Develop Reference

savedInstanceState gives me a wrong value

I have a stopwatch app and it has just one activity. Three buttons start, stop, reset and a textview to show the timer. Here is my code :
public class StopwatchActivity extends AppCompatActivity {
private int mNumberOfSeconds = 0;
private boolean mRunning = false;
private Handler handler = new Handler();
private Runnable runnable;
private TextView timeview;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_stopwatch);
if (savedInstanceState != null){
mNumberOfSeconds = savedInstanceState.getInt("number_of_second");
mRunning = savedInstanceState.getBoolean("is_running");
Log.e("after orient mSecond :" , String.valueOf(mNumberOfSeconds));
Log.e("after orient mRunning :" , String.valueOf(mRunning));
runner();
}
}
public void onClickStart(View view){
handler.removeCallbacks(runnable);
mRunning = true;
runner();
}
public void onClickStop(View view){
mRunning = false;
handler.removeCallbacks(runnable);
}
public void onClickReset(View view){
mRunning = false;
//mNumberOfSeconds = 0;
//timeview.setText("0:00:00");
}
public void runner(){
timeview = (TextView) findViewById(R.id.time_view);
runnable = new Runnable() {
#Override
public void run() {
int hours = mNumberOfSeconds/3600;
int minutes = (mNumberOfSeconds%3600)/60;
int second = mNumberOfSeconds%60;
String time = String.format("%d:%02d:%02d" , hours , minutes , second );
timeview.setText(time);
if (mRunning){
mNumberOfSeconds++;
}
handler.postDelayed(this , 1000);
}
};
handler.post(runnable);
}
#Override
protected void onSaveInstanceState(Bundle outState) {
outState.putInt("number_of_seconds" , mNumberOfSeconds);
outState.putBoolean("is_running" , mRunning);
Log.e("befor rotation second:" , String.valueOf(mNumberOfSeconds));
Log.e("befor rotaion mrunning" , String.valueOf(mRunning));
}
I want to save some of my variables in onSaveInstanceState to get use of them again after orientation changing. As you can see in the code the log message show the value of mNumberOfSeconds and mRunning before and after orientation changes. And after orientation changes mNumberOfSeconds will give me 0 instead of the value I saved. But mRunning gives me the right value. Can anyone give me any solution?

You can avoid this in the future by using tags in the put() and get() calls:
private static final String KEY_NUM_SECS = "NUM_SECS";
then use it like this:
mNumberOfSeconds = savedInstanceState.getInt(KEY_NUM_SECS);
and:
outState.putInt(KEY_NUM_SECS, mNumberOfSeconds);

You can see it clearly if I compare your code:
outState.putInt("number_of_seconds" , mNumberOfSeconds);
mNumberOfSeconds = savedInstanceState.getInt("number_of_second");
you put in value with key "number_of_seconds" but get int value with key "number_of_second", this is the wrong place.

Update TextView every second in Android [duplicate]

This question already has answers here:
Update TextView Every Second
(11 answers)
Closed 4 years ago.
i want to update my textview every second.
on button click i am calling one method,
loopMethod(milli); //suppose milli= 50000 i.e 50 sec.
so my loopMethod(int m) is as follows:
public void loopMethod(int m){
timer=(TextView) findViewById(R.id.timerText);
if(m>=1000){
try {
timer.setText(""+m);//timer is a textview
System.out.println(m);
m=m-1000;
Thread.sleep(1000);
} catch(InterruptedException ex) {
ex.printStackTrace();
}
loopMethod(m);
}
}
so what i am expecting is, my timer textview should print the value of m every second.
but i am getting only console output i.e system.out.println(m)...
printing value on console working fine...
but its not updating my textview at all

You can use following code:
Runnable updater;
void updateTime(final String timeString) {
timer=(TextView) findViewById(R.id.timerText);
final Handler timerHandler = new Handler();
updater = new Runnable() {
#Override
public void run() {
timer.setText(timeString);
timerHandler.postDelayed(updater,1000);
}
};
timerHandler.post(updater);
}
In this line:
timerHandler.post(updater);
time will set for the first time. i.e, updater will execute. After first execution it will be posted after every 1 second time interval. It will update your TextView every one second.
You need to remove it when the activity destroys, else it will leak memory.
#Override
protected void onDestroy() {
super.onDestroy();
timerHandler.removeCallbacks(updater);
}
Hope it will help you.

