Best approach to replace 0 with amount, when user enters an amount in edittext

Question

I am working on app where an edittext is having $0 as pre-defined text. Zero is editable. But as soon as user enters an amount like $80, its showing $080. I am using textwatcher to non deleted $ and replaced at time of printing value.

How can i achieve the output as $80 when user is typing an amount

preset value - $0 after typing $80, Output = $080 Expected = $80

Thanks in advance.

   amountEdittext.setText("$0");
    Selection.setSelection(amountEdittext.getText(), 
 amountEdittext.getText().length());
    amountEdittext.addTextChangedListener(new TextWatcher() {

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

        }

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

        @Override
        public void afterTextChanged(Editable s) {
            if (!s.toString().startsWith("$")) {
                amountEdittext.setText("$");
                Selection.setSelection(amountEdittext.getText(), amountEdittext.getText().length());

            }

        }
    });

Answer 1

This should solve your question.

    amountEdittext.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) {
            if (editable.length() > 2) {
                for (int i = 0; i < editable.length() - 1; i++) {
                    if (editable.charAt(i) == '$' && editable.charAt(i + 1) == '0') {
                        editable.delete(i + 1, i + 2);
                    }
                }
            }
        }
    });
}