Must I specify the parent activity name in the Android Manifest?

Question

I have an activity that starts another activity.
Is it mandatory that I specify the parent activity in the Android Manifest? Im asking this because there might be other activities that will start this one as well, so should I specify all of them?

android:parentActivityName="com.example.myfirstapp.MainActivity"  

Answer 1

As per docs -> section android:parentActivityName:

The system reads this attribute to determine which activity should be started when the user presses the Up button in the action bar. The system can also use this information to synthesize a back stack of activities with TaskStackBuilder.

So you only need to specify that if you're going to use up-navigation (as opposed to navigation by back button) or TaskStackBuilder. In other cases, you don't need it.

For more information, see the up-navigation docs. (Archived from the original, which now redirects to the Jetpack Navigation docs on designing navigation graphs)

Answer 2

While it should be defined if upward navigation or backstack synthesis is desired, note that the attribute android:parentActivityName was introduced in API Level 16.

For prior releases, parent activity information is accessed from attributes defined inside of a <meta-data> tag that is declared inside of the child <activity> tag.

Example:

    <activity         android:name=".DetailActivity"         android:parentActivityName=".MainActivity">         <meta-data             android:name="android.support.PARENT_ACTIVITY"             android:value=".MainActivity"/>     </activity> 

Inside of the <meta-data> tag, set the android:name attribute to android.support.PARENT_ACTIVITY, and the android:value attribute to the parent activity class name (i.e. the same class name as that assigned to android:parentActivityName).

Unless API level is known, both the <meta-data> and inline specifications are recommended.

For more on specifying the parent activity, see: https://developer.android.com/training/implementing-navigation/ancestral.html#SpecifyParent

In addition, consider defining the android:launchMode attribute inside of your main <activity> tag to set the desired behavior of upward navigation: https://developer.android.com/guide/topics/manifest/activity-element.html#lmode