/*
 * SimplyHTML, a word processor based on Java, HTML and CSS
 * Copyright (C) 2002 Ulrich Hilger
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

package com.lightdev.app.shtm;

import java.awt.Frame;
import java.awt.Dialog;
import java.awt.Container;
import java.awt.Dimension;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.JButton;
import javax.swing.JTextField;
import java.awt.BorderLayout;
import java.awt.GridBagLayout;
import java.awt.GridBagConstraints;
import javax.swing.border.TitledBorder;
import javax.swing.border.EtchedBorder;
import javax.swing.text.html.HTML;
import javax.swing.text.html.HTMLDocument;
import javax.swing.SwingConstants;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFileChooser;










import com.sun.demo.ExampleFileFilter;
import java.io.File;
import javax.swing.event.ListSelectionListener;
import javax.swing.event.ListSelectionEvent;
import javax.swing.ImageIcon;
import javax.swing.text.SimpleAttributeSet;
import javax.swing.JScrollPane;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import javax.swing.event.ChangeListener;
import javax.swing.event.ChangeEvent;
import java.util.Vector;
import java.io.StringWriter;
import javax.swing.text.AttributeSet;
import javax.swing.JOptionPane;

/**
 * A dialog providing an image repository and a way to edit display options
 * for images from the repository.
 *
 * @author Ulrich Hilger
 * @author Light Development
 * @author <a href="http://www.lightdev.com">http://www.lightdev.com</a>
 * @author <a href="mailto:info@lightdev.com">info@lightdev.com</a>
 * @author published under the terms and conditions of the
 *      GNU General Public License,
 *      for details see file gpl.txt in the distribution
 *      package of this software
 *
 *
 */

class ImageDialog extends DialogShell
    implements ActionListener, ListSelectionListener, ChangeListener
{
  /** directory this ImageDialog maintains */
  private File imgDir;

  /** KeyListener for watching changes in the scale text field */
  private KeyHandler keyHandler = new KeyHandler();

  /** FocusListener for watching changes in the scale text field */
  private FocusHandler focusHandler = new FocusHandler();

  private SimpleAttributeSet originalAttributes = new SimpleAttributeSet();

  /**
   * indicates whether or not changes in a SizeSelectorPanel are
   * to be processed. Usually, changes caused by a method of this
   * class are to be ignored
   */
  private boolean ignoreChangeEvents = false;

  /** list with images in this image repository */
  private JList imgFileList;

  /** button to add an image file to the repository */
  private JButton addImgBtn;

  /** button to delete an image file from the repository */
  private JButton delImgBtn;

  /** text field for manipulating the scale of an image */
  private JTextField scale;

  /** component to manipulate the image width */
  private SizeSelectorPanel imgWidth;

  /** component to manipulate the image height */
  private SizeSelectorPanel imgHeight;

  /** component to display the original width of an image */
  private JLabel oWidth;

  /** component to display the original height of an image */
  private JLabel oHeight;

  /** component to preview an image */
  private ImagePreview preview;

  /** component to scroll an image inside the preview */
  private JScrollPane scPrev;

  /**
   * contains all components having attributes for the image represented
   * in this <code>ImageDialog</code>
   */
  private Vector attributeComponents = new Vector();

  /** the help id for this dialog */
  private static final String helpTopicId = "item166";

  /** the document the image came from, if any */
  private SHTMLDocument doc;

  /**
   * construct a new ImageDialog
   *
   * @param parent  the parent frame of this ImageDialog
   * @param title  the title of this ImageDialog
   * @param imgDir  the directory of the image repository
   */
  public ImageDialog(Dialog parent, String title, File imgDir) {
    super(parent, title, helpTopicId);
    initDialog(title, imgDir);
  }

  /**
   * construct a new ImageDialog
   *
   * @param parent  the parent frame of this ImageDialog
   * @param title  the title of this ImageDialog
   * @param imgDir  the directory of the image repository
   */
  public ImageDialog(Frame parent, String title, File imgDir) {
    super(parent, title, helpTopicId);
    initDialog(title, imgDir);
  }

  public ImageDialog(Frame parent, String title, File imgDir, SHTMLDocument sourceDoc) {
    super(parent, title, helpTopicId);
    this.doc = sourceDoc;
    initDialog(title, imgDir);
  }

