In the following example, we use a ContentObserver to monitor updates to the SMS Provider. This Observer is created and started before the SMS Intent is fired, and checks the Provider changes against the destination address. The Activity that creates the Observer must implement the SmsSendObserver.SmsSendListener interface to receive the callback.
The Observer's constructor includes a timeout parameter (in milliseconds) to allow the Observer to be properly unregistered if the message is not sent after a reasonable amount of time. This can be set to NO_TIMEOUT if desired. However, the class, as written, is meant for "one shot" use, and it will unregister itself and nullify members upon callback. The stop() method can be used to clean up if no callback occurs. In either case, the instance is no longer usable, and any reference to it should be set to null.
Example Activity:
public class MainActivity extends Activity
implements SmsSendObserver.SmsSendListener {
...
private void sendMessage(String phoneNumber, String messageBody) {
// This example has a timeout set to 15 seconds
new SmsSendObserver(this, phoneNumber, 15000).start();
Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("smsto:" + phoneNumber));
intent.putExtra("address", phoneNumber);
intent.putExtra("sms_body", messageBody);
intent.putExtra("exit_on_sent", true);
startActivity(intent);
}
public void onSmsSendEvent(boolean sent) {
Toast.makeText(this, sent ? "Message was sent" : "Timed out",
Toast.LENGTH_SHORT).show();
}
}
The SmsSendObserver class:
public class SmsSendObserver extends ContentObserver {
public static final int NO_TIMEOUT = -1;
private static final Handler handler = new Handler();
private static final Uri uri = Uri.parse("content://sms/");
private static final String COLUMN_ADDRESS = "address";
private static final String COLUMN_TYPE = "type";
private static final String[] PROJECTION = { COLUMN_ADDRESS, COLUMN_TYPE };
private static final int MESSAGE_TYPE_SENT = 2;
private Context context = null;
private ContentResolver resolver = null;
private String phoneNumber = null;
private long timeout = NO_TIMEOUT;
private boolean wasSent = false;
private boolean timedOut = false;
public SmsSendObserver(Context context, String phoneNumber, long timeout) {
super(handler);
if (context instanceof SmsSendListener) {
this.context = context;
this.resolver = context.getContentResolver();
this.phoneNumber = phoneNumber;
this.timeout = timeout;
}
else {
throw new IllegalArgumentException(
"Context must implement SmsSendListener interface");
}
}
private Runnable runOut = new Runnable() {
@Override
public void run() {
if (!wasSent) {
timedOut = true;
callBack();
}
}
};
public void start() {
if (resolver != null) {
resolver.registerContentObserver(uri, true, this);
if (timeout > NO_TIMEOUT) {
handler.postDelayed(runOut, timeout);
}
}
else {
throw new IllegalStateException(
"Current SmsSendObserver instance is invalid");
}
}
public void stop() {
if (resolver != null) {
resolver.unregisterContentObserver(this);
resolver = null;
context = null;
}
}
private void callBack() {
((SmsSendListener) context).onSmsSendEvent(wasSent);
stop();
}
@Override
public void onChange(boolean selfChange) {
if (wasSent || timedOut)
return;
Cursor cursor = null;
try {
cursor = resolver.query(uri, PROJECTION, null, null, null);
if (cursor != null && cursor.moveToFirst()) {
final String address =
cursor.getString(cursor.getColumnIndex(COLUMN_ADDRESS));
final int type =
cursor.getInt(cursor.getColumnIndex(COLUMN_TYPE));
if (PhoneNumberUtils.compare(address, phoneNumber) &&
type == MESSAGE_TYPE_SENT) {
wasSent = true;
callBack();
}
}
}
finally {
if (cursor != null) {
cursor.close();
}
}
}
public interface SmsSendListener {
// Passes true if the message was sent
// Passes false if timed out
public void onSmsSendEvent(boolean sent);
}
}
