扩展JTextPane,使其有关键字自动加亮功能。 (转)

扩展JTextPane,使其有关键字自动加亮功能。 (转)[@more@]

import Java.util.StringTokenizer;

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;
import javax.swing.text.*;
import javax.swing.event.*;
import javax.swing.text.rtf.RTFEditorKit;

public class MyTextPane extends JTextPane {

  protected StyleContext m_context;
  protected DefaultStyledDocument m_doc;
  private  MutableAttributeSet keyAttr,normalAttr;
  private  MutableAttributeSet inputAttributes =
  new RTFEditorKit().getInputAttributes();

 private String[] keyword={"select","FROM","WHERE"};

  public MyTextPane() {
  super();
  m_context = new StyleContext();
  m_doc = new DefaultStyledDocument(m_context);
  this.setDocument(m_doc);

  this.addKeyListener(new KeyAdapter() {
  public void keyReleased(KeyEvent ke) {
  syntaxParse();
  }
  });

 file://定义关键字显示属性
  keyAttr = new SimpleAttributeSet();
  StyleConstants.setForeground(keyAttr, Color.blue);

 file://定义一般文本显示属性
  normalAttr = new SimpleAttributeSet();
  StyleConstants.setForeground(normalAttr, Color.black);
  }

  public void syntaxParse() {
  try {
  String s = null;
  Element root = m_doc.getDefaultRootElement();
file://取光标当前行
  int cursorPos = this.getCaretPosition();  file://当前光标的位置
  int line = root.getElementIndex(cursorPos); file://取当前行

  Element para = root.getElement(line);
  int start = para.getStartOffset();
  int end = para.getEndOffset() - 1; file://删除r字符
  s = m_doc.getText(start, end - start).toUpperCase();

  int i = 0;
  int xStart = 0;

file://分析关键字---
  m_doc.setCharacterAttributes(start, s.length(),normalAttr, false);
  MyStringTokenizer st = new MyStringTokenizer(s);
  while( st.hasMoreTokens()) {
  s = st.nextToken();
  if ( s == null) return;
  for (i = 0; i < keyWord.length; i++ ) {
  if (s.equals(keyWord[i])) break;
  }
  if ( i >= keyWord.length ) continue;

  xStart = