Android deep linking - Back stack

Question

I am trying to implement deep linking in my Android application. I have been following this guide. I have an Android Activity that is started from and intent-filter in the Android manifest:

<activity
    android:name=".MyActivity"
    android:parentActivityName=".MainActivity" >
    <intent-filter android:label="@string/filter_title_deep_link">
        <action android:name="android.intent.action.VIEW" />
        <category android:name="android.intent.category.DEFAULT" />
        <category android:name="android.intent.category.BROWSABLE" />
        <data android:scheme="com.example" />
    </intent-filter>
    <meta-data
        android:name="android.support.PARENT_ACTIVITY"
        android:value=".MainActivity"/>
</activity>

I am spawning this intent from adb:

adb shell am start -W -a android.intent.action.VIEW -d "com.example://test" com.example

The activity is being created with the correct intent data and runs as expected. However, on press of the back button, the application exits. I was expecting the back stack to be built with MainActivity, as specified by parentActivityName in the Android manifest. Obviously this is not the case.

How can I add a parent activity to the back stack in this case?

I wondered if I could use a TaskStackBuilder as shown here in the context of notifications, but wasn't sure how it would work.

Perhaps I should have an intermediate Activity to build the main activity using something like:

TaskStackBuilder.create(this)
                .addParentStack(MyActivity.class)
                .addNextIntent(new Intent(this, MyActivity.class))
                .startActivities();

?

Answer 1

I came across the exact same problem. So, if you want your user to go to your parent activity, whenever they presses the UP button, you can define the parent activity in the AndroidManifest.xml and then programmatically control the up-navigation.

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    // Respond to the action bar's Up/Home button
    case android.R.id.home:
        NavUtils.navigateUpFromSameTask(this);
        return true;
    }
    return super.onOptionsItemSelected(item);
}

@Override
public void onBackPressed() {
    NavUtils.navigateUpFromSameTask(this);
}

You may do the same in all activities to constantly navigate the user up back to the home screen. Additionally, you may create the full back stack before navigating the user back. Read more in the following documentation.

Providing Up Navigation

A Straight Forward Solution

You can simply check if the deep-linked activity has a back stack to go back in your app's task itself by calling isTaskRoot(). I'm not quite sure if it does have any caveats though.

@Override
public void onBackPressed() {
    if(isTaskRoot()) {
        Intent parentIntent = new Intent(this, ParentActivity.class);
        startActivity(parentIntent);
        finish();
    } else {
        super.onBackPressed();
    }
}

In this case, you don't really have to declare parent activities in the Android Manifest.