android How to open last activity when tapping notification

Question

I have observed several similar questions but they couldn`t help me. I need to display last activity when user click notification. Here is my code:

NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(YourService.this)
        .setContentTitle(getResources().getText(R.string.app_name))
        .setContentText(getServiceStateDescription(YourService.this))
        .setSmallIcon(iconId)
        .setWhen(System.currentTimeMillis());

Intent nIntent = getPreviousIntent();
TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
// Adds the back stack
stackBuilder.addParentStack(MainActivity_.class);
stackBuilder.addNextIntent(nIntent);
PendingIntent pendingIntent =
        stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT);
notificationBuilder.setContentIntent(pendingIntent);

startForeground(ContextConstants.LAUNCHER_SERVICE_NOTE_ID, notificationBuilder.build());


private Intent getPreviousIntent() {
Intent newIntent = null;
final ActivityManager activityManager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    final List<ActivityManager.AppTask> recentTaskInfos = activityManager.getAppTasks();
    if (!recentTaskInfos.isEmpty()) {
        for (ActivityManager.AppTask appTaskTaskInfo: recentTaskInfos) {
            if (appTaskTaskInfo.getTaskInfo().baseIntent.getComponent().getPackageName().equals(ContextConstants.PACKAGE_NAME)) {
                newIntent = appTaskTaskInfo.getTaskInfo().baseIntent;
                newIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            }
        }
    }
} else {
    final List<ActivityManager.RecentTaskInfo> recentTaskInfos = activityManager.getRecentTasks(1024, 0);
    if (!recentTaskInfos.isEmpty()) {
        for (ActivityManager.RecentTaskInfo recentTaskInfo: recentTaskInfos) {
            if (recentTaskInfo.baseIntent.getComponent().getPackageName().equals(ContextConstants.PACKAGE_NAME)) {
                newIntent = recentTaskInfo.baseIntent;
                newIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            }
        }
    }
}
if (newIntent == null) newIntent = new Intent();
return newIntent;

}

Second point is that if i used deprecated metods in order to build notification, displaying last activity works great as i wanted here is code:

Notification note = new Notification(iconId,
            getResources().getText(R.string.serviceStarted),
            System.currentTimeMillis());
    note.flags |= Notification.FLAG_ONGOING_EVENT;
    note.flags |= Notification.FLAG_NO_CLEAR;

    Intent nIntent = new Intent();
    nIntent = getPreviousIntent(nIntent);
    PendingIntent pi = PendingIntent.getActivity(this, 0, nIntent, 0);
    note.setLatestEventInfo(this,
            getResources().getText(R.string.app_name), getServiceStateDescription(YourService.this), pi);

    startForeground(ContextConstants.LAUNCHER_SERVICE_NOTE_ID, note);

But i don't want use deprecated metods anymore, that's why i'm here explaining. Thanks in advance!

And i've seen this doc as well.

Here is my manifest:

<?xml version="1.0" encoding="utf-8"?>

<permission android:name="com.my.package.permission.C2D_MESSAGE" android:protectionLevel="signature" />
<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.READ_PHONE_STATE"/>
<uses-permission android:name="android.permission.VIBRATE"/>
<uses-permission android:name="android.permission.WAKE_LOCK"/>
<uses-permission android:name="android.permission.READ_CONTACTS"/>
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<uses-permission android:name="com.my.package.permission.C2D_MESSAGE" />
<uses-permission android:name="android.permission.GET_TASKS"/>

<application
    android:name=".MyApplication"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/Theme.AppCompat.Light">
    <activity android:name=".activity.StartingActivity_"  android:label="@string/app_name">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name=".activity.MainActivity_"
        android:configChanges="orientation|screenSize">
    </activity>
    <activity
        android:name=".activity.ComposeEmailActivity_"
        android:configChanges="orientation|screenSize"
        android:parentActivityName=".activity.MainActivity_">
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value=".activity.MainActivity_" />
    </activity>
    <activity
        android:name=".activity.EditAccountActivity_"
        android:configChanges="orientation|screenSize"
        android:parentActivityName=".activity.MainActivity_">
        <meta-data
            android:name="android.support.PARENT_ACTIVITY"
            android:value=".activity.MainActivity_" />
    </activity>               

    <!--android:process=":remote" is for working in background-->
    <service android:enabled="true" android:name=".service.YourService"/>       

</application>

Answer 1

Your problem isn't with the methods you are using to build the Notification. Your problem is your use of TaskStackBuilder. Using this class performs a lot of hidden magic behind the scenes and it makes a lot of assumptions about how your want the app to behave. Unfortunately, these assumptions are mostly wrong :-(

If you just want to bring your application to the foreground in whatever state it was in when it went to the background, you don't want to use TaskStakBuilder and you also don't have to use all those nasty ActivityManager methods. Just do this:

NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(YourService.this)
    .setContentTitle(getResources().getText(R.string.app_name))
    .setContentText(getServiceStateDescription(YourService.this))
    .setSmallIcon(iconId)
    .setWhen(System.currentTimeMillis());

Intent nIntent = getPackageManager().
        getLaunchIntentForPackage(ContextConstants.PACKAGE_NAME);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, nIntent,
    PendingIntent.FLAG_UPDATE_CURRENT);
notificationBuilder.setContentIntent(pendingIntent);

startForeground(ContextConstants.LAUNCHER_SERVICE_NOTE_ID,
    notificationBuilder.build());