Develop Reference

How can I control a timer in android?

I want to make an application about mini game.
Detail : In 2 seconds you must to answer a question if you don't answer or the answer is wrong -> Game Over . But if your answer is true the Timer will reset become 0 and countdown again with diffirent question.
I have already seen many code about timer in website but I don't understand clearly about it :(
So I want to ask : How can i set up a timer run only 2 seconds and how can i reset it and continue with a new question ?
Please help me.

you can use CountDownTimer in android like this:
public class Myclass {
myTimer timer =new myTimer(2000,1000);
public void creatQuestion(){
timer.start();
//method you init question and show it to user
}
public void getUserAnswer(/*evry thing you expected*/)
{
//if answer is true call timer.start()
//else call timer.onFinish(); to run onfinish in timer
}
public class myTimer extends CountDownTimer {
public myTimer(long millisInFuture, long countDownInterval) {
super(millisInFuture, countDownInterval);
}
#Override
public void onTick(long millisUntilFinished) {
// you can update ui here
}
#Override
public void onFinish() {
this.cancel();
//fire game over event
}
}
}
i hope it make you satisfy

I've done something similar using Thread/Runnable.
Thread t = new Thread(new Runnable() {
public void run() {
final long startTime = getTime();
final long maxEndTime = startTime + 2000L;
try {
while (shouldContinueWaiting()) {
if (getTime() > maxEndTime) {
throw new TimeoutException();
}
sleep();
}
} catch (InterruptedException e) {
handleInterrupt();
} catch (TimeoutException e) {
handleTimeout();
}
}
boolean shouldContinueWaiting() {
// Has the user already answered?
}
void handleInterrupt() {
// The user has answered. Dispose of this thread.
}
void handleTimeout() {
// User didn't answer in time
}
void sleep() throws InterruptedException {
Thread.sleep(SLEEP_DURATION_IN_MILLIS);
}
void getTime() {
return System.currentTimeMillis();
}
then you can start/restart the thread by:
t = new Thread(same as above...);
t.start();
and stop by:
t.interrupt();

We want to use the Timer class.
private Timer timer;
When you're ready for the timer to start counting -- let's say it's after you press a certain button -- do this to start it:
timer = new Timer();
timer.scheduleAtFixedRate(incrementTime(), 0, 100);
The first line is us creating a new Timer. Pretty standard. The second line, however, is the one I wanted you to see.
incrementTime() is a method that is called at the end of every "tick" of the clock. This method can be called whatever you want, but it has to return an instance of TimerTask. You could even make an anonymous interface if you want, but I prefer moving it off into its own section of code.
The 0 is our starting location. We start counting from here. Simple.
The 100 is how large a "tick" of the clock is (in milliseconds). Here, it's every 100 milliseconds, or every 1/10 of a second. I used this value at the time of writing this code because I was making a stopwatch application and I wanted my clock to change every 0.1 seconds.
As for your project, I'd suggest making the timer's task be your question switch method. Make it happen every 2000 milliseconds, or 2 seconds.

You can use a Handler.
Handler h = new Handler();
h.postDelayed(new Runnable() {
#Override
public void run() {
//this will happen after 2000 ms
}
}, 2000);

Maybe this can help you:
Handler handler = new Handler();
handler.post(new Runnable() {
#Override
public void run() {
// FIRE GAME OVER
handler.postDelayed(this, 2000); // set time here to refresh textView
}
});
You can fire your game over after 2000 milliseconds.
If you get the question correct -> remove callback from handler and reset it when the next question starts.

How to wait button clicks for a while in android

I am developing an application for blinds.
I have 4 screen sized buttons (overlapped). Every step of program one button will be clickable and every button has more than one job.
My program starts with a voice (Android TTS engine). Like "please touch screen to do x". After this step I want to wait 3 seconds for button click, if button is not clicked vocalize "please touch screen to do y" and wait 3 seconds again for job y. (x and y is first button's jobs).
Button should do one of them according to touching screen. But how can I wait 3 seconds for button click and continue to vocalize next options and wait 3 seconds again.
If first button is clicked, it will disappear-button 2 will be clickable- and TTS engine will start to vocalize second buttons options. Application will be work like this but I am stuck in waiting button clicks part.

I would advise you to use android.os.Handler instead. In your case you could do something like this:
public void onCreate() {
this.handler = new Handler()
playTheVoiceOfThingX()
viewToTap.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
doThingX();
}
});
handler.postDelayed(new PrepareThingYTask(), 3000);
}
class PrepareThingYTask() implements Runnable {
viewToTap.setOnClickListener(new OnClickListener(){
#Override
public void onClick() {
doThingY();
}
});
handler.postDelayed(new PrepareThingZTask(), 3000);
}
class PrepareThingZTask() implements Runnable {
....
}
A good reminder, the runnable executed by the handler can be executed in UIThread, so no heavy work on it, or create a different looper to run it.
Regards

