@Override
	public void append(LogEvent event) {

		if (logListener == null) {
			return;
		}
		
		// An error is identified as any log that is tagged ERROR or FATAL.
		boolean isError = event.getLevel().isMoreSpecificThan(Level.ERROR);
		String message = event.getMessage().getFormattedMessage();
		logListener.messageLogged(message, isError);
	}
Log4j appender that writes messages to the log panel in the main Ghidra window. 
This is configured in the various log4j configuration files 
(generic.log4j.xml, generic.logjdev.xml, etc...).
<p>
Note: This appender is created when the log4j configuration is processed and will 
start receiving log messages immediately. These messages will be dropped on the 
floor however, until an implementation of {@link LogListener} is instantiated and 
the {@link #setLogListener(LogListener)} method is invoked.
Ghidra/Framework/Generic/src/main/java/log/LogPanelAppender.java