libjava/classpath/javax/swing/text/PlainDocument.java

/* PlainDocument.java --
   Copyright (C) 2002, 2004, 2006  Free Software Foundation, Inc.

This file is part of GNU Classpath.

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
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General Public License for more details.

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Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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package javax.swing.text;

import java.util.ArrayList;

/**
 * A simple document class which maps lines to {@link Element}s.
 *
 * @author Anthony Balkissoon (abalkiss@redhat.com)
 * @author Graydon Hoare (graydon@redhat.com)
 * @author Roman Kennke (roman@kennke.org)
 * @author Michael Koch (konqueror@gmx.de)
 * @author Robert Schuster (robertschuster@fsfe.org)
 */
public class PlainDocument extends AbstractDocument
{
  private static final long serialVersionUID = 4758290289196893664L;

  public static final String lineLimitAttribute = "lineLimit";
  public static final String tabSizeAttribute = "tabSize";

  /**
   * The default root element of this document. This is made type Element
   * because the RI seems to accept other types of elements as well from
   * createDefaultRoot() (when overridden by a subclass).
   */
  private Element rootElement;

  public PlainDocument()
  {
    this(new GapContent());
  }

  public PlainDocument(AbstractDocument.Content content)
  {
    super(content);
    rootElement = createDefaultRoot();

    // This property has been determined using a Mauve test.
    putProperty("tabSize", new Integer(8));
  }

  private void reindex()
  {
    Element[] lines;
    try
      {
        String str = content.getString(0, content.length());

        ArrayList elts = new ArrayList();
        int j = 0;
        for (int i = str.indexOf('\n', 0); i != -1; i = str.indexOf('\n', i + 1))
          {
            elts.add(createLeafElement(rootElement, SimpleAttributeSet.EMPTY, j, i + 1));
            j = i + 1;
          }

        if (j < content.length())
          elts.add(createLeafElement(rootElement, SimpleAttributeSet.EMPTY, j, content.length()));

        lines = new Element[elts.size()];
        for (int i = 0; i < elts.size(); ++i)
          lines[i] = (Element) elts.get(i);
      }
    catch (BadLocationException e)
      {
        lines = new Element[1];
        lines[0] = createLeafElement(rootElement, SimpleAttributeSet.EMPTY, 0, 1);
      }

    ((BranchElement) rootElement).replace(0, rootElement.getElementCount(), lines);
  }

  protected AbstractDocument.AbstractElement createDefaultRoot()
  {
    BranchElement root =
      (BranchElement) createBranchElement(null, null);

    Element[] array = new Element[1];
    array[0] = createLeafElement(root, null, 0, 1);
    root.replace(0, 0, array);

    return root;
  }

  protected void insertUpdate(DefaultDocumentEvent event,
                              AttributeSet attributes)
  {

    String text = null;
    int offset = event.getOffset();
    int length = event.getLength();
    try
      {
        text = getText(offset, length);
      }
    catch (BadLocationException ex)
      {
        AssertionError err = new AssertionError();
        err.initCause(ex);
        throw err;
      }

    boolean hasLineBreak = text.indexOf('\n') != -1;
    boolean prevCharIsLineBreak = false;
    try
      {
        prevCharIsLineBreak =
          offset > 0 && getText(offset - 1, 1).charAt(0) == '\n';
      }
    catch (BadLocationException ex)
      {
        AssertionError err = new AssertionError();
        err.initCause(ex);
        throw err;
      }
    boolean lastCharIsLineBreak = text.charAt(text.length() - 1) == '\n';
    int lineIndex = -1;
    int lineStart = -1;
    int lineEnd = -1;
    Element[] removed = null;
    BranchElement root = (BranchElement) rootElement;
    boolean updateStructure = true;

