Validating an EditText

Question

I have an EditText (et) in my app. I want to be able to limit the character count AND to validate the input.

My input type is a string sequence for example, n = number, a = alpha. If I have say, 10 (max) chars, my input string will be something like...

aannnnnnna

I am having problems making this all work. It seems to be failing on my character count first (I commented the validation out). I am getting a strange problem where my text is doubling up. Here is my code...

et.setFilters(new InputFilter[] {
    new InputFilter() {
        @Override
        public CharSequence filter(CharSequence source, int start, int end, Spanned dest, int dstart, int dend) {

            if (source.equals("")) {
                return source;
            }
            else {
                String boxInput = source.toString();
                String textFormat = options.getFormattedTextFormat();
                int maxChars = options.getFormattedTextMaxChars();
                if (maxChars > 0 && source.length() > maxChars) {
                    Toast.makeText(OpenForm.this, R.string.maxCharsText + " " + maxChars, Toast.LENGTH_SHORT).show();
                    boxInput = source.toString().substring(0,maxChars - 1);
                    source = boxInput;
                }
                if (!textFormat.isEmpty()) {
                    for (int i = 0; i < boxInput.length(); i++) {
                        char c = boxInput.charAt(i);
                        char test = textFormat.charAt(i);

                        if (test == 'n' && !Character.isDigit(c)) {
                            // Testing for a number, but character is not a number
                            Toast.makeText(OpenForm.this, R.string.badNumber + " " + i, Toast.LENGTH_SHORT).show();
                        } else if (test == 'a' && Character.isDigit(c)) {
                            // Testing for a letter but character is a number
                            Toast.makeText(OpenForm.this, R.string.badLetter + " " + i, Toast.LENGTH_SHORT).show();
                        }

                        //return boxInput;
                    }
                }

                return boxInput;
            }
        }
    }
});

Answer 1

In XML you can add this.

android:maxLength="10"

to get the text from it to validate you can do this..

String text = editText.getText().toString().trim();

if (text.equals("whatev") {

}

To limit the edit text programmatically....

InputFilter[] filter = new InputFilter[1];
filter[0] = new InputFilter.LengthFilter(10);
editText.setFilters(filter);

You can still get the text out of it like above.