i have an Activity and a Sticky Service. The Activity needs to show some values in it´s UserInterface depending on the values of the Sticky Service. So whenever the Service changes his data, the Activity needs to update it´s UserInterface.
But how should the Service notify the Activity to change it´s values??
Please remind that the Activity sometimes isn´t alive, only the Service is Sticky.
Use LocalBroadcasts
in your service class:
public class LocalMessage extends IntentService{
private Intent broadcast;
public static final String BROADCAST = "LocalMessage.BROADCAST";
public LocalMessage(String name) {
super(name);
broadcast = new Intent(name);
}
#Override
protected void onHandleIntent(Intent intent) {
if (broadcast != null) LocalBroadcastManager.getInstance(context).sendBroadcast(broadcast);
}
}
and here is method inside service to broadcast
private void sendLocalMessage(){
(new LocalMessage(LocalMessage.BROADCAST)).onHandleIntent(null);
}
In your activity:
private void registerBroadcastReciever() {
IntentFilter filter = new IntentFilter(YourService.LocalMessage.BROADCAST);
LocalBroadcastManager.getInstance(getApplicationContext()).registerReceiver(receiver, filter);
}
private BroadcastReceiver receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
//doSmth
}
};
in your activity onDestroy() method unregister receiver;
Related
I have a broadcast receiver that gets triggered on geofencing events and either "clocks in" or "clocks out" with the server. If my application's "Attendance" activity is already open I would like it to display the clocking status change but I don't want the Broadcast Receiver to start the activity if it's not open - in other words display the change "live" while the activity is open only.
The way I imagine doing this is with the Broadcast Receiver sending an Intent to the activity but name "startActivity()" doesn't sound encouraging unless there are any special flags I can pass to prevent starting an Activity that isn't already open - I can't seem to find any.
The other option would be to constantly poll the value while the activity is open but it doesn't seem optimal so I would only use it if there wasn't another way and I can't think of a reason why it couldn't be possible with Intents.
There are several different ways to accomplish the same task. One is registering a listener like the following example:
MainActivity
public class MainActivity extends AppCompatActivity
{
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Receiver.setOnReceiveListener(new Receiver.OnReceiveListener() {
public void onReceive(Context Context, Intent intent)
{
//Do something.
}
});
}
#Override
protected void onDestroy()
{
super.onDestroy();
Receiver.setOnReceiveListener(null);
}
}
Receiver
public class Receiver extends BroadcastReceiver
{
private static OnReceiveListener static_listener;
public static abstract interface OnReceiveListener
{
public void onReceive(Context context, Intent intent);
}
public static void setOnReceiveListener(OnReceiveListener listener)
{
static_listener = listener;
}
#Override
public final void onReceive(Context context, Intent intent)
{
if(static_listener != null) {
static_listener.onReceive(context, intent);
}
}
}
Just have your BroadcastReceiver send a broadcast Intent. Your Activity should register a listener from this broadcast Intent and if it gets triggered, it can update the UI.
Here's an example:
Declare a private member variable in your Activity:
private BroadcastReceiver receiver;
In Activity.onCreate(), register the BroadcastReceiver:
IntentFilter filter = new IntentFilter();
filter.addAction("my.package.name.CLOCK_STATUS_CHANGE");
receiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
// Here you can update the UI ...
}
};
registerReceiver(receiver, filter);
And in onDestroy() you can unregister it (probably not necessary, but cleaner):
if (receiver != null) {
unregisterReceiver(receiver);
receiver = null;
}
In your BroadcastReceiver that detects the geofencing event, you should create and send a broadcast Intent:
Intent broadcastIntent = new Intent("my.package.name.CLOCK_STATUS_CHANGE");
sendBroadcast(broadcastIntent);
I'm trying to add to my broadcast receiver an if, so I will start a different activity if a call has been answered, to the regular activity I start usually, if the screen has just been turned on.
Now as you can see down here I have the class screenJump starting when the user wakes up phone.
