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codename native Android application subclassing issues

My codenameone application crashes anything I use this native code
package com.mycompany.interfaces;
import android.app.Application;
import android.content.Context;
import com.google.firebase.FirebaseApp;
import com.google.firebase.FirebaseOptions;
import com.google.firebase.iid.FirebaseInstanceId;
import com.google.firebase.messaging.FirebaseMessaging;
public class InitialiseApp extends Application{
private static Context context;
public static Context getContext() {
return context;
}
#Override
public void onCreate()
{
super.onCreate();
context = getApplicationContext();
try
{
FirebaseApp.initializeApp(this, new FirebaseOptions.Builder().
setApiKey("XXXXXXXXXXXXXX").
setApplicationId("XXXXXXXX").
setGcmSenderId("XXXXXXXXXX")
.build());
FirebaseInstanceId.getInstance().deleteInstanceId();
FirebaseInstanceId.getInstance().getToken("XXXXXXXXXX",FirebaseMessaging.INSTANCE_ID_SCOPE);
FirebaseMessaging.getInstance().subscribeToTopic("test");
}
catch(Exception c)
{
c.printStackTrace();
}
}
}
I declare the class in the android.xapplication_attr android:name="com.mycompany.interfaces.InitialiseApp"
Need a assistance

Are you putting this in the native interface stub or in the CN1 part of the code?
Also, I don’t think that’s how you get a context in CN1. Look in the developer guide and video tutorials for Native Interfaces. I also recall a series of blog posts about native interfaces that dive into writing the Android code. You’ll need to use something from the AndroidNativeUtil class like: AndroidNativeUtil.getActivity().

Should the Presenter know about the Activity in Android MVP architecture?

I am wondering if the Activity should be referenced or not within Presenter code when using the Android MVP architecture?
The example MVP architecture that I have found so far doesn't reference it, but in my code it's not a property on the Presenter, but an argument in some methods. Could this lead to issues? Does this not follow Android MVP?
Here is a code example from one Presenter:
package com.example.example;
import android.net.Uri;
import android.support.v4.app.FragmentActivity;
import android.support.v4.content.FileProvider;
import com.example.example.util.Constants;
import com.example.example.util.ImageFile;
import java.io.IOException;
/**
* Presenter from home screen, (Main), of the app
*/
public class MainPresenter implements MainContract.Presenter {
private final MainContract.View mView;
private final ImageFile mImageFile;
public MainPresenter(MainContract.View mainView, ImageFile imageFile) {
mView = mainView;
mImageFile = imageFile;
}
#Override
public void takePicture(FragmentActivity activity) throws IOException {
mImageFile.create(activity);
Uri photoUri = FileProvider.getUriForFile(
activity,
Constants.FILE_PROVIDER_PATH,
mImageFile.getFile());
mView.openCamera(photoUri);
}
Uri getImageFileUri() {
return mImageFile.getUri();
}
}

In proper MVP implementation, Presenter should not know about the activity. If we'll use activity then we'll have to mock the activity during testing, that'll make the testing difficult. So, in your case, you should pass your mImageFile to activity through the view reference and create the URI inside activity class.

Simple MainActivity and BroadcastReceiver derived class communication Issue

This should be very simple and I'm really not sure what is going wrong. I have created a SMSReceiver java class that basically receives messages and then gives them to my MainActivity. When the onReceive() function fires, the app crashes because it is having issues sending the data back to MainActivity. It has been throwing a NullPointerException on the Zout() call in onReceive().
Here is the SmsReceiver class:
package ...; //you don't need to see my dumb package name.
import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.telephony.SmsMessage;
import android.util.Log;
import android.widget.Toast;
import java.util.ArrayList;
public class SmsReceiver extends BroadcastReceiver {
ArrayList<String> phoneNumbers;
ArrayList<String> textMessages;
private Activity mainAct; //our reference to MainActivity
//very simple constructor
public SmsReceiver() {
}
//this function is called in onCreate() in MainActivity to provide reference to MainActivity
public void SetSMSReceiverActivity(Activity a){
mainAct = a;
//talk to our main activity
MainActivity mainComm = (MainActivity)mainAct;
mainComm.Zout("SMSReceiver initialized bro"); //this works just fine
}
#Override
public void onReceive(Context context, Intent intent) {
//THIS IS WHAT CAUSES ISSUES! This call to MainActivity does NOT work for whatever reason. Rude.
MainActivity mainComm = (MainActivity)mainAct;
mainComm.Zout("This message won't send"); //this does NOT work fine for whatever reason. Throws NullPointerException.
//...more code down here that actually works!
}
}
The function Zout() in my MainActivity is a simple print to TextView for debugging purposes. I will be using a function in MainActivity to receive the data once onReceive() stops being moody.
I'm sorry if this is a dumb question. I haven't programmed in Java for a few years and I'm quite rusty. I have no idea why this isn't working. I'll be tossing out +1's to whoever can help!

I believe it is because you have not initialized your mainAct variable.
for onCreate(){}
you do initialize
mainAct = a;
but not for onReceive.

Using accelerometer code in a separate class

Hi Im trying to use a different java class for accelerometer usage so it can be called from another class to manipulate results. such as doing calculations using accelerometer class object.Following class does not have a view. I have done the below code with completed methods when an layout was assigned to it. Please tell me how to use the accelerometer class without a layout so i can call from another class.
(I dont want to use the on create method since im not using a view)
Thank you
package com.example.vehiclecollisiondetection;
import android.app.Activity;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
public class AccelerometerClass extends Activity implements SensorEventListener {
SensorManager sm = (SensorManager)getSystemService(SENSOR_SERVICE);
Sensor accelerometer = sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
sm.
IDE gives an error here "Syntax error on token, misspelled construct and code hinting does not detect for sm. object
#Override
public void onSensorChanged(SensorEvent event) {
}
#Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
}
I figured out that i need to use OnCreate method. But is there anyway to use the code without a layout? (calling from another class)

You shouldn't be deriving from Activity. All you need to do is implement SensorEventListener and be registered for the sensor.

The method is undefined for the type in Eclipse

Method is undefined for the type in Eclipse. Can't seem to solve it. The error is in the lines: msg.setTimestamp( System.currentTimeMillis() ); and msg.setBody("this is a test SMS message");
package com.example.smsnotification;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.AlertDialog.Builder;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
public class PopSMSActivity extends Activity{
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//Retrieve serializable sms message object by the key "msg" used to pass to it
Intent in = this.getIntent();
PopMessage msg = (PopMessage) in.getSerializableExtra("msg");
//Case where we launch the app to test the UI EG: No incoming SMS
if(msg==null){
msg = new PopMessage();
con.setPhone("0123456789");
msg.setTimestamp( System.currentTimeMillis() );
msg.setBody("this is a test SMS message");
}
showDialog(msg);
}

Remove the code and write it back to eclipse. It worked for me....You can try copy and paste to after writing signature of function/class.

This means the PopMessage class doesn't provide the methods setTimestamp(long) and setBody(String).
There is no import statement for PopMessage in your code so I assume it is a class which you have implemented and is contained in the same package as the Activity which you have posted.
So you could either solve this by implementing those two methods in PopMessage or by removing the calls.

You may also extend your Eclipse Settings by activating the "save Actions" (Window->Preferences->Java->Editor->Save Actions) and use the Option "Organize Imports". This would at least add the propbably missing Import "...PopMessage" while you press Ctrl+S.