We Keep Coding

How to Kill an activity on back button pressed

One of my activity displays a down count timer by the help of CountDownTImer() method. The onFinish() method of the Down count timer is displaying a toast to tell the user that the time has elapsed. When it reaches 00:00. The issue is when I press the back button before the time elapses I still get the toast message even if the activity is not visible.
So, I try to kill the activity on the back button pressed by overriding the onBackPressed() as follows, but still, the toast is displaying even if the activity is invisible.
public void onBackPressed(){
super.onBackPressed();
this.finish();
}

Why you don't cancel CountDownTimer() :
public void onBackPressed(){
yourCountDownTimer.cancel();
super.onBackPressed();
}

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();
}

how to close main activity after closing another activity in android?

I am developing an android application. So in there I have button called "Aboutus". when I click that one it starts another activity and show corresponding view.
Here is the code for button Aboutus click event.
aboutus.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
Intent intent = new Intent(MainActivity.this,AboutUs.class);
startActivity(intent);
}
});
}
And then in that aboutus activity I have back button.when we press that back button it will go to the main activity again.
back button key event goes like this..
back.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
Intent intent = new Intent(AboutUs.this,MainActivity.class);
intent.putExtra("aboutus", true);
startActivity(intent);
finish();
System.exit(0);
}
});
here i put some intent extras for some other purposes.In this case they do not matter. So and then again in mainactivity i have exit button. which should kill whole app.
and my exit button code goes like this.
exit.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
finish();
System.exit(0);
}
});
Exit button works perfectly (it ends the app) except for one scenario. if we click on aboutus and go to that activity and then press back button on that aboutus activity and then again come back to main activity and finally when i want to exit it won't kill whole app, instead it again goes to the about activity.
in conclusion,
MainActivity---> click aboutus button(no problem in here.this will start aboutus activity)
Aboutus----->click back button(this also works fine. go back to main activity)
MainActivity--> Exit button (not working .it goes to aboutus activity again)
So how to fix this problem?

i dont see why you have to start MainActivity.java ...the user can just hit the back button as long as its on the activity stack. Also The system.exit(0) is bad. Just let the app finish gracefully with finish().
if you want to pass something to the activity when aboutUS is done, you can look up onNewIntent() method.

use intent flag ACTIVITY_CLEAR_TOP to clear all activities on top of it:
Intent intent = new Intent(AboutUs.this,MainActivity.class);
intent.putExtra("aboutus", true);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)
startActivity(intent);
FLAG_ACTIVITY_CLEAR_TOP From the doc:
If set, and the activity being launched is already running in the
current task, then instead of launching a new instance of that
activity, all of the other activities on top of it will be closed and
this Intent will be delivered to the (now on top) old activity as a
new Intent.

Android backround music across multiple activities; How to catch Home button presses

I want to play an audio file in the background of my app. Easy enough. I want the music to persist and NOT stop or pause while switching between activities in my app. Also fairly easy and accomplished simply by doing this in the onCreate method:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
...
mp = MediaPlayer.create(MainActivity.this, R.raw.lostmexicancity);
mp.setLooping(true);
mp.start();
}
The problem? Getting the music to stop when I press the HOME button.
Killing the sound when the user presses the back button seems easy. Here's what I have for that and works great:
public void onPause() {
if(this.isFinishing()){ //BACK was pressed from this activity
mp.stop();
}
super.onPause(); }
Not complicated, but this does not catch presses of the HOME button. If the Home button is pressed, the music keeps playing even while the user no longer sees my app.
I have seen answers that involve setting permission in the manifest to Get Tasks which I shouldn't have to do and appears dangerous to users. Besides that, the solution didn't even work. I've seen solutions that involve using a service, but none of those work either because the home button STILL plays the music just like before because there doesn't seem to be a way to catch it and it doesn't 'finish' the app (not to mention that every time someone suggest using a service for this task multiple people come in and state that this is not a proper use for services)
It seems the only way to kill the music when the Home button is pressed is to use a non-conditional stop() within onPause, but that's no good because that's called when I swap activities with intents, causing the music to end between activities which is no good.
I have trouble imagining that such a common function like background music is this hard, but I've seen post after post with the same issue as me and no proper answers other than ones that would kill the music between activities within the app.
How do all the other apps on the Google play store accomplish this and yet there appears to be no clear answer online? I could just stop and start the music with each onPause(), but that would cause unprofessional gaps in audio not to mention it would start the background audio from the beginning over and over again which is unacceptable.

