usb accessory, catch USB_ACCESSORY_ATTACHED by intent-filter of Service

Question

In android usb accessory documentation, there is example of android manifest, where Activity catch USB_ACCESSORY_ATTACHED by intent-filter. Im asking myself, its possible to catch the same intent by intent-filter of Service/IntentService ?

EDIT

I tried this,but without success:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.entreprise.ws.main"
    android:versionCode="1"

    android:versionName="1.0" >


    <uses-sdk android:minSdkVersion="10" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />


    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"

        >
            <activity
            android:name="com.entreprise.ws.main.WeatherStationClientActivity"
            android:exported="true"
            android:screenOrientation="portrait"
             >
<!--              <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>  -->

        </activity>

        <activity android:name=".EntryPointActivity"

            android:screenOrientation="portrait" >

            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

            <activity
            android:name="com.entreprise.ws.main.WiFiListActivity"
            android:label="@string/appname_wifilist" >
            </activity> 


            <uses-library android:name="com.android.future.usb.accessory" />


         <activity
            android:screenOrientation="portrait"
            android:name=".WSInstallatorActivity"
            android:exported="true"
             >



        </activity> 

    <service class="services.MyService" android:name="services.MyService">
                     <intent-filter>
            <action android:name="android.hardware.usb.action.USB_ACCESSORY_ATTACHED" />
            <action android:name="android.hardware.usb.action.USB_ACCESSORY_DETACHED" />
        </intent-filter>

                                <meta-data android:name="android.hardware.usb.action.USB_ACCESSORY_ATTACHED"
                android:resource="@xml/accessory_filter" />
    </service>




    </application>

</manifest>

service:

package services;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;
import android.widget.Toast;

public class MyService extends Service {

    final static String TAG = "MyService";
    @Override
    public void onCreate() {
        super.onCreate();
        Log.i("TAG", "onCreate");
        Toast.makeText(this, "Service created...", Toast.LENGTH_LONG).show();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.i("TAG", "onDestroy");
        Toast.makeText(this, "Service destroyed...", Toast.LENGTH_LONG).show();
    }
    @Override
    public IBinder onBind(Intent intent) {
        Log.i("TAG", "onBind");
        // TODO Auto-generated method stub
        return null;
    }
}

P.S for activity, this works fine

EDIT2

I experimenting by moving intent-filter and meta-data to my broadcast receiver: I not receive no more attach event. What is funny, I continue receive detach event. Its looks like USB_ACCESSORY_ATTACHED works only with activity, despite "Broadcast Action" classification in documentation.

EDIT3: Final conclusion

Its looks like USB_ACCESSORY_ATTACHED can be caught only in activity (in reason of possible dialog with user ?! ). detach event can be catch in receivers.

Answer 1

I am also exploring USB support on android for my project, and ended up browsing through Android source for this matter.

Yes USB_ACCESSORY_ATTACHED and USB_DEVICE_ATTACHED both intents can be caught only in activities but Not in Service. I could not find yet exactly why is it so. Like you, I believed it should be possible to directly notify a Service about USB state(device attached, accessory attached). But this is not the way it is implemented in Android. will post if I find something more on this.

Detach intents can be caught in BroadCastReceivers.

If you want to adventure yourself in Android source you can start from this directory - ICS_SOURCE/frameworks/base/services/java/com/android/server/usb and read from there.