source: src/main/java/weka/gui/visualize/PrintableComponent.java @ 18

 /*
  *    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.
  */

 /*
  *    PrintableComponent.java
  *    Copyright (C) 2005 University of Waikato, Hamilton, New Zealand
  *
  */

package weka.gui.visualize;

import weka.gui.ExtensionFileFilter;
import weka.gui.GenericObjectEditor;

import java.awt.Dimension;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.util.Collections;
import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Properties;
import java.util.Vector;

import javax.swing.JCheckBox;
import javax.swing.JComponent;
import javax.swing.JFileChooser;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;

/** 
 * This class extends the component which is handed over in the constructor
 * by a print dialog.
 * The Print dialog is accessible via Alt+Shift+LeftMouseClick. <p>
 * The individual JComponentWriter-descendants can be accessed by the
 * <code>getWriter(String)</code> method, if the parameters need to be changed.
 *
 * @see #getWriters()
 * @see #getWriter(String)
 * @author FracPete (fracpete at waikato dot ac dot nz)
 * @version $Revision: 1.8 $
 */
public class PrintableComponent
  implements PrintableHandler {
  
  /** the parent component of this print dialog. */
  protected JComponent m_Component;
  
  /** the filechooser for saving the panel. */
  protected static JFileChooser m_FileChooserPanel;

  /** the checkbox for the custom dimensions. */
  protected static JCheckBox m_CustomDimensionsCheckBox;
  
  /** the edit field for the custom width. */
  protected static JTextField m_CustomWidthText;
  
  /** the edit field for the custom height. */
  protected static JTextField m_CustomHeightText;

  /** the checkbox for keeping the aspect ration. */
  protected static JCheckBox m_AspectRatioCheckBox;
  
  /** the title of the save dialog. */
  protected String m_SaveDialogTitle = "Save as...";
  
  /** the x scale factor. */
  protected double m_xScale = 1.0;
  
  /** the y scale factor. */
  protected double m_yScale = 1.0;

  /** the aspect ratio. */
  protected double m_AspectRatio;

  /** whether to ignore the update of the text field (in case of "keep ratio"). */
  protected boolean m_IgnoreChange;
  
  /** whether to print some debug information. */
  private static final boolean DEBUG = false;
  
  /** whether the user was already asked about the tooltip behavior. */
  protected static boolean m_ToolTipUserAsked = false;

  /** the property name for showing the tooltip. */
  protected final static String PROPERTY_SHOW = "PrintableComponentToolTipShow";

  /** the property name whether the user was already asked. */
  protected final static String PROPERTY_USERASKED = "PrintableComponentToolTipUserAsked";
  
  /** whether to display the tooltip or not. */
  protected static boolean m_ShowToolTip = true;
  static {
    try {
      m_ShowToolTip = Boolean.valueOf(
          VisualizeUtils.VISUALIZE_PROPERTIES.getProperty(
            PROPERTY_SHOW, 
            "true")).booleanValue();
      m_ToolTipUserAsked = Boolean.valueOf(
          VisualizeUtils.VISUALIZE_PROPERTIES.getProperty(
            PROPERTY_USERASKED, 
            "false")).booleanValue();
    }
    catch (Exception e) {
      // ignore exception
      m_ToolTipUserAsked = false;
      m_ShowToolTip      = true;
    }
  }
  
  /** output if we're in debug mode */
  static {
    if (DEBUG)
      System.err.println(PrintablePanel.class.getName() + ": DEBUG ON");
  }
  
  /**
   * initializes the panel.
   * 
   * @param component     the component to enhance with printing functionality
   */
  public PrintableComponent(JComponent component) {
    super();
    
    m_Component   = component;
    m_AspectRatio = Double.NaN;
    
    getComponent().addMouseListener(new PrintMouseListener(this));
    getComponent().setToolTipText(getToolTipText(this));
    initFileChooser();
  }
  
