package se.sics.mspsim.extutil.highlight;import java.awt.*;import javax.swing.*;import javax.swing.text.*;import javax.swing.event.*;import java.io.*;// Public domain, no restrictions, Ian Holyer, University of Bristol./** * Display text with syntax highlighting. Highlighting is done with full * accuracy, using a given language scanner. Large amounts of re-highlighting * are done in small bursts to make sure the user interface doesn't freeze. */public class SyntaxHighlighter extends JTextPane implements DocumentListener, TokenTypes {  private static final long serialVersionUID = -1801145479677890566L;  private StyledDocument doc;  private Scanner scanner;  private int rows, columns;  private int currentY, currentHeight = -1;  /**   * Create a graphics component which displays text with syntax highlighting.   * Provide a rows and columns, in characters, and a language scanner.   */  public SyntaxHighlighter(int rows, int columns, Scanner scanner) {    super(new DefaultStyledDocument());    doc = (StyledDocument) getDocument();    this.rows = rows;    this.columns = columns;    this.scanner = scanner;    doc.addDocumentListener(this);    Font font = new Font("Monospaced", Font.PLAIN, getFont().getSize());    changeFont(font);    initStyles();    // Quick fix to highlight selected line    addCaretListener(new CaretListener() {      public void caretUpdate(CaretEvent e) {        int caret = getCaretPosition();        if (caret >= 0) {          try {            Rectangle r = getUI().modelToView(SyntaxHighlighter.this, caret);            if (currentHeight > 0) {              repaint(0, currentY, getWidth(), currentHeight);            }            if (r != null && r.height > 0) {              currentY = r.y;              currentHeight = r.height;              repaint(0, r.y, getWidth(), r.height);            } else {              currentHeight = -1;            }          } catch (BadLocationException e1) {            // Ignore          }        }      }    });    setOpaque(false);  }  public int getColumns() {    return columns;  }  public int getRows() {    return rows;  }  /**   * Change the component's font, and change the size of the component to match.   */  public void changeFont(Font font) {    int borderOfJTextPane = 3;    setFont(font);    FontMetrics metrics = getFontMetrics(font);    int paneWidth = columns * metrics.charWidth('m') + 2 * borderOfJTextPane;    int paneHeight = rows * metrics.getHeight() + 2 * borderOfJTextPane;    Dimension size = new Dimension(paneWidth, paneHeight);    setMinimumSize(size);    setPreferredSize(size);    invalidate();  }  /**   * Read new text into the component from a <code>Reader</code>. Overrides   * <code>read</code> in <code>JTextComponent</code> in order to highlight   * the new text.   */  public void read(Reader in, Object desc) throws IOException {    int oldLength = getDocument().getLength();    doc.removeDocumentListener(this);    super.read(in, desc);    doc = (StyledDocument) getDocument();    doc.addDocumentListener(this);    int newLength = getDocument().getLength();    firstRehighlightToken = scanner.change(0, oldLength, newLength);    repaint();  }  // An array of styles, indexed by token type. Default styles are set up,  // which can be used for any languages.  private Style[] styles;  private void initStyles() {    styles = new Style[typeNames.length];    changeStyle(UNRECOGNIZED, Color.black);    changeStyle(WHITESPACE, Color.black);    changeStyle(WORD, Color.black);    changeStyle(NUMBER, Color.black);    changeStyle(PUNCTUATION, Color.blue);    changeStyle(COMMENT, new Color(178,34,34), Font.ITALIC);    changeStyle(START_COMMENT, new Color(178,34,34), Font.ITALIC);    changeStyle(MID_COMMENT, new Color(178,34,34), Font.ITALIC);    changeStyle(END_COMMENT, new Color(178,34,34), Font.ITALIC);    changeStyle(TAG, Color.blue, Font.BOLD);    changeStyle(END_TAG, Color.blue, Font.BOLD);    changeStyle(KEYWORD, new Color(160,32,240));    changeStyle(KEYWORD2, new Color(160,32,240));    changeStyle(IDENTIFIER, Color.black);    changeStyle(LITERAL, Color.green.darker());    changeStyle(STRING, new Color(188,143,143));    changeStyle(CHARACTER, new Color(188,143,143));    changeStyle(OPERATOR, Color.black, Font.BOLD);    changeStyle(BRACKET, Color.black);    changeStyle(SEPARATOR, Color.black);    changeStyle(URL, Color.blue.darker());    for (int i = 0; i < styles.length; i++) {      if (styles[i] == null) {        styles[i] = styles[WHITESPACE];      }    }  }  /**   * Change the style of a particular type of token.   */  public void changeStyle(int type, Color color) {    Style style = addStyle(typeNames[type], null);    StyleConstants.setForeground(style, color);    styles[type] = style;  }  /**   * Change the style of a particular type of token, including adding bold or   * italic using a third argument of <code>Font.BOLD</code> or   * <code>Font.ITALIC</code> or the bitwise union   * <code>Font.BOLD|Font.ITALIC</code>.   */  public void changeStyle(int type, Color color, int fontStyle) {    Style style = addStyle(typeNames[type], null);    StyleConstants.setForeground(style, color);    if ((fontStyle & Font.BOLD) != 0)      StyleConstants.setBold(style, true);    if ((fontStyle & Font.ITALIC) != 0)      StyleConstants.setItalic(style, true);    styles[type] = style;  }  public int getLineCount() {    return getDocument().getDefaultRootElement().getElementCount();  }  public int getLineStartOffset(int line) {    Element root = getDocument().getDefaultRootElement();    if (line < 0 || line >= root.getElementCount()) {      throw new IndexOutOfBoundsException("illegal line");    }    return root.getElement(line).getStartOffset();  }  public int getLineEndOffset(int line) {    Element root = getDocument().getDefaultRootElement();    if (line < 0 || line >= root.getElementCount()) {      throw new IndexOutOfBoundsException("illegal line");    }    return root.getElement(line).getEndOffset();  }  /**   * <font style='color:gray;'>Ignore this method. Responds to the underlying   * document changes by re-highlighting.</font>   */  public void insertUpdate(DocumentEvent e) {    int offset = e.getOffset();    int length = e.getLength();    firstRehighlightToken = scanner.change(offset, 0, length);    repaint();  }  /**   * <font style='color:gray;'>Ignore this method. Responds to the underlying   * document changes by re-highlighting.</font>   */  public void removeUpdate(DocumentEvent e) {    int offset = e.getOffset();    int length = e.getLength();    firstRehighlightToken = scanner.change(offset, length, 0);    repaint();  }  /**   * <font style='color:gray;'>Ignore this method. Responds to the underlying   * document changes by re-highlighting.</font>   */  public void changedUpdate(DocumentEvent e) {    // Do nothing.  }  // Scan a small portion of the document. If more is needed, call repaint()  // so the GUI gets a go and doesn't freeze, but calls this again later.  private Segment text = new Segment();  private int firstRehighlightToken;  private int smallAmount = 100;  private Color highlightColor = new Color(0, 240, 0, 255);  /**   * <font style='color:gray;'>Ignore this method. Carries out a small amount of   * re-highlighting for each call to <code>repaint</code>.</font>   */  protected void paintComponent(Graphics g) {    if (currentHeight > 0) {      g.setColor(highlightColor);      g.fillRect(0, currentY, getWidth(), currentHeight);    }    super.paintComponent(g);    int offset = scanner.position();    if (offset < 0)      return;    int tokensToRedo = 0;    int amount = smallAmount;    while (tokensToRedo == 0 && offset >= 0) {      int length = doc.getLength() - offset;      if (length > amount) {        length = amount;      }      try {        doc.getText(offset, length, text);      } catch (BadLocationException e) {        return;      }      tokensToRedo = scanner.scan(text.array, text.offset, text.count);      offset = scanner.position();      amount = 2 * amount;    }    for (int i = 0; i < tokensToRedo; i++) {      Token t = scanner.getToken(firstRehighlightToken + i);      int length = t.symbol.name.length();      int type = t.symbol.type;      if (type < 0) {        type = UNRECOGNIZED;      }      doc.setCharacterAttributes(t.position, length, styles[type], false);    }    firstRehighlightToken += tokensToRedo;    if (offset >= 0) {      repaint(2);    }  }  public void viewLine(int line) {    if (line >= 0 && line < getLineCount()) {      try {        int pos = getLineStartOffset(line);        // Quick fix to position the line somewhere in the center        Rectangle r = getUI().modelToView(this, pos);        if (r != null && r.height > 0) {          Rectangle vr = getVisibleRect();          vr.y = r.y - vr.height / 2;          if (vr.y < 0) {            vr.y = 0;          }          scrollRectToVisible(vr);        }        setCaretPosition(pos);      } catch (BadLocationException e1) {        // Ignore      }    }  }}