Log.java

/* The MIT License (MIT)
 * Copyright (c) 2014 Nicholas Wright
 * http://opensource.org/licenses/MIT
 */

package com.github.dozedoff.commonj.gui;

import java.text.DateFormat;
import java.util.Calendar;
import java.util.GregorianCalendar;

import javax.swing.JTextArea;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * This class outputs Strings sent to it to a TextField. The class also maintains the TextFied, limiting the amount of text displayed on it.
 */
public class Log {
	static private JTextArea logArea;
	static private int logNr = 0;
	static private final Logger logger = LoggerFactory.getLogger(Log.class);

	public static void setLogArea(JTextArea logArea) {
		Log.logArea = logArea;
	}

	public static void setLogNr(int nr) {
		Log.logNr = nr;
	}

	public static void clear() {
		Log.logArea.setText("");
		Log.logNr = 0;
	}

	public static int getLogNr() {
		return logNr;
	}

	/**
	 * Will output a message to the GUI log. The message will have the current date and time as a prefix.
	 * 
	 * @param add
	 *            message to add to log
	 */
	public static void add(String add) {
		if (logArea == null) {
			logger.warn("No output textfield set for GUI log");
			return;
		}
		Calendar cal = new GregorianCalendar();
		DateFormat df;
		df = DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.MEDIUM);

		logArea.append(df.format(cal.getTime()) + "  " + add + "\n");
		if (logNr > 50) {
			logArea.replaceRange("", 0, 1 + logArea.getText().indexOf("\n"));
		} else {
			logNr++; // to avoid overflow
		}
		// logArea.setCaretPosition(logArea.getText().length());
	}
}