  /**
   * returns the GUI component this print dialog is part of.
   * 
   * @return            the GUI component
   */
  public JComponent getComponent() {
    return m_Component;
  }

  /**
   * Returns a tooltip only if the user wants it. If retrieved for the first,
   * a dialog pops up and asks the user whether the tooltip should always
   * appear or not. The weka/gui/visualize/Visualize.props is then written
   * in the user's home directory.
   *
   * @param component the PrintableComponent to ask for
   * @return null if the user doesn't want the tooltip, otherwise the text
   */
  public static String getToolTipText(PrintableComponent component) {
    String        result;
    int           retVal;
    Properties    props;
    String        name;
    Enumeration   names;
    String        filename;

    // ToolTip is disabled for the moment...
    if (true)
      return null;

    // ask user whether the tooltip should be shown
    if (!m_ToolTipUserAsked) {
      m_ToolTipUserAsked = true;
      
      retVal = JOptionPane.showConfirmDialog(
          component.getComponent(),
            "Some panels enable the user to save the content as JPEG or EPS.\n"
          + "In order to see which panels support this, a tooltip can be "
          + "displayed. Enable tooltip?",
          "ToolTip for Panels...",
          JOptionPane.YES_NO_OPTION);

      m_ShowToolTip = (retVal == JOptionPane.YES_OPTION);

      // save props file
      VisualizeUtils.VISUALIZE_PROPERTIES.setProperty(
               PROPERTY_SHOW, "" + m_ShowToolTip);
      VisualizeUtils.VISUALIZE_PROPERTIES.setProperty(
               PROPERTY_USERASKED, "" + m_ToolTipUserAsked);
      try {
        // NOTE: properties that got inherited from another props file don't
        //       get saved. I.e., one could overwrite the existing props
        //       file with an (nearly) empty one.
        //       => transfer all properties into a new one
        props = new Properties();
        names = VisualizeUtils.VISUALIZE_PROPERTIES.propertyNames();
        while (names.hasMoreElements()) {
          name = names.nextElement().toString();
          props.setProperty(
              name,  
              VisualizeUtils.VISUALIZE_PROPERTIES.getProperty(name, ""));
        }
        filename = System.getProperty("user.home") + "/Visualize.props";
        props.store(
            new BufferedOutputStream(new FileOutputStream(filename)), null);

        // inform user about location of props file and name of property
        JOptionPane.showMessageDialog(
            component.getComponent(), 
            "You can still manually enable or disable the ToolTip via the following property\n"
            + "    " + PROPERTY_SHOW + "\n"
            + "in the following file\n"
            + "    " + filename);
      }
      catch (Exception e) {
        JOptionPane.showMessageDialog(
            component.getComponent(), 
              "Error saving the props file!\n"
            + e.getMessage() + "\n\n"
            + "Note:\n"
            + "If you want to disable these messages from popping up, place a file\n"
            + "called 'Visualize.props' either in your home directory or in the directory\n"
            + "you're starting Weka from and add the following lines:\n"
            + "    " + PROPERTY_USERASKED + "=true\n"
            + "    " + PROPERTY_SHOW + "=" + m_ShowToolTip,
            "Error...",
            JOptionPane.ERROR_MESSAGE);
      }
    }
    
    if (m_ShowToolTip)
      result = "Click left mouse button while holding <alt> and <shift> to display a save dialog.";
    else
      result = null;

    return result;
  }
  
  /**
   * initializes the filechooser, i.e. locates all the available writers in
   * the current package
   */
  protected void initFileChooser() {
    Vector              writerNames;
    int                 i;
    Class               cls;
    JComponentWriter    writer;
    JPanel              accessory;
    JLabel              label;

    // already initialized?
    if (m_FileChooserPanel != null)
      return;

    m_FileChooserPanel = new JFileChooser();
    m_FileChooserPanel.resetChoosableFileFilters();
    m_FileChooserPanel.setAcceptAllFileFilterUsed(false);

