rtextareabase.java

具有不同语法高亮的编辑器实例

      /*****************************************************************************/

  /**
   * Returns the default caret color.
   *
   * @return The default caret color.
   */
  public static final Color getDefaultCaretColor() {
    return DEFAULT_CARET_COLOR;
  }

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  /**
   * Returns the "default" color for highlighting the current line.  Note
   * that this color was chosen only because it looks nice (to me) against a
   * white background.
   *
   * @return The default color for highlighting the current line.
   */
  public static final Color getDefaultCurrentLineHighlightColor() {
    return DEFAULT_CURRENT_LINE_HIGHLIGHT_COLOR;
  }

      /*****************************************************************************/

  /**
   * Returns the default color for the margin line.
   *
   * @return The default margin line color.
   * @see #getMarginLineColor
   * @see #setMarginLineColor
   */
  public static final Color getDefaultMarginLineColor() {
    return DEFAULT_MARGIN_LINE_COLOR;
  }

      /*****************************************************************************/

  /**
   * Returns the default margin line position.
   *
   * @return The default margin line position.
   * @see #getMarginLinePosition
   * @see #setMarginLinePosition
   */
  public static final int getDefaultMarginLinePosition() {
    return DEFAULT_MARGIN_LINE_POSITION;
  }

      /*****************************************************************************/

  /**
   * Returns the default selection color for this text area.  This
   * color was chosen because it's light and <code>RTextArea</code>
   * does not change text color between selected/unselected text for
   * contrast like regular <code>JTextArea</code>s do.
   *
   * @return The default selection color.
   */
  public static Color getDefaultSelectionColor() {
    return DEFAULT_SELECTION_COLOR;
  }

      /*****************************************************************************/

  /**
   * Returns the default tab size, in spaces.
   *
   * @return The default tab size.
   */
  public static final int getDefaultTabSize() {
    return DEFAULT_TAB_SIZE;
  }

      /*****************************************************************************/

  /**
   * Returns whether the current line highlight is faded.
   *
   * @return Whether the current line highlight is faded.
   * @see #setFadeCurrentLineHighlight
   */
  public boolean getFadeCurrentLineHighlight() {
    return fadeCurrentLineHighlight;
  }

      /*****************************************************************************/

  /**
   * Returns the offset of the last character of the line that the caret is
   * on.
   *
   * @return The last offset of the line that the caret is currently on.
   */
  public final int getLineEndOffsetOfCurrentLine() {
    try {
      return getLineEndOffset(getCaretLineNumber());
    }
    catch (BadLocationException ble) {
      /* Will never happen. */
      return 0;
    }
  }

      /*****************************************************************************/

  /**
   * Returns the height of a line of text in this text area.
   *
   * @return The height of a line of text.
   */
  public int getLineHeight() {
    return getRowHeight();
  }

      /*****************************************************************************/

  /**
   * Returns the offset of the first character of the line that the caret is
   * on.
   *
   * @return The first offset of the line that the caret is currently on.
   */
  public final int getLineStartOffsetOfCurrentLine() {
    try {
      return getLineStartOffset(getCaretLineNumber());
    }
    catch (BadLocationException ble) {
      /* Will never happen. */
      return 0;
    }
  }

      /*****************************************************************************/

  /**
   * Returns the color used to paint the margin line.
   *
   * @return The margin line color.
   * @see #setMarginLineColor
   */
  public Color getMarginLineColor() {
    return marginLineColor;
  }

      /*****************************************************************************/

  /**
   * Returns the margin line position (in pixels) from the left-hand side of
   * the text area.
   *
   * @return The margin line position.
   * @see #getDefaultMarginLinePosition
   * @see #setMarginLinePosition
   */
  public int getMarginLinePixelLocation() {
    return marginLineX;
  }

      /*****************************************************************************/

  /**
   * Returns the margin line position (which is the number of 'm' widths in
   * the current font the margin line is over).
   *
   * @return The margin line position.
   * @see #getDefaultMarginLinePosition
   * @see #setMarginLinePosition
   */
  public int getMarginLinePosition() {
    return marginSizeInChars;
  }

      /*****************************************************************************/

  /**
   * Returns whether selection edges are rounded in this text area.
   *
   * @return Whether selection edges are rounded.
   * @see #setRoundedSelectionEdges
   */
  public boolean getRoundedSelectionEdges() {
    return roundedSelectionEdges;
  }

      /*****************************************************************************/

  /**
   * Returns whether or not tabs are emulated with spaces (i.e., "soft"
   * tabs).
   *
   * @return <code>true</code> if tabs are emulated with spaces;
   *         <code>false</code> if they aren't.
   * @see #setTabsEmulated
   */
  public boolean getTabsEmulated() {
    return tabsEmulatedWithSpaces;
  }

