CurrencyFormat.java

package com.code44.finance.utils;

import android.text.TextUtils;

import com.code44.finance.common.model.GroupSeparator;
import com.code44.finance.data.model.Currency;

import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;

public final class CurrencyFormat {
    private final DecimalFormat decimalFormat;

    public CurrencyFormat() {
        decimalFormat = (DecimalFormat) DecimalFormat.getInstance();
    }

    public CurrencyFormat(Currency currency) {
        decimalFormat = (DecimalFormat) DecimalFormat.getInstance();

        // Setup symbols
        final DecimalFormatSymbols symbols = decimalFormat.getDecimalFormatSymbols();
        final char groupSeparator = currency.getGroupSeparator() != GroupSeparator.None ? currency.getGroupSeparator().symbol().charAt(0) : 0;
        symbols.setGroupingSeparator(groupSeparator);
        symbols.setDecimalSeparator(currency.getDecimalSeparator().symbol().charAt(0));

        // Setup format
        decimalFormat.setDecimalFormatSymbols(symbols);
        decimalFormat.setMinimumFractionDigits(currency.getDecimalCount());
        decimalFormat.setMaximumFractionDigits(currency.getDecimalCount());
        final String symbol = currency.getSymbol();
        final boolean hasSymbol = !TextUtils.isEmpty(symbol);
        switch (currency.getSymbolPosition()) {
            case FarLeft:
                if (hasSymbol) {
                    decimalFormat.setPositivePrefix(symbol + " ");
                    decimalFormat.setNegativePrefix(symbol + " -");
                } else {
                    decimalFormat.setNegativePrefix("-");
                }

                break;

            case CloseLeft:
                if (hasSymbol) {
                    decimalFormat.setPositivePrefix(symbol);
                    decimalFormat.setNegativePrefix(symbol + "-");
                } else {
                    decimalFormat.setNegativePrefix("-");
                }

                break;

            case FarRight:
                if (hasSymbol) {
                    decimalFormat.setPositiveSuffix(" " + symbol);
                    decimalFormat.setNegativeSuffix(" " + symbol);
                }
                break;

            case CloseRight:
                if (hasSymbol) {
                    decimalFormat.setPositiveSuffix(symbol);
                    decimalFormat.setNegativeSuffix(symbol);
                }
                break;

            default:
                throw new IllegalArgumentException("Symbol position " + currency.getSymbolPosition() + " is not supported.");
        }
    }

    public String format(double value) {
        return decimalFormat.format(value);
    }
}