Einfaches Syntax-Highlighting

CPU · 28. August 2009

Hallo,

ich plane eine ganz einfache Syntax-Highlightingfunktion mit Java und dem JTextPane zu implementieren. Dazu habe ich ja schon mal einen Eintrag hier geschrieben, der aber nicht beantwortet wurde.

Daher habe ich mir selbst Gedanken gemacht und scheitere am Verständnis dieser Klasse:

Code:

import java.awt.Color;
import java.util.Vector;

import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.DefaultStyledDocument;
import javax.swing.text.Element;
import javax.swing.text.SimpleAttributeSet;
import javax.swing.text.StyleConstants;
/*
 * http://java.sys-con.com/node/36509
 */
public class CodeDocument extends DefaultStyledDocument{
  private String word = "";
  private SimpleAttributeSet bold = new SimpleAttributeSet();
  private SimpleAttributeSet string = new SimpleAttributeSet();
  private SimpleAttributeSet normal = new SimpleAttributeSet();
  private SimpleAttributeSet number = new SimpleAttributeSet();
  private SimpleAttributeSet comments = new SimpleAttributeSet();
  private int currentPos = 0;
  private Vector keywords = new Vector();
  public static int STRING_MODE = 10;
  public static int TEXT_MODE = 11;
  public static int NUMBER_MODE = 12;
  public static int COMMENT_MODE = 13;
  private int mode = TEXT_MODE;
 

  public CodeDocument() {
   //set the bold attribute
   StyleConstants.setBold(bold, true);
   StyleConstants.setForeground(string, Color.red);
   StyleConstants.setForeground(number, Color.magenta);
   StyleConstants.setForeground(comments, Color.blue);
   StyleConstants.setItalic(comments, true);
  }
 

  private void insertKeyword(String str, int pos){
    try{
      //remove the old word and formatting
      this.remove(pos - str.length(), str.length());
      /*replace it with the same word, but new formatting
      *we MUST call the super class insertString method here, otherwise we
      *would end up in an infinite loop !!!!!*/
      super.insertString(pos - str.length(), str, bold);
    }
    catch (Exception ex){
      ex.printStackTrace();
    }
  }
 

  private void insertTextString(String str, int pos){
    try{
      //remove the old word and formatting
      this.remove(pos,str.length());
      super.insertString(pos, str, string);
    }
    catch (Exception ex){
      ex.printStackTrace();
    }
  }
 

  private void insertNumberString(String str, int pos){
    try{
      //remove the old word and formatting
      this.remove(pos,str.length());
      super.insertString(pos, str, number);
    }
    catch (Exception ex){
      ex.printStackTrace();
    }
  }
 

  private void insertCommentString(String str, int pos){
    try{
      //remove the old word and formatting
      this.remove(pos,str.length());
      super.insertString(pos, str, comments);
    }
    catch (Exception ex){
      ex.printStackTrace();
    }
  }
 

  private void checkForString(){
    int offs = this.currentPos;
    Element element = this.getParagraphElement(offs);
    String elementText = "";
    try{
      //this gets our chuck of current text for the element we're on
      elementText = this.getText(element.getStartOffset(),
                                 element.getEndOffset() -
element.getStartOffset());
    }
    catch(Exception ex){
      //whoops!
      System.out.println("no text");
    }
    int strLen = elementText.length();
    if (strLen == 0) {return;}
    int i = 0;
 

    if (element.getStartOffset() > 0){
      //translates backward if neccessary
      offs = offs - element.getStartOffset();
    }
    int quoteCount = 0;
    if ((offs >= 0) && (offs <= strLen-1)){
      i = offs;
      while (i >0){
      //the while loop walks back until we hit a delimiter
 

        char charAt = elementText.charAt(i);
        if ((charAt == '"')){
         quoteCount ++;
        }
        i--;
      }
      int rem = quoteCount % 2;
      //System.out.println(rem);
      mode = (rem == 0) ? TEXT_MODE: STRING_MODE;
    }
  }
 

  private void checkForKeyword(){
    if (mode != TEXT_MODE) {
      return;
    }
    int offs = this.currentPos;
    Element element = this.getParagraphElement(offs);
    String elementText = "";
    try{
      //this gets our chuck of current text for the element we're on
      elementText = this.getText(element.getStartOffset(),
element.getEndOffset() - element.getStartOffset());
    }
    catch(Exception ex){
      //whoops!
      System.out.println("no text");
    }
    int strLen = elementText.length();
    if (strLen == 0) {return;}
    int i = 0;
 

    if (element.getStartOffset() > 0){
      //translates backward if neccessary
      offs = offs - element.getStartOffset();
    }
    if ((offs >= 0) && (offs <= strLen-1)){
      i = offs;
      while (i >0){
      //the while loop walks back until we hit a delimiter
        i--;
        char charAt = elementText.charAt(i);
        if ((charAt == ' ') | (i == 0) | (charAt =='(') | (charAt ==')') |
            (charAt == '{') | (charAt == '}')){ //if i == 0 then we're at the begininng
          if(i != 0){
            i++;
          }
          word = elementText.substring(i, offs);//skip the period
 

