CODEWITHSUNDEEP
javafxtextfield
Carmine
Carmine

Reputation: 155

Javafx Formatting decimal number textfield

I have a problem with formatting a currency decimal number in TextField. I set the TextFormatter with a class DecimalFormatter that extend a StringConverter which converts a BigDecimal to String and vice-versa. When I should change the value, if delete all the data and insert a new completed value it works, but if I have to add/change a part of value e.g. 13.00 in 13.10 the change is not applied and re-proposes the old value 13.00.
How can I solve it?
Thank you

public class DecimalFormatter extends StringConverter<BigDecimal> {

    private NumberFormat numberFormat;

....

    @Override
    public String toString(BigDecimal value) {
        if ( value == null )
            value = new BigDecimal();
        return numberFormat.format(value.doubleValue());
    }

    @Override
    public BigDecimal fromString(String value) {
        return new BigDecimal(value);
    }

}

....

tfDecimal.setTextFormatter(new DecimalFormatter());

Upvotes: 1

Views: 1086

Answers (1)

Carmine
Carmine

Reputation: 155

My intention was to manage amounts with decimals separated by a comma in a textfield. I added a filter to allow only double amounts. The complete code:


public class DecimalFormatter extends StringConverter {

    private final NumberFormat numberFormat = NumberFormat.getNumberInstance(Locale.ITALY);

    public DecimalFormatter(int fractionsLenght) {
        numberFormat.setMaximumFractionDigits(fractionsLenght);
        numberFormat.setMinimumFractionDigits(fractionsLenght);
    }

    public DecimalFormatter() {
        numberFormat.setMaximumFractionDigits(2);
        numberFormat.setMinimumFractionDigits(2);
    }

    @Override
    public String toString(BigDecimal value) {
        if ( value == null )
            value = new BigDecimal(0);
        return numberFormat.format(value.doubleValue());
    }

    @Override
    public Decimal fromString(String value) {
        value = value.replaceAll(",", ".");
        return new BigDecimal(value);
    }
} 
public class DecimalFilter implements UnaryOperator {

    private static final char DECIMAL_SEPARATOR = DecimalFormatSymbols.getInstance().getDecimalSeparator();

    private Pattern DIGIT_PATTERN;

    public DecimalFilter() {
        DIGIT_PATTERN = Pattern.compile("-?\\d*(\\" + DECIMAL_SEPARATOR  + "\\d{0,2})?");
    }

    public DecimalFilter(int fractionsLenght) {
        DIGIT_PATTERN = Pattern.compile("-?\\d*(\\" + DECIMAL_SEPARATOR  + "\\d{0," + fractionsLenght + "})?");
    }

    @Override
    public Change apply(TextFormatter.Change aT) {
        return DIGIT_PATTERN.matcher(aT.getText()).matches() ? aT : null;
    }
} 

tfDecimalValue.setTextFormatter(
    new TextFormatter(new DecimalFormatter(), new BigDecimal(0), new DecimalFilter()));

Upvotes: 1

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