/**
 * SystemPropertyInfo lists all properties available from
 * the System class.
 *
 * Copyright &copy; 1996-1998 Martin Minow. All Rights Reserved.<p>
 *
 * Permission to use, copy, modify, and redistribute this software and its
 * documentation for personal, non-commercial use is hereby granted provided that
 * this copyright notice and appropriate documentation appears in all copies. This
 * software may not be distributed for fee or as part of commercial, "shareware,"
 * and/or not-for-profit endevors including, but not limited to, CD-ROM collections,
 * online databases, and subscription services without specific license.<p>
 *
 * @author <a href="mailto:minow@apple.com">Martin Minow</a>
 * @version 1.0.1
 * Edit History:
 * 1998.03.29 MM Redo property list as an Enumeration, including
 *		the properties listed in Jef Poskanzer's StatusProperties
 *		applet. See <http://acme.com/> for his source distribution.
 *
 * Set tabs every 4 characters.
 *
 */
import java.awt.*;
import java.util.*;

public class SystemPropertyInfo extends SystemInfo
{
	/*
	 * This is a default list of system properties that we will use
	 * if the Security Manager doesn't let us extract the "real" list.
	 */
	public static final String defaultProperties =
			""
			+ "browser "
			+ "file.separator "
			+ "java.class.version "
			+ "java.vendor "
			+ "java.vendor.url "
			+ "java.version "
			+ "line.separator "
			+ "os.arch "
			+ "os.name "
			+ "os.version "
			+ "path.separator ";

	public static final String hexPropertyNames =
			  " file.separator "
			+ "line.separator "
			+ "path.separator ";
	public static final String urlPropertyNames =
			  " browser.vendor.url "
			+ " java.class.path "
			+ "java.home "
			+ "user.dir "
			+ "user.home "
			+ "user.name ";
	
			
	public SystemPropertyInfo(
			EtchedBorder		border
		)
	{
		super(border);
		try {
			Properties props = System.getProperties();
			/*
			 * Unfortunately, enumerating System.getProperties() returns
			 * them in an unsatisfactory order. To make the display
			 * esthetically pleasing, we'll extract the property names
			 * (i.e. the keys) into a vector, then sort the vector, then
			 * use the vector as an enumeration. props.size() is not
			 * trustworthy (bug in MRJ?)
			 */
			setBorderText("System Properties");
			/*
			 * Count the actual size of the System property list.
			 */
			int size = 0;
			Enumeration enum = props.propertyNames();
			while (enum.hasMoreElements()) {
				++size;
				enum.nextElement();
			}
			String[] names = new String[size];
			enum = props.propertyNames();
			for (int i = 0; enum.hasMoreElements(); i++) {
				names[i] = (String) enum.nextElement();
			}
			if (size < 1) {
				append("No System Properties");
			}
			else {
				JavaInfo.quickSort(names, 0, names.length - 1);
				for (int i = 0; i < size; i++) {
					addOneSystemProperty(names[i]);
				}
			}
		}
		catch (SecurityException e) {
			setBorderText("Default Applet Properties");
			StringTokenizer t = new StringTokenizer(defaultProperties, " ");
			while (t.hasMoreElements()) {
				addOneSystemProperty(t.nextToken());
			}
		}
		catch (Exception e) {
			append("Strange Exception getting system properties: " + e);
		}
	}
	public void addOneSystemProperty(
			String			name
		)
	{
		try {
			String propValue	= System.getProperty(name);
			/*
			 * On the Macintosh (under MRJ), a bunch of font names
			 * are loaded into the property list. We toss them
			 * to avoid confusion.
			 */
			if (propValue != null && name.equals(propValue) == false) {
				append(name + ":");
				boolean isReadable = true;
				for (int i = 0; i < propValue.length(); i++) {
					char	c	= propValue.charAt(i);
					if (isControlCharacter(c)) {
						isReadable = false;
						break;
					}
				}
				if (isReadable == false) {
					for (int i = 0; i < propValue.length(); i++) {
						char	c	= propValue.charAt(i);
						if (Character.isLetterOrDigit(c)) {
							append(" '" + c + "'");
						}
						else {
							append(" 0x");
							if (c < 0x10) {
								append("0");
							}
							append(Integer.toHexString(c));
						}
					}
				}
				else if (isURLProperty(name)) {
					StringBuffer	fixed = new StringBuffer();
					int		start	= 0;
					int		hit		= 0;
					while ((hit = propValue.indexOf('%', start)) >= 0) {
						fixed.append(propValue.substring(start, hit));
						int		value	=
							Integer.parseInt(propValue.substring(hit + 1, hit + 3), 16);
						fixed.append(((char) value));
						start = hit + 3;
					}
					append(" \"" + fixed + "\"");
				}
				else {
					append(" " + propValue);
				}
				append("\n");
			} /* If the property name was found */
		} /* Try to fetch the property name */
		catch (SecurityException e) {
			append(name + ": Security Exception\n"	);
		}
		catch (Exception e) {
			append(name 	+ ": " + e + "\n");
		}
	}
	protected boolean isHexProperty(
			String			thisName
		)
	{
		int	index	= hexPropertyNames.indexOf(" " + thisName + " ");
		return (index >= 0);
	}
	protected boolean isURLProperty(
			String			thisName
		)
	{
		int	index	= urlPropertyNames.indexOf(" " + thisName + " ");
		return (index >= 0);
	}
	/**
	 * Replicate the Java 1.1 isISOControl method (for Java 1.0.2 compatibility)
	 */
	private boolean isControlCharacter(
			char			c
		)
	{
		return ((c >= '\u0000' && c <= '\u001f')
			 || (c >= '\u007f' && c <= '\u009f')); 
	}
}