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/StatusBar.java

@@ -0,0 +1,104 @@
+/*
+The contents of this file are subject to the THDL Open Community License
+Version 1.0 (the "License"); you may not use this file except in compliance
+with the License. You may obtain a copy of the License on the THDL web site 
+(http://www.thdl.org/).
+
+Software distributed under the License is distributed on an "AS IS" basis, 
+WITHOUT WARRANTY OF ANY KIND, either express or implied. See the 
+License for the specific terms governing rights and limitations under the 
+License. 
+
+The Initial Developer of this software is the Tibetan and Himalayan Digital
+Library (THDL). Portions created by the THDL are Copyright 2001 THDL.
+All Rights Reserved. 
+
+Contributor(s): ______________________________________.
+*/
+
+package org.thdl.util;
+
+import java.awt.*;
+import java.awt.event.*;
+import javax.swing.*;
+import java.util.Stack;
+
+/** A StatusBar can be added to a component, typically to the bottom
+    of it, in order to show the user the status of the program.  There
+    are methods to change the status, and there are actually a LIFO
+    stack of status messages if you wish to use them. */
+public class StatusBar extends JPanel {
+    /** The current status is the String on top of the stack. */
+    private Stack statuses;
+
+    private JLabel label;
+
+    /** Creates a status bar. */
+    public StatusBar() {
+        super();
+        setLayout(new BoxLayout(this, BoxLayout.X_AXIS));
+        statuses = new Stack();
+        label = new JLabel("Visit 'http://www.thdl.org/'.");
+        label.setHorizontalAlignment(SwingConstants.LEFT);
+        add(label);
+    }
+
+    /** Creates a status bar with the initial message msg. */
+    public StatusBar(String msg) {
+        this();
+        pushStatus(msg);
+    }
+
+    /** Sets the status to msg, replacing the current status message. */
+    public void replaceStatus(String msg) throws NullPointerException {
+        if (msg == null)
+            throw new NullPointerException();
+        if (!statuses.empty())
+            statuses.pop();
+        statuses.push(msg);
+        updateLabel();
+    }
+
+    /** Sets the status to msg, leaving the previous status on the
+        stack. */
+    public void pushStatus(String msg) throws NullPointerException {
+        if (msg == null)
+            throw new NullPointerException();
+        statuses.push(msg);
+        updateLabel();
+    }
+
+    /** Removes the current status message.  If the stack is then
+        empty, the message will be the empty string.  Otherwise, the
+        message will be the message then topmost on the stack.
+        
+        @throws NullPointerException if msg is null
+    */
+    public void popStatus() {
+        if (!statuses.empty()) {
+            statuses.pop();
+            updateLabel();
+        }
+    }
+    
+    /** Returns the String currently displayed in the status bar. */
+    public String currentStatus() {
+        return getMsgOnTopOfStack();
+    }
+
+    /** Returns the status message on top of the stack, or "" if the
+        stack is empty. */
+    private String getMsgOnTopOfStack() {
+        if (statuses.empty())
+            return "";
+        else
+            return (String)statuses.peek();
+    }
+
+    /** Sets the displayed text to what's on top of the stack, or ""
+        if the stack is empty. */
+    private void updateLabel() {
+        label.setText("  " + // FIXME: nasty hack to make everything show up
+                      getMsgOnTopOfStack());
+    }
+}

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);