I would like to start a phoneActivity I wrote when the user wakes up phone, but only when a call has been answered.
This is my service now.
public class MyService extends Service {
BroadcastReceiver bd;
public MyService() {
}
class ScreenReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
Intent startupIntent = new Intent(context, ScreenJump.class);
startupIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
context.startActivity(startupIntent);
}
public ScreenReceiver()
{
}
}
#Override
public void onCreate()
{
super.onCreate();
IntentFilter filter = new IntentFilter(Intent.ACTION_USER_PRESENT);
bd = new ScreenReceiver();
registerReceiver(bd, filter);
}
}
I IntentService that I would like to send message to the main Activity it is nested in. I am using a broadcast receiver to broadcast the message I got from the IntentService as such:
public static class ResponseReceiver extends BroadcastReceiver {
public static final String ACTION_RESP = "com.mypackage.intent.action.MESSAGE_PROCESSED";
#Override
public void onReceive(Context context, Intent intent) {
String text;
text = intent.getStringExtra(RegistrationIntentService.PARAM_OUT);
regid = text;
}
}
I have registered the receiver in the Oncreate method of the main Activity. How can I send the "text" in this case? It is weird that regid in this case is null while "text" has the string data I wanted.
you can user result receiver with intent service to get the result into activity or fragment, follow the following links,
http://sohailaziz05.blogspot.in/2012/05/intentservice-providing-data-back-to.html
In your service you do
Intent intent = new Intent();
intent.setAction(yourActionToMatchBroadcastReceiverIntentFilter);
intent.putExtra(RegistrationIntentService.PARAM_OUT, yourText);
LocalBroadcastManager.getInstance(context).sendBroadcast(intent);
In activity register your BroadcastReceiver in onResume() and unregister it in onPause(). Whenever your activity is active the receiver will receive intents from your IntentService.
EDIT
public static class ResponseReceiver extends BroadcastReceiver {
MapActivity activity;
public ResponseReceiver(MapActivity activity) {
this.activity = activity;
}
#Override
public void onReceive(Context context, Intent intent) {
activity.regid = intent.getStringExtra(RegistrationIntentService.PARAM_OUT);
// do whatever you need here
}
}
When registering, this was what worked for me
IntentFilter filter = new IntentFilter(ResponseReceiver.ACTION_RESP);
filter.addCategory(Intent.CATEGORY_DEFAULT);
receiver = new ResponseReceiver();
LocalBroadcastManager.getInstance(this).registerReceiver(receiver, filter);
as opposed to
registerReceiver(receiver, filter);
#Override
public void onReceive(Context context, Intent intent) {
final String text = intent.getStringExtra(RegistrationIntentService.PARAM_OUT);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
//access the string text and send it to backend
}
});
}
I hope this will help someone. Sending the string like suggested in the comments didn't work for me. I was getting nullpointerexception at that specific line where I assigned ma.regid = text;
I have a service that listens for (ON_BATTERY_CHANGE), then onReceive service sends a Broadcast to My MainActivity. The problem is that I somehow can't get them from service to my main activity. Code: Main Activity:
public class MainActivity extends Activity
private BroadcastReceiver batteryReceiverService;
private TextView text2;
....
protected void onCreate(Bundle savedInstanceState) {
text2=(TextView)findViewById(R.id.TV_text2);
batteryReceiverService = new BroadcastReceiver(){
#Override
public void onReceive(Context context, Intent intent) {
text2.setText("left: "+intent.getStringExtra("H")+" hours "+intent.getStringExtra("M")+" minute(s)");
Log.e("text2","text2 HHH " +intent.getStringExtra("H")); //log shows 0
Log.e("text2","text2 MMM " +intent.getStringExtra("H")); // log shows 0
}
};
registerReceiver(batteryReceiverService, new IntentFilter(UltimateBatterySaverService.BROADCAST_ACTION));
....
