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Android - Handling event on an add button issue

I want to insert text from field into a String array every time the add button is pressed, and when done so, the field should empty itself for a new string.
Here is my code:
Editor note: no code provided as example, only a screenshot of the code

Is the add function ever called? Otherwise you are sitting with a button without an onClickListener.
Try assigning The onClickListener in oncreate instead.

How to retrieve the text entered in an EditText Field from the Listener?

My first android project! I have a Login Activity. Within it there are two EditText fields, "username" and "password". I've made a listener for when the user has completed the field, namely an onEditorActionListener. My motivation behind this is that I need the username and password fields as a String Variable to send to Volley and onto an API. The password Listener is nearly identical to the code below.
final EditText loginEditText_User = (EditText) findViewById(R.id.login_user);
loginEditText_User.setOnEditorActionListener(new TextView.OnEditorActionListener() {
#Override
public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
if (actionId == EditorInfo.IME_ACTION_NEXT){
// TODO Retrieve Username here
Log.d("[userName]", loginEditText_User.getText().toString());
loginEditText_Pass.requestFocus();
}
return true;
}
});
I've tried simply declaring a variable String userName before the listener and setting the value within the block via userName = loginEditText_User.getText().toString();, but this doesn't work because "the variable 'userName' is accessed from within inner class, needs to be declared final". However, but when declared final, I obviously "cannot assign value to final variable".
I've seen related questions such as this and this, but they're not quite the same thing.
Thanks in advance!

You can just define you userName variable as a field of your activity, and then you will have an access to it in your scope:
private String userName;

I just answered someone else's question about the same thing here: Edit text first time to input a letter validation
If you use a TextWatcher interface instead, you can get the updated text every time the user adds or removes a letter. Now, If you don't care about the current text until they hit your login button, then you could just do something like. editText.getText() and that returns the current text. The nice thing about the TextWatcher, is you can enable/disable the login button with valid/invalid text. And, it gets you around that whole 'final' issue you mentioned.

This is a known issue every programmer has to deal with a couple of times, there are some options to work around this problem :
1)Use a set function to change the value of the variable, functions can be called anywhere within an inner class.
2)Assign a new variable, which you initialized inside the inner class, with the value you want and use the new variable

Update text watcher based on other events

In one of my screen i am using text watcher to check value against a range and for invalid range color of text is being changed.
Now there is one more requirement.
Along with EditText i need to use CheckBox to set completely different range.
The problem i am facing is that changing the checkbox value requires to call afterTextChanged in which i have put all validations for both set of ranges.
So basically my requirement is to update textWatcher anyhow so that afterTextChanged get called after i change value of checkbox.
I get a strange feeling that i am forgetting something very simple here,if so please let me know.
Thanks in advance.

Perhaps move your code from the callback in the textWatcher and put it into another function ie
private void checkRange() {
// do checks here
String color = text.getEditableText().toString();
}
and call this method from your textWatcher and from the listener on the checkbox.

some EditTexts with only one TextWatcher

I'm trying to user TextWatcher interface in order to detect which EditText was changed.
I have an activity with 10 EditTexts, and it looks weird to use 10 TextWatchers for each one of them.
There is any way to use only one TextWatcher and to use switch statement on the Editable in the functions afterTextChanged?

What I would do is to create a class that extends EditText and create a TextWatcher in that class. You can then implement those EditTexts in your XML or create them programmatically in Java with the TextWatcher listening for each EditText.
Don't know if this will work for you but you can give it a try.

I have never tried this before, but it should work if you check if the EditText is in focus. There are a few ways to go about this and the most straightforward one is to check the focus of the EditText inside your TextWatcher methods. You'll need to do something like this:
if(mEdit1.hasFocus()) {
...
} else if(mEdit2.hasFocus()) {
...
} else if(mEdit3.hasFocus()) {
...
}
A different approach would be to use an OnGlobalFocusChangeListener on your root view and set a variable indicating with EditText currently has focus. It would still require a lot of if statements to check for which EditText has the focus, but may be a more reusable solution.

How to check the edittext Listener is remove or not

I am using the the two editext and add the seperate textWatcher classes object
when some one give the focus then second one textListener is remove.
Then
My Question is how to check the textListener is add or remove
thnax in advance

AFAIK, There is no method to get the current assigne TextWatcher instance of the EditText object.
Rather you just can do like,
mEdiText.addTextChangedListener(null);
before you assign any TextWatcher and then assign the Watcher object mEdiText.addTextChangedListener(new MyTextWatcher()); to the EditText in any event or any condition.
Assigning null will remove the previous TextWatcher.
And to know is it really worked or not, just run your app and test it once.