          String s = word.trim().toLowerCase();
          //this is what actually checks for a matching keyword
          if (keywords.contains(s)){
            insertKeyword(word, currentPos);
          }
          break;
        }
      }
    }
  }
 

  private void checkForNumber(){
    int offs = this.currentPos;
    Element element = this.getParagraphElement(offs);
    String elementText = "";
    try{
      //this gets our chuck of current text for the element we're on
      elementText = this.getText(element.getStartOffset(),
element.getEndOffset() - element.getStartOffset());
    }
    catch(Exception ex){
      //whoops!
      System.out.println("no text");
    }
    int strLen = elementText.length();
    if (strLen == 0) {return;}
    int i = 0;
 

    if (element.getStartOffset() > 0){
      //translates backward if neccessary
      offs = offs - element.getStartOffset();
    }
    mode = TEXT_MODE;
    if ((offs >= 0) && (offs <= strLen-1)){
      i = offs;
      while (i >0){
      //the while loop walks back until we hit a delimiter
        char charAt = elementText.charAt(i);
        if ((charAt == ' ') | (i == 0) | (charAt =='(') | (charAt ==')') |
            (charAt == '{') | (charAt == '}') /*|*/){ //if i == 0 then we're at the begininng
          if(i != 0){
            i++;
          }
          mode = NUMBER_MODE;
          break;
        }
        else if (!(charAt >= '0' & charAt <= '9' | charAt=='.'
                  | charAt=='+' | charAt=='-'
                  | charAt=='/' | charAt=='*'| charAt=='%' | charAt=='=')){
          mode = TEXT_MODE;
          break;
        }
        i--;
      }
    }
  }
 

  private void checkForComment(){
    int offs = this.currentPos;
    Element element = this.getParagraphElement(offs);
    String elementText = "";
    try{
      //this gets our chuck of current text for the element we're on
      elementText = this.getText(element.getStartOffset(),
element.getEndOffset() - element.getStartOffset());
    }
    catch(Exception ex){
      //whoops!
      System.out.println("no text");
    }
    int strLen = elementText.length();
    if (strLen == 0) {return;}
    int i = 0;
 

    if (element.getStartOffset() > 0){
      //translates backward if neccessary
      offs = offs - element.getStartOffset();
    }
    if ((offs >= 1) && (offs <= strLen-1)){
      i = offs;
      char commentStartChar1 = elementText.charAt(i-1);
      char commentStartChar2 = elementText.charAt(i);
      if (commentStartChar1 == '/' && commentStartChar2 == '*'){
          mode = COMMENT_MODE;
          this.insertCommentString("/*", currentPos-1);
      }
      else if (commentStartChar1 == '*' && commentStartChar2 == '/'){
          mode = TEXT_MODE;
          this.insertCommentString("*/", currentPos-1);
      }
    }
  }
 

  private void processChar(String str){
    char strChar = str.charAt(0);
    if (mode != this.COMMENT_MODE){
      mode = TEXT_MODE;
    }
      switch (strChar){
        case ('{'):case ('}'):case (' '): case('\n'):
        case ('('):case (')'):case (';'):case ('.'):{
          checkForKeyword();
          if (mode == STRING_MODE && strChar == '\n'){
            mode = TEXT_MODE;
          }
        }
        break;
        case ('"'):{
          insertTextString(str, currentPos);
          this.checkForString();
        }
        break;
        case ('0'):case ('1'):case ('2'):case ('3'):case ('4'):
        case ('5'):case ('6'):case ('7'):case ('8'):case ('9'):{
          checkForNumber();
        }
        break;
        case ('*'):case ('/'):{
          checkForComment();
        }
        break;
      }
      if (mode == this.TEXT_MODE){
        this.checkForString();
      }
      if (mode == this.STRING_MODE){
        insertTextString(str, this.currentPos);
      }
      else if (mode == this.NUMBER_MODE){
        insertNumberString(str, this.currentPos);
      }
      else if (mode == this.COMMENT_MODE){
        insertCommentString(str, this.currentPos);
      }
 

  }
 

  private void processChar(char strChar){
      char[] chrstr = new char[1];
      chrstr[0] = strChar;
      String str = new String(chrstr);
      processChar(str);
  }
 

  public void insertString(int offs,
                          String str,
                          AttributeSet a) throws BadLocationException{
    super.insertString(offs, str, normal);
 

    int strLen = str.length();
    int endpos = offs + strLen;
    int strpos;
    for (int i=offs;i<endpos;i++){
      currentPos = i;
      strpos = i - offs;
      processChar(str.charAt(strpos));
    }
    currentPos = offs;
  }
 

  public Vector getKeywords(){
    return this.keywords;
  }
 

  public void setKeywords(Vector aKeywordList){
    if (aKeywordList != null){
      this.keywords = aKeywordList;
    }
  }
}

Könntet Ihr mal drüberschauen und mir erklären, wie die Syntax erkannt wird und gehighlightet wird? Mit "insertString(...)" fängt ja alles sozusagen an ...

Danke,
CPU

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Einfaches Syntax-Highlighting

CPU

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