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android edittext onchange listener

Posted by: admin November 30, 2017 Leave a comment

Questions:

I know a little bit about TextWatcher but that fires on every character you enter. I want a listener that fires whenever the user finishes editing. Is it possible? Also in TextWatcher I get an instance of Editable but I need an instance of EditText. How do I get that?

EDIT: the second question is more important. Please answer that.

Answers:

first, you can see if the user finished to edit the text if the EditText lose focus or if the user presses done button (this depends on your implementation and on what fits the best for you).
Second, you can’t get an EditText instance within the textwatcher only if you have declared the EditText as a instance object. Even though you shouldn’t edit the EditText within the textwatcher because it is not safe.

EDIT:

To be able to get the EditText instance into your TextWatcher implementation you should try something like this:

public class YourClass extends Activity {

 private EditText yourEditText;

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.main);
        yourEditText = (EditText) findViewById(R.id.yourEditTextId);

        yourEditText.addTextChangedListener(new TextWatcher() {

          public void afterTextChanged(Editable s) {

            // you can call or do what you want with your EditText here
            yourEditText. ... 

          }

          public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

          public void onTextChanged(CharSequence s, int start, int before, int count) {}
       });
    }

}

Note that the above sample might have some errors but I just wanted to show you an example.

Questions:
Answers:

Anyone using ButterKnife. You can use like:

@OnTextChanged(R.id.zip_code)
void onZipCodeTextChanged(CharSequence zipCode, int start, int count, int after) {

}

Questions:
Answers:

It was bothering me that implementing a listener for all of my EditText fields required me to have ugly, verbose code so I wrote the below class. May be useful to anyone stumbling upon this.

public abstract class TextChangedListener<T> implements TextWatcher {
    private T target;

    public TextChangedListener(T target) {
        this.target = target;
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {}

    @Override
    public void afterTextChanged(Editable s) {
        this.onTextChanged(target, s);
    }

    public abstract void onTextChanged(T target, Editable s);
}

Now implementing a listener is a little bit cleaner.

editText.addTextChangedListener(new TextChangedListener<EditText>(editText) {
            @Override
            public void onTextChanged(EditText target, Editable s) {
                //Do stuff
            }
        });

As for how often it fires, one could maybe implement a check to run their desired code in //Do stuff after a given a

Questions:
Answers:

I have done it using AutotextView:

AutotextView textView = (AutotextView) findViewById(R.id.autotextview);
textView.addTextChangedListener(new TextWatcher() {

    @Override
    public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
        seq = cs;
    }

    @Override
    public void beforeTextChanged(CharSequence s, int arg1, int arg2, int arg3) {

    }

    @Override
    public void afterTextChanged(Editable arg0) {
        new SearchTask().execute(seq.toString().trim());
    }

});

Questions:
Answers:

TextWatcher didn’t work for me as it kept firing for every EditText and messing up each others values.

Here is my solution:

public class ConsultantTSView extends Activity {
    .....

    //Submit is called when I push submit button.
    //I wanted to retrieve all EditText(tsHours) values in my HoursList

    public void submit(View view){

        ListView TSDateListView = (ListView) findViewById(R.id.hoursList);
        String value = ((EditText) TSDateListView.getChildAt(0).findViewById(R.id.tsHours)).getText().toString();
    }
}

Hence by using the getChildAt(xx) method you can retrieve any item in the ListView and get the individual item using findViewById. And it will then give the most recent value.

Questions:
Answers:
 myTextBox.addTextChangedListener(new TextWatcher() {  
    public void afterTextChanged(Editable s) {}  
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {}  
    public void onTextChanged(CharSequence s, int start, int before, int count) {  

    TextView myOutputBox = (TextView) findViewById(R.id.myOutputBox);  
    myOutputBox.setText(s);  

    }  
});  

Questions:
Answers:

As far as I can think bout it, there’s only two ways you can do it. How can you know the user has finished writing a word? Either on focus lost, or clicking on an “ok” button. There’s no way on my mind you can know the user pressed the last character…

So call onFocusChange(View v, boolean hasFocus) or add a button and a click listener to it.