How do I set my app as the default SMS app?

Question

I am following this tutorial on setting my app as the default SMS app, but for some reason, my app does not appear in the list of available options. I have tried to research this as much as possible, but everything points back to that same tutorial, or is outdated. Do I need a <receiver> as well? Can someone explain what I am doing wrong?

The code:

@Override
protected void onResume()
{
    super.onResume();
    Log.i("MainAcitvity", "On Resume Called");
    // Only do these checks/changes on KitKat+, the "mSetDefaultSmsLayout" has its visibility
    // set to "gone" in the xml layout so it won't show at all on earlier Android versions.
    final String myPackageName = getPackageName();

    if (Utility.hasKitKat())
    {
        if (Utility.isDefaultSmsApp(this))
        {
            // This app is the default, remove the "make this app the default" layout and
            // enable message sending components.
            mSetDefaultSmsLayout.setVisibility(View.GONE);
        }
        else
        {
            Log.i("MainActivity", "Not Default App");
            // Not the default, show the "make this app the default" layout and disable
            // message sending components.
            mSetDefaultSmsLayout.setVisibility(View.VISIBLE);

            Button button = (Button) findViewById(R.id.set_default_sms_button);
            button.setOnClickListener(new OnClickListener()
            {
                @Override
                public void onClick(View view)
                {                        
                    Log.i("MainActivity", "Button Pushed");
                    //Utility.setDefaultSmsApp(MainActivity.this);
                    Intent intent = new Intent(Telephony.Sms.Intents.ACTION_CHANGE_DEFAULT);
                    intent.putExtra(Telephony.Sms.Intents.EXTRA_PACKAGE_NAME, myPackageName);
                    startActivity(intent);
                }
            });
        }
    }
}

The manifest:

<activity
    android:name=".MainActivity"
    android:label="@string/app_name">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
        <action android:name="android.intent.action.SEND" />
        <action android:name="android.intent.action.SENDTO" />
        <category android:name="android.intent.category.DEFAULT" />
        <category android:name="android.intent.category.BROWSABLE" />
        <data android:scheme="sms" />
        <data android:scheme="smsto" />
        <data android:scheme="mms" />
        <data android:scheme="mmsto" />
    </intent-filter>
</activity>

Answer 1

In order for your app to be eligible to be selected as the default messaging app (as far as the system is concerned), you must list all of the components in the manifest as shown in that blog post, whether those components' classes actually exist or not.

<manifest>
    ...
    <application>
        <!-- BroadcastReceiver that listens for incoming SMS messages -->
        <receiver android:name=".SmsReceiver"
            android:permission="android.permission.BROADCAST_SMS">
            <intent-filter>
                <action android:name="android.provider.Telephony.SMS_DELIVER" />
            </intent-filter>
        </receiver>

        <!-- BroadcastReceiver that listens for incoming MMS messages -->
        <receiver android:name=".MmsReceiver"
            android:permission="android.permission.BROADCAST_WAP_PUSH">
            <intent-filter>
                <action android:name="android.provider.Telephony.WAP_PUSH_DELIVER" />
                <data android:mimeType="application/vnd.wap.mms-message" />
            </intent-filter>
        </receiver>

        <!-- Activity that allows the user to send new SMS/MMS messages -->
        <activity android:name=".ComposeSmsActivity" >
            <intent-filter>
                <action android:name="android.intent.action.SEND" />                
                <action android:name="android.intent.action.SENDTO" />
                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.BROWSABLE" />
                <data android:scheme="sms" />
                <data android:scheme="smsto" />
                <data android:scheme="mms" />
                <data android:scheme="mmsto" />
            </intent-filter>
        </activity>

        <!-- Service that delivers messages from the phone "quick response" -->
        <service android:name=".HeadlessSmsSendService"
            android:permission="android.permission.SEND_RESPOND_VIA_MESSAGE"
            android:exported="true" >
            <intent-filter>
                <action android:name="android.intent.action.RESPOND_VIA_MESSAGE" />
                <category android:name="android.intent.category.DEFAULT" />
                <data android:scheme="sms" />
                <data android:scheme="smsto" />
                <data android:scheme="mms" />
                <data android:scheme="mmsto" />
            </intent-filter>
        </service>
    </application>
</manifest>

Since the system only inspects an app's manifest to determine if it can act as the default messaging app, not all of those components' classes must exist for your app to show in the default selection list. This is useful for learning and testing, but, obviously, if your app is to act as a user's default messaging client, it should fully implement all of the specified components.

If you do intend to perform any SMS/MMS-related tasks, you will also need the relevant permissions. Though the system apparently doesn't check for these when determining eligible default app candidates, the following permissions are necessary for their corresponding operations:

<uses-permission android:name="android.permission.SEND_SMS" />
<uses-permission android:name="android.permission.RECEIVE_SMS" />
<uses-permission android:name="android.permission.READ_SMS" />
<uses-permission android:name="android.permission.WRITE_SMS" />
<uses-permission android:name="android.permission.RECEIVE_MMS" />

If you're missing the SEND_SMS, READ_SMS, or WRITE_SMS permission when you attempt to perform the given action, a SecurityException will be thrown. However, if you're missing a RECEIVE_* permission, your app will just not be delivered the pertinent broadcasts, and it might seem as though nothing is happening when testing those functionalities.