1 /*******************************************************************************
2 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
4 * All rights reserved. This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License v1.0
6 * which accompanies this distribution, and is available at
7 * http://www.eclipse.org/legal/epl-v10.html
10 * VTT Technical Research Centre of Finland - initial API and implementation
11 *******************************************************************************/
12 package org.simantics.utils.format;
14 import java.math.BigDecimal;
15 import java.math.MathContext;
16 import java.text.DecimalFormat;
17 import java.text.DecimalFormatSymbols;
18 import java.text.FieldPosition;
19 import java.text.Format;
20 import java.text.NumberFormat;
21 import java.text.ParsePosition;
22 import java.util.Locale;
25 * @author Antti Villberg
27 public class FormattingUtils {
29 public static final FormattingUtil US = new FormattingUtil(5, 5, Locale.US);
30 public static final FormattingUtil DEFAULT = US;
32 public static String engineeringFormat(Object value) {
33 return DEFAULT.engineeringFormat(value);
36 public static Format significantDigitFormat(int withSignificantDigits) {
37 return significantDigitFormat(withSignificantDigits, false);
40 public static Format significantDigitFormat(int withSignificantDigits, boolean stripTrailingZeros) {
41 if (withSignificantDigits < 1)
42 throw new IllegalArgumentException("withSignificantDigits must be > 0, got " + withSignificantDigits);
43 StringBuilder sb = new StringBuilder(withSignificantDigits + 3);
45 for (int i = 0; i < withSignificantDigits-1; i++)
48 NumberFormat low = new DecimalFormat(sb.toString());
49 low.setGroupingUsed(false);
50 NumberFormat hi = new SignificantDigitFormat(withSignificantDigits, stripTrailingZeros);
51 Format format = new SwitchFormat(0.1, 1, low, hi, hi);
55 private static class SignificantDigitFormat extends NumberFormat {
57 private static final long serialVersionUID = 1079268918077141671L;
59 private MathContext mc;
60 private boolean stripTrailingZeros;
61 private boolean fixDecimalSeparator;
62 private char decimalSeparator;
64 public SignificantDigitFormat(int digits, boolean stripTrailingZeros) {
65 this.mc = new MathContext(digits);
66 this.stripTrailingZeros = stripTrailingZeros;
67 DecimalFormatSymbols symbols = DecimalFormatSymbols.getInstance();
68 decimalSeparator = symbols.getDecimalSeparator();
69 // BigDecimal always formats doubles with '.' as decimal separator.
70 if (decimalSeparator != '.')
71 fixDecimalSeparator = true;
73 fixDecimalSeparator = false;
77 public StringBuffer format(double number, StringBuffer toAppendTo, FieldPosition pos) {
78 BigDecimal big = new BigDecimal(number, mc);
79 if (stripTrailingZeros)
80 big = big.stripTrailingZeros();
81 String str = big.toString();
82 if (fixDecimalSeparator)
83 str = str.replace('.', decimalSeparator);
84 return toAppendTo.append(str);
88 public StringBuffer format(long number, StringBuffer toAppendTo, FieldPosition pos) {
89 return toAppendTo.append(number);
93 public Number parse(String source, ParsePosition parsePosition) {