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Activity with countDown timer pops up after time is up, how to kill it?

I have kind of a game with 2 activities: Start Activity (with high score, start button and tutorial button) and main game activity which is is based on countdown timer, when time is up, game returns to start activity.
Problem is when user starts game and then hits home button and goes back to home screen (just leaving game by home button) Everything is ok until time is up, then Start activity appears on screen with lost message.
I've tried various combined methods like onPause witch finish(); inside and so on but it doesn't work or causes app force close.
I can't handle home button click like in onBackPressed() which I did in that case.
Is there any way to suspend app and pause all threads while it isn't in foreground?

I suggest two way
1
Create global variable like
private isInForgrand = false;
And in onStop() or onPause() and onResume() change it
#Override
public void onStop() {
isInForgrand = false;
super.onStop();
}
#Override
public void onResume() {
super.onResume();
isInForgrand = true;
}
And in onFinish() check it
#Override
public void onFinish() {
if(isInForgrand){
//do what you want
}else{
//your app NOT in Forgrannd
}
2
You can cancel CountDownTimer in onStop()
#Override
public void onStop() {
super.onStop();
mCountDownTimer.cancel();
}

I want the sound to stop when the user clicks the home button, but not when a new content view is called

The onStop method and onPause method is called whenever the home button is pressed and when calling setContentView. I want to be able to differentiate between the two to when the home button is pressed, the sound stops and when a new view is set, the sound continues. I'm a noob to java, but I have searched for a long time and can't find a solution.
#Override
protected void onResume() {
super.onResume();
if (btnSound.isChecked()){
snd.start();
}
}
#Override
protected void onStop() {
super.onStop();
snd.pause();
}

Well, to answer your question, the time between both the calls between onResume() and onStop() calls, might be so narrow that, you are not able to differentiate. You can try this if you may:
#Override
protected void onPause() {
super.onPause();
snd.start(); // Sound start
// SLEEP 2 SECONDS HERE ...
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
public void run() {
snd.pause();
}
}, 2000);
}

Android Thread Allocation - growing heap?

Hi everyone out there,
i am developing an android application against API 7 at the moment in which i use an activity which need to be restarted. Lets say my activity looks like this:
public class AllocActivity extends Activity implements OnClickListener{
Button but;
private Handler hand = new Handler();
#Override
protected void onCreate(Bundle savedInstanceState) {
setContentView(R.layout.activity_alloc);
but = (Button) findViewById(R.id.button);
but.setText("RELOAD");
but.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0){
Intent intent = getIntent();
startActivity(intent);
finish();
}
});
}
#Override
protected void onDestroy(){
super.onDestroy();
System.gc();
}
/****** THREADS AND RUNNABLES ******/
final Runnable fullAnim = new Thread(new Runnable(){
#Override
public void run(){
try{
hand.post(anim1);
Thread.sleep(2000);
hand.post(anim2);
Thread.sleep(1000);
// and so on
}catch(InterruptedException ie){ie.printStackTrace();}
}
});
final Runnable anim1 = new Runnable() {
#Override
public void run(){
// non-static method findViewById
ImageView sky = (ImageView)findViewById(R.id.sky);
}
};
}
The problem is that the gc doesnt seem to free the fullAnim thread so that the heap is growing by ~100K at every restart - till it slows down and crashes. Declaring fullAnim as static does solve this problem - but as i use non static references this doesnt work out for me.
So at this point i am kindof lost - and i hope u can advice me where to go next. Is there something i might be doing wrong or is there a tool i can use to manage threads to drop and free heap after restart.
kindly regards
UPDATE
thanks to everyone who answered - helped alot. using TimerTask did the trick in the end. i did the following change:
/****** THREADS AND RUNNABLES ******/
final TimerTask fullAnim = new TimerTask(){
#Override
public void run(){
try{
hand.post(anim1);
Thread.sleep(2000);
hand.post(anim2);
Thread.sleep(1000);
// and so on
}catch(InterruptedException ie){ie.printStackTrace();}
}
};
as the activity was more than 6k loc long this was a pretty decent solution without facing bigger impacts. KUDOS!
i dont use a Timer to shedule the task - dont know if its bad practice but
the animation is called like this:
Thread t = new Thread(fullAnim);
t.start();

A running Thread is never garbage collected.
A Thread is not stopped automatically if your Activity stops or is destroyed. It could run forever.
Every non-static inner class keeps a reference to the enclosing instance. E.g. hand.post(anim1); works inside that inner class because it has an implicit reference to AllocActivity.this.
So what you effectively do is to keep a reference to your Activity alive for longer than it is supposed to be alive, i.e. until after onDestroy.
Make sure to stop threads manually if you don't want them anymore.