#Override
protected void onDestroy() {
unregisterReceiver(batteryReceiverService);
super.onDestroy();
}
Service:
public class UltimateBatterySaverService extends Service {
private Intent intent;
static final String BROADCAST_ACTION = "lt.whitegroup.ultimatebatterysaver";
private BroadcastReceiver batteryLevelReceiver;
....
public void onCreate() {
super.onCreate();
intent = new Intent(BROADCAST_ACTION);
}
#Override
public void onDestroy() {
unregisterReceiver(batteryLevelReceiver);
super.onDestroy();
}
IntentFilter batteryLevelFilter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
batteryLevelReceiver = new BroadcastReceiver(){
#Override
public void onReceive(Context context, Intent intent){
// Receiving data, calculating and etc
averageChargingH=timeAllInHours;
averageChargingM=timeAllInMinutes;
// to put extras and send broadcast
does();
......
public void does(){
String strLong = Long.toString(averageChargingH);
String strLong2 = Long.toString(averageChargingM);
Log.e("cccccc","strLong h "+strLong); // getting good value not 0(everything ok)
Log.e("cccccc","strLong2 m"+strLong2); // getting good value not 0(everything ok)
intent.putExtra("H", strLong);
intent.putExtra("M", strLong2);
sendBroadcast(intent);
}
Any ideas why my information is not transfered correctly?
The does() method seems to be using variables in the same scope as onReceive so I'm guessing that the intent variable in does() is actually the Intent passed in from onReceive.
Try adding some logging before sending the broadcast to check if the action of the intent is correct, or simply create the broadcast intent in the onReceive method and name it intent2.
I have an Android application which uses C2DM services (aka push).
I have a separate class which implements the registration process and which receives the data (and extends BroadcastReceiver).
I want to communicate this data to the activity which currently is in the foreground. The activity currently in the foreground may differ depending on user action.
What's the best way to communicate in between the receiver and the current activity?
Thanks.
I solved this problem by sending out a new broadcast from the C2DMReceiver class, which looked something like this.
The C2DMReceiver class:
public class C2DMReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals("com.google.android.c2dm.intent.REGISTRATION")) {
handleRegistration(context, intent);
} else if (intent.getAction().equals("com.google.android.c2dm.intent.RECEIVE")) {
handleMessage(context, intent);
}
}
private void handleRegistration(Context context, Intent intent) {
// handle registration
}
private void handleMessage(Context context, Intent intent) {
Intent i = new Intent("push");
i.putExtras(intent);
// context.sendOrderedBroadcast(i, null);
context.sendBroadcast(i);
}
}
Another class I called PushReceiver. This is the class that will extend BroadcastReceiver and receive the broadcast sent by C2DMReceiver.
public class PushReceiver extends BroadcastReceiver {
public PushReceiver() {
}
#Override
public void onReceive(Context context, Intent intent) {
// do stuff
abortBroadcast();
}
public static class PushFilter extends IntentFilter {
private static final int DEFAULT_PUSH_PRIORITY = 1;
public PushFilter() {
this(DEFAULT_PUSH_PRIORITY);
}
public PushFilter(int priority) {
super("push");
setPriority(priority);
}
}
}
And the activity class, in this case called MyActivity. This should work well if you are using a base activity class that all other activities extend. That way every activity registers the receiver. By doing the register/unregister in onResume/onPause, you should be able to guarantee that only the current activity receives the broadcast. If not, you can send an ordered broadcast from C2DMReceiver and use priority in the PushFilter.
public class MyActivity extends Activity {
private PushReceiver pushReceiver;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// your onCreate method
pushReceiver = new PushReceiver();
}
public void onResume() {
super.onResume();
// your onResume method
registerReceiver(pushReceiver, new PushReceiver.PushFilter());
}
public void onPause() {
super.onPause();
// your onPause method
unregisterReceiver(pushReceiver);
}
}
In my case, I wrote the PushReceiver constructor to take a View and then "did stuff" with the view in the onReceive method. Without knowing more about what your trying to do, I can't elaborate on this, but hopefully this can provide a decent template to work from.