Subversion Repositories openrisc

/* NavigationFilterDemo.java -- An example for the NavigationFilter class.

   Copyright (C) 2006  Free Software Foundation, Inc.

This file is part of GNU Classpath examples.

GNU Classpath 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, or (at your option)

any later version.

GNU Classpath 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 GNU Classpath; see the file COPYING.  If not, write to the

Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

02110-1301 USA.

*/

package gnu.classpath.examples.swing;

import java.awt.BorderLayout;

import java.awt.Point;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.JButton;

import javax.swing.JComponent;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JTextArea;

import javax.swing.SwingConstants;

import javax.swing.SwingUtilities;

import javax.swing.text.BadLocationException;

import javax.swing.text.JTextComponent;

import javax.swing.text.NavigationFilter;

import javax.swing.text.Position;

import javax.swing.text.Utilities;

/**

 * A demonstration of the <code>javax.swing.text.NavigationFilter</code> class.

 *

 * <p>It shows a NavigationFilter which lets you walk word-wise

 * through a text.</p>

 *

 * @author Robert Schuster

 */

public class NavigationFilterDemo

  extends JPanel

  implements ActionListener

{

  JTextArea textArea;

  /**

   * Creates a new demo instance.

   */

  public NavigationFilterDemo()

  {

    createContent();

    // initFrameContent() is only called (from main) when running this app

    // standalone

  }

  /**

   * When the demo is run independently, the frame is displayed, so we should

   * initialise the content panel (including the demo content and a close

   * button).  But when the demo is run as part of the Swing activity board,

   * only the demo content panel is used, the frame itself is never displayed,

   * so we can avoid this step.

   */

  void initFrameContent()

  {

    JPanel closePanel = new JPanel();

    JButton closeButton = new JButton("Close");

    closeButton.setActionCommand("CLOSE");

    closeButton.addActionListener(this);

    closePanel.add(closeButton);

    add(closePanel, BorderLayout.SOUTH);

  }

  private void createContent()

  {

    setLayout(new BorderLayout());

    add(textArea = new JTextArea(10, 20));

    textArea.setWrapStyleWord(true);

    textArea.setLineWrap(true);

    textArea.setNavigationFilter(new WordFilter());

    textArea.setText("GNU Classpath, Essential Libraries for Java, " +

                     "is a GNU project to create free core class " +

                     "libraries for use with virtual machines and " +

                     "compilers for the java programming language.");

  }

  public void actionPerformed(ActionEvent e)

  {

    if (e.getActionCommand().equals("CLOSE"))

      System.exit(0);

  }

  public static void main(String[] args)

  {

    SwingUtilities.invokeLater

    (new Runnable()

     {

       public void run()

       {

         NavigationFilterDemo app = new NavigationFilterDemo();

         app.initFrameContent();

         JFrame frame = new JFrame("NavigationFilterDemo");

         frame.getContentPane().add(app);

         frame.pack();

         frame.setVisible(true);

         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

       }

     });

  }

  /**

   * Returns a DemoFactory that creates a NavigationFilterDemo.

   *

   * @return a DemoFactory that creates a NavigationFilterDemo

   */

  public static DemoFactory createDemoFactory()

  {

    return new DemoFactory()

    {

      public JComponent createDemo()

      {

        return new NavigationFilterDemo();

      }

    };

  }

  class WordFilter extends NavigationFilter

  {

    public int getNextVisualPositionFrom(JTextComponent text,

                                         int pos,

                                         Position.Bias bias,

                                         int direction,

                                         Position.Bias[] biasRet)

                                  throws BadLocationException

    {

      Point pt;

      int newpos = pos;

      switch (direction)

      {

        case SwingConstants.NORTH:

          // Find out where the caret want to be positioned ideally.

          pt = text.getCaret().getMagicCaretPosition();

          // Calculate its position above.

          newpos = Utilities.getPositionAbove(text, pos, (pt != null) ? pt.x : 0);

          // If we have a valid position, then calculate the next word start

          // from there.

          if (newpos != -1)

            return Utilities.getWordStart(text, newpos);

          else

            return pos;

        case SwingConstants.SOUTH:

          // Find out where the caret want to be positioned ideally.

          pt = text.getCaret().getMagicCaretPosition();

          // Calculate its position below.

          newpos = Utilities.getPositionBelow(text, pos, (pt != null) ? pt.x : 0);

          // If we have a valid position, then calculate the next word start

          // from there.

          if (newpos != -1)

            return Utilities.getWordStart(text, newpos);

          else

            return pos;

        case SwingConstants.WEST:

          // Calculate the next word start.

          newpos = Utilities.getWordStart(text, newpos);

          // If that means that the caret will not move, return

          // the start of the previous word.

          if (newpos != pos)

            return newpos;

          else

            return Utilities.getPreviousWord(text, newpos);

        case SwingConstants.EAST:

          return Utilities.getNextWord(text, newpos);

        default:

          // Do whatever the super implementation did.

          return super.getNextVisualPositionFrom(text, pos, bias,

                                                 direction, biasRet);

      }

    }

  }

}