    // setup the accessory
    accessory = new JPanel();
    accessory.setLayout(null);
    accessory.setPreferredSize(new Dimension(200, 200));
    accessory.revalidate();
    m_FileChooserPanel.setAccessory(accessory);
 
    m_CustomDimensionsCheckBox = new JCheckBox("Use custom dimensions");
    m_CustomDimensionsCheckBox.setBounds(14, 7, 200, 21);
    m_CustomDimensionsCheckBox.addItemListener(new ItemListener() {
      public void itemStateChanged(ItemEvent e) {
        boolean custom = m_CustomDimensionsCheckBox.isSelected();
        m_CustomWidthText.setEnabled(custom);
        m_CustomHeightText.setEnabled(custom);
        m_AspectRatioCheckBox.setEnabled(custom);
        if (custom) {
          m_IgnoreChange = true;
          m_CustomWidthText.setText("" + m_Component.getWidth());
          m_CustomHeightText.setText("" + m_Component.getHeight());
          m_IgnoreChange = false;
        }
        else {
          m_IgnoreChange = true;
          m_CustomWidthText.setText("-1");
          m_CustomHeightText.setText("-1");
          m_IgnoreChange = false;
        }
      }
    });
    accessory.add(m_CustomDimensionsCheckBox);
    
    m_CustomWidthText = new JTextField(5);
    m_CustomWidthText.setText("-1");
    m_CustomWidthText.setEnabled(false);
    m_CustomWidthText.setBounds(65, 35, 50, 21);
    m_CustomWidthText.getDocument().addDocumentListener(new DocumentListener() {
      public void changedUpdate(DocumentEvent e) {
        updateDimensions(m_CustomWidthText);
      }
      
      public void insertUpdate(DocumentEvent e) {
        updateDimensions(m_CustomWidthText);
      }
      
      public void removeUpdate(DocumentEvent e) {
        updateDimensions(m_CustomWidthText);
      }
    });
    label = new JLabel("Width");
    label.setLabelFor(m_CustomWidthText);
    label.setDisplayedMnemonic('W');
    label.setBounds(14, 35, 50, 21);
    accessory.add(label);
    accessory.add(m_CustomWidthText);
    
    m_CustomHeightText = new JTextField(5);
    m_CustomHeightText.setText("-1");
    m_CustomHeightText.setEnabled(false);
    m_CustomHeightText.setBounds(65, 63, 50, 21);
    m_CustomHeightText.getDocument().addDocumentListener(new DocumentListener() {
      public void changedUpdate(DocumentEvent e) {
        updateDimensions(m_CustomHeightText);
      }
      
      public void insertUpdate(DocumentEvent e) {
        updateDimensions(m_CustomHeightText);
      }
      
      public void removeUpdate(DocumentEvent e) {
        updateDimensions(m_CustomHeightText);
      }
    });
    label = new JLabel("Height");
    label.setLabelFor(m_CustomHeightText);
    label.setDisplayedMnemonic('H');
    label.setBounds(14, 63, 50, 21);
    accessory.add(label);
    accessory.add(m_CustomHeightText);
    
    m_AspectRatioCheckBox = new JCheckBox("Keep aspect ratio");
    m_AspectRatioCheckBox.setBounds(14, 91, 200, 21);
    m_AspectRatioCheckBox.setEnabled(false);
    m_AspectRatioCheckBox.setSelected(true);
    m_AspectRatioCheckBox.addItemListener(new ItemListener() {
      public void itemStateChanged(ItemEvent e) {
        boolean keep = m_AspectRatioCheckBox.isSelected();
        if (keep) {
          m_IgnoreChange = true;
          m_CustomWidthText.setText("" + m_Component.getWidth());
          m_CustomHeightText.setText("" + m_Component.getHeight());
          m_IgnoreChange = false;
        }
      }
    });
    accessory.add(m_AspectRatioCheckBox);
    
