Android - Overriding ActionBar Back And Device Back Button

In my app I have a MainActivity and a TimerActivity. In normal circumstances in TimerActivity the device back button and the ActionBar's up button work as they should - they lead f

Solution 1:

1. To override Actionbar Up button, use:

   @Override
   public boolean onOptionsItemSelected(MenuItem item) 
   {
       switch(item.getItemId()) {
           case android.R.id.home:
               //User clicked home, do whatever you want
               return true;
           default:        
               return super.onOptionsItemSelected(item);
       }
   }
   

2. To auto return to previous activity, please specify previous activity in AndroidManifest.xml:

   <activity
       android:name=".SecondActivity"              
       android:label="@string/label_myLabel"
       android:parentActivityName=".FirstActivity">
       <meta-data
           android:name="android.support.PARENT_ACTIVITY"
           android:value="com.yourpackage.FirstActivity"/>
   </activity>
   

Solution 2:

onBackPressed() doesn't affect the ActionBar's up button.

The "back" button and the "up" button are two different means of navigation.

From the docs:

Up

The Up button is used to navigate within an app based on the hierarchical relationships between screens.

Back

The system Back button is used to navigate, in reverse chronological order, through the history of screens the user has recently worked with. It is generally based on the temporal relationships between screens, rather than the app's hierarchy.

So, what you're describing as your problem is actually the recommended way to navigate through your app.

Nevertheless, if you want your users to go to your MainActivity from your TimerActivity after pressing your Notification, the easiest way to implement that would be to include an Intent extra to check when you're launching the Activity from your Notification.

Here's an example:

Intent resultIntent = new Intent(this, TimerActivity.class);
resultIntent.putExtra("fromNotification", true);

In your TimerActivity

private boolean mFromNotification;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    final Bundle args = getIntent().getExtras();
    if (args != null) {
        mFromNotification = args.getBoolean("fromNotification");
    }
}

@Override
public void onBackPressed() {
    if (mFromNotification) {
        startActivity(new Intent(this, MainActivity.class));
        finish();
    } else {
        super.onBackPressed();
    }
}

Solution 3:

As explained in the Notifications Setting up a regular activity PendingIntent, you should use TaskStackBuilder to build a synthetic back stack so that your back button functions as if the user had navigated to their normally:

...
Intent resultIntent = new Intent(this, ResultActivity.class);
TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
// Adds the back stack
stackBuilder.addParentStack(ResultActivity.class);
// Adds the Intent to the top of the stack
stackBuilder.addNextIntent(resultIntent);
// Gets a PendingIntent containing the entire back stack
PendingIntent resultPendingIntent =
    stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT);
...
NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
builder.setContentIntent(resultPendingIntent);
NotificationManager mNotificationManager =
    (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
mNotificationManager.notify(id, builder.build());

The Action Bar Up action, as you noticed, does not differ whether you are coming from a notification or not (as expected if you've set it up correctly).