  /**
   * build the dialog contents after construction
   *
   * @param title  the title of this ImageDialog
   * @param imgDir  the directory of the image repository
   */
  private void initDialog(String title, File imgDir) {

    //System.out.println("ImageDialog.initDialog imgDir=" + imgDir.getAbsolutePath());

    this.imgDir = imgDir;

    Dimension dim;

    // create an image directory panel
    JPanel dirPanel = new JPanel(new BorderLayout());
    dirPanel.setBorder(new TitledBorder(new EtchedBorder(
                  EtchedBorder.LOWERED),
                  Util.getResourceString(
                  "imgDirPanelTitle")));

    // create a list to disply image files in
    imgFileList = new JList();
    dim = new Dimension(100, 100);
    imgFileList.setMinimumSize(dim);
    imgFileList.setPreferredSize(dim);
    imgFileList.addListSelectionListener(this);
    updateFileList();

    // create a panel with action buttons for image files
    JPanel dirBtnPanel = new JPanel();

    // create image directory action buttons
    addImgBtn = new JButton(Util.getResourceString(
                  "addImgBtnTitle"));
    addImgBtn.addActionListener(this);
    delImgBtn = new JButton(Util.getResourceString(
                  "delImgBtnTitle"));
    delImgBtn.addActionListener(this);

    // add action buttons to button panel
    dirBtnPanel.add(addImgBtn);
    dirBtnPanel.add(delImgBtn);

    // add components to image directory panel
    dirPanel.add(imgFileList, BorderLayout.CENTER);
    dirPanel.add(dirBtnPanel, BorderLayout.SOUTH);

    // create an image preview panel
    JPanel previewPanel = new JPanel(new BorderLayout());
    previewPanel.setBorder(new TitledBorder(new EtchedBorder(
                  EtchedBorder.LOWERED),
                  Util.getResourceString(
                  "imgPreviewPanelTitle")));

    // add a new ImagePreview object to the preview panel
    preview = new ImagePreview();
    dim = new Dimension(250, 250);
    preview.setMinimumSize(dim);
    preview.setPreferredSize(dim);
    scPrev = new JScrollPane(preview);
    previewPanel.add(scPrev, BorderLayout.CENTER);

    // layout and constraints to use later on
    GridBagLayout g = new GridBagLayout();
    GridBagConstraints c = new GridBagConstraints();

    // create an image properties panel
    JPanel eastPanel = new JPanel(new BorderLayout());
    JPanel propertiesPanel = new JPanel(g);
    eastPanel.add(propertiesPanel, BorderLayout.NORTH);
    eastPanel.setBorder(new TitledBorder(new EtchedBorder(
                  EtchedBorder.LOWERED),
                  Util.getResourceString(
                  "imgPropertiesPanelTitle")));

    // add scale component
    Util.addGridBagComponent(propertiesPanel,
                             new JLabel(
                             Util.getResourceString(
                             "imgScaleLabel")),
                             g, c, 0, 0,
                             GridBagConstraints.EAST);
    scale = new JTextField();
    scale.addKeyListener(keyHandler);
    scale.addFocusListener(focusHandler);
    dim = new Dimension(50, 20);
    scale.setMinimumSize(dim);
    scale.setPreferredSize(dim);
    JPanel helperPanel = new JPanel();
    helperPanel.add(scale);
    helperPanel.add(new JLabel(SizeSelectorPanel.UNIT_PERCENT, SwingConstants.LEFT));
    Util.addGridBagComponent(propertiesPanel, helperPanel, g, c, 1, 0,
                             GridBagConstraints.WEST);

    // add width component
    Util.addGridBagComponent(propertiesPanel,
                             new JLabel(
                             Util.getResourceString(
                             "imgWidthLabel")),
                             g, c, 0, 1,
                             GridBagConstraints.EAST);
    imgWidth = new SizeSelectorPanel(HTML.Attribute.WIDTH, null, false, SizeSelectorPanel.TYPE_LABEL);
    attributeComponents.addElement(imgWidth);
    imgWidth.getValueSelector().addChangeListener(this);
    Util.addGridBagComponent(propertiesPanel, imgWidth, g, c, 1, 1,
                             GridBagConstraints.WEST);