    // determine all available writers and add them to the filechooser
    writerNames = GenericObjectEditor.getClassnames(JComponentWriter.class.getName());
    Collections.sort(writerNames);
    for (i = 0; i < writerNames.size(); i++) {
      try {
        cls    = Class.forName(writerNames.get(i).toString());
        writer = (JComponentWriter) cls.newInstance();
        m_FileChooserPanel.addChoosableFileFilter(
            new JComponentWriterFileFilter(
                writer.getExtension(), 
                writer.getDescription() + " (*" + writer.getExtension() + ")", 
                writer));
      }
      catch (Exception e) {
        System.err.println(writerNames.get(i) + ": " + e);
      }
    }
    
    // set first filter as active filter
    if (m_FileChooserPanel.getChoosableFileFilters().length > 0)
      m_FileChooserPanel.setFileFilter(m_FileChooserPanel.getChoosableFileFilters()[0]);
  }
  
  /**
   * updates the dimensions if necessary (i.e., if aspect ratio is to be kept).
   * 
   * @param sender      the JTextField which send the notification to update
   */
  protected void updateDimensions(JTextField sender) {
    int         newValue;
    int         baseValue;
    
    // some sanity checks
    if (!m_AspectRatioCheckBox.isSelected() || m_IgnoreChange)
      return;
    if (!(sender instanceof JTextField) || (sender == null))
      return;
    if (sender.getText().length() == 0)
      return;
    
    // is it a valid integer, greater than 0?
    try {
      baseValue = Integer.parseInt(sender.getText());
      newValue  = 0;
      if (baseValue <= 0)
        return;

      if (Double.isNaN(m_AspectRatio)) {
        m_AspectRatio = (double) getComponent().getWidth() / 
        (double) getComponent().getHeight();
      }
    }
    catch (Exception e) {
      // we can't parse the string!
      return;
    }

    // computer and update
    m_IgnoreChange = true;
    if (sender == m_CustomWidthText) {
      newValue = (int) (((double) baseValue) * (1/m_AspectRatio));
      m_CustomHeightText.setText("" + newValue);
    }
    else if (sender == m_CustomHeightText) {
      newValue = (int) (((double) baseValue) * m_AspectRatio);
      m_CustomWidthText.setText("" + newValue);
    }
    m_IgnoreChange = false;
  }
  
  /**
   * returns a Hashtable with the current available JComponentWriters in the 
   * save dialog. the key of the Hashtable is the description of the writer.
   * 
   * @return all currently available JComponentWriters 
   * @see JComponentWriter#getDescription()
   */
  public Hashtable getWriters() {
    Hashtable         result;
    int               i;
    JComponentWriter  writer;
    
    result = new Hashtable();
    
    for (i = 0; i < m_FileChooserPanel.getChoosableFileFilters().length; i++) {
      writer = ((JComponentWriterFileFilter) m_FileChooserPanel.getChoosableFileFilters()[i]).getWriter();
      result.put(writer.getDescription(), writer);
    }
    
    return result;
  }
  
  /**
   * returns the JComponentWriter associated with the given name, is 
   * <code>null</code> if not found.
   * 
   * @param name the name of the writer
   * @return the writer associated with the given name
   * @see JComponentWriter#getDescription()
   */
  public JComponentWriter getWriter(String name) {
    return (JComponentWriter) getWriters().get(name);
  }

  /**
   * sets the title for the save dialog.
   * 
   * @param title the title of the save dialog
   */
  public void setSaveDialogTitle(String title) {
    m_SaveDialogTitle = title;
  }
  
  /**
   * returns the title for the save dialog.
   * 
   * @return the title of the save dialog
   */
  public String getSaveDialogTitle() {
    return m_SaveDialogTitle;
  }
  
  /**
   * sets the scale factor.
   * 
   * @param x the scale factor for the x-axis 
   * @param y the scale factor for the y-axis 
   */
  public void setScale(double x, double y) {
    m_xScale = x;
    m_yScale = y;
    if (DEBUG)
      System.err.println("x = " + x + ", y = " + y);
  }
  
