ptolemy.gui
Class MessageHandler

java.lang.Object
  |
  +--ptolemy.gui.MessageHandler

Direct Known Subclasses:

GraphicalMessageHandler

public class MessageHandler

extends java.lang.Object

This is a class that is used to report errors. It provides a set of static methods that are called to report errors. However, the actual reporting of the errors is deferred to an instance of this class that is set using the setMessageHandler() method. Normally there is only one instance, set up by the application, so the class is a singleton. But this is not enforced.

This base class simply writes the errors to System.err. When an applet or application starts up, it may wish to set a subclass of this class as the message handler, to allow a nicer way of reporting errors. For example, a swing application will probably want to report errors in a dialog box, using for example the derived class GraphicalMessageHandler.

Since:

Ptolemy II 1.0

Version:

$Id: MessageHandler.java,v 1.18 2002/02/21 19:08:08 cxh Exp $

Author:

Edward A. Lee, Steve Neuendorffer

See Also:

GraphicalMessageHandler

Constructor Summary

MessageHandler()

Method Summary

protected void	_error(java.lang.String info) Show the specified error message.
protected void	_error(java.lang.String info, java.lang.Exception exception) Show the specified message and exception information.
protected void	_message(java.lang.String info) Show the specified message.
protected void	_warning(java.lang.String info) Show the specified message in a modal dialog.
protected void	_warning(java.lang.String info, java.lang.Exception exception) Show the specified message and exception information in a modal dialog.
static void	error(java.lang.String info) Defer to the set message handler to show the specified error message.
static void	error(java.lang.String info, java.lang.Exception exception) Defer to the set message handler to show the specified message and exception information.
static MessageHandler	getMessageHandler() Return the message handler instance that is used by the static methods in this class.
static void	message(java.lang.String info) Defer to the set message handler to show the specified message.
static void	setMessageHandler(MessageHandler handler) Set the message handler instance that is used by the static methods in this class.
static void	warning(java.lang.String info) Defer to the set message handler to show the specified message in a modal dialog.
static void	warning(java.lang.String info, java.lang.Exception exception) Show the specified message and exception information in a modal dialog.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MessageHandler

public MessageHandler()

Method Detail

error

public static void error(java.lang.String info)

Defer to the set message handler to show the specified error message.

Parameters:

info - The message.

error

public static void error(java.lang.String info,
                         java.lang.Exception exception)

Defer to the set message handler to show the specified message and exception information. If the exception is an instance of CancelException, then it is not shown. By default, only the message of the exception is thrown. The stack trace information is only shown if the user clicks on the "Display Stack Trace" button.

Parameters:

info - The message.

exception - The exception.

See Also:

CancelException

getMessageHandler

public static MessageHandler getMessageHandler()

Return the message handler instance that is used by the static methods in this class.

message

public static void message(java.lang.String info)

Defer to the set message handler to show the specified message.

Parameters:

info - The message.

setMessageHandler

public static void setMessageHandler(MessageHandler handler)

Set the message handler instance that is used by the static methods in this class. If the given handler is null, then do nothing.

Parameters:

handler - The message handler.

warning

public static void warning(java.lang.String info)
                    throws CancelException

Defer to the set message handler to show the specified message in a modal dialog. If the user clicks on the "Cancel" button, then throw an exception. This gives the user the option of not continuing the execution, something that is particularly useful if continuing execution will result in repeated warnings.

Parameters:

info - The message.

Throws:

CancelException - If the user clicks on the "Cancel" button.

warning

public static void warning(java.lang.String info,
                           java.lang.Exception exception)
                    throws CancelException

Show the specified message and exception information in a modal dialog. If the user clicks on the "Cancel" button, then throw an exception. This gives the user the option of not continuing the execution, something that is particularly useful if continuing execution will result in repeated warnings. By default, only the message of the exception is thrown. The stack trace information is only shown if the user clicks on the "Display Stack Trace" button.

Parameters:

info - The message.

Throws:

CancelException - If the user clicks on the "Cancel" button.

_error

protected void _error(java.lang.String info)

Show the specified error message.

Parameters:

info - The message.

_error

protected void _error(java.lang.String info,
                      java.lang.Exception exception)

Show the specified message and exception information. If the exception is an instance of CancelException, then it is not shown. By default, only the message of the exception is thrown. The stack trace information is only shown if the user clicks on the "Display Stack Trace" button.

Parameters:

info - The message.

exception - The exception.

See Also:

CancelException

_message

protected void _message(java.lang.String info)

Show the specified message.

Parameters:

info - The message.

_warning

protected void _warning(java.lang.String info)
                 throws CancelException

Show the specified message in a modal dialog. If the user clicks on the "Cancel" button, then throw an exception. This gives the user the option of not continuing the execution, something that is particularly useful if continuing execution will result in repeated warnings.

Parameters:

info - The message.

Throws:

CancelException - If the user clicks on the "Cancel" button.

_warning

protected void _warning(java.lang.String info,
                        java.lang.Exception exception)
                 throws CancelException

Show the specified message and exception information in a modal dialog. If the user clicks on the "Cancel" button, then throw an exception. This gives the user the option of not continuing the execution, something that is particularly useful if continuing execution will result in repeated warnings. By default, only the message of the exception is thrown. The stack trace information is only shown if the user clicks on the "Display Stack Trace" button.

Parameters:

info - The message.

Throws:

CancelException - If the user clicks on the "Cancel" button.