Because final variable have low priority for GC. So you need to explicitly release the runneable objects in onPause() method because there is not ensurence onDestory() will call immediate after finish() call .
#Override
protected void onPause(){
super.onPause();
//cancel timer to stop animations
if(t!=null){
t.cancel();
}
System.gc();
}
UPDATE
use timer to achieve this
boolean isFirstAnim=true;
Timer t = new Timer();
t.schedule(new TimerTask() {
#Override
public void run() {
if(isFirstAnim){
// play your first animation at every
}else{
// play your second animation at every
}
}
}, 0, 3000);

What happens when all activities of an application finishes?
"When you call finish() this doesn't mean the Activity instance is
garbage collected. You're telling Android you want to close the
Activity (do not show it anymore). It will still be present until
Android decides to kill the process (and thus terminate the DVM) or
the instance is garbage-collected."
You need to implement your own stop method to stop the running thread, you can make a call to it in onDestroy
refer this Stopping a runnable
Alternatively
you can perform your operation in an asynctask and use onProgressUpdate() to publish progress on UI thread and use cancel(true) in combination with check in doInBackground() whether cancel has been called to stop the task.

App crash by showing Dialog in Timer (in runOnUiThread) after closing app.

I'm making a little game and in it I have to check if a value is zero every second. When it is zero the game should stop and show a dialog instead.
As from now the game never ever shoud work until the app is reinstalled.
So, I have an timer with an timertask which executes a runOnUiThread.
Timer:
private void update(){
Timer timer = new Timer();
timer.schedule(new TimerTask(){
#Override
public void run() {
onChange();
}
},0,(1000* getResources().getInteger(R.integer.remove_speed_inSecond)));
}
runOnUiThread: (with try/catch to catch the exeption at this point but i want to fix and not just ignore it.)
private void onChange(){
runOnUiThread(new Runnable() {
#Override
public void run() {
try{
checkupifexpire();
}
catch (Exception ex) {
}
}
});
}
The Method where i show the dialog:
private void checkupifexpire() {
if(eat == 0 || drink == 0 || wash == 0 || care == 0){
dialog = new Dialog(this, android.R.style.Theme_Black_NoTitleBar_Fullscreen);
dialog.setOnCancelListener(new DialogInterface.OnCancelListener()
{
#Override
public void onCancel(DialogInterface dialog)
{
GameEngine.this.finish();
}
});
dialog.setContentView(R.layout.activity_rip);
dialog.show();
}
}
Always when I press the back button or just the home button then the App crashes.
Any Idea how to fix this?

So, the logcat tells us that is crashes on line 306 of GameEngine.java, in the method checkupifexpire, which looks like it is the dialog.show() line.
I'm not 100% sure, but from what you've said, it would seem to me that when back or home is pressed, the app will lose its UI thread. This means that checkuponexpire cannot do what it does.
To solve your crash problem, there are three obvious options:
You could use onPause in your main activity to catch when the app loses the screen. At this point you need to either stop the timer, or switch it to using Toast to communicate information.
Only use Toast in checkuponexpire
Decide that when the back or home is pressed the game is over anyway and cancel the Timer.
To Actually get the dialog, it may also be helpful to change the context you use to create the dialog with. Although it should be used sparingly, it may be that getApplicationContext() is what you need here (possibly this.getApplicationContext()).

Thanks to Neil Townsend and WELLCZECH. :)
My problem was the Lifecycles.
Mostly i had the App running in the onCreat() and had no onStart() method.
Just didn't know that thies methods were as much important as they are.
Also i didn't need a dialog shown. Instead i just have to start a new activity and cancel the old one.

Easiest way of creating a timer in android?

Im trying to make a timer for a game, and I'm stuck atm.
This is my code so far. I made a new activity for the intent, cause I read somewhere that's one way to do it.
public class MainActivity extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//Timer timer = new Timer();
//task = new TimerTask() {
Button b1 = (Button) findViewById(R.id.button1);
b1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v){
startActivity(new Intent("com.loltimer.Timer"));
}
});
};
}
When I press the first button I want to have a timer that goes from 5minutes down to 0. And at 0 I want a sound to be played.
Thanks in advance!

Has got to be the Android count down timer class: http://developer.android.com/reference/android/os/CountDownTimer.html

Timing operations are best handled by a Handler in Android.
http://developer.android.com/reference/android/os/Handler.html
You can wrap the operation you want to run in the future as a Runnable and pass it to postDelayed(). If the operation needs to run repeatedly on that interval, you can call postDelayed() at the end of the Runnable to schedule the next run.
CountdownTimer can also be useful if you need to run some code a finite number of times on a regular interval. This class is actually just a thin wrapper around Handler.