// HTMLParser Library $Name: v1_6_20060319 $ - A java-based parser for HTML
// http://sourceforge.org/projects/htmlparser
// Copyright (C) 2003 Derrick Oswald
//
// Revision Control Information
//
// $Source: /cvsroot/htmlparser/htmlparser/src/org/htmlparser/lexerapplications/thumbelina/Sequencer.java,v $
// $Author: derrickoswald $
// $Date: 2004/07/31 16:42:30 $
// $Revision: 1.2 $
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
package org.htmlparser.lexerapplications.thumbelina;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Image;
import java.awt.Insets;
import java.awt.Point;
import java.net.URL;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.JViewport;
/**
* Display received images at a constant rate.
*/
public class Sequencer
extends
Thread
{
/**
* The default delay time, {@value} milliseconds.
*/
protected static final int DEFAULT_DELAY = 500;
/**
* The thumbelina object to drive.
*/
protected Thumbelina mThumbelina;
/**
* Pictures awaiting display.
*/
protected ArrayList mPending;
/**
* Activity state.
* <code>true</code> means fetching and displaying, <code>false</code> not.
*/
protected boolean mActive;
/**
* Delay between picture displays.
*/
protected int mDelay;
/**
* Random number generator for picture placement.
*/
protected Random mRandom;
/**
* Creates a new instance of a Sequencer.
* @param thumbelina The object to push images to.
*/
public Sequencer (final Thumbelina thumbelina)
{
mThumbelina = thumbelina;
mPending = new ArrayList ();
mActive = true;
setDelay (DEFAULT_DELAY);
mRandom = new Random ();
setName ("Sequencer"); // only good if there's just one of these
start ();
}
/**
* Clears the pending images list.
*/
public void reset ()
{
synchronized (mPending)
{
mPending.clear ();
mThumbelina.mReadyProgress.setValue (0);
mPending.notify ();
}
}
/**
* Compute a random point to load the image.
* Generate a random point for one of the corners of the image and
* then condition the numbers so the image is on screen.
* @param url The url this picture was fetched from.
* Used in computing the random position, so the picture is always
* placed in the same location, even when refetched.
* @param width The width of the image.
* @param height The height of the image.
* @return The random point to use.
*/
protected Point random (final String url, final int width, final int height)
{
Component parent;
Component grandparent;
Dimension dim;
Insets insets;
int minx;
int miny;
int maxx;
int maxy;
int rndx;
int rndy;
int corner;
Point ret;
parent = mThumbelina.getPicturePanel ().getParent ();
if (parent instanceof JViewport)
{
grandparent = parent.getParent (); // JScrollPane
dim = grandparent.getSize ();
}
else
dim = mThumbelina.getPicturePanel ().getSize ();
insets = mThumbelina.getPicturePanel ().getInsets ();
dim.width -= (insets.left + insets.right);
dim.height -= (insets.top + insets.bottom);
minx = insets.left;
miny = insets.top;
maxx = minx + dim.width;
maxy = miny + dim.height;
mRandom.setSeed ((((long)(width + height)) << 32) + url.hashCode ());
rndx = (int)(mRandom.nextDouble () * dim.width);
rndy = (int)(mRandom.nextDouble () * dim.height);
corner = (int)(mRandom.nextDouble () * 4); // the panel has four corners
ret = new Point (0, 0);
switch (corner)
{
case 0: // upper left
if (rndx + width >= maxx)
ret.x = maxx - width;
else
ret.x = rndx;
if (rndy + height >= maxy)
ret.y = maxy - height;
else
ret.y = rndy;
break;
case 1: // upper right
if (rndx - width < minx)
ret.x = minx;
else
ret.x = rndx - width;
if (rndy + height >= maxy)
ret.y = maxy - height;
else
ret.y = rndy;
break;
case 2: // lower right
if (rndx - width < minx)
ret.x = minx;
else
ret.x = rndx - width;
if (rndy - height < miny)
ret.y = miny;
else
ret.y = rndy - height;
break;
case 3: // lower left
if (rndx + width >= maxx)
ret.x = maxx - width;
else
ret.x = rndx;
if (rndy - height < miny)
ret.y = miny;
else
ret.y = rndy - height;
break;
default:
throw new IllegalStateException ("random corner = " + corner);
}
// if it's really large stuff it in the upper left hand corner
if (ret.x < 0)
ret.x = 0;
if (ret.y < 0)
ret.y = 0;
return (ret);
}
/**
* Add an image to the pending list.
* @param image The image to add.
* @param url The url the image came from.
*/
public void add (final Image image, final URL url)
{
add (image, url, true);
}
/**
* Add an image to the panel.
* @param image The image to add.
* @param url The url the image came from.
* @param background If <code>true</code>, just add to pending list.
*/
public void add (final Image image, final URL url, final boolean background)
{
Picture picture;
int size;
picture = new Picture ();
picture.setImage (image);
picture.setURL (url);
if (background)
synchronized (mPending)
{
mPending.add (picture);
size = mPending.size ();
if (mThumbelina.mReadyProgress.getMaximum () < size)
mThumbelina.mReadyProgress.setMaximum (size);
mThumbelina.mReadyProgress.setValue (size);
mPending.notify ();
}
else
place (picture, false);
}
/**
* Place a picture in the display area.
* Places the picture at a random location on screen.
* @param picture The picture to place on screen.
* @param add If <code>true</code>, the picture is added to the history.
*/
protected void place (final Picture picture, final boolean add)
{
Point p;
if (Picture.ORIGIN == picture.getOrigin ())
{
// never been placed before
p = random (
picture.getURL ().toExternalForm (),
picture.width,
picture.height);
picture.x = p.x;
picture.y = p.y;
picture.setOrigin (p);
}
mThumbelina.getPicturePanel ().draw (picture, add);
}
//
// Runnable interface
//
/**
* Display pictures from pending list with delay between.
* If the list is empty it waits on the pending list for new pictures.
*/
public void run ()
{
Picture picture;
int size;
while (true)
{
try
{
picture = null;
synchronized (mPending)
{
if (mActive && !mPending.isEmpty ())
picture = (Picture)mPending.remove (0);
else
try
{
mPending.wait ();
}
catch (InterruptedException ie)
{
ie.printStackTrace ();
}
size = mPending.size ();
if (mThumbelina.mReadyProgress.getMaximum () < size)
mThumbelina.mReadyProgress.setMaximum (size);
mThumbelina.mReadyProgress.setValue (size);
}
if (null != picture)
{
place (picture, true);
if (0 != getDelay ())
try
{
sleep (getDelay ());
}
catch (InterruptedException ie)
{
ie.printStackTrace ();
}
}
}
catch (Throwable t)
{
t.printStackTrace ();
}
}
}
/**
* Getter for property delay.
* @return Value of property delay.
*/
public int getDelay ()
{
return (mDelay);
}
/**
* Setter for property delay.
* @param delay New value of property delay.
*/
public void setDelay (final int delay)
{
mDelay = delay;
}
}
/*
* Revision Control Modification History
*
* $Log: Sequencer.java,v $
* Revision 1.2 2004/07/31 16:42:30 derrickoswald
* Remove unused variables and other fixes exposed by turning on compiler warnings.
*
* Revision 1.1 2003/09/21 18:20:56 derrickoswald
* Thumbelina
* Created a lexer GUI application to extract images behind thumbnails.
* Added a task in the ant build script - thumbelina - to create the jar file.
* You need JDK 1.4.x to build it. It can be run on JDK 1.3.x in crippled mode.
* Usage: java -Xmx256M thumbelina.jar [URL]
*
*
*/