Android studio add text to edit text on key down

Question

I have an EditText and where user is supposed to enter a time in format: hh:mm. When the user has entered the hour I want to add a semicolon to the edit text automatically. I thought of something like an onKeyDown method that checks if the edit text consists of two numbers, in that case add a semicolon. Is this possible? If so, how?

Possible duplicate of [How to use the TextWatcher class in Android?](http://stackoverflow.com/questions/8543449/how-to-use-the-textwatcher-class-in-android) — wake-0, Jan 04 '17 at 12:20

Marat · Accepted Answer · 2017-01-04T13:20:24.297

You will need to use TextWatcher that does exactly what you need. Basically it has 3 methods: beforeTextChanged(), onTextChanged(), afterTextChanged().

First two methods are not used to change text inside of EditText, they are just used to keep track of changes made on text. The last one is the method where we can modify and style text. The code will look something like this:

String text = "";

yourEditText.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void afterTextChanged(Editable editable) {

            // work with editable here and add :

            String newValue = editable.toString();

            if (newValue.length() > text.length()) {
                text = editable.toString();
                if (text.length() == 2) {
                    yourEditText.setText(text + ":");
                }
            }
            else if (newValue.length() < text.length()) {
                text = editable.toString();
            }
        }
    });

This worked great. I have one problem tho, if have typed "13:30" and wants to delete it, when I delete the semicolon, it prints out the semicolon again because there are two number after the text changed. I tried searching for this but couldn't find anything that worked, I want something like if(keyCode != KeyEvent.KEYCODE_DEL) — Simon Andersson, Jan 04 '17 at 13:07
@SimonAndersson I have updated my answer. Take a carefull look at it — Marat, Jan 04 '17 at 13:20

score 2 · Answer 2 · answered Jan 04 '17 at 12:24

editText.addTextChangedListener(new TextWatcher() {

@Override
public void afterTextChanged(Editable s) {}

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

@Override    
public void onTextChanged(CharSequence s, int start,int before, int count) {
  if(s.length() == 2)
   editText.setText(S+":");
  if(s.length() == 5) //(hh:mm) length is 5
   editText.setEnabled(false); //it accept only 5 char.
}
});

Android studio add text to edit text on key down

2 Answers2