Starting app only if its not currently running

Question

I am sending push notification to users which when clicking on it opens the app.

My problem is that when the app is already open, clicking on the notification start

Answer 1

notificationIntent.addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP|Intent.FLAG_ACTIVITY_CLEAR_TOP|Intent.FLAG_ACTIVITY_NEW_TASK );

notificationIntent.putExtras(bundle);
PendingIntent pintent = PendingIntent.getActivity(context, 0, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT);

Answer 2

first of all set a default Task android:taskAffinity="com.example.testp.yourPreferredName" in your Application element in the Manifest file. Maintain your android:launchMode="singleTask" on your SplashActivity. Now since your SplashActivity is your main entry add this code to both onResume(), onNewIntent() and onCreate() (on a second thought onResume() is not recomended) -follow the comments in the code

//Note these following lines of code will work like magic only if its UPVOTED.
//so upvote before you try it.-or it will crash with SecurityException
ActivityManager am = (ActivityManager) this.getSystemService(ACTIVITY_SERVICE);

List< ActivityManager.RunningTaskInfo > taskInfo = am.getRunningTasks(1000);    
    for(int i =0; i< taskInfo.size(); i++){
        String PackageName = taskInfo.get(i).baseActivity.getPackageName();
        if(PackageName.equals("packagename.appname")){// suppose stackoverflow.answerer.Elltz
            //if the current runing actiivity is not the splash activity. it will be 1
            //only if this is the first time your <taskAffinity> is be called as a task
            if(taskInfo.get(i).numActivities >1){
                //other activities are running, so kill this splash dead!! reload!!                 
                finish();
                // i am dying in onCreate..(the user didnt see nothing, that's the good part)
                //about this code. its a silent assassin
            }
            //Operation kill the Splash is done so retreat to base.
            break;
        }
    }

This code will not work on api 21+; to make it work you need to use AppTask, this will save you extra lines of code as you will not be in a Loop to find your Task.

Hope it helps

Answer 3

String appPackageName = "";

private void isApplicationInForeground() throws Exception {
    ActivityManager am = (ActivityManager) getSystemService(ACTIVITY_SERVICE);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        final List<ActivityManager.RunningAppProcessInfo> processInfos = am
                .getRunningAppProcesses();
        ActivityManager.RunningAppProcessInfo processInfo = processInfos
                .get(0);
        // for (ActivityManager.RunningAppProcessInfo processInfo : processInfos) {
        if (processInfo.importance == ActivityManager.RunningAppProcessInfo.IMPORTANCE_FOREGROUND) {
            // getting process at 0th index means our application is on top on all apps or currently open 
            appPackageName = (Arrays.asList(processInfo.pkgList).get(0));
        }
        // }
    }
    else {
        List<ActivityManager.RunningTaskInfo> taskInfo = am.getRunningTasks(1);
        ComponentName componentInfo = null;
        componentInfo = taskInfo.get(0).topActivity;
        appPackageName = componentInfo.getPackageName();
    }
}

private void notifyMessage(String text) {
    if (appPackageName.contains("com.example.test")) {
        // do not notify
    }
    else {          
        // create notification and notify user  
    }
}

Answer 4

Instead of showing the Splash activity on notification click, show your MainActivity because your splash activity will closed after some time but MainActivity will be remain open and

<activity 
android:name=".MainActivity"
android:launchMode="singleTask"

Answer 5

Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT

And maybe don't start the Splash Activity and reopen (bring to front) the MainActivity and update the UI with a listener that tells you, that you have a new notification (with a flag - boolean or with an Interface to make a listener).

Answer 6

You can use an ordered broadcast to accomplish this.

1) Change your PendingIntent to start a BroadcastReceiver which will decide whether to start the activity or do nothing:

PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0, new Intent(this, DecisionReceiver.class), 0);

2) Create the decision BroadcastReceiver:

public class DecisionReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        context.sendOrderedBroadcast(new Intent(MainActivity.NOTIFICATION_ACTION), null, new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                if (getResultCode() == MainActivity.IS_ALIVE) {
                    // Activity is in the foreground
                }
                else {
                    // Activity is not in the foreground
                }
            }
        }, null, 0, null, null);
    }
}

3) Create a BroadcastReceiver in your activity that will signal that it is alive:

public static final String NOTIFICATION_ACTION = "com.mypackage.myapplication.NOTIFICATION";
public static final int IS_ALIVE = 1;
private BroadcastReceiver mAliveReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        setResultCode(IS_ALIVE);
    }
};

// Register onResume, unregister onPause
// Essentially receiver only responds if the activity is the foreground activity
@Override
protected void onResume() {
    super.onResume();
    registerReceiver(mAliveReceiver, new IntentFilter(NOTIFICATION_ACTION));
}

@Override
protected void onPause() {
    super.onPause();
    unregisterReceiver(mAliveReceiver);
}