Source for java.util.Formattable

   1: /* Formattable.java -- Objects which can be passed to a Formatter
   2:    Copyright (C) 2005 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: 
  39: package java.util;
  40: 
  41: /**
  42:  * <p>
  43:  * The <code>Formattable</code> interface is used to provide customised
  44:  * formatting to arbitrary objects via the {@link Formatter}.  The
  45:  * {@link #formatTo} method is called for <code>Formattable</code>
  46:  * objects used with the 's' conversion operator, allowing the object
  47:  * to provide its own formatting of its internal data.
  48:  * </p>
  49:  * <p>
  50:  * Thread safety is left up to the implementing class.  Thus,
  51:  * {@link Formattable} objects are not guaranteed to be thread-safe,
  52:  * and users should make their own provisions for multiple thread access.
  53:  * </p>
  54:  *
  55:  * @author Tom Tromey (tromey@redhat.com)
  56:  * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
  57:  * @since 1.5
  58:  */
  59: public interface Formattable
  60: {
  61: 
  62:   /**
  63:    * Formats the object using the supplied formatter to the specification
  64:    * provided by the given flags, width and precision.
  65:    *
  66:    * @param formatter the formatter to use for formatting the object.
  67:    *                  The formatter gives access to the output stream
  68:    *                  and locale via {@link Formatter#out()} and
  69:    *                  {@link Formatter#locale()} respectively.
  70:    * @param flags a bit mask constructed from the flags in the
  71:    *              {@link FormattableFlags} class.  When no flags
  72:    *              are set, the implementing class should use its
  73:    *              defaults.
  74:    * @param width the minimum number of characters to include.
  75:    *              A value of -1 indicates no minimum.  The remaining
  76:    *              space is padded with ' ' either on the left
  77:    *              (the default) or right (if left justification is
  78:    *              specified by the flags).
  79:    * @param precision the maximum number of characters to include.
  80:    *              A value of -1 indicates no maximum.  This value
  81:    *              is applied prior to the minimum (the width).  Thus,
  82:    *              a value may meet the minimum width initially, but
  83:    *              not when the width value is applied, due to
  84:    *              characters being removed by the precision value.
  85:    * @throws IllegalFormatException if there is a problem with
  86:    *                                the syntax of the format
  87:    *                                specification or a mismatch
  88:    *                                between it and the arguments.
  89:    */
  90:   public void formatTo(Formatter formatter, int flags, int width,
  91:                        int precision);
  92: }