You could solve your problem with busy wait.
So after you first vocalized "please touch screen..." you would start a background thread which waits for a specific amount of time, like so:
new Thread(new Runnable() {
public void run() {
Thread.sleep(3000);
runOnUiThread(new Runnable() {
#Override
public void run() {
//vocalize
}
});
}
}).start();
As you can see, from within the thread a new runnable is started after 3 seconds which again runs on the UI Thread. This, because I think I remember that you should make such sound-things (depending on your method of how to play the file / sound) only from the UI Thread.
However, this is just an idea and I could not test-run my code!
But I hope I inspired you!
Regards
Me

Small android animation delay issue

I just want to call a function after every 3secs on click of a button
What is going wrong here-
galleryBtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
final Handler handler = new Handler();
for(int i = 0;i<3;i++){
handler.postDelayed(new Runnable() {
#Override
public void run() {
// Do something after 5s = 5000ms
viewAnimator.showNext();
}
}, 3000);
}
}
});

You don't actually say what goes wrong but I'll take a wild guess that nothing happens (i.e. no animations) and the reason for that is probably that your Handler is being GC'd long before it gets to handle anything. Try keeping moving 'handlers' scope from local variable to class member.
(Also note that, even when it works, all 3 of your functions will run at more or less the same time. If you want them to run 3 seconds apart you should change the '3000' to 'i*3000'.)

I'd like to make a countdown timer do a continuous loop in android - need opinions on how to do it

Is there a way to continuously loop through a countdown timer? I have a basic timer of going though 60 seconds, then updating a text field and it's working, but I want to add the functionality: when it's counted down, to automatically restart again until the user cancels it? Maybe run it through a thread? Not sure how to handle it. Here is what I have, and again, this code works, but I can only stop and start the countdown timer, not do a continuous loop:
cdt = new CountDownTimer(60000,1000) {
public void onTick(long millisUntilFinished) {
tvTimer.setText("remaining : " + millisUntilFinished/1000 + " secs");
}
public void onFinish() {
tvTimer.setText("");
bell.start();
}
};
/***************On Click/Touch Listeners*******************/
btnNext.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
tvTimer.setText("");
btnStart.setText("Start Timer");
SetImageView2(myDbHelper);
cdt.cancel();
}
});
btnStart.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
if (!TimerTicking){
cdt.start();
btnStart.setText("Stop Timer");
}
else {
tvTimer.setText("");
cdt.cancel();
btnStart.setText("Start Timer");
}
}
});

One very basic way to loop a CountDownTimer is to call start() in onFinished().
public void onFinish() {
...
start(); // Start this timer over
}
(Make sure you cancel your CountDownTimer in onPause() when you do this otherwise the timer might leak and keep firing in the background... Oops.)
However CountDownTimers has fundamental flaws (in my opinion): it often skips the last call to onTick() and it gains a few milliseconds each time onTick() is called... :( I re-wrote CountDownTimer in a previous question to be more accurate and call every tick.

The first value to the CountDownTimer() constructor, the total time to run, is a long and can hold a value approaching 300 million years. That ought to be long enough for most mobile applications. :-)
So just call it with cdt = new CountDownTimer(Long.MAX_VALUE, 1000) for a one second loop that will run continously.

How to set an image with a delay

I have an "Activity" with three images. When one image is clicked, all the images are to switch to another picture. Is there a way to make the switches such that there is a 2 second delay before the images actually change (i.e. a 2 second delay in every 'for loop' below)? I am trying to do this with a timer but it does not actually to the delay when I run my program:
protected void onCreate(Bundle savedInstanceState) {
image1.setOnClickListener(this);
#Override
public void onClick(View arg0)
{
do_switches();
}
private void do_switches()
{
//loop through all images and change them
for(int j=1 ;j<=3; j++)
{
final int curr2=current;
final Handler handler = new Handler();
Timer t = new Timer();
t.schedule(new TimerTask() {
public void run() {
handler.post(new Runnable() {
public void run() {
switch(curr2){
case 1:
image1.setImageResource(ImageArray[1]);
break;
case 2:
image2.setImageResource(ImageArray[2]);
break;
case 3:
image3.setImageResource(ImageArray[3]);
break;
}
}
});
}
}, 2000);
}
}
I have also tried using just SystemClock.sleep(2000) instead of the timer but I that didnt work either.I also tried setting up a Thread with a try/catch with no luck or maybe I didn't implement it properly. Is there a way to put this delay on every iteration of my for loop?
Thanks

Not one of best option, but still you can try CountDownTimer.
http://developer.android.com/reference/android/os/CountDownTimer.html

You can use handler.postDelayed(Runnable r, long timeInMillis). Make your runnable that changes the pictures and then call postDelayed() and pass in the runnable and 2000 for the time delay.
Edit: Ahh I see what you are trying to do. As far as I know you aren't going to be able to make a for loop pause for 2 seconds each time through. You can get the same effect though if you chain the postDelayed() calls. Just set up the next runnable and call postDelayed() on it inside the first one, and same for the third one from inside the second one. You will end up with the same functionality as a for loop that pauses for 2 seconds each iteration.