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How to pass a value in snakebar of an activity class from non activity (non view )java class?

I wish to pass a argument to snakebar function ,which is in main activity function from a non activity simple java class. Simply instantiating a activity class and passing value as argument does not work as I tried below. How can I achieve it in below scenario.
public class MainActivity extends AppCompatActivity {
private ConstraintLayout coordinatorLayout;
private Button button;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
coordinatorLayout=findViewById(R.id.coordinator);
button= findViewById(R.id.james);
button.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View view){
showSnackbar("its not working ");
}
});
}
public void showSnackbar(String james){
Snackbar snackbar=Snackbar.make(coordinatorLayout,james,Snackbar.LENGTH_INDEFINITE);
snackbar.show();
}
}
2nd class without activity ,simple non view class
class MyAccount extends Account
{
#Override
public void onRegState(OnRegStateParam prm)
{
MyApp.observer.notifyRegState(prm.getCode(), prm.getReason(),
prm.getExpiration());
if(prm.getReason().equals("OK")) {
/ /when ever above value equals ok , I wish to send a below message as snakebar // message on the main activity class. but below code does not works
MainActivity2 main2= new MainActivity2(); // trying to call snakebar function from main activity.
if(prm.getReason().equals("Service Unavailable")){
Log.e("javan007", prm.getReason());
main2.showSnackbar("service Unavailable");
}
}
}

How can I use interface from a for loop

I have two inner classes named CalculatorClass and UpdatePayment in MainActivity class.
In UpdatePayment class there is a for loop and I have a array of Buttons.
I want to add listener to each button in loop. Those buttons will initialize the CalculatorClass and get value of calculations.
Demo code is:
public static class MainActivity{
private interface UpdateEditText{
void onCallback(String s);
}
private class CalculatorClass extends Dialog{
UpdateEditText updateEditText;
public CalculatorInterface(#NonNull Context context, UpdateEditText updateEditText) {
super(context);
this.updateEditText = updateEditText;
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.calculator);
initialize();
}
initialize(){
.......................
s = "Some texts";
updateEditText.onCallback(s);
}
}
private class UpdatePayment extends Dialog{
private Button[] button = new Button[100];
private EditText[] editText = new EditText[100];
public CalculatorInterface(#NonNull Context context) {
super(context);
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.update);
initialize();
}
initialize(){
.......................
for(int i = 0; i < MAXSize; i++){
button[i] = new Button(MainActivity.this);
editText[i] = new EditText(MainActivity.this);
//add buttons to view to layout
button[i].setOnclickListener(new View.OnClickListener(){
public void onClick(View v) {
CalculatorClass calculator = new
CalculatorClass(MainActivity.this,
new UpdateEditText() {
#Override
public void onCallback(String s) {
editText[i - 1].setText(s);
}
});
calculator.show();
}
);
}
}
}
}
Problem is the line editText[i].setText(s) work for the last editText what ever button I click, i.e, any button I click, it fills the editText[MaxSize -1]
What should I do?
How can I perform this action for all i?
Please help me, I tried a lot searching in internet, still I didn't get any solution.

Anonymous classes are very much treated like static variables in java.It's happenning because your i value after your activity is initialized is equal to 1 less than the length of the edit text array.
editText[indicies_of_button_clicke].setText(s)
How you will get the indicies of button clicked is by :
se the tag to button below this line "editText[i] = new EditText(MainActivity.this);", like this :
button[i].setTag(i)
to retreive the index of your actual button clicked inside button clicklisteners,
v.getTag()// this will give you an integer value which will be the indices of actual button clicked
//use this value to set your edit text value.

Solution:
After a whole night, I got answer, now I feel awwww, this was easy go!
I never came in this thought.
button[i].setId(i);
then call:
CalculatorClass calculator = new CalculatorClass(MainActivity.this, v.getId(),
new UpdateEditText() {
#Override
public void onUpdate(String s, int ID) {
Log.i("test", ID + "");
editText[ID].setText(s);
}
});
At the same time, #Rishabh Ritweek answered correctly.
Thanks to him.

Using a button with the code inside of a different class

I am trying to make an app and I have the code for a button inside of a different class. When I start my app and click the first button it brings me to a different layout where the button is located. But when I click this button it doesn't do anything, just the little click down animation.
First Button Code:
public class TextAdd extends AppCompatActivity {
public static EditText Text;
public static Button Set;
public static String[] Checkagainst = new String[1000];
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.Text_Checker);
Text = (EditText) findViewById(R.id.LPN);
Set = (Button) findViewById(R.id.Set);
Set.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String Text_Value = Text.getText().toString();
if (!Arrays.asList(Checkagainst).contains(Text_Value) && Text_Value.length() >= 1 && Text_Value.length() <= 7) {
setContentView(R.layout.add);
for (int i = 0; i < Checkagainst.length; i++) {
if (Checkagainst[i] == null) {
Checkagainst[i] = Text_Value;
break;
}
}
} else if (Arrays.asList(Checkagainst).contains(Text_Value) && Text_Value.length() >= 1 && Text_Value.length() <= 7) {
setContentView(R.layout.have);
}
}
});
}
}
Second Button Code:
public class Have extends AppCompatActivity {
private Button HaveBack;
private TextView Have;
#Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.have);
HaveBack = (Button) findViewById(R.id.HaveBack);
Have= (TextView) findViewById(R.id.Have);
String Text_Value= TextAdd.License.getText().toString();
String Extra = Text_Value + " is already part of Your license plates";
Have.setText(Extra);
HaveBack.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
setContentView(R.layout.Text_Checker);
}
});
}
}
Does anyone know what is wrong? If so can you please help me.

