/* JTextArea.java --    Copyright (C) 2004, 2005  Free Software Foundation, Inc.This file is part of GNU Classpath.GNU Classpath is free software; you can redistribute it and/or modifyit under the terms of the GNU General Public License as published bythe 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, butWITHOUT ANY WARRANTY; without even the implied warranty ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNUGeneral Public License for more details.You should have received a copy of the GNU General Public Licensealong with GNU Classpath; see the file COPYING.  If not, write to theFree Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA02110-1301 USA.Linking this library statically or dynamically with other modules ismaking a combined work based on this library.  Thus, the terms andconditions of the GNU General Public License cover the wholecombination.As a special exception, the copyright holders of this library give youpermission to link this library with independent modules to produce anexecutable, regardless of the license terms of these independentmodules, and to copy and distribute the resulting executable underterms of your choice, provided that you also meet, for each linkedindependent module, the terms and conditions of the license of thatmodule.  An independent module is a module which is not derived fromor based on this library.  If you modify this library, you may extendthis exception to your version of the library, but you are notobligated to do so.  If you do not wish to do so, delete thisexception statement from your version. */package javax.swing;import java.awt.Dimension;import java.awt.FontMetrics;import java.awt.Rectangle;import javax.accessibility.AccessibleContext;import javax.accessibility.AccessibleStateSet;import javax.swing.text.BadLocationException;import javax.swing.text.Document;import javax.swing.text.Element;import javax.swing.text.JTextComponent;import javax.swing.text.PlainDocument;import javax.swing.text.View;/** * The <code>JTextArea</code> component provides a multi-line area for displaying * and editing plain text.  The component is designed to act as a lightweight * replacement for the heavyweight <code>java.awt.TextArea</code> component, * which provides similar functionality using native widgets. * <p> * * This component has additional functionality to the AWT class.  It follows * the same design pattern as seen in other text components, such as * <code>JTextField</code>, <code>JTextPane</code> and <code>JEditorPane</code>, * and embodied in <code>JTextComponent</code>.  These classes separate the text * (the model) from its appearance within the onscreen component (the view).  The * text is held within a <code>javax.swing.text.Document</code> object, which can * also maintain relevant style information where necessary.  As a result, it is the * document that should be monitored for textual changes, via * <code>DocumentEvent</code>s delivered to registered * <code>DocumentListener</code>s, rather than this component. * <p> * * Unlike <code>java.awt.TextArea</code>, <code>JTextArea</code> does not * handle scrolling.  Instead, this functionality is delegated to a * <code>JScrollPane</code>, which can contain the text area and handle * scrolling when required.  Likewise, the word wrapping functionality * of the AWT component is converted to a property of this component * and the <code>rows</code> and <code>columns</code> properties * are used in calculating the preferred size of the scroll pane's * view port. * * @author Michael Koch  (konqueror@gmx.de) * @author Andrew John Hughes  (gnu_andrew@member.fsf.org) * @see java.awt.TextArea * @see javax.swing.text.JTextComponent * @see javax.swing.JTextField * @see javax.swing.JTextPane * @see javax.swing.JEditorPane * @see javax.swing.text.Document * @see javax.swing.event.DocumentEvent * @see javax.swing.event.DocumentListener */public class JTextArea extends JTextComponent{  /**   * Provides accessibility support for <code>JTextArea</code>.   *   * @author Roman Kennke (kennke@aicas.com)   */  protected class AccessibleJTextArea extends AccessibleJTextComponent  {    /**     * Creates a new <code>AccessibleJTextArea</code> object.     */    protected AccessibleJTextArea()    {      super();    }    /**     * Returns the accessible state of this <code>AccessibleJTextArea</code>.     *     * @return  the accessible state of this <code>AccessibleJTextArea</code>     */    public AccessibleStateSet getAccessibleStateSet()    {      AccessibleStateSet state = super.getAccessibleStateSet();      // TODO: Figure out what state must be added here to the super's state.      