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How to pass a variable from activities to start a CountDownTimer service?

This is my first question and I've been trying to find a solution to this for hours but can't get it to work. I'm building an android app that takes an input from the user (number of hours) to fast (not eat). The input is then taken to the service where it does a countdown in the background. Along the way, I'd like the user to access other activities that could you the results from the countdown timer (eg, time_left/total_time = percentage complete). So far, my button that I've created works to make the call for the service. but the service never gets called to update the text view. Thanks
Here is what I have,
public class StartFast extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_start_fast);
startService(new Intent(this, MyService.class));
Log.i("Started service", "hello started service...");
registerReceiver(br, new IntentFilter("COUNTDOWN_UPDATED"));
}
private BroadcastReceiver br = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
intent.getExtras();
long millisUntilFinished = intent.getLongExtra("countdown",0);
String time = Long.toString((millisUntilFinished));
TextView tv = findViewById(R.id.timeView1);
tv.setText(time);
}
};
public void BeginFast(View view){
//Intent intent = new Intent( this, StartFast.class);
// below is how to pass an intent for use in a Service to run in the backgroun
Intent intent =new Intent(this, MyService.class);
startService(intent);
// intent.putExtra() // putExtra longs ...will do after static run succeeds
//intent.putExtra("data", data); //adding the data
Intent intent1 = new Intent(this, Heart.class);
startActivity(intent1);
}
}
and here is the service class,
public class MyService extends Service {
private final static String TAG = "MyService";
public static final String COUNTDOWN_BR = "FastBreak.countdown_br";
Intent bi = new Intent(COUNTDOWN_BR);
CountDownTimer cdt = null;
public void OnCreate(){
super.onCreate();
Log.i(TAG, "starting timer...");
cdt = new CountDownTimer(30000,1000) {
#Override
public void onTick(long millisUntilFinished){
Log.i(TAG, "Countdown seconds remaining: " +millisUntilFinished /1000);
bi.putExtra("countdown", millisUntilFinished);
sendBroadcast(bi);
}
#Override
public void onFinish(){
Log.i(TAG, "Timer finished");
}
};
cdt.start();
}
#Override
public void onDestroy() {
cdt.cancel();
Log.i(TAG, "Timer cancelled");
super.onDestroy();
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
return super.onStartCommand(intent, flags, startId);
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}

https://github.com/greenrobot/EventBus
Check this out. This library is the best and easiest implementation of broadcasts. You can send any data to any object (StartFast service in your case) from any other object (StartFast activity in your case) and write code to run.

First, you need to start the service and register it in the manifest. After the service is started by an activity, it will keep running in the background.
You can send intents with a service and anybody who has registered a broadcast receiver listening to that intent can hear it.
Let's say FirstActivity started the service and registers receiver listening to intent with the tag BOBBY. The service is the one sending an intent BOBBY to anyone who is interested and has registered for it.
You want to move on to SecondActivity. Before you do that, onPause of FirstActivity you need to unregister that broadcastreceiver.
SecondActivity is interested in the intent with tag BOBBY, so he creates his own broadcast receiver and registers for it.
I hope you can see where this is going.A broadcastreceiver can listen to all sorts of intents that you make up.
Have fun.

change value of string from other activity in java

I have two classes Class "A" and Class "B". In class A i have declared a
String password ="admin" .Now in class B i am taking value from user and i
want to change that value of string in class A and want to store value that
user entered. How can i do that? Any help please?
class A
forgetpassword.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent j = new Intent(MainActivity.this,newpassword.class);
startActivity(j);
Class B
EditText newpassword;
Button change;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_new_password);
newpassword = (EditText)findViewById(R.id.newpassword);
change = (Button)findViewById(R.id.chnage);
change.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
MainActivity.b= newpassword.getText().toString();
Intent y= new Intent(NewPassword.this,MainActivity.class);
startActivity(y);
}
});

