001/* Formattable.java -- Objects which can be passed to a Formatter 002 Copyright (C) 2005 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package java.util; 040 041/** 042 * <p> 043 * The <code>Formattable</code> interface is used to provide customised 044 * formatting to arbitrary objects via the {@link Formatter}. The 045 * {@link #formatTo} method is called for <code>Formattable</code> 046 * objects used with the 's' conversion operator, allowing the object 047 * to provide its own formatting of its internal data. 048 * </p> 049 * <p> 050 * Thread safety is left up to the implementing class. Thus, 051 * {@link Formattable} objects are not guaranteed to be thread-safe, 052 * and users should make their own provisions for multiple thread access. 053 * </p> 054 * 055 * @author Tom Tromey (tromey@redhat.com) 056 * @author Andrew John Hughes (gnu_andrew@member.fsf.org) 057 * @since 1.5 058 */ 059public interface Formattable 060{ 061 062 /** 063 * Formats the object using the supplied formatter to the specification 064 * provided by the given flags, width and precision. 065 * 066 * @param formatter the formatter to use for formatting the object. 067 * The formatter gives access to the output stream 068 * and locale via {@link Formatter#out()} and 069 * {@link Formatter#locale()} respectively. 070 * @param flags a bit mask constructed from the flags in the 071 * {@link FormattableFlags} class. When no flags 072 * are set, the implementing class should use its 073 * defaults. 074 * @param width the minimum number of characters to include. 075 * A value of -1 indicates no minimum. The remaining 076 * space is padded with ' ' either on the left 077 * (the default) or right (if left justification is 078 * specified by the flags). 079 * @param precision the maximum number of characters to include. 080 * A value of -1 indicates no maximum. This value 081 * is applied prior to the minimum (the width). Thus, 082 * a value may meet the minimum width initially, but 083 * not when the width value is applied, due to 084 * characters being removed by the precision value. 085 * @throws IllegalFormatException if there is a problem with 086 * the syntax of the format 087 * specification or a mismatch 088 * between it and the arguments. 089 */ 090 public void formatTo(Formatter formatter, int flags, int width, 091 int precision); 092}