return state;    }  }  /**   * Compatible with Sun's JDK   */  private static final long serialVersionUID = -6141680179310439825L;    /**   * The number of rows used by the component.   */  private int rows;  /**   * The number of columns used by the component.   */  private int columns;  /**   * Whether line wrapping is enabled or not.   */  private boolean lineWrap;  /**   * The number of characters equal to a tab within the text.   */  private int tabSize = 8;  private boolean wrapStyleWord;  /**   * Creates a new <code>JTextArea</code> object.   */  public JTextArea()  {    this(null, null, 0, 0);  }  /**   * Creates a new <code>JTextArea</code> object.   *   * @param text the initial text   */  public JTextArea(String text)  {    this(null, text, 0, 0);  }  /**   * Creates a new <code>JTextArea</code> object.   *   * @param rows the number of rows   * @param columns the number of cols   *   * @exception IllegalArgumentException if rows or columns are negative   */  public JTextArea(int rows, int columns)  {    this(null, null, rows, columns);  }  /**   * Creates a new <code>JTextArea</code> object.   *   * @param text the initial text   * @param rows the number of rows   * @param columns the number of cols   *   * @exception IllegalArgumentException if rows or columns are negative   */  public JTextArea(String text, int rows, int columns)  {    this(null, text, rows, columns);  }  /**   * Creates a new <code>JTextArea</code> object.   *   * @param doc the document model to use   */  public JTextArea(Document doc)  {    this(doc, null, 0, 0);  }  /**   * Creates a new <code>JTextArea</code> object.   *   * @param doc the document model to use   * @param text the initial text   * @param rows the number of rows   * @param columns the number of cols   *   * @exception IllegalArgumentException if rows or columns are negative   */  public JTextArea(Document doc, String text, int rows, int columns)  {    setDocument(doc == null ? createDefaultModel() : doc);    setText(text);    setRows(rows);    setColumns(columns);  }  /**   * Appends the supplied text to the current contents   * of the document model.   *   * @param toAppend the text to append   */  public void append(String toAppend)  {      try	  {	      getDocument().insertString(getText().length(), toAppend, null);	  }      catch (BadLocationException exception)	  {	      /* This shouldn't happen in theory -- but, if it does...  */	      throw new RuntimeException("Unexpected exception occurred.", exception);	  }      if (toAppend != null && toAppend.length() > 0)        revalidate();  }  /**   * Creates the default document model.   *   * @return a new default model   */  protected Document createDefaultModel()  {    return new PlainDocument();  }  /**   * Returns true if the width of this component should be forced   * to match the width of a surrounding view port.  When line wrapping   * is turned on, this method returns true.   *   * @return true if lines are wrapped.   */  public boolean getScrollableTracksViewportWidth()  {    return lineWrap ? true : super.getScrollableTracksViewportWidth();  }  /**   * Returns the increment that is needed to expose exactly one new line   * of text. This is implemented here to return the values of   * {@link #getRowHeight} and {@link #getColumnWidth}, depending on   * the value of the argument <code>direction</code>.   *   * @param visibleRect the view area that is visible in the viewport   * @param orientation either {@link SwingConstants#VERTICAL} or   *     {@link SwingConstants#HORIZONTAL}   * @param direction less than zero for up/left scrolling, greater   *     than zero for down/right scrolling   *   * @return the increment that is needed to expose exactly one new row   *     or column of text   *   * @throws IllegalArgumentException if <code>orientation</code> is invalid   */  public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation,                                        int direction)  {    if (orientation == SwingConstants.VERTICAL)      return getRowHeight();    else if (orientation == SwingConstants.HORIZONTAL)      return getColumnWidth();    else      throw new IllegalArgumentException("orientation must be either "                                     + "javax.swing.SwingConstants.VERTICAL "                                     + "or "                                     + "javax.swing.SwingConstants.HORIZONTAL"                                     );  }  /**   * Returns the preferred size of that text component in the case   * it is embedded within a JScrollPane. This uses the column and