    if (prevCharIsLineBreak && ! lastCharIsLineBreak)
      {
        // We must fix the structure a little if the previous char
        // is a linebreak and the last char isn't.
        lineIndex = root.getElementIndex(offset - 1);
        Element prevLine = root.getElement(lineIndex);
        Element nextLine = root.getElement(lineIndex + 1);
        lineStart = prevLine.getStartOffset();
        lineEnd = nextLine.getEndOffset();
        removed = new Element[]{ prevLine, nextLine };
      }
    else if (hasLineBreak)
      {
        lineIndex = root.getElementIndex(offset);
        Element line = root.getElement(lineIndex);
        lineStart = line.getStartOffset();
        lineEnd = line.getEndOffset();
        removed = new Element[]{ line };
      }
    else
      {
        updateStructure = false;
      }

    if (updateStructure)
      {
        // Break the lines between lineStart and lineEnd.
        ArrayList lines = new ArrayList();
        int len = lineEnd - lineStart;
        try
          {
            text = getText(lineStart, len);
          }
        catch (BadLocationException ex)
          {
            AssertionError err = new AssertionError();
            err.initCause(ex);
            throw err;
          }
        int prevLineBreak = 0;
        int lineBreak = text.indexOf('\n');
        do
          {
            lineBreak++;
            lines.add(createLeafElement(root, null, lineStart + prevLineBreak,
                                        lineStart + lineBreak));
            prevLineBreak = lineBreak;
            lineBreak = text.indexOf('\n', prevLineBreak);
          } while (prevLineBreak < len);

        // Update the element structure and prepare document event.
        Element[] added = (Element[]) lines.toArray(new Element[lines.size()]);
        event.addEdit(new ElementEdit(root, lineIndex, removed, added));
        root.replace(lineIndex, removed.length, added);
      }
    super.insertUpdate(event, attributes);
  }

  protected void removeUpdate(DefaultDocumentEvent event)
  {
    super.removeUpdate(event);

    // added and removed are Element arrays used to add an ElementEdit
    // to the DocumentEvent if there were entire lines added or removed
    // from the Document
    Element[] added = new Element[1];
    Element[] removed;
    int p0 = event.getOffset();

    // check if we must collapse some elements
    int i1 = rootElement.getElementIndex(p0);
    int i2 = rootElement.getElementIndex(p0 + event.getLength());
    if (i1 != i2)
      {
        // If there were lines removed then we have to add an ElementEdit
        // to the DocumentEvent so we set it up now by filling the Element
        // arrays "removed" and "added" appropriately
        removed = new Element [i2 - i1 + 1];
        for (int i = i1; i <= i2; i++)
          removed[i-i1] = rootElement.getElement(i);

        int start = rootElement.getElement(i1).getStartOffset();
        int end = rootElement.getElement(i2).getEndOffset();
        added[0] = createLeafElement(rootElement,
                                          SimpleAttributeSet.EMPTY,
                                          start, end);

        // Now create and add the ElementEdit
        ElementEdit e = new ElementEdit(rootElement, i1, removed, added);
        event.addEdit(e);

        // collapse elements if the removal spans more than 1 line
        ((BranchElement) rootElement).replace(i1, i2 - i1 + 1, added);
      }
  }

  public Element getDefaultRootElement()
  {
    return rootElement;
  }

  public Element getParagraphElement(int pos)
  {
    Element root = getDefaultRootElement();
    return root.getElement(root.getElementIndex(pos));
  }

  /**
   * Inserts a string into the document. If the document property
   * '<code>filterNewLines</code>' is set to <code>Boolean.TRUE</code>, then
   * all newlines in the inserted string are replaced by space characters,
   * otherwise the superclasses behaviour is executed.
   *
   * Inserting content causes a write lock to be acquired during this method
   * call.
   *
   * @param offs the offset at which to insert the string
   * @param str the string to be inserted
   * @param atts the text attributes of the string to be inserted
   *
   * @throws BadLocationException
   */
  public void insertString(int offs, String str, AttributeSet atts)
    throws BadLocationException
  {
    String string = str;
    if (str != null && Boolean.TRUE.equals(getProperty("filterNewlines")))
      string = str.replaceAll("\n", " ");
    super.insertString(offs, string, atts);
  }
}