start();
}
public void StopTimer(View v) {
Log.v("stopbutton", "durdu");
mycounter.Stop();
}
public void RefreshTimer()
{
final Handler handler = new Handler();
final Runnable counter = new Runnable(){
public void run(){
timeText.setText(Long.toString(mycounter.getCurrentTime()));
handler.postDelayed(this, 100);
}
};
handler.postDelayed(counter, 100);
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:weightSum="1">
<TextView android:textAppearance="?android:attr/textAppearanceLarge"
android:text="TextView" android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:id="#+id/time">
</TextView>
<Button android:text="Start"
android:id="#+id/start"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="StartTimer">
</Button>
<Button android:text="Stop"
android:id="#+id/stop"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:onClick="StopTimer">
</Button>
</LinearLayout>
I've spent hours trying to figure out this problem, and I'm happy to show you a nice work around. Don't bother waiting for the onFinish() call, just add 1 (or whatever your interval is) to your units, then add an if statement in the onTick() calls. Just do your onFinish() task(s) on the last onTick(). Here's what I've got:
new CountDownTimer( (countDownTimerValue + 1) * 1000, 1000) { //Added 1 to the countdownvalue before turning it into miliseconds by multiplying it by 1000.
public void onTick(long millisUntilFinished) {
//We know that the last onTick() happens at 2000ms remaining (skipping the last 1000ms tick for some reason, so just throw in this if statement.
if (millisUntilFinished < 2005){
//Stuff to do when finished.
}else{
mTextField.setText("Time remaining: " + (((millisUntilFinished) / 1000) - 1)); //My textfield is obviously showing the remaining time. Note how I've had to subtrack 1 in order to display the actual time remaining.
}
}
public void onFinish() {
//This is when the timer actually finishes (which would be about 1000ms later right? Either way, now you can just ignore this entirely.
}
}.start();
The most simple solution I came up with is as follows. Note that it only works if you need a simple screen to display with a seconds countdown.
mTimer = new CountDownTimer(5000, 100){
public void onTick(long millisUntilFinished) {
mTimerView.setText(Long.toString(millisUntilFinished/1000));
}
public void onFinish() {
mTimerView.setText("Expired");
}
};
mTimer.start();
In the code above the onTick() is called every 100 milliseconds but visually only seconds are displayed.
While the solution above is valid, it can be further improved. It unnecessarily has a runnable inside another class (which can already be treated on it's own). So just create a class that extends a thread (or runnable).
class MyTimer extends Thread {
private long millisInFuture;
private long countDownInterval;
final Handler mHandler = new Handler();
public MyTimer(long pMillisInFuture, long pCountDownInterval) {
this.millisInFuture = pMillisInFuture;
this.countDownInterval = pCountDownInterval;
}
public void run() {
if(millisInFuture <= 0) {
Log.v("status", "done");
} else {
millisInFuture -= countDownInterval;
mHandler.postDelayed(this, countDownInterval);
}
}
}
I found easy solution. I need CountDown to update ProgressBar, so I did this:
new CountDownTimer(1000, 100) {
private int counter = 0;
#Override
public void onTick(long millisUntilFinished) {
Log.d(LOG_TAG, "Tick: " + millisUntilFinished);
if (++counter == 10) {
timeBar.setProgress(--lenght); // timeBar and lenght defined in calling code
counter = 0;
}
}
#Override
public void onFinish() {
Log.d(LOG_TAG, "Finish.");
timeBar.setProgress(0);
}
};
Small tick do the trick :)
So I think I went a little over board because my timer runs in its own thread instead of using postDelay handlers, though it always posts back to the thread it was created in. I also knew that I only cared about seconds so its simplified around that idea. It also lets you cancel it and restart it. I do not have pausing built in because that's not in my needs.
/**
* Created by MinceMan on 8/2/2014.
*/
public abstract class SecondCountDownTimer {
private final int seconds;
private TimerThread timer;
private final Handler handler;
/**
* #param secondsToCountDown Total time in seconds you wish this timer to count down.
*/
public SecondCountDownTimer(int secondsToCountDown) {
seconds = secondsToCountDown;
handler = new Handler();
timer = new TimerThread(secondsToCountDown);
}
/** This will cancel your current timer and start a new one.
