Launch a Toast in a static method of a non-activity class

Question

I want to launch a toast message in a static method of a non-Activity class. I read a loto of threads about that, but my situation is a bit more complicated, in particular:

I have a service and in OnStartCommand I call with fixed interval a static method of another class, in this called method I want to show in some particular cases a toast message.

I try also to create a support class that extends Application in which I have the application context to get when I need, but nothing to do.

This is the method in the Service class that calls the static method AllInterfacesActived:

    public int onStartCommand(Intent intent, int flags, int startId) {

    //flag variable that indicates if service is scanning
    isScanning = true;

    final int result;

    turnGPSOn();


    /*GET WIFI DATA, we use a thread and with scheduleAtFixedRate we run it repeatedly with the wifi scan interval*/ 
    Wifitimer.scheduleAtFixedRate(new TimerTask() {


        @Override
        public void run() {
            String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(Calendar.getInstance().getTime());

            //we are in wifi case, we set umts string result to "" because we don't perform a umts scansion
            String resultUMTS = "";

            //call the SCANWIFI METHOD to scan the networks and to obtain their data
            String resultScan = scanWifi();
            Intent mIntent = new Intent();
            mIntent.setAction(INTENT_ACTION);

            //put information on wifi and umts in the intent
            mIntent.putExtra(INTENT_EXTRA_WIFI, "Waiting for umts scansion...\nWIFI SCAN PERFOMED"+resultScan+"\nUMTS\n"+resultUMTS);

            //broadcast of data
            Bundle xtra = new Bundle();
            sendBroadcast(mIntent);

            /*
             * when all interfaces are actived we call AllInterfacesActived() of OracoloBrain.java
             */
            if(getUseOracolo())
                if(isAPNEnabled(getApplicationContext()) && isGpsEnable() && isWifiEnabled()){
                    OracoloBrain.AllInterfacesActived();     
                }


        }
    }, 0,MainActivity.getWifiInterval());

//other code of the onStartCommand method...

In the OracoloBrain class (non activity class) I have the static method AllInterfacesActived. I leave out the code about this method, but in a particular case I want to show a Toast. I try to create a another class called MyApplication.java:

public class MyApplication extends Application {

private static Context context;

public void onCreate(){
    super.onCreate();
    MyApplication.context = getApplicationContext();
}

public static Context getAppContext() {
    return MyApplication.context;
}
}

So I try to launch toast using this context but nothing to do.

to be able to show the toast, you need the Activity rather than a Context — injecteer, Aug 27 '14 at 15:11
I still don't get your problem, you can create a Toast from a Service even without an activity. what is your problem? And where is your code to show the Toast — Marco Acierno, Aug 27 '14 at 15:34

score 1 · Accepted Answer · answered Aug 27 '14 at 15:21

You could create a handler object on the main thread and then you could use it later to show your toast. Below is a sample code that will help you out.

class MyService extends Service{
Handler handler ;
onStartCommand(intent int , int flags,int startId){
handler = new Handler(); // this will get instantiated on the main thread;
new Thread(new Runnable() {

                    @Override
                    public void run() {
                        dispatchMessage("this is a toast");

                    }
                }).start();


}
public void dispatchMessage(final String message) {
        handler.post(new Runnable() {
            @Override
            public void run() {
                System.out.println(message);
                Toast.makeText(MyService.this, message, Toast.LENGTH_SHORT).show();
            }
        });

    }

}

You can read more on Handlers to understand what I have done to show Toast on other threads apart from main thread.

It's the right way. I used that code to find the solution. Thank you. — Milioli Luca, Aug 27 '14 at 15:58

score 0 · Answer 2 · answered Aug 27 '14 at 15:09

0

You can send context of application to your class:

In your non-activity class:

private static Context c;

public static Context getAndSetMyContext(Context c) {
this.c = c;
}

after that you can:

Toast.makeText (c, "YOUR TEXT", Toast.LENGTH_LONG).show();

And in your activity class:

YourClass.getAndSetMyContext(getBaseContext());

answered Aug 27 '14 at 15:09

buxik

2,583
24
31

Warning: Save always the application context in a static field – Marco Acierno Aug 27 '14 at 15:23

score 0 · Answer 3 · answered Aug 27 '14 at 15:26

0

What is the super class of your service? If it's IntentService than Toast is not being showed because you're not posting it on main UI thread. You have to do this in this way:

Handler handler = new Handler(Looper.getMainLooper());
handler.post(new Runnable { 
    @Override
    public void run() {
        Toast.makeText(context/*Use app context here from your Application subclass*/, "", Toast.SHORT);
});

answered Aug 27 '14 at 15:26

michal.z

2,025
1
15
10

The superclass is Service – Milioli Luca Aug 27 '14 at 15:28

Launch a Toast in a static method of a non-activity class

3 Answers3