You should use RxJava library to do so:
Subscription s =
Observable.interval(1, TimeUnit.SECONDS)
.observeOn(AndroidSchedulers.mainThread())
.subscribe(v -> {
// update your ui here
}, e -> {
});
// call when you no longer need an update:
if (s != null && !s.isUnsubscribed()){
s.unsubscribe();
s = null;
}
That's it. Do NOT use .postDelay(), Timer because it is error prone.

You might want to consider using the Chronometer class: https://developer.android.com/reference/android/widget/Chronometer.html
just use timer.start(); on the button click

Using handler can be used like this
TextView timer;
int m =0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
timer=(TextView) findViewById(R.id.timerText);
Handler handler = new UpdateHandler();
m = 10;
handler.sendEmptyMessageDelayed(1, 1000);//start after 1000
}
class UpdateHandler extends Handler{
#Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (msg.what) {
case 1:
timer=(TextView) findViewById(R.id.timerText);
timer.setText("Text :" +m);
m = m-1000;
sendEmptyMessageDelayed(1, 1000); //seng again after 1000
//add some stop logic
break;
default:
break;
}
}
}

Try this code Initialize textview in
onCreate
timer=(TextView) findViewById(R.id.timerText);
public void loopMethod(int m){
if(m>=1000){
try {
System.out.println(m);
m=m-1000;
final ScheduledThreadPoolExecutor c = new ScheduledThreadPoolExecutor(1);
c.schedule(new Runnable() {
#Override
public void run() {
timer.setText(""+m);//timer is a textview
c.shutdownNow();
}
}, 1, TimeUnit.SECONDS);
} catch(InterruptedException ex) {
ex.printStackTrace();
}
loopMethod(m);
}
}

I've added some logics to stop the Timer. If you have any qyestion, ask freely
private int m = 0;
private int milliseconds = 1000;
public void loopMethod(int m){
timer=(TextView) findViewById(R.id.timerText);
Timer t = new Timer();
//schedule a timer
t.scheduleAtFixedRate(new TimerTask() {
#Override
public void run() {
runOnUiThread(new Runnable() {
#Override
public void run() {
timer.setText(String.valueOf(m));//avoid using composite string in the setText
System.out.println(String.valueOf(m));
//remove from the total the amount of millisecond passed
m=m-milliseconds;
if(m <= milliseconds) { //or <= what you want
//stop the timer repeatitions
t.cancel();
}
}
});
}
//"0" is the amount of time to wait for the timer to start
//"milliseconds" is the duration
},0,milliseconds);
}
Add
For a correct analysis you should add more infos in your question. the problem of not-updating textview might be caused by the setText("" + int) because it's always better to avoid the setText with an int. I edited it with String.valueOf, but if it's not working you should add the xml and the onCreate
Hope this helped

I have created timer for seconds.
public class TimerForSeconds extends AppCompatActivity {
private int seconds = 60;
private TextView tvTimer;
private Handler mHandler;
private Runnable runnable = new Runnable() {
#Override
public void run() {
if(seconds == 0){
mHandler.removeCallbacks(runnable);
}
else{
tvTimer.setText(seconds + "");
seconds--;
mHandler.postDelayed(runnable,1000);
}
}
};
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.test_activity);
tvTimer = (TextView) findViewById(R.id.tv_timer);
mHandler = new Handler();
mHandler.postDelayed(runnable,1000);
}
}
//and also removCallback onDestroy too.