* This call will override your timer duration only one time. **/
public SecondCountDownTimer start(int secondsToCountDown) {
if (timer.getState() != State.NEW) {
timer.interrupt();
timer = new TimerThread(secondsToCountDown);
}
timer.start();
return this;
}
/** This will cancel your current timer and start a new one. **/
public SecondCountDownTimer start() {
return start(seconds);
}
public void cancel() {
if (timer.isAlive()) timer.interrupt();
timer = new TimerThread(seconds);
}
public abstract void onTick(int secondsUntilFinished);
private Runnable getOnTickRunnable(final int second) {
return new Runnable() {
#Override
public void run() {
onTick(second);
}
};
}
public abstract void onFinish();
private Runnable getFinishedRunnable() {
return new Runnable() {
#Override
public void run() {
onFinish();
}
};
}
private class TimerThread extends Thread {
private int count;
private TimerThread(int count) {
this.count = count;
}
#Override
public void run() {
try {
while (count != 0) {
handler.post(getOnTickRunnable(count--));
sleep(1000);
}
} catch (InterruptedException e) { }
if (!isInterrupted()) {
handler.post(getFinishedRunnable());
}
}
}
}
To expand on Nantoka's answer. Here's my code to ensure the view is updated correctly:
countDownTimer = new CountDownTimer(countDownMsec, 500)
{
public void onTick(long millisUntilFinished)
{
if(millisUntilFinished!=countDownMsec)
{
completedTick+=1;
if(completedTick%2==0) // 1 second has passed
{
// UPDATE VIEW HERE based on "seconds = completedTick/2"
}
countDownMsec = millisUntilFinished; // store in case of pause
}
}
public void onFinish()
{
countDownMsec = 0;
completedTick+=2; // the final 2 ticks arrive together
countDownTimer = null;
// FINAL UPDATE TO VIEW HERE based on seconds = completedTick/2 == countDownMsec/1000
}
}
I also faced the same issue with CountDownTimer and I tried different approaches.
So one of the easiest ways is in solution provided by #Nantoca - he suggests to double the frequency from 1000ms to 500ms. But I don't like this solution because it makes more work which will consume some extra battery resource.
So I decided to use #ocanal's soultion and to write my own simple CustomCountDownTimer.
But I found couple of flaws in his code:
It's a bit inefficient (creating second handler to publish results)
It starts to publish first result with a delay. (You need to do a post() method rather than postDelayed() during first initialization)
odd looking. Methods with capital letter, status instead of classic isCanceled boolean and some other.
So I cleaned it a bit and here is the more common version of his approach:
private class CustomCountDownTimer {
private Handler mHandler;
private long millisUntilFinished;
private long countDownInterval;
private boolean isCanceled = false;
public CustomCountDownTimer(long millisUntilFinished, long countDownInterval) {
this.millisUntilFinished = millisUntilFinished;
this.countDownInterval = countDownInterval;
mHandler = new Handler();
}
public synchronized void cancel() {
isCanceled = true;
mHandler.removeCallbacksAndMessages(null);
}
public long getRemainingTime() {
return millisUntilFinished;
}
public void start() {
final Runnable counter = new Runnable() {
public void run() {
if (isCanceled) {
publishUpdate(0);
} else {
//time is out
if(millisUntilFinished <= 0){
publishUpdate(0);
return;
}
//update UI:
publishUpdate(millisUntilFinished);
millisUntilFinished -= countDownInterval;
mHandler.postDelayed(this, countDownInterval);
}
}
};
mHandler.post(counter);
}
}
if Your time Interval is more than 4 sec then every onTick() call would not be proper. So if you want precise result then keep interval less than 5 sec. The Reseaon is at the start of every tick, before onTick() is called, the remaining time until the end of the countdown is calculated and If this time is smaller than the countdown time interval, onTick() would not not called anymore. Instead only the next tick (where the onFinish() method will be called) is scheduled.
Add a few milliseconds to your timer to allow it time to process the code.
I added +100 to your timer-length, and also Math.ceil() to round up the result, rather than adding 1.
Also... the first tick is AFTER 2000 millis, so you won't get a "10 seconds left" entry unless you add it.
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final TextView tv = (TextView) findViewById(R.id.tv);
tv.setText("10 Seconds remain\n"); //displayed before the first tick.
new CountDownTimer(10000+25, 1000) { //25 to account for processing time
public void onTick(long m) {
long sec = (long) Math.ceil(m / 2000 ); //round up, don't add 1
tv.append(sec + " seconds remain\n");
}
public void onFinish() {
tv.append("Done!");
}
}.start();
}
You are calculating time remaining incorrectly. The callback gets the number of milliseconds until completion of the task.
public void onTick(long m) {
long sec = m/1000+1;
tv.append(sec+" seconds remain\n");
}
should be
public void onTick(long m) {
long sec = m/1000;
tv.append(sec+" seconds remain\n");
}
I've never used this class myself but it looks like you will not get a callback the instant it starts, which is why it appears like you're missing an entry. e.g. 10000 ms, 1000 ms per tick you'd get a total of 9 update callbacks, not 10 - 9000, 8000, 7000, 6000, 5000, 4000, 3000, 2000, 1000, finish.