jtextarea.java

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   * row settings if they are explicitly set, or fall back to
   * the superclass's behaviour.
   *
   * @return the preferred size of that text component in the case
   *     it is embedded within a JScrollPane
   */
  public Dimension getPreferredScrollableViewportSize()
  {
    if ((rows > 0) && (columns > 0))
      return new Dimension(columns * getColumnWidth(), rows * getRowHeight());
    else
      return super.getPreferredScrollableViewportSize();
  }

  /**
   * Returns the UI class ID string.
   *
   * @return the string "TextAreaUI"
   */
  public String getUIClassID()
  {
    return "TextAreaUI";
  }

  /**
   * Returns the current number of columns.
   *
   * @return number of columns
   */
  public int getColumns()
  {
    return columns;
  }
  
  /**
   * Sets the number of rows.
   *
   * @param columns number of columns
   *
   * @exception IllegalArgumentException if columns is negative
   */
  public void setColumns(int columns)
  {
    if (columns < 0)
      throw new IllegalArgumentException();
    
    if (columns != this.columns)
      {
        this.columns = columns;
        revalidate();
      }
  }

  /**
   * Returns the current number of rows.
   *
   * @return number of rows
   */
  public int getRows()
  {
    return rows;
  }

  /**
   * Sets the number of rows.
   *
   * @param rows number of rows
   *
   * @exception IllegalArgumentException if rows is negative
   */
  public void setRows(int rows)
  {
    if (rows < 0)
      throw new IllegalArgumentException();
   
    if (rows != this.rows)
      {
        this.rows = rows;
        revalidate();
      }
  }

  /**
   * Checks whether line wrapping is enabled.
   *
   * @return <code>true</code> if line wrapping is enabled,
   * <code>false</code> otherwise
   */
  public boolean getLineWrap()
  {
    return lineWrap;
  }

  /**
   * Enables/disables line wrapping.
   *
   * @param flag <code>true</code> to enable line wrapping,
   * <code>false</code> otherwise
   */
  public void setLineWrap(boolean flag)
  {
    if (lineWrap == flag)
      return;

    boolean oldValue = lineWrap;
    lineWrap = flag;
    firePropertyChange("lineWrap", oldValue, lineWrap);
  }

  /**
   * Checks whether word style wrapping is enabled.
   *
   * @return <code>true</code> if word style wrapping is enabled,
   * <code>false</code> otherwise
   */
  public boolean getWrapStyleWord()
  {
    return wrapStyleWord;
  }
  
  /**
   * Enables/Disables word style wrapping.
   *
   * @param flag <code>true</code> to enable word style wrapping,
   * <code>false</code> otherwise
   */
  public void setWrapStyleWord(boolean flag)
  {
    if (wrapStyleWord == flag)
      return;
    
    boolean oldValue = wrapStyleWord;
    wrapStyleWord = flag;
    firePropertyChange("wrapStyleWord", oldValue, wrapStyleWord);
  }
  
  /**
   * Returns the number of characters used for a tab.
   * This defaults to 8.
   *
   * @return the current number of spaces used for a tab.
   */
  public int getTabSize()
  {
    return tabSize;
  }

  /**
   * Sets the number of characters used for a tab to the
   * supplied value.  If a change to the tab size property
   * occurs (i.e. newSize != tabSize), a property change event
   * is fired.
   * 
   * @param newSize The new number of characters to use for a tab.
   */
  public void setTabSize(int newSize)
  {
    if (tabSize == newSize)
      return;
    
    int oldValue = tabSize;
    tabSize = newSize;
    firePropertyChange("tabSize", oldValue, tabSize);
  }

  protected int getColumnWidth()
  {
    FontMetrics metrics = getToolkit().getFontMetrics(getFont());
    return metrics.charWidth('m');
  }

  public int getLineCount()
  {
    return getDocument().getDefaultRootElement().getElementCount();
  }

  public int getLineStartOffset(int line)
     throws BadLocationException
  {
    int lineCount = getLineCount();
    
    if (line < 0 || line > lineCount)
      throw new BadLocationException("Non-existing line number", line);

    Element lineElem = getDocument().getDefaultRootElement().getElement(line);
    return lineElem.getStartOffset();
  }

  public int getLineEndOffset(int line)
     throws BadLocationException
  {
    int lineCount = getLineCount();
    
    if (line < 0 || line > lineCount)
      throw new BadLocationException("Non-existing line number", line);

    Element lineElem = getDocument().getDefaultRootElement().getElement(line);
    return lineElem.getEndOffset();
  }

  public int getLineOfOffset(int offset)
    throws BadLocationException
  {
    Document doc = getDocument();

    if (offset < doc.getStartPosition().getOffset()
	|| offset >= doc.getEndPosition().getOffset())
      throw new BadLocationException("offset outside of document", offset);

    return doc.getDefaultRootElement().getElementIndex(offset);
  }

  protected int getRowHeight()
  {
    FontMetrics metrics = getToolkit().getFontMetrics(getFont());
    return metrics.getHeight();
  }

  /**
   * Inserts the supplied text at the specified position.  Nothing
   * happens in the case that the model or the supplied string is null
   * or of zero length.
   *
   * @param string The string of text to insert.
   * @param position The position at which to insert the supplied text.
   * @throws IllegalArgumentException if the position is &lt; 0 or greater
   * than the length of the current text.
   */
  public void insert(String string, int position)
  {
    // Retrieve the document model.
    Document doc = getDocument();
      
    // Check the model and string for validity.
    if (doc == null
	|| string == null
	|| string.length() == 0)
      return;

    // Insert the text into the model.
    try
      {
	doc.insertString(position, string, null);
      }
    catch (BadLocationException e)
      {
	throw new IllegalArgumentException("The supplied position, "
					   + position + ", was invalid.");
      }
  }

  public void replaceRange(String text, int start, int end)
  {
    Document doc = getDocument();
    
    if (start > end
	|| start < doc.getStartPosition().getOffset()
	|| end >= doc.getEndPosition().getOffset())
      throw new IllegalArgumentException();

    try
      {
        doc.remove(start, end - start);
        doc.insertString(start, text, null);
      }
    catch (BadLocationException e)
      {
	// This cannot happen as we check offset above.
      }
  }

  /**
   * Returns the preferred size for the JTextArea. This is the maximum of
   * the size that is needed to display the content and the requested size
   * as per {@link #getColumns} and {@link #getRows}.
   *
   * @return the preferred size of the JTextArea
   */
  public Dimension getPreferredSize()
  {
    int reqWidth = getColumns() * getColumnWidth();
    int reqHeight = getRows() * getRowHeight();
    View view = getUI().getRootView(this);
    int neededWidth = (int) view.getPreferredSpan(View.HORIZONTAL);
    int neededHeight = (int) view.getPreferredSpan(View.VERTICAL);
    return new Dimension(Math.max(reqWidth, neededWidth),
                          Math.max(reqHeight, neededHeight));
  }

  /**
   * Returns the accessible context associated with the <code>JTextArea</code>.
   *
   * @return the accessible context associated with the <code>JTextArea</code>
   */
  public AccessibleContext getAccessibleContext()
  {
    if (accessibleContext == null)
      accessibleContext = new AccessibleJTextArea();
    return accessibleContext;
  }
}