I'm a bit new to Android Programming (few months) and today, I faced the same problem you did (maybe you still do?)
I made it work as the following :
Lets say I have MainActivity, and in MainActivity I have Btn2 which leads to SecondActivity, and Btn3 which leads to ThirdActivity.
I declared at the beginning of MainActivity :
public static boolean shouldPlay = false;
I then implemented my onStop() method :
public void onStop() {
super.onStop();
if (!shouldPlay) { // it won't pause music if shouldPlay is true
player.pause();
player = null;
}
}
If the boolean shouldPlay is set to true, then my onStop() won't be called entirely and my music won't turn off. I then have to decide when I set it to true. When I switch from MainActivity to SecondActivity, I do it through an Intent and that's when I'll set shouldPlay to true :
Button Btn2 = (Button) findViewById(R.id.Btn2);
Btn2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, SecondActivity.class);
shouldPlay = true;
startActivity(intent);
}
});
And the same is done for Btn3.
Now, the last thing we want to be looking for is that if I was to go back to MainActivity after visiting SecondActivity or ThirdActivity, shouldPlay would then have been set to true. The first thing I tried was to set it to false as soon as Second and ThirdActivity are called (in their onCreate()) but it want to work, maybe because the onStop() from Main and onCreate() from others are called simultaneously (frankly I don't really get life cycle for now).
What worked is simply to set shouldPlay to false every time we launch onCreate() of Main :
shouldPlay = false;
This works properly for me.
Let me know if it does for you,
Cheers,
bRo.

#Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
if(keyCode == KeyEvent.KEYCODE_HOME){
Log.d("Jorgesys", "Home button pressed!!!");
}
return super.onKeyDown(keyCode, event);
}
but hey! This no longer works as of 4.0 + , Read this: Capture Home Key Event
Try with Back button:
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK ) {
Log.d("Jorgesys", "Back button pressed!!!");
}
return super.onKeyDown(keyCode, event);
}
To stop the media player, you are using the method:
isFinishing(): if the activity is finishing, returns true; else
returns false, but you are only pausing the activity not finishing the
activity.
public void onPause() {
if(this.isFinishing()){ //INCORRECT, Here you are pausing you activity not finishing.
mp.stop();
}
super.onPause();
}
so change to:
public void onPause() {
if(mp.isPlaying())
{
mp.stop();
}
super.onPause();
}
When your activity is on pause, evaluates if your MediaPlayer is playing, if this is true then stops the audio.

Avoid splash screen activity when pressing Back button

In my application, I have two activities. First is a splash screen, which simply shows the application name and few other info.
Upon clicking on the splash screen activity, I'm loading the main activity. My app works fine, but I'm facing a small issue. If I press back button from my main activity, control is going to splash screen activity. But I don't want to show the splash screen activity again, I want to avoid splash screen activity when pressing Back button.
Is it possible? If so how?

In your AndroidManifest.xml file, add android:noHistory="true" attribute in your splash screen <activity>.

As I understand, you want the splash activity to not show after changing activity. You should note activities save On Stack and with starting new activity push on it and with finish you pop on top stack. I think that if you the call finish() method your problem fix as in your splash screen activity where you call StartActivity insert finish() after
public void onClick(View v) {
Intent intent = new Intent(Main.this, Splash.class);
startActivity(intent);
finish();
}
Hope to be useful :)

You can just call
finish();
In your Splash screen when you jump to the second screen.

In addition to the above answers, you should note
that:
1: by calling the finish() method, the Splash activity
will close after execution, meaning that it will not be
available in the stack.
#Override
protected void onCreate(Bundle saveInstsnceState){
super.onCreate( saveInstanceState);
\\ do something here
Intent intentSplash = new Intent(SplashActivity.this, NextActivity.class);
StartActivity(intentSplash);
finish ();
}
You will achieve your aim using the method above
but...
2: If you want to prevent your users from force
exiting the app (pressing back button) while the
splash activity in still ongoing which is the best
practice in android, then you need to call the
onBackPressed () method.
Class NoBackSplash{
#Override
protected void onCreate(Bundle saveInstsnceState){
super.onCreate( saveInstanceState);
\\ do something here
Intent intentSplash = new Intent(SplashActivity.this, NextActivity.class);
StartActivity(intentSplash);
finish ();
}
#Override
public void OnBackPressed(){
};
}
With this OnBackPressed() method, your splash activity will not be force to exit no matter how hard the user try.

I understand, you want the splash activity to not show when you click on back button. First of all you should know that all the activities on android are in form of STACK. So what we need we just end the splash activity after it execute. we can do this by calling finish() method in android studio. here is the solution:
Intent intent = new Intent(MainActivity.this, home.class);
startActivity(intent);
finish();

public class Splash extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
Handler hd = new Handler();
hd.postDelayed(new Runnable() {
#Override
public void run() {
Intent i = new Intent(Splash.this,MainActivity.class);
startActivity(i);
#by calling finish() method,splash activity will close after execution
finish();
}
},3000);
}}