Use StartActivityForResult()
When you intend to get some result back from an Activity you should start activity using startActivityForResult(intent,requestcode)
Its easy Follow these steps
StartActivity
Intent i = new Intent(MainActivity.this, ForgotPasswordActivity.class);
startActivityForResult(i, 1);
Set new password in ForgotPasswordActivity
Now you are in ForgotPasswordActivity, set your new password and return back to MainActivity on Button click like this.
change.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent y= new Intent(NewPassword.this,MainActivity.class);
y.putExtra("someKey",newpassword.getText().toString()); //set new password
setResult(Activity.RESULT_OK, returnIntent); // set your result
finish(); // return back to MainActivity
}
});
Retrive new Password in MainActivity
Now you navigated back to MainActivty to retrieve your new password override onActivityResultMethod().
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == 1) {
if(resultCode == Activity.RESULT_OK){
String newPassword=data.getStringExtra("someKey");
}
if (resultCode == Activity.RESULT_CANCELED) {
//Write your code if there's no result
}
}
}
Here a link on startActivityForResult()

You can send data from one activity to another in the intent, Use the putExtra() methods the intent class to pass data.Send the data like this
Intent y= new Intent(NewPassword.this,MainActivity.class);
y.putExtra("yourKey",newpassword.getText().toString())
startActivity(y);
and in the onCreate() of MianActivity you can retrieve the value using getStringExtra("yourKey") like this
Intent callingIntent = getIntent();
String password = callingIntent.getStringExtra("yourKey");
and use the password.
Or you can start the NewPassword activity for a result and get the data back in onActivityResult()
Intent newPasswordIntent = new Intent(this,NewPassword.class);
startActivityForResult(newPasswordIntent ,REQUEST_CODE);
and in the change button click handler,
Intent intent= new Intent();
intent.putExtra("yourKey",newpassword.getText().toString());
setResult(Activity.RESULT_OK, intent);
finish();
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
String password = data.getStringExtra("yourKey")
}
Public static variables are easy to call, be aware that they can cause memory leaks

This can lead to context leaking or NPE when you finish the activity.
Instead use an Application class and initialize the string variable in it and with the use of getters() and setters() you can access the variable.
public class BaseApplication extends android.app.Application{
private String admin;
#Override
onCreate(...){
this.admin = "";
}
public String getAdmin(){
return this.admin;
}
public void setAdmin(String admin){
this.admin = admin;
}
}
classA:
...
((BaseApplication) getApplicationContext()).setAdmin("!mpr355!v3");
...
classB:
...
String myAdmin = ((BaseApplication) getApplicationContext()).getAdmin();
...
Also in your manifest file.
<application
android:name=".BaseApplication"
` ...>
UPDATE
Before startActivity(y);
just call
y.putExtra("pass", password);
and in your MainActivity, call getIntent().getStringExtra("pass");
Check for null pointers and you are good to go! :)

Muhammad,
There are many ways to do that and some of the listing here,
Use Broadcast receiver
Use start activity for result
Use static variable
From all of this if you want to change much time then I think broadcast receiver is good one,
Here is the example of broadcast receiver,
In your activity A register broadcast receiver with specific action,
private BroadcastReceiver brodcastRec=new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
if(intent!=null && intent.getAction().equals("changePassword")){
String newPassword=intent.getStringExtra("newPassword");
//do whatever you want to do here after getting new password
}
}
};
And then after write following code in your on create of activity A
IntentFilter intentFilter=new IntentFilter("changePassword");
registerReceiver(brodcastRec,intentFilter);
And In your activity B or click event of Button
Intent intent=new Intent();
intent.setAction("changePassword");
intent.putExtra("newPassword","yourValue");
sendBroadcast(intent);

How does a service notify an activity class by sending an object and calling a method from that activity with the sent object?