    // add height component
    Util.addGridBagComponent(propertiesPanel,
                             new JLabel(
                             Util.getResourceString(
                             "imgHeightLabel")),
                             g, c, 0, 2,
                             GridBagConstraints.EAST);
    imgHeight = new SizeSelectorPanel(HTML.Attribute.HEIGHT, null, false, SizeSelectorPanel.TYPE_LABEL);
    attributeComponents.addElement(imgHeight);
    imgHeight.getValueSelector().addChangeListener(this);
    Util.addGridBagComponent(propertiesPanel, imgHeight, g, c, 1, 2,
                             GridBagConstraints.WEST);

    // add hspace component
    Util.addGridBagComponent(propertiesPanel,
                             new JLabel(
                             Util.getResourceString(
                             "imgHSpaceLabel")),
                             g, c, 0, 3,
                             GridBagConstraints.EAST);
    SizeSelectorPanel hSpace = new SizeSelectorPanel(
        HTML.Attribute.HSPACE, null, false, SizeSelectorPanel.TYPE_LABEL);
    attributeComponents.addElement(hSpace);
    Util.addGridBagComponent(propertiesPanel, hSpace, g, c, 1, 3,
                             GridBagConstraints.WEST);

    // add vspace component
    Util.addGridBagComponent(propertiesPanel,
                             new JLabel(
                             Util.getResourceString(
                             "imgVSpaceLabel")),
                             g, c, 0, 4,
                             GridBagConstraints.EAST);
    SizeSelectorPanel vSpace = new SizeSelectorPanel(
        HTML.Attribute.VSPACE, null, false, SizeSelectorPanel.TYPE_LABEL);
    attributeComponents.addElement(vSpace);
    Util.addGridBagComponent(propertiesPanel, vSpace, g, c, 1, 4,
                             GridBagConstraints.WEST);

    // add alignment component
    Util.addGridBagComponent(propertiesPanel, new JLabel(
                             Util.getResourceString(
                             "imgAlignLabel")),
                             g, c, 0, 5, GridBagConstraints.EAST);
    String[] items = new String[] {
      Util.getResourceString("imgAlignTop"),
      Util.getResourceString("imgAlignMiddle"),
      Util.getResourceString("imgAlignBottom"),
      Util.getResourceString("imgAlignLeft"),
      Util.getResourceString("imgAlignCenter"),
      Util.getResourceString("imgAlignRight")};
    String[] names = new String[] {"top", "middle", "bottom", "left",
      "center", "right"};
    AttributeComboBox imgAlign = new AttributeComboBox(
        items, names, null, HTML.Attribute.ALIGN);
    attributeComponents.addElement(imgAlign);
    Util.addGridBagComponent(propertiesPanel, imgAlign, g, c, 1, 5,
                             GridBagConstraints.WEST);

    // add original width component
    Util.addGridBagComponent(propertiesPanel,
                             new JLabel(
                             Util.getResourceString(
                             "oWidthLabel")),
                             g, c, 0, 6,
                             GridBagConstraints.EAST);
    oWidth = new JLabel("");
    Util.addGridBagComponent(propertiesPanel, oWidth, g, c, 1, 6,
                             GridBagConstraints.WEST);

    // add original height component
    Util.addGridBagComponent(propertiesPanel,
                             new JLabel(
                             Util.getResourceString(
                             "oHeightLabel")),
                             g, c, 0, 7,
                             GridBagConstraints.EAST);
    oHeight = new JLabel("");
    Util.addGridBagComponent(propertiesPanel, oHeight, g, c, 1, 7,
                             GridBagConstraints.WEST);

    // add border component
    Util.addGridBagComponent(propertiesPanel,
                             new JLabel(
                             Util.getResourceString(
                             "imgBorderLabel")),
                             g, c, 0, 8,
                             GridBagConstraints.EAST);
    SizeSelectorPanel imgBorder = new SizeSelectorPanel(
        HTML.Attribute.BORDER, null, false, SizeSelectorPanel.TYPE_LABEL);
    attributeComponents.addElement(imgBorder);
    Util.addGridBagComponent(propertiesPanel, imgBorder, g, c, 1, 8,
                             GridBagConstraints.WEST);

