/* * Copyright 2006-2007 JavaAtWork All rights reserved. * Use is subject to license terms. */package javaatwork.myuploader.dialog;import java.awt.Dimension;import java.awt.Graphics;import java.awt.Image;import java.beans.PropertyChangeEvent;import java.beans.PropertyChangeListener;import java.io.File;import javaatwork.myuploader.FileTable;import javaatwork.myuploader.domain.FormFileField;import javax.swing.ImageIcon;import javax.swing.JComponent;import javax.swing.JFileChooser;import javax.swing.ListSelectionModel;import javax.swing.event.ListSelectionEvent;import javax.swing.event.ListSelectionListener;/** * Class for displaying a thumbnail. *  * @author Johannes Postma */public class ImagePreview extends JComponent implements PropertyChangeListener, ListSelectionListener {	/**	 * serialVersionUID	 */	private static final long serialVersionUID = -1228147931360116788L;	private ImageIcon thumbnail = null;	private WorkerThread thread = null;	private Object lock = new Object();	private File thumbFile = null;	private FileTable table = null;	private ListSelectionModel rowSM = null;	/**	 * Creates ImagePreview	 * 	 * @param fileChooser	 *            The JFileChooser	 */	public ImagePreview(JFileChooser fileChooser) {		setPreferredSize(new Dimension(100, 50));		fileChooser.addPropertyChangeListener(this);		thread = new WorkerThread();		thread.setPriority(Thread.MIN_PRIORITY);		thread.start();	}	public ImagePreview(FileTable table) {		this.table = table;		rowSM = table.getSelectionModel();		rowSM.addListSelectionListener(this);		thread = new WorkerThread();		thread.setPriority(Thread.MIN_PRIORITY);		thread.start();	}	/**	 * Will be invoked when the property is changed of the filechooser.	 * 	 * @param e  PropertyChangeEvent	 */	public void propertyChange(PropertyChangeEvent e) {		String prop = e.getPropertyName();		// If the directory changed, don't show an image.		if (JFileChooser.DIRECTORY_CHANGED_PROPERTY.equals(prop)) {			synchronized (lock) {				thumbFile = null;				lock.notifyAll();			}			// If a file became selected, find out which one.		} else if (JFileChooser.SELECTED_FILE_CHANGED_PROPERTY.equals(prop)) {			File file = (File) e.getNewValue();			if (file != null) {				synchronized (lock) {					thumbFile = file;					lock.notifyAll();				}			}		}	}	/**	 * Will be invoked when the value of ListSelectionEvent is changed.	 * 	 * @param e ListSelectionEvent	 */	public void valueChanged(ListSelectionEvent e) {		ListSelectionModel lsm = (ListSelectionModel) e.getSource();		if (lsm.isSelectionEmpty()) {			synchronized (lock) {								thumbFile = null;				lock.notifyAll();			}					} else {			int selectedRow = lsm.getMinSelectionIndex();			int selectedMaxRow = lsm.getMaxSelectionIndex();			if (selectedRow == selectedMaxRow) {				FormFileField[] fileFields = table.getFormFileFields();				File file = fileFields[selectedRow].getFile();				if (file != null) {					synchronized (lock) {						thumbFile = file;						lock.notifyAll();					}				} else {					synchronized (lock) {						thumbFile = null;						lock.notifyAll();											}				}				// multiple selection -> remove icon			} else {				synchronized (lock) {					thumbFile = null;					lock.notifyAll();				}			}		}	}	/**	 * Paints the component.	 * 	 * @param g  Graphics	 */	protected void paintComponent(Graphics g) {		if (thumbnail != null) {			int x = getWidth() / 2 - thumbnail.getIconWidth() / 2;			int y = getHeight() / 2 - thumbnail.getIconHeight() / 2;			if (y < 0) {				y = 0;			}			if (x < 5) {				x = 5;			}			thumbnail.paintIcon(this, g, x, y);		}	}	/**	 * A thread for reading the images and creating the thumbnails.	 */	class WorkerThread extends Thread {		String path = null;		public void run() {			images: while (true) {				try {										synchronized (lock) {						if (thumbFile == null) {							thumbnail = null;							repaint();														lock.wait();														continue images;													} else {														// the thumbfile must be read in an not synchronized block otherwise the normal thread will hang							// therefore a copy must be made of the original thumbfile							path = thumbFile.getPath();						}											}										ImageIcon tmpIcon = new ImageIcon(path);										// check if the thumbFile has changed					synchronized (lock) {												if (thumbFile == null || !path.equals(thumbFile.getPath())) {														thumbnail = null;							repaint();														continue images;						}					}															// create thumbnail					if (tmpIcon.getIconWidth() > 90) {						thumbnail = new ImageIcon(tmpIcon.getImage().getScaledInstance(90, -1, Image.SCALE_AREA_AVERAGING));					} else { // no need to miniaturize						thumbnail = tmpIcon;					}										synchronized (lock) {											// check if the thumbFile has changed						if (thumbFile == null || !path.equals(thumbFile.getPath())) {													thumbnail = null;							repaint();													} 												// paint the thumbnail						else {							repaint();							lock.wait();						}						}				} catch (Exception exc) {					// do nothing				}			}		}	}}