Android Pause and Resume Background Activity

In one activity of my app, there are an imagview and a textview that are changing every 3 seconds.
I first set this up with a handler and thread runnable. It works fine, but when I use removeCallbacks with the pause button, it will not pause in the middle of the Thread. It completes the Thread runnable before pausing. I need it to pause when the button is clicked no matter where it is in the runnable.
I thought about using an asynctask but I'm not sure how this would work.
I know there has to be a way to do this, as you can pause almost any game you download. Does anyone have any suggestions on the best/easiest way to do this?
Thanks so much!! :)
public class Workout extends AppCompatActivity {
private String[] messages = {"1", "2", "3", "4", "5"};
final Handler handler = new Handler();
private int nextIndex;
String mDrawableName[] = {"bodypart70", "equipment70", "settings70", "time70", "bodypart70"};
private int nextImage;
ImageView image;
private ProgressBar progressBar;
private int progressStatus = 0;
Runnable r = null;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.workout);
image = (ImageView) findViewById(R.id.exerciseImage);
final TextView text = (TextView)findViewById(R.id.textView4);
progressBar = (ProgressBar) findViewById(R.id.progressBar1);
//changing
r = new Runnable(){
#Override
public void run(){
if (messages.length > nextIndex) {
//change textview
text.setText(messages[nextIndex++]);
//change image
int resID = getResources().getIdentifier(mDrawableName[nextImage++] , "drawable", getPackageName());
image.setImageResource(resID);
//restart progress bar
progressStatus = 0;
progress();
//do it after 3 seconds
handler.postDelayed(this, 3000);
}
}
};
handler.postDelayed(r, 0);
}
public void progress(){
new Thread(new Runnable() {
public void run() {
long timerEnd = System.currentTimeMillis() + 3 * 1000;
while (timerEnd > System.currentTimeMillis()) {
progressStatus = 3 - (int) (timerEnd - System.currentTimeMillis()) / 1000;
// Update the progress bar
handler.post(new Runnable() {
public void run() {
progressBar.setProgress(progressStatus);
}
});
try {
Thread.sleep(10);
} catch (InterruptedException e) {
Log.w("App", "Progress thread cannot sleep");
}
}
}
}).start();
}
public void pauseWorkout(View view){
handler.removeCallbacks(r);
}
public void resumeWorkout(View view){
handler.postDelayed(r, 0);
}
}

It looks like the while-loop in your progress() function is still working after you press your pause button.
Try the following: Create a global boolean that indicates you're in a paused or resuming state. Put it at the top of your code:
boolean resume = true;
Update your while condition in progress()
while (resume && timerEnd > System.currentTimeMillis()) {
Update your workout functions:
public void pauseWorkout(View view){
handler.removeCallbacks(r);
resume = false;
}
public void resumeWorkout(View view){
handler.postDelayed(r, 0);
resume = true;
}

How do I add extra time to a timer in android

I dont know how I add extra time to a timer that is running.
Evertime I press a button I want to add 1 second.
So my question is, how do I do this?
Here is my timer(code):
private void TimerGame(){
new CountDownTimer(15000, 1000) {
TextView mTextField = (TextView) findViewById(R.id.timeTv);
Button start = (Button)findViewById(R.id.startGameBtn);
TextView go = (TextView)findViewById(R.id.tvGo);
public void onTick(long millisUntilFinished) {
mTextField.setText("" +millisUntilFinished / 1000);
}
public void onFinish() {
mTextField.setText("15");
start.setVisibility(View.VISIBLE);
go.setVisibility(View.INVISIBLE);
reset();
}
}.start();
}

As far as I looked into CountDownTimer there is no method to what you want.
However, I made a small example of what you can do. I haven't tested it but it shouldn't be too hard to put it on track.
private Handler countdownHandler = new Handler();
private Runnable updateCountdownTask = new UpdateCountdownTaskRunnable();
private int timeSeconds;
private class UpdateCountdownTaskRunnable implements Runnable {
#Override
public void run() {
timeSeconds -= 1;
if (timeSeconds == 0) {
stopWhatever();
} else {
updateWhatever();
countdownHandler.postDelayed(this, 1000);
}
}
}
private void start() {
timeSeconds = 20;//seconds
countdownHandler.postDelayed(updateCountdownTask, 0);
}
private void stop(){};
private void update(){};
private void addTime(int time){ timeSeconds += time; };

