jj2000.j2k.util

Interface MsgLogger

All Known Implementing Classes:

J2KImageReader, StreamMsgLogger

public interface MsgLogger

This class provides a simple common abstraction of a facility that logs and/or displays messages or simple strings. The underlying facility can be a terminal, text file, text area in a GUI display, dialog boxes in a GUI display, etc., or a combination of those.

Messages are short strings (a couple of lines) that indicate some state of the program, and that have a severity code associated with them (see below). Simple strings is text (can be long) that has no severity code associated with it. Typical use of simple strings is to display help texts.

Each message has a severity code, which can be one of the following: LOG, INFO, WARNING, ERROR. Each implementation should treat each severity code in a way which corresponds to the type of diplay used.

Messages are printed via the 'printmsg()' method. Simple strings are printed via the 'print()', 'println()' and 'flush()' methods, each simple string is considered to be terminated once the 'flush()' method has been called. The 'printmsg()' method should never be called before a previous simple string has been terminated.

Field Summary

Fields

Modifier and Type	Field and Description
static int	ERROR Severity of message.
static int	INFO Severity of message.
static int	LOG Severity of message.
static int	WARNING Severity of message.

Method Summary

Modifier and Type	Method and Description
void	flush() Writes any buffered data from the println() method to the device.
void	println(String str, int flind, int ind) Prints the string 'str' to the output device, appending a line return.
void	printmsg(int sev, String msg) Prints the message 'msg' to the output device, appending a newline, with severity 'sev'.

Field Detail

LOG

static final int LOG

Severity of message. LOG messages are just for bookkeeping and do not need to be displayed in the majority of cases

See Also:

Constant Field Values

INFO

static final int INFO

Severity of message. INFO messages should be displayed just for user feedback.

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Constant Field Values

WARNING

static final int WARNING

Severity of message. WARNING messages denote that an unexpected state has been reached and should be given as feedback to the user.

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Constant Field Values

ERROR

static final int ERROR

Severity of message. ERROR messages denote that something has gone wrong and probably that execution has ended. They should be definetely displayed to the user.

See Also:

Constant Field Values

Method Detail

printmsg

void printmsg(int sev,
              String msg)

Prints the message 'msg' to the output device, appending a newline, with severity 'sev'. Some implementations where the appended newline is irrelevant may not append the newline. Depending on the implementation the severity of the message may be added to it. The message is reformatted as appropriate for the output devic, but any newline characters are respected.

Parameters:

sev - The message severity (LOG, INFO, etc.)

msg - The message to display

println

void println(String str,
             int flind,
             int ind)

Prints the string 'str' to the output device, appending a line return. The message is reformatted as appropriate to the particular diplaying device, where 'flind' and 'ind' are used as hints for performing that operation. However, any newlines appearing in 'str' are respected. The output device may not display the string until flush() is called. Some implementations may automatically flush when this method is called. This method just prints the string, the string does not make part of a "message" in the sense that no severity is associated to it.

Parameters:

str - The string to print

flind - Indentation of the first line

ind - Indentation of any other lines.

flush

void flush()

Writes any buffered data from the println() method to the device.