Added a class representing a GUI element, a status bar.

Added great flexibility to the code that creates the log file.  It is property
driven at present, and the default behavior is the same as the old default
behavior, except that a message is printed to standard output telling the
user which log file is being used, and that they should include its contents
in bug reports.

You can log to the temporary directory, a directory of your choice, or (by
default) the current directory.  Edward's related feature request can now
quickly be fulfilled.

source/org/thdl/util/ThdlDebug.java

@@ -20,6 +20,7 @@ package org.thdl.util;
 
 import java.io.PrintStream;
 import java.io.FileOutputStream;
+import java.io.File;
 
 import org.thdl.util.TeeStream;
 
@@ -119,11 +120,68 @@ public class ThdlDebug {
 
 	/** Sets it up so that a call to System.out or System.err prints
      *  to standard output/error but ALSO prints to the log file named
-     *  logFile. */
-	public static void attemptToSetUpLogFile(String logFile) {
+     *  (prefix + suffix).  Be sure the log file name is a relative
+     *  path, because we may put this file into an arbitrary
+     *  directory. */
+	public static void attemptToSetUpLogFile(String prefix, String suffix) {
+        final String tempDirProp = "thdl.use.temp.file.directory.for.log";
+        final String logDirProp = "thdl.log.directory";
+        File logFile = null;
+
+        if (Boolean.getBoolean(tempDirProp)) {
+            /* The log file won't be named 'jskad.log', it'll be named
+               'jskad-SAKFJDS3134.log', and they'll all just pile up,
+               because we don't deleteOnExit. */
+
+            /* First, ensure that the user hasn't set conflicting options. */
+            try {
+                if (null != System.getProperty("thdl.log.directory"))
+                    throw new Error("You cannot set the property "
+                                    + tempDirProp + " and the property "
+                                    + logDirProp
+                                    + " at the same time because they both affect the same thing, the location of the log file.");
+            } catch (Exception e) {
+                /* SecurityExceptions, e.g., will trigger this. */
+
+                /* Leave logDir null. */
+            } catch (Error e) {
+                throw e;
+            }
+
+            /* Now, create the temporary file. */
+            try {
+                logFile = File.createTempFile(prefix, suffix);
+            } catch (Exception e) {
+                noteIffyCode();
+            }
+        } else {
+            /* If the user has set the system property
+               thdl.log.directory, respect their choice. */
+            String logDir = null;
+            try {
+                logDir = System.getProperty(logDirProp);
+            } catch (Exception e) {
+                /* SecurityExceptions, e.g., will trigger this.  We
+                   leave logDir null. */
+                noteIffyCode();
+            }
+            if (null != logDir) {
+                logFile = new File(logDir, prefix + suffix);
+            } else {
+                /* Create the log file in the current directory.  For
+                   Windows users, this is often the desktop.
+
+                   FIXME: by default, put the log file in a smarter place.
+                */
+                logFile = new File(prefix + suffix);
+            }
+        }
 		try {
 			PrintStream logFilePrintStream
 				= new PrintStream(new FileOutputStream(logFile));
+            System.out.println("Logging to "
+                               + logFile.getAbsolutePath().toString()
+                               + "; please include the contents of this file in any bug reports.");
 			PrintStream psOut = new TeeStream(System.out, logFilePrintStream);
 			PrintStream psErr = new TeeStream(System.err, logFilePrintStream);
 			System.setErr(psErr);