Android - How to stop and pause timer

I have been running through alot of issues try to pause and unpause a timer, and if I lock the orientation to portrait or landscape it works, but thats not exactly what I want to do. Of course, the onCreate method is called when you change orientation, so im canceling my timertask and setting it to null, but after running through the orientation more than once, it doesnt cancel the timertask anymore. Ive looked through other peoples questions on here but none seem to hold the answer to my quesiton. Heres my code. Its a little sloppy at the moment because ive been trying about everything I can to get it to work.
public class singleTimer extends Activity implements OnClickListener {
private Integer setTime = 0;
private Integer tmrSeconds = 0;
private Integer tmrMilliSeconds = 0;
private Timer myTimer = new Timer();
private TimerTask myTimerTask;
private TextView timerText;
private boolean isPaused = true;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.single_timer);
Bundle extras = getIntent().getExtras();
setTime = extras.getInt("com.bv.armyprt.timer_duration");
if (myTimerTask != null) {
myTimerTask.cancel();
myTimerTask = null;
}
if (savedInstanceState != null) {
if (savedInstanceState.getInt("tmrSeconds") == 0) {
tmrSeconds = setTime;
} else {
tmrSeconds = savedInstanceState.getInt("tmrSeconds");
tmrMilliSeconds = savedInstanceState.getInt("tmrMilliseconds");
if (isPaused == false) {
myTimer = new Timer();
myTimerTask = new TimerTask() {
#Override
public void run() {
TimerMethod();
}
};
myTimer.schedule(myTimerTask, 0, 100);
}
}
} else {
tmrSeconds = setTime;
}
timerText = (TextView)findViewById(R.id.timerText);
timerText.setText(String.format("%03d.%d", tmrSeconds, tmrMilliSeconds));
TextView timerDesc = (TextView)findViewById(R.id.timerDescription);
timerDesc.setText("Timer for: " + setTime.toString());
Button startButton = (Button)findViewById(R.id.timerStart);
Button stopButton = (Button)findViewById(R.id.timerStop);
Button closeButton = (Button)findViewById(R.id.timerClose);
closeButton.setOnClickListener(this);
startButton.setOnClickListener(this);
stopButton.setOnClickListener(this);
}
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case (R.id.timerStart):
isPaused = false;
myTimer = new Timer();
myTimerTask = new TimerTask() {
#Override
public void run() {
TimerMethod();
}
};
myTimer.schedule(myTimerTask,0, 100);
break;
case (R.id.timerStop):
isPaused = true;
myTimerTask.cancel();
myTimerTask = null;
myTimer.cancel();
break;
case (R.id.timerClose):
onDestroy();
this.finish();
break;
}
}
private void TimerMethod()
{
//This method is called directly by the timer
//and runs in the same thread as the timer.
//We call the method that will work with the UI
//through the runOnUiThread method.
this.
tmrMilliSeconds--;
this.runOnUiThread(Timer_Tick);
}
private Runnable Timer_Tick = new Runnable() {
public void run() {
//This method runs in the same thread as the UI.
if (tmrSeconds > 0) {
if (tmrMilliSeconds <= 0) {
tmrSeconds--;
tmrMilliSeconds = 9;
}
} else {
Vibrator v = (Vibrator)getSystemService(Context.VIBRATOR_SERVICE);
v.vibrate(1000);
myTimer.cancel();
tmrSeconds = setTime;
tmrMilliSeconds = 0;
isPaused = true;
}
//Do something to the UI thread here
timerText.setText(String.format("%03d.%d", tmrSeconds, tmrMilliSeconds));
}
};
#Override
public void onSaveInstanceState(Bundle savedInstanceState){
savedInstanceState.putInt("setTimer", setTime);
savedInstanceState.putInt("tmrSeconds", tmrSeconds);
savedInstanceState.putInt("tmrMilliseconds", tmrMilliSeconds);
super.onSaveInstanceState(savedInstanceState);
}
#Override
public void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
setTime = savedInstanceState.getInt("setTimer");
tmrSeconds = savedInstanceState.getInt("tmrSeconds");
tmrMilliSeconds = savedInstanceState.getInt("tmrMilliSeconds");
}
}

you can simply add a boolean variable
boolean stopTImer = false ;
and in your timerTask , do something like this :
#Overrride
public void run(){
if(!stopTimer){
//do stuff ...
//...
}
and when you want to stop it , put the boolean to true

You should stop the timer during onStop. Android might create another instance of your Activity and you will lose the reference to your previous timer(task) when you change orientation.
All objects tied to an activity follow the activity lifecycle. That means you have to store the references to objects elsewhere if you want to keep them even if the activity gets deleted (which can happen quite often).