source: 3thparty/jupload/src/main/java/wjhk/jupload2/gui/JUploadTextArea.java @ 3951

//
// $Id: JUploadTextArea.java 95 2007-05-02 03:27:05Z
// /C=DE/ST=Baden-Wuerttemberg/O=ISDN4Linux/OU=Fritz
// Elfert/CN=svn-felfert@isdn4linux.de/emailAddress=fritz@fritz-elfert.de $
//
// jupload - A file upload applet.
// Copyright 2007 The JUpload Team
//
// Created: ?
// Creator: William JinHua Kwong
// Last modified: $Date: 2010-06-29 16:47:31 -0300 (Ter, 29 Jun 2010) $
//
// This program is free software; you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free Software
// Foundation; either version 2 of the License, or (at your option) any later
// version. This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
// details. You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software Foundation, Inc.,
// 675 Mass Ave, Cambridge, MA 02139, USA.

package wjhk.jupload2.gui;

import java.awt.Color;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;

import javax.swing.JTextArea;

import wjhk.jupload2.policies.UploadPolicy;

/**
 * This class represents the text area for debug output.
 */
@SuppressWarnings("serial")
public class JUploadTextArea extends JTextArea {

        /**
         * Maximum number of characters in the logWindow.
         */
        public final static int MAX_LOG_WINDOW_LENGTH = 800000;

        /**
         * The size we truncate the output to, when the maximum size of debug output
         * is reach. We remove 20%.
         */
        public final static int SIZE_TO_TRUNCATE_TO = (int) (MAX_LOG_WINDOW_LENGTH * 0.8);

        /**
         * The current upload policy
         */
        UploadPolicy uploadPolicy;

        /**
         * Indicates whether the logging in the LogMessageThread is active or not.
         * It's marked as active before starting this thread. It's marked as
         * non-active, when this thread is interrupted, in {@link #unload()}
         */
        boolean loggingActive = false;

        /**
         * The ConcurrentLinkedQueue that'll contain the messages.
         */
        private BlockingQueue<String> messages;

        /**
         * This value is logged in the debug file, and in the debug output, for each
         * line. This allows to sort the outputed line correctly.
         * 
         * @see #displayMsg(String, String)
         */
        private int messageId = 1;

        /**
         * A thread, that will be called in the EventDispatcherThread, to have a
         * tread-safe update of the GUI. This thread is responsible to display one
         * String.
         */
        static class LogMessageThread extends Thread {

                /**
                 * The text area that'll contain the messages.
                 */
                private JUploadTextArea textArea;

                /**
                 * @param textArea
                 */
                LogMessageThread(JUploadTextArea textArea) {
                        this.textArea = textArea;
                        setDaemon(true);
                }

                /** The run method of the Runnable Interface */
                @Override
                public void run() {
                        String nextMessage = null;

                        if (this.textArea.uploadPolicy.getDebugLevel() >= 30) {
                                int messageBackup = this.textArea.messageId;
                                this.textArea.messageId = 0;
                                this.textArea.setText(this.textArea.formatMessageOutput(
                                                "[DEBUG]", "Logging system is initialized\n"));
                                this.textArea.messageId = messageBackup;
                        }

                        while (this.textArea.loggingActive) {
                                try {
                                        nextMessage = this.textArea.messages.take() + "\n";

                                        // Ah, a new message has been delivered...

                                        synchronized (this.textArea) {
                                                String content = this.textArea.getText();
                                                int contentLength = content.length();
                                                // If the current content is too long, we truncate it.
                                                if (contentLength > JUploadTextArea.MAX_LOG_WINDOW_LENGTH) {
                                                        content += nextMessage;
                                                        String newContent = content.substring(content
                                                                        .length()
                                                                        - SIZE_TO_TRUNCATE_TO, content.length());
                                                        this.textArea.setText(newContent);
                                                        contentLength = SIZE_TO_TRUNCATE_TO;
                                                } else {
                                                        // The result is not too long
                                                        this.textArea.append(nextMessage);
                                                        contentLength += nextMessage.length();
                                                }
                                                this.textArea.setCaretPosition(contentLength - 1);
                                        } // synchronized
                                } catch (InterruptedException e) {
                                        // If we're not running any more, then this 'stop' is
                                        // not a
                                        // problem any more. We're then just notified we must
                                        // stop
                                        // the thread.
                                        if (this.textArea.loggingActive) {
                                                // This should not happen, and we can not put in the
                                                // standard JUpload output, as this thread is
                                                // responsible for it.
                                                e.printStackTrace();
                                        }
                                }// try
                        }// while
                }
        }

        /**
         * The thread, that will put messages in the debug log.
         */
        LogMessageThread logMessageThread = null;

