Activate button when write text in editText android

Question

I have a layout where I have some edittexts and one button. This button is setEnabled(false). How I can change his status when user write some text in edittext? I want to when user put some text to edit text button setEnabled on true?

Answer 1

You need to use TextWatcher:

editText.addTextChangedListener(new TextWatcher() {
            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {

                // TODO Auto-generated method stub
            }

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

                // TODO Auto-generated method stub
            }

            @Override
            public void afterTextChanged(Editable s) {

                // TODO Auto-generated method stub
            }
        });

Answer 2

Its a good idea to also notify user why the Button is disabled.

Use a TextWatcher to disable/enable button and also set a error hint for EditText:

mEditText.addTextChangedListener(new EmptyValidator());

private class EmptyValidator implements 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) {
            if (editable.length() == 0) {
                mEditText.setError("Required");
                mButton.setEnabled(false);
            } else {
                mEditText.setError(null);
                mButton.setEnabled(true);
            }
        }

    }