    // add to content pane of DialogShell
    Container contentPane = super.getContentPane();
    contentPane.add(dirPanel, BorderLayout.WEST);
    contentPane.add(previewPanel, BorderLayout.CENTER);
    contentPane.add(eastPanel, BorderLayout.EAST);

    // cause optimal placement of all elements
    pack();

    scPrev.addComponentListener(new ResizeListener());
  }

  public Integer getImgWidth() {
    return imgWidth.getIntValue();
  }

  public Integer getImgHeight() {
    return imgHeight.getIntValue();
  }

  /**
   * set dialog content from a given set of image attributes
   *
   * @param a  the set of attributes to set dialog contents from
   */
  public void setImageAttributes(AttributeSet a) {
    //System.out.println("ImageDialog.setImageAttributes");
    ignoreChangeEvents = true;
    originalAttributes.addAttributes(a);
    if(a.isDefined(HTML.Attribute.SRC)) {
      File imgFile = null;
      if(doc != null) {
        imgFile = new File(Util.resolveRelativePath(a.getAttribute(HTML.Attribute.SRC).toString(), doc.getBase().getFile()));
      }
      else {
        imgFile = new File(a.getAttribute(HTML.Attribute.SRC).toString());
      }
      //System.out.println("ImageDialog.setImageAttribute imgFile=" + imgFile.getAbsolutePath());
      imgFileList.setSelectedValue(imgFile.getName().toLowerCase(), true);
    }
    for(int i = 0; i < attributeComponents.size(); i++) {
      ((AttributeComponent) attributeComponents.get(i)).setValue(a);
    }
    if(a.isDefined(HTML.Attribute.WIDTH)) {
      preview.setPreviewWidth(
          Integer.parseInt(a.getAttribute(HTML.Attribute.WIDTH).toString()));
    }
    if(a.isDefined(HTML.Attribute.HEIGHT)) {
      preview.setPreviewHeight(
          Integer.parseInt(a.getAttribute(HTML.Attribute.HEIGHT).toString()));
    }
    int scalePct = preview.getScale();
    scale.setText(Integer.toString(scalePct));
    ignoreChangeEvents = false;
  }

  public void setImage(String fName, String w, String h) {
    //System.out.println("ImageDialog.setImage fName=" + fName);
    imgFileList.setSelectedValue(new File(fName).getName(), true);
    preview.setImage(new ImageIcon(fName));
    try {
      if(w != null && w.length() > 0) {
        preview.setPreviewWidth(Integer.parseInt(w));
      }
      if(h != null && h.length() > 0) {
        preview.setPreviewHeight(Integer.parseInt(h));
      }
    }
    catch(Exception e) {
      Util.errMsg(this, null, e);
    }
  }

  /**
   * get the HTML representing the image selected in this
   * <code>ImageDialog</code>
   */
  public String getImageHTML() {
    SimpleAttributeSet set = new SimpleAttributeSet(originalAttributes);
    StringWriter sw = new StringWriter();
    SHTMLWriter w = new SHTMLWriter(sw, doc == null ? new HTMLDocument() : doc);
    for(int i = 0; i < attributeComponents.size(); i++) {
      set.addAttributes(((AttributeComponent) attributeComponents.get(i)).getValue());
    }
    set.addAttribute(HTML.Attribute.SRC, getImageSrc());
    try {
      w.writeStartTag(HTML.Tag.IMG.toString(), set);
    }
    catch(Exception e) {
      Util.errMsg(this, e.getMessage(), e);
    }
    return sw.getBuffer().toString();
  }

  /**
   * get the value for the SRC attribute of an image tag
   *
   * @return the value of the SRC attribute of an image tag
   */
  public String getImageSrc() {
    StringBuffer buf = new StringBuffer();
    Object value = imgFileList.getSelectedValue();
    if(value != null) {
      buf.append(SHTMLPanelImpl.IMAGE_DIR);
      buf.append(Util.URL_SEPARATOR);
      buf.append(value.toString());
    }
    return buf.toString();
  }