I am aware of the BroadCastReceiver, but how can I use it to call a method in my activity. So if I get a notification from my service, a button in my UI turns red, and red being the object that has been sent from the service and turning red the method that has been called by the activity.
sorry for bad english :)

Register a BroadcastReceiver in your activity
private BroadcastReceiver mMessageReceiver = new BroadcastReceiver()
{
#Override
public void onReceive(Context context, Intent intent)
{
String message = intent.getStringExtra("message");
Log.d("receiver", "Got message: " + message);
if (message.equals("eventOne"))
{
//do something
}
else if (message.equals("eventTwo"))
{
//do something else
}
}
};
Override onResume and onDestroy of your activity
#Override
protected void onResume()
{
super.onResume();
LocalBroadcastManager.getInstance(this).registerReceiver(mMessageReceiver,
new IntentFilter("my-event"));
}
#Override
protected void onDestroy()
{
LocalBroadcastManager.getInstance(this).unregisterReceiver(mMessageReceiver);
super.onDestroy();
}
To check if your service is running add the following on your activity
private static boolean isServiceRunning(String serviceName, Context context)
{
ActivityManager manager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
for (ActivityManager.RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE))
{
if (serviceName.equals(service.service.getClassName()))
{
return true;
}
}
return false;
}
Call it like this
boolean isServiceRunning = isServiceRunning(MyService.class.getName(), this.getApplicationContext());
if (!isServiceRunning)
{
Intent startMyServiceIntent = new Intent(this.getApplicationContext(), MyService.class);
startService(startMyServiceIntent);
}
Finally on your service add a method like that and call it whenever you want
private void sendMessage(String event)
{
Intent intent = new Intent("my-event");
intent.putExtra("message", event);
LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
}
#Override
public int onStartCommand(Intent intent, int flags, int startId)
{
Toast.makeText(this, "Service Started", Toast.LENGTH_SHORT).show();
sendMessage("eventOne");
return START_STICKY;
}
And don't forget to add your service to manifest
<application
...
...
<service android:name=".MyService"/>
</application>

You can use a BroadcastReceiver, an event bus or an observable. In your activity, listen for the event and call a method that updates your UI how you want.
I do something similarly for GCM intent service. I use an rxBus that posts when the service is triggered. My activity subscribes to the bus and reacts when it sees the post.

Android - Call a function from outside an activity (through AlarmManager and Notification)

Ok, so I have a main activity called 'Main.java'. This main activity starts an AlarmManager which fires an intent leading to 'AlarmReceiver.java'.
This 'AlarmReceiver.java' then creates a notification which has two buttons on it. One of the buttons is a deletion button, and so when the user clicks on that button, another intent is fired, leading it to 'DelPair.java'.
In DelPair.java, I modify a table in a Database, but then I need the UI of Main.java to reflect this change. I have created two functions in Main.java called updateArrayFromDB() and updateUIFromArray() to do this for me:
updateArrayFromDB() will sync an ArrayList created in Main.java to a
certain table in the DB.
updateUIFromArray() will change the UI of
Main.java to represent the ArrayList that has just been changed.
The problem is that I cannot call these two functions from DelPair.java (they don't exist in that space). I have come across Serializables in trying to find an answer but I don't know enough to know if they apply here or exactly how to implement them across the AlarmManager and the NotificationManager.
How can I access these methods from DelPair.java?
In Main.java:
public void updateArrayFromDB(){
//... The code for this is long and irrelevant
}
public void updateUIFromArray(){
//... The code for this is long and irrelevant
}
private void SendNotification() {
Intent intent = new Intent(this, AlarmReceiver.class);
//...
PendingIntent sender = PendingIntent.getBroadcast(this, 2 , intent, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
am.setRepeating(AlarmManager.RTC_WAKEUP, 5000, notif_freq, sender);
}
In AlarmReceiver.java:
Intent delPairI = new Intent(context, DelPair.class);
PendingIntent delPairPI = PendingIntent.getService(context, 0, delPairI, PendingIntent.FLAG_UPDATE_CURRENT);
Notification noti;
noti = new Notification.Builder(context)
//...
.addAction(R.drawable.ic_delete_icon, "Delete the thing", delPairPI)
.build();
NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(0, noti);
and then in DelPair.java:
public class DelPair extends IntentService {
//...
#Override
protected void onHandleIntent(final Intent intent) {
//...
Intent it = new Intent(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
getApplicationContext().sendBroadcast(it);
handler.post(new Runnable() {
#Override
public void run() {
//... here is where I update the database, which works perfectly
//now need to update the UI and array in Main.java
updateArrayFromDB(); //these lines
updateUIFromArray(); //obviously don't work
}
});
}
}