You should use setContentView() only once in your onCreate() method. Calling it multiple times is not correct. If you want to show a small layout above your current layout, you should use a Dialog and if you want to show a completely different layout above everything, you have to use Intents to go to another activity and do the rest of the work in that one.
besides, use lowercase letters at start of your variables' and objects' names and start Class names with Uppercase letters. That's the standard for knowing what is a class and what is an object. e.g.
Button firstButton, secondButton;

Andorid : setOnClickListener does not work when calling Twice

I'm using setOnClickListener for listening on the click event on imageButton in two methods, but it's does not fire in my another method,my first listener firing but my second listener does not fire please see my codes :
Class FirstActivity extends BaseActivity
{
#Override
public void onCreate()
{
super.onCreate();
this.methodA();
this.methodB();
}
public void methodA()
{
ImageButton imageButton = (ImageButton) RContextHelper.getActivity().findViewById(R.id.my_location_button);
imageButton.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
//event firing when image button touched
}
});
}
public void methodB()
{
Test test = new Test(this);
test.methodA();
}
}
class Test
{
Context con;
public Test(Context con)
{
this.con = con;
}
public void methodA()
{
ImageButton imageButton = (ImageButton) getActivity().findViewById(R.id.my_location_button);
imageButton.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
//event does not fire when image button touched
}
});
}
protected ActionBarActivity getActivity()
{
return (ActionBarActivity) con;
}
}

As you can guess from the name setOnClickListener sets the new listener and replaces the old one. That is the case with all the set* listeners in Java. If it was addOnClickListener then you could expect that both listeners should be called.
If you want both of them to be called, you can write a composite on click listener and add both of the listeners to it and set the composite listener to the target.
class CompositeListener implements OnEventListener {
private List<OnEventListener> registeredListeners = new ArrayList<OnEventListener>();
public void registerListener (OnEventListener listener) {
registeredListeners.add(listener);
}
public void onEvent(Event e) {
for(OnEventListener listener:registeredListeners) {
listener.onEvent(e);
}
}
}
And then:
CompositeListener composite = new CompositeListener();
composite.registerListener(listener1);
composite.registerListener(listener2);
imageButton.setOnEventListener(composite);
Source

Very confusing to code with two methodA functions. You never call the second one. At least you are not showing code for that. Moreover - as has been said already - there can only be one listener.

Passing string from class to main activity

I'm trying to pass something from one class to my MainActivity, but it doesn't seem to work, I don't understand why.
I have my GPS Tracker on another class (not the MainActivity) in order to reuse it.
When the location changes, I want my other class to call a method from within the MainActivity to update my UI.
I summarized my code like that :
My MAIN ACTIVITY :
public class MainActivity extends Activity implements OnClickListener {
TextView tv;
EditText et;
Button btun;
int arg0;
int stuff;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv = (TextView) findViewById(R.id.tv);
et = (EditText) findViewById(R.id.et);
btun = (Button) findViewById(R.id.btun);
btun.setOnClickListener(this);
}
private void setter(int stuff) {
tv.setText(stuff);
}
public void setText(int _stuff) {
_stuff = stuff;
setter(_stuff);
}
#Override
public void onClick(View v) {
Getter get = new Getter();
get.getInfo(Integer.parseInt(et.getText().toString()));
}
The other Class :
public class Getter {
int _getString;
MainActivity main = new MainActivity();
public void getInfo(int getString) {
_getString = getString * 8;
main.setText(_getString);
}
}
I end up having a NullPointerException in my LogCat
at :
- tv.setText(stuff);
- setter(_stuff);
- main.setText(_getString);
- get.getInfo(Integer.parseInt(et.getText().toString()));
and I don't really know why, and above all, how to fix it.
I'll appreciate any help !
(PS : My GPS tracker thingy is working fine, it's just about invoking my setter() method.

Instantiaing an Object of MainActivity doesn't automatically call onCreate method but this method is called when you start an activity using Intent; And using the same intent you can pass extra values. For example:
Intent intent = new Intent(context, MainActivity.class);
intent.putExtra("key", value);
context.startActivity(intent);
and then in your main activity onCreate method:
String value = getIntent.getStringExtra("key");
Edit:
In your case why don't you change your void getInfo(int getString) to return a String value i.e.
public class Getter {
...
...
public String getInfo(int getString) {
_getString = getString * 8;
return Integer.toString(_getString);
}
}
and then in onClick event of MainActivity bind this returned text to TextView

It's maybe because the MainActivity's onCreate()-Method hasn't been called. Therefore the tv is still null causing the NullPointerException

One problem is here. main is an Activity, but it should be the MainActivity calling this object.
public class Getter {
int _getString;
MainActivity main = new MainActivity();
public void getInfo(int getString) {
_getString = getString * 8;
main.setText(_getString);
}
}
I cannot really make out what you are trying to achieve in the Getter class, but either:
1: Pass the Activity instance to the object
public class Getter {
int _getString;
MainActivity _main = null;
public Getter(MainActivity main) {
_main = main;
}
public void getInfo(int getString) {
_getString = getString * 8;
_main.setText(_getString);
}
}
#Override
public void onClick(View v) {
Getter get = new Getter(this);
get.getInfo(Integer.parseInt(et.getText().toString()));
}
or
2: set the text in the Activity and only get the value from the Getter (My choice)
public class Getter {
int _getString;
MainActivity main = new MainActivity();
public void getInfo(int getString) {
return getString * 8;
}
}
#Override
public void onClick(View v) {
Getter get = new Getter();
int info = get.getInfo(Integer.parseInt(et.getText().toString()));
setText(Integer.toString(info));
}

Use Application Class or create a separate Class and declare a static variable in it. Use getter & setter methods to get the value. To update the Textview in mainacivity from other class pass the texview reference variable from main activity and put null check condition in other class if textview is not null then update the value.