  /**
   * handle the event when the user pressed the 'Add...' button
   * to add a new image to the repository
   */
  private void handleAddImage() {
    try {
      JFileChooser chooser = new JFileChooser();
      chooser.setMultiSelectionEnabled(true);
      ExampleFileFilter filter = new ExampleFileFilter();
      filter.addExtension("gif");
      filter.addExtension("jpg");
      filter.addExtension("jpeg");
      filter.setDescription(Util.getResourceString(
          "imageFileDesc"));
      chooser.setFileFilter(filter);
      if(chooser.showOpenDialog(this) == JFileChooser.APPROVE_OPTION) {
        File[] sFiles = chooser.getSelectedFiles();
        if(!imgDir.exists()) {
          imgDir.mkdirs();
        }
        String imgDirName = imgDir.getAbsolutePath();
        for(int i = 0; i < sFiles.length; i++) {
          //System.out.println("file selected: " + sFiles[i] + " new name= " + imgDirName + File.separator + sFiles[i].getName());
          Util.copyFile(sFiles[i],
                new File(imgDirName + File.separator + sFiles[i].getName()));
          updateFileList();
        }
      }
    }
    catch(Exception e) {
      Util.errMsg(this, e.getMessage(), e);
    }
  }

  /**
   * handle the event occurring when the user pressed the 'Delete' button
   * to remove an image from the repository
   */
  private void handleDeleteImage() {
    String fName = imgFileList.getSelectedValue().toString();
    if(Util.msg(JOptionPane.YES_NO_OPTION, "confirmDelete", "deleteFileQuery", fName, "\r\n")) {
      File delFile = new File(imgDir.getAbsolutePath() + File.separator + fName);
      delFile.delete();
      updateFileList();
    }
  }

  /**
   * display all files found in the image directory
   */
  private void updateFileList() {
    if(imgDir != null && imgFileList != null) {
      String[] files = imgDir.list();
      if(files != null && files.length > 0) {
        for(int i = 0; i < files.length; i++) {
          files[i] = files[i].toLowerCase();
        }
        imgFileList.setListData(files);
      }
    }
  }

  /**
   * update all image property displays to the current setting
   */
  private void updateControls() {
    ignoreChangeEvents = true;
    int scalePct = preview.getScale();
    SimpleAttributeSet set = new SimpleAttributeSet();
    oWidth.setText(Integer.toString(preview.getOriginalWidth()));
    oHeight.setText(Integer.toString(preview.getOriginalHeight()));
    //System.out.println("updateControls origW=" + preview.getOriginalWidth());
    //System.out.println("updateControls add WIDTH attr as " + Integer.toString(
    //            preview.getOriginalWidth() * scalePct / 100) + SizeSelectorPanel.UNIT_PT);
    set.addAttribute(HTML.Attribute.WIDTH, Integer.toString(
                preview.getOriginalWidth() * scalePct / 100) + SizeSelectorPanel.UNIT_PT);
    set.addAttribute(HTML.Attribute.HEIGHT, Integer.toString(
                preview.getOriginalHeight() * scalePct / 100) + SizeSelectorPanel.UNIT_PT);
    imgWidth.setValue(set);
    imgHeight.setValue(set);
    scale.setText(Integer.toString(scalePct));
    ignoreChangeEvents = false;
  }

  /**
   * apply a scale set by the user through respective text field and
   * update all related image property displays
   */
  private void applyPreviewScale() {
    //System.out.println("applyPreviewScale scale=" + scale.getText());
    ignoreChangeEvents = true;
    try {
      preview.setScale(Integer.parseInt(scale.getText()));
      updateControls();
    }
    catch(Exception e) {}
    ignoreChangeEvents = false;
  }

  /**
   * apply a new width set by the user and update
   *  all related image property displays
   */
  private void applyPreviewWidth() {
    //System.out.println("applyPreviewWidth width=" + imgWidth.getIntValue().intValue());
    ignoreChangeEvents = true;
    preview.setPreviewWidth(imgWidth.getIntValue().intValue());
    int scalePct = preview.getScale();
    //System.out.println("applyPreviewWidth scale now " + scalePct);
    SimpleAttributeSet set = new SimpleAttributeSet();
    scale.setText(Integer.toString(scalePct));
    set.addAttribute(HTML.Attribute.HEIGHT, Integer.toString(
        preview.getOriginalHeight() * scalePct / 100) + SizeSelectorPanel.UNIT_PT);
    //System.out.println("applyPreviewWidth, changing height to " + Integer.toString(
    //    preview.getOriginalHeight() * scalePct / 100) + SizeSelectorPanel.UNIT_PT);
    imgHeight.setValue(set);
    ignoreChangeEvents = false;
  }

