Android Edittext Filter.

FilterProvider.java

import android.text.InputFilter;
import android.text.Spanned;

/**
 * Created by vaibhav.jani on 17-Dec-15.
 */
public class FilterProvider {

    public static InputFilter getFilter(final int maxDigitsBeforeDecimalPoint, final int maxDigitsAfterDecimalPoint) {

        InputFilter filter = new InputFilter() {

            //final int maxDigitsBeforeDecimalPoint = 4;

            //final int maxDigitsAfterDecimalPoint = 1;

            @Override
            public CharSequence filter(CharSequence source, int start, int end,
                                       Spanned dest, int dstart, int dend) {

                StringBuilder builder = new StringBuilder(dest);

                builder.replace(dstart, dend, source
                        .subSequence(start, end).toString());

                if (!builder.toString().matches(
                        "(([1-9]{1})([0-9]{0," + (maxDigitsBeforeDecimalPoint - 1) + "})?)?(\\.[0-9]{0," + maxDigitsAfterDecimalPoint + "})?"

                )) {
                    if (source.length() == 0)
                        return dest.subSequence(dstart, dend);
                    return "";
                }

                return null;

            }
        };

        return filter;
    }
}