source: gli/trunk/src/org/greenstone/gatherer/download/DownloadScrollPane.java@ 18221

/**
 *#########################################################################
 *
 * A component of the Gatherer application, part of the Greenstone digital
 * library suite from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * <BR><BR>
 *
 * Author: John Thompson, Greenstone Digital Library, University of Waikato
 *
 * <BR><BR>
 *
 * Copyright (C) 1999 New Zealand Digital Library Project
 *
 * <BR><BR>
 *
 * 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.
 *
 * <BR><BR>
 *
 * 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.
 *
 * <BR><BR>
 *
 * 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 org.greenstone.gatherer.download;

import java.awt.*;
import java.io.*;
import java.net.*;
import java.util.*;
import javax.swing.*;
import javax.swing.tree.*;
import org.greenstone.gatherer.*;

/** This class provides access to the functionality of the WGet program, either by calling it via a shell script or by the JNI. It maintains a queue of pending jobs, and the component for showing these tasks to the user.
 * @author John Thompson, Greenstone Digital Library, University of Waikato
 * @version 2.3
 */
public class DownloadScrollPane
    extends Thread {
    
    /** <i>true</i> if verbose debug messages should be displayed, <i>false</i> otherwise. */
    private boolean debug = false;
    /** <i>true</i> if successfully completed tasks should be automatically removed from the job queue. */
    private boolean remove_complete_jobs = true;

    private JPanel filler_pane = null;
    /** The panel that the task list will be shown in. */
    private JPanel list_pane;
    /** The job currently underway. */
    private DownloadJob job;
    /** A scroll pane which will be used to display the list of pending tasks. */
    private JScrollPane list_scroll;
    /** A queue of download tasks. */
    private Vector job_queue;
    static final private boolean simple = true;

        
    public DownloadScrollPane() {
    job = null;
    job_queue = new Vector();
    filler_pane = new JPanel();
    list_pane = new JPanel();
    list_pane.setLayout(new BoxLayout(list_pane, BoxLayout.Y_AXIS));
    list_scroll = new JScrollPane(list_pane);
    }

    public void deleteDownloadJob(DownloadJob delete_me) {
    if (delete_me == job) {
        try {
        // Wait for the job to finish cleaning up, before we can continue cleaning up here.
        // But sometimes the job has completed (terminated naturally) and in that case there's
        // nothing to wait for.
        synchronized(delete_me) {
            if (!delete_me.hasSignalledStop()) { // don't wait if DownloadJob.COMPLETED 
            delete_me.wait();
            }
        }
        } catch (Exception e) {
        e.printStackTrace();
        }       
    }
    // Close button pressed, get rid of this download's dedicated pane
    finishedDownloadJob(delete_me, true);
    }

    /** To be called when a download job has terminated naturally or was prematurely stopped
     *  via the close button. 
     *  Gets rid of this download's pane with buttons and progress bar if prematurely stopped. */
    protected void finishedDownloadJob(DownloadJob delete_me, boolean removeDisplay) {
    if (delete_me.hasSignalledStop()) {
        if(removeDisplay) {
        list_pane.remove(delete_me.getProgressBar());
        list_pane.remove(filler_pane);
        }
        job_queue.remove(delete_me);
        if(job_queue.size() > 0) {
        Dimension progress_bar_size = delete_me.getProgressBar().getPreferredSize();
        Dimension list_pane_size = list_pane.getSize();
        int height = list_pane_size.height - (job_queue.size() * progress_bar_size.height);
        progress_bar_size = null;
        if(height > 0) {
            filler_pane.setPreferredSize(new Dimension(list_pane_size.width, height));
            list_pane.add(filler_pane);
        }
        list_pane_size = null;
        }
        list_pane.updateUI();
    }
    else {
        DebugStream.println("Somehow we're trying to delete a job that is still running.");
    }
    }

    public synchronized void downloadComplete() {
    job.downloadComplete();
    }

    public synchronized void downloadFailed() {
    job.downloadFailed();
    }

    public synchronized void downloadWarning() {
    job.downloadWarning();
    }

    public JScrollPane getDownloadJobList() {
    return list_scroll;
    }

    public synchronized boolean hasSignalledStop() {
    return job.hasSignalledStop();
    }

    public void newDownloadJob(Download download, String mode, String proxy_url) {
    // Create the job and fill in the details from gatherer.config.

    DebugStream.println("About to create a new job");
    
        DownloadJob new_job = new DownloadJob(download, Configuration.proxy_pass, Configuration.proxy_user, this, mode, proxy_url);
    // Tell it to run as soon as possible

    new_job.setState(DownloadJob.RUNNING);
    
    // Add to job_queue job list.
    job_queue.add(new_job);

    // Now add it to the visual component, job list.

    list_pane.remove(filler_pane);

    Dimension progress_bar_size = new_job.getProgressBar().getPreferredSize();

    Dimension list_pane_size = list_pane.getSize();

    int height = list_pane_size.height - (job_queue.size() * progress_bar_size.height);

    progress_bar_size = null;

    list_pane.add(new_job.getProgressBar());

    if(height > 0) {
        filler_pane.setPreferredSize(new Dimension(list_pane_size.width, height));
        list_pane.add(filler_pane);
    }

    list_pane_size = null;
    //list_pane.setAlignmentX(Component.LEFT_ALIGNMENT);
    list_pane.updateUI();
    new_job = null;         //job = (DownloadJob) job_queue.get(index);

    synchronized(this) {
        notify(); // Just incase its sleeping.
    }
    }
    
    public synchronized void updateProgress(long current, long expected) {
    job.updateProgress(current, expected);
    }
    
    /* There may be times when the download thread is sleeping, but the
     * user has indicated that a previously paused job should now begin
     * again. The flag within the job will change, so we tell the thread
     * to start again.
     */
    public void resumeThread() {
    synchronized(this) {
        notify(); // Just incase its sleeping.
    }
    }
    
    public void run() {
    while(true) {
        if(job_queue.size() > 0) {
        while(!job_queue.isEmpty()) { 
            job = (DownloadJob) job_queue.firstElement(); 
            
            if(job.getState() == DownloadJob.RUNNING) {
            DownloadJob delete_me = job;
            String jobDisplayString = job.toString();
            DebugStream.println("DownloadJob " + jobDisplayString + " Begun.");
            System.err.println("DownloadJob " + job.port + " " + job.toString() + " Begun.");
            job.callDownload();
            // Job is done. Ended naturally, don't get rid of this download's separate display panel
            finishedDownloadJob(delete_me, false); 
            System.err.println("DownloadJob " + jobDisplayString + " complete.");
            DebugStream.println("DownloadJob " + jobDisplayString + " complete."); // by this point job is null!
            job = null;
            delete_me = null;
            }
        }
        try {
            synchronized(this) {
            DebugStream.println("WGet thread is waiting for DownloadJobs.");
            wait();
            }
        } catch (InterruptedException e) {
            // Time to get going again.
        }
        }
        else {
        try {
            synchronized(this) {
            DebugStream.println("WGet thread is waiting for DownloadJobs.");
            wait();
            }
        } catch (InterruptedException e) {
            // Time to get going again.
        }
        }
    }
    }
}