001/*
002 * $RCSfile: MsgLogger.java,v $
003 * $Revision: 1.1 $
004 * $Date: 2005/02/11 05:02:26 $
005 * $State: Exp $
006 *
007 * Class:                   MsgLogger
008 *
009 * Description:             Facility to log messages (abstract)
010 *
011 *
012 *
013 * COPYRIGHT:
014 *
015 * This software module was originally developed by Raphaël Grosbois and
016 * Diego Santa Cruz (Swiss Federal Institute of Technology-EPFL); Joel
017 * Askelöf (Ericsson Radio Systems AB); and Bertrand Berthelot, David
018 * Bouchard, Félix Henry, Gerard Mozelle and Patrice Onno (Canon Research
019 * Centre France S.A) in the course of development of the JPEG2000
020 * standard as specified by ISO/IEC 15444 (JPEG 2000 Standard). This
021 * software module is an implementation of a part of the JPEG 2000
022 * Standard. Swiss Federal Institute of Technology-EPFL, Ericsson Radio
023 * Systems AB and Canon Research Centre France S.A (collectively JJ2000
024 * Partners) agree not to assert against ISO/IEC and users of the JPEG
025 * 2000 Standard (Users) any of their rights under the copyright, not
026 * including other intellectual property rights, for this software module
027 * with respect to the usage by ISO/IEC and Users of this software module
028 * or modifications thereof for use in hardware or software products
029 * claiming conformance to the JPEG 2000 Standard. Those intending to use
030 * this software module in hardware or software products are advised that
031 * their use may infringe existing patents. The original developers of
032 * this software module, JJ2000 Partners and ISO/IEC assume no liability
033 * for use of this software module or modifications thereof. No license
034 * or right to this software module is granted for non JPEG 2000 Standard
035 * conforming products. JJ2000 Partners have full right to use this
036 * software module for his/her own purpose, assign or donate this
037 * software module to any third party and to inhibit third parties from
038 * using this software module for non JPEG 2000 Standard conforming
039 * products. This copyright notice must be included in all copies or
040 * derivative works of this software module.
041 *
042 * Copyright (c) 1999/2000 JJ2000 Partners.
043 *
044 *
045 *
046 */
047
048
049package jj2000.j2k.util;
050
051/**
052 * This class provides a simple common abstraction of a facility that logs
053 * and/or displays messages or simple strings. The underlying facility can be
054 * a terminal, text file, text area in a GUI display, dialog boxes in a GUI
055 * display, etc., or a combination of those.
056 *
057 * <P>Messages are short strings (a couple of lines) that indicate some state
058 * of the program, and that have a severity code associated with them (see
059 * below). Simple strings is text (can be long) that has no severity code
060 * associated with it. Typical use of simple strings is to display help texts.
061 *
062 * <P>Each message has a severity code, which can be one of the following:
063 * LOG, INFO, WARNING, ERROR. Each implementation should treat each severity
064 * code in a way which corresponds to the type of diplay used.
065 *
066 * <P>Messages are printed via the 'printmsg()' method. Simple strings are
067 * printed via the 'print()', 'println()' and 'flush()' methods, each simple
068 * string is considered to be terminated once the 'flush()' method has been
069 * called. The 'printmsg()' method should never be called before a previous
070 * simple string has been terminated.
071 *
072 * */
073public interface MsgLogger {
074
075    /** Severity of message. LOG messages are just for bookkeeping and do not
076     * need to be displayed in the majority of cases */
077    public static final int LOG = 0;
078
079    /** Severity of message. INFO messages should be displayed just for user
080     *  feedback. */
081    public static final int INFO = 1;
082
083    /** Severity of message. WARNING messages denote that an unexpected state
084     * has been reached and should be given as feedback to the user. */
085     public static final int WARNING = 2;
086
087    /** Severity of message. ERROR messages denote that something has gone
088     * wrong and probably that execution has ended. They should be definetely
089     * displayed to the user. */
090    public static final int ERROR = 3;
091
092    /**
093     * Prints the message 'msg' to the output device, appending a newline,
094     * with severity 'sev'. Some implementations where the appended newline is
095     * irrelevant may not append the newline. Depending on the implementation
096     * the severity of the message may be added to it. The message is
097     * reformatted as appropriate for the output devic, but any newline
098     * characters are respected.
099     *
100     * @param sev The message severity (LOG, INFO, etc.)
101     *
102     * @param msg The message to display
103     *
104     *
105     * */
106    public void printmsg(int sev, String msg);
107
108    /**
109     * Prints the string 'str' to the output device, appending a line
110     * return. The message is reformatted as appropriate to the particular
111     * diplaying device, where 'flind' and 'ind' are used as hints for
112     * performing that operation. However, any newlines appearing in 'str' are
113     * respected. The output device may not display the string until flush()
114     * is called. Some implementations may automatically flush when this
115     * method is called. This method just prints the string, the string does
116     * not make part of a "message" in the sense that no severity is
117     * associated to it.
118     *
119     * @param str The string to print
120     *
121     * @param flind Indentation of the first line
122     *
123     * @param ind Indentation of any other lines.
124     *
125     *
126     * */
127    public void println(String str, int flind, int ind);
128
129    /**
130     * Writes any buffered data from the println() method to the device.
131     *
132     *
133     * */
134    public void flush();
135}