        /**
         * Constructs a new empty TextArea with the specified number of rows and
         * columns.
         * 
         * @param rows
         *            The desired number of text rows (lines).
         * @param columns
         *            The desired number of columns.
         * @param uploadPolicy
         *            The current uploadPolicy
         */
        public JUploadTextArea(int rows, int columns, UploadPolicy uploadPolicy) {
                super(rows, columns);
                this.uploadPolicy = uploadPolicy;
                this.messages = new LinkedBlockingQueue<String>();
                setBackground(new Color(255, 255, 203));
                setEditable(false);
                setLineWrap(true);
                setWrapStyleWord(true);

                // The queue, where messages to display will be posted.
                this.logMessageThread = new LogMessageThread(this);
                this.logMessageThread.setName(this.logMessageThread.getClass()
                                .getName());
                // NO START HERE: the logMessageThread needs to know the upload policy,
                // to run properly. The thread is started in the setUploadPolicy method.

                // The unload callback will be registered, once the uploadPolicy has
                // been built, by DefaultJUploadContext.init(JUploadApplet)
        }

        /**
         * Add a string to the queue of string to be added to the logWindow. This is
         * necessary, to manage the non-thread-safe Swing environment.
         * 
         * @param tag
         *            The tag (eg: INFO, DEBUG...)
         * @param msg
         *            The message to add, at the end of the JUploadTextArea.
         * @return The formatted text that was added to the log window.
         */
        public final String displayMsg(String tag, String msg) {
                String fullMessage = formatMessageOutput(tag, msg);

                try {
                        // messages is a BlockingQueue. So the next line may 'block' the
                        // applet main thread. But, we're optimistic: this should not happen
                        // as we instanciate an unbound LinkedBlockingQueue. We'll be
                        // blocked at Integer.MAX_VALUE, that is ... much after an
                        // OutOfMemory is thrown !
                        this.messages.put(fullMessage);
                } catch (InterruptedException e) {
                        System.out.println("WARNING - [" + this.getClass().getName()
                                        + "] Message lost due to " + e.getClass().getName() + " ("
                                        + fullMessage + ")");
                }
                return fullMessage;
        }

        /**
         * This call must be synchronized, so that there is no interaction with the
         * LogMessageThread thread.
         * 
         * @see JTextArea#append(String)
         */
        synchronized public void append(String t) {
                super.append(t);
        }

        /**
         * This call must be synchronized, so that there is no interaction with the
         * LogMessageThread thread.
         * 
         * @see JTextArea#insert(String, int)
         */
        synchronized public void insert(String str, int pos) {
                super.insert(str, pos);
        }

        /**
         * This call must be synchronized, so that there is no interaction with the
         * LogMessageThread thread.
         * 
         * @see JTextArea#replaceRange(String, int, int)
         */
        synchronized public void replaceRange(String str, int start, int end) {
                super.replaceRange(str, start, end);
        }

        /**
         * This call must be synchronized, so that there is no interaction with the
         * LogMessageThread thread.
         * 
         * @see JTextArea#setText(String)
         */
        synchronized public void setText(String t) {
                super.setText(t);
        }

        /**
         * @param uploadPolicy
         *            the uploadPolicy to set
         */
        public void setUploadPolicy(UploadPolicy uploadPolicy) {
                this.uploadPolicy = uploadPolicy;
                this.uploadPolicy.getContext().registerUnload(this, "unload");
                // We can now start the log thread.
                this.loggingActive = true;
                this.logMessageThread.start();
        }

        /**
         * Free any used ressources. Actually close the LogMessageThread thread.
         */
        public synchronized void unload() {
                this.loggingActive = false;
                this.logMessageThread.interrupt();
        }

        /**
         * Format the message, with the given tag. This method also add the time and
         * the Thread name.<BR>
         * e.g.:<BR>
         * messageId[tab]14:04:30.718[tab]FileUploadManagerThread[tab][DEBUG][tab]
         * Found one reader for jpg extension
         * 
         * @param tag
         *            The tag ([WARN], [ERROR]...)
         * @param msg
         *            The message to format.
         * @return The formatted message, without trailing EOL character.
         */
        String formatMessageOutput(String tag, String msg) {
                final String stamp = String.format("%1$05d", this.messageId++) + " \t"
                                + new SimpleDateFormat("HH:mm:ss.SSS ").format(new Date())
                                + "\t" + Thread.currentThread().getName() + "\t" + tag + " \t";
                while (msg.endsWith("\n")) {
                        msg = msg.substring(0, msg.length() - 1);
                }
                return (stamp + msg.replaceAll("\n", "\n" + stamp));
        }

}