  /**
   * apply a new height set by the user and update
   *  all related image property displays
   */
  private void applyPreviewHeight() {
    //System.out.println("applyPreviewHeight height=" + imgHeight.getIntValue().intValue());
    ignoreChangeEvents = true;
    preview.setPreviewHeight(imgHeight.getIntValue().intValue());
    int scalePct = preview.getScale();
    //System.out.println("applyPreviewHeight scale now " + scalePct);
    SimpleAttributeSet set = new SimpleAttributeSet();
    scale.setText(Integer.toString(scalePct));
    set.addAttribute(HTML.Attribute.WIDTH, Integer.toString(
        preview.getOriginalWidth() * scalePct / 100) + SizeSelectorPanel.UNIT_PT);
    //System.out.println("applyPreviewHeight, changing width to " + Integer.toString(
    //    preview.getOriginalWidth() * scalePct / 100) + SizeSelectorPanel.UNIT_PT);
    imgWidth.setValue(set);
    ignoreChangeEvents = false;
  }

  /* ---------------- event handling start ------------------------- */

  /**
   * implements the ActionListener interface to be notified of
   * clicks onto the file repository buttons.
   */
  public void actionPerformed(ActionEvent e) {
    Object src = e.getSource();
    if(src == addImgBtn) {
      handleAddImage();
    }
    else if(src == delImgBtn) {
      handleDeleteImage();
    }
    else {
      super.actionPerformed(e);
    }
  }

  /**
   * Listener for changes in the image list.
   *
   * <p>updates the image preview and property displays according
   * to the current selection (if any)</p>
   */
  public void valueChanged(ListSelectionEvent e) {
    if(!imgFileList.isSelectionEmpty()) {
      /*System.out.println("ImageDialog.valueChanged setting preview image to " + imgDir.getAbsolutePath() +
                           File.separator +
                           imgFileList.getSelectedValue().toString());*/
      preview.setImage(new ImageIcon(imgDir.getAbsolutePath() +
                           File.separator +
                           imgFileList.getSelectedValue().toString()));
      updateControls();
    }
    else {
      preview.setImage(null);
      int vWidth = scPrev.getWidth() - 5;
      int vHeight = scPrev.getHeight() - 5;
      preview.setPreferredSize(new Dimension(vWidth, vHeight));
      preview.revalidate();
    }
  }

  /**
   * Listener for resize events.
   *
   * <p>used on the JScrollPane holding the image preview
   * to adjust the preview to size changes and to synchronize
   * property displays accordingly.</p>
   */
  private class ResizeListener extends ComponentAdapter {
    public void componentResized(ComponentEvent e) {
      int vWidth = scPrev.getWidth() - 5;
      int vHeight = scPrev.getHeight() - 5;
      preview.setPreferredSize(new Dimension(vWidth, vHeight));
      preview.revalidate();
      updateControls();
    }
  }

  /**
   * Listener for key events
   *
   * <p>Used to adjust preview properties according to
   * user settings in the scale text field</p>
   */
  private class KeyHandler extends KeyAdapter {
    public void keyReleased(KeyEvent e) {
      Object source = e.getSource();
      int keyCode = e.getKeyCode();
      if(source.equals(scale)) {
        if(keyCode == KeyEvent.VK_ENTER)
        {
          applyPreviewScale();
        }
      }
    }
  }

  /**
   * Listener for focus events
   *
   * <p>Used to adjust preview properties according to
   * user settings in the scale text field</p>
   */
  private class FocusHandler extends FocusAdapter {
    public void focusLost(FocusEvent e) {
      Object source = e.getSource();
      if(source.equals(scale)) {
        applyPreviewScale();
      }
    }
  }

  /**
   * Listener for change events
   *
   * <p>Used to adjust preview properties according to
   * user settings in SizeSelectorPanels</p>
   */
  public void stateChanged(ChangeEvent e) {
    if(!ignoreChangeEvents) {
      Object source = e.getSource();
      if(source.equals(imgWidth.getValueSelector())) {
        applyPreviewWidth();
      }
      else if(source.equals(imgHeight.getValueSelector())) {
        applyPreviewHeight();
      }
    }
  }

  /* ---------------- event handling end ------------------------- */

}