      /*****************************************************************************/

  /**
   * Determines the word closest to/at the given model position.
   * Uses BreakIterator.getWordInstance() to actually get the words.
   *
   * @param offs The offset in the document >= 0
   * @return The word closest to/at that position.
   * @exception BadLocationException if the offset is out of range
   */
  public final String getWordAtOffset(int offs) throws BadLocationException {
    Document doc = getDocument();
    Element map = doc.getDefaultRootElement();
    int lineNumber = map.getElementIndex(offs);
    Element line = map.getElement(lineNumber);
    int lineStart = line.getStartOffset();
    int lineEnd = Math.min(line.getEndOffset(), doc.getLength());

    String s = doc.getText(lineStart, lineEnd - lineStart);
    if (s != null && s.length() > 0) {
      BreakIterator words = BreakIterator.getWordInstance();
      words.setText(s);
      int wordPosition = offs - lineStart;
      if (wordPosition >= words.last()) {
        wordPosition = words.last() - 1;
      }
      //words.following(wordPosition);
      int end = lineStart + words.following(wordPosition);
      int start = lineStart + words.previous();
      return doc.getText(start, end - start);
    }
    return null;
  }

      /*****************************************************************************/

  /**
   * Returns whether or not the current line is highlighted.
   *
   * @return Whether or the current line is highlighted.
   * @see #setCurrentLineHighlightEnabled
   * @see #getCurrentLineHighlightColor
   * @see #setCurrentLineHighlightColor
   */
  public final boolean isCurrentLineHighlightEnabled() {
    return highlightCurrentLine;
  }

      /*****************************************************************************/

  /**
   * Returns whether or not the margin line is being painted.
   *
   * @return Whether or not the margin line is being painted.
   * @see #setMarginLineEnabled
   */
  public boolean isMarginLineEnabled() {
    return marginLineEnabled;
  }

      /*****************************************************************************/

  /**
   * Paints the text area.
   *
   * @param g The graphics context with which to paint.
   */
  public void paintComponent(Graphics g) {

    //long startTime = System.currentTimeMillis();

    backgroundPainter.paint(g, getVisibleRect());

    // Paint the main part of the text area.
    TextUI ui = getUI();
    if (ui != null) {
      // Not allowed to modify g, so make a copy.
      Graphics scratchGraphics = g.create();
      try {
        ui.update(scratchGraphics, this);
      }
      finally {
        scratchGraphics.dispose();
      }
    }

    //long endTime = System.currentTimeMillis();
    //System.err.println(endTime-startTime);

  }

      /*****************************************************************************/

  /**
   * Updates the current line highlight location.
   */
  protected void possiblyUpdateCurrentLineHighlightLocation() {

    int width = getWidth();
    int lineHeight = getLineHeight();
    int caretPos = getCaretPosition();

    // If we're wrapping lines we need to check the actual y-coordinate
    // of the caret, not just the line number, since a single logical
    // line can span multiple physical lines.
    if (getLineWrap()) {
      try {
        Rectangle temp = modelToView(caretPos);
        if (temp != null) {
          currentCaretY = temp.y;
        }
      }
      catch (BadLocationException ble) {
        ble.printStackTrace(); // Should never happen.
      }
    }

    // No line wrap - we can simply check the line number (quicker).
    else {
      Document doc = getDocument();
      if (doc != null) {
        Element map = doc.getDefaultRootElement();
        int caretLine = map.getElementIndex(caretPos);
        Rectangle alloc = ( (RTextAreaUI) getUI()).
            getVisibleEditorRect();
        if (alloc != null) {
          currentCaretY = alloc.y + caretLine * lineHeight;
        }
      }
    }

    // Repaint current line (to fill in entire highlight), and old line
    // (to erase entire old highlight) if necessary.
    repaint(0, currentCaretY, width, lineHeight);
    if (currentCaretY != previousCaretY) {
      repaint(0, previousCaretY, width, lineHeight);
    }
    previousCaretY = currentCaretY;

  }

      /*****************************************************************************/

  /**
   * Overridden so we can tell when the text area is resized and update the
   * current-line highlight, if necessary (i.e., if it is enabled and if
   * lineWrap is enabled.
   *
   * @param e The component event about to be sent to all registered
   *          <code>ComponentListener</code>s.
   */
  protected void processComponentEvent(ComponentEvent e) {

    // In line wrap mode, resizing the text area means that the caret's
    // "line" could change - not to a different logical line, but a
    // different physical one.  So, here we force a repaint of the current
    // line's highlight if necessary.
    if (e.getID() == ComponentEvent.COMPONENT_RESIZED &&
        getLineWrap() == true && isCurrentLineHighlightEnabled()) {
      previousCaretY = -1; // So we are sure to repaint.
      fireCaretUpdate(mouseListener);
    }

    super.processComponentEvent(e);

  }

      /*****************************************************************************/

  /**
   * Sets the background color of this text editor.  Note that this is
   * equivalent to calling <code>setBackgroundObject(bg)</code>.
   *
   * NOTE:  the opaque property is set to <code>true</code> when the
   * background is set to a color (by this method).  When an image is used
   * for the background, opaque is set to false.  This is because
   * we perform better when setOpaque is true, but if we use an
   * image for the background when opaque is true, we get on-screen