  /**
   * returns the scale factor for the x-axis.
   * 
   * @return the scale factor
   */
  public double getXScale() {
    return m_xScale;
  }
  
  /**
   * returns the scale factor for the y-axis.
   * 
   * @return the scale factor
   */
  public double getYScale() {
    return m_xScale;
  }
  
  /**
   * displays a save dialog for saving the panel to a file.  
   * Fixes a bug with the Swing JFileChooser: if you entered a new
   * filename in the save dialog and press Enter the <code>getSelectedFile</code>
   * method returns <code>null</code> instead of the filename.<br>
   * To solve this annoying behavior we call the save dialog once again s.t. the
   * filename is set. Might look a little bit strange to the user, but no 
   * NullPointerException! ;-)
   */
  public void saveComponent() {
    int                           result;
    JComponentWriter              writer;
    File                          file;
    JComponentWriterFileFilter    filter;
    
    // display save dialog
    m_FileChooserPanel.setDialogTitle(getSaveDialogTitle());
    do {
      result = m_FileChooserPanel.showSaveDialog(getComponent());
      if (result != JFileChooser.APPROVE_OPTION)
        return;
    }
    while (m_FileChooserPanel.getSelectedFile() == null);
    
    // save the file
    try {
      filter = (JComponentWriterFileFilter) m_FileChooserPanel.getFileFilter();
      file   = m_FileChooserPanel.getSelectedFile();
      writer = filter.getWriter();
      if (!file.getAbsolutePath().toLowerCase().endsWith(writer.getExtension().toLowerCase()))
        file = new File(file.getAbsolutePath() + writer.getExtension()); 
      writer.setComponent(getComponent());
      writer.setFile(file);
      writer.setScale(getXScale(), getYScale());
      writer.setUseCustomDimensions(m_CustomDimensionsCheckBox.isSelected());
      if (m_CustomDimensionsCheckBox.isSelected()) {
        writer.setCustomWidth(Integer.parseInt(m_CustomWidthText.getText()));
        writer.setCustomHeight(Integer.parseInt(m_CustomHeightText.getText()));
      }
      else {
        writer.setCustomWidth(-1);
        writer.setCustomHeight(-1);
      }
      writer.toOutput();
    }
    catch (Exception e) {
      e.printStackTrace();
    }
  }
  
  /**
   * a specialized filter that also contains the associated filter class.
   */
  protected class JComponentWriterFileFilter extends ExtensionFileFilter {
    /** the associated writer. */
    private JComponentWriter m_Writer; 
    
    /**
     * Creates the ExtensionFileFilter.
     *
     * @param extension       the extension of accepted files.
     * @param description     a text description of accepted files.
     * @param writer          the associated writer 
     */
    public JComponentWriterFileFilter(String extension, String description, JComponentWriter writer) {
      super(extension, description);
      m_Writer = writer;
    }
    
    /**
     * returns the associated writer.
     * 
     * @return          the writer
     */
    public JComponentWriter getWriter() {
      return m_Writer;
    }
  }

  /**
   * The listener to wait for Ctrl-Shft-Left Mouse Click.
   */
  private class PrintMouseListener extends MouseAdapter {
    /** the listener's component. */
    private PrintableComponent m_Component;
    
    /**
     * initializes the listener.
     * 
     * @param component the component for which to create the listener
     */
    public PrintMouseListener(PrintableComponent component){
      m_Component = component;
    }
    
    /**
     * Invoked when the mouse has been clicked on a component.
     * 
     * @param e the event
     */
    public void mouseClicked(MouseEvent e) {
      int modifiers = e.getModifiers();
      if (((modifiers & MouseEvent.SHIFT_MASK) == MouseEvent.SHIFT_MASK) && 
          ((modifiers & MouseEvent.ALT_MASK) == MouseEvent.ALT_MASK) &&
          ((modifiers & MouseEvent.BUTTON1_MASK) == MouseEvent.BUTTON1_MASK)) {
        e.consume();
        m_Component.saveComponent();
      }
    }
  }
}