Why not use broadcasts ? in onHandleIntent just send a broadcast
Intent i = new Intent();
i.setAction(CUSTOM_INTENT);
//put relevant data in intent
getApplicationContext().sendBroadcast(i);
The broadcast receiver:
public class IncomingReceiver extends BroadcastReceiver {
private MainActivity act;
public IncomingReceiver(MainActivity main){
this.act = act;
}
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(CUSTOM_INTENT)) {
System.out.println("GOT THE INTENT");
// call the method on act
}
}
}
In your activity onResume - register new IncomingReceiver, onPause unregister
private IncomingReceiver receiver;
public void onCreate(Bundle bOs){
//other codes
receiver = new IncomingReceiver(this);
}
#Override
protected void onResume() {
IntentFilter filter = new IntentFilter();
filter.addAction(CUSTOM_INTENT);
registerReceiver(receiver, filter);
super.onResume();
}
#Override
protected void onPause() {
unregisterReceiver(receiver);
super.onPause();
}

Since you need to have an updated UI based on database changes, you can call updateArrayFromDB() and updateUIFromArray() in the onResume() method of your activity so the UI gets updated each time the user enters the activity.

howto get startActivityForResult within GCM receiver

Please help me. I need to get activity result from GCM receiver, the code is below
On MainActivity.class
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
//PARSE RESULT CODE
if (resultCode == RESULT_OK){
Toast.makeText(_context,"WAS LOGIN", Toast.LENGTH_LONG).show();
mainProgram();
}else if(resultCode == RESULT_CANCELED){
Toast.makeText(_context,"WAS NOT LOGIN", Toast.LENGTH_LONG).show();
showLoginForm();
}
}
#Override
protected void onCreate(Bundle savedInstanceState) {
setTheme(SampleList.THEME); // Used for theme switching in samples
super.onCreate(savedInstanceState);
Intent intent = new Intent(MainActivity.this, LoginProc.class);
startActivityForResult(intent, 0);
}
private void mainProgram(){
setContentView(R.layout.mainlayout);
}
and in LoginProc.class
#Override
protected void onCreate(Bundle savedInstanceState) {
GCMRegistrar.checkDevice(this);
GCMRegistrar.checkManifest(this);
GCMRegistrar.register(this, SENDER_ID);
registerReceiver(mHandleMessageReceiver,new IntentFilter(DISPLAY_MESSAGE_ACTION));
this.regId = GCMRegistrar.getRegistrationId(this);
GCMRegistrar.register(this, SENDER_ID);
}
private final BroadcastReceiver mHandleMessageReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String newMessage = intent.getExtras().getString(EXTRA_MESSAGE);
// Waking up mobile if it is sleeping
WakeLocker.acquire(getApplicationContext());
Toast.makeText(getApplicationContext(),"New Message On MHandled:"+newMessage, Toast.LENGTH_LONG).show();
// Releasing wake lock
WakeLocker.release();
//hide progress
showProgress(false);
//set result vars for this intent
Intent i=new Intent();
LoginProc.this.setResult(RESULT_OK,i);
//Intent i = new Intent();
//setResult(RESULT_CANCELED, i);
finish();
}
};
and the result is always show ToastText "WAS NOT LOGIN" even after event GCM is success (Toas "New Message On MHandled" displayer).
Need right direction here, thanks a lot

Make sure you have given all needed permission and this receives messages via GCMIntentService which would have to register in Manifest.
Check this link
This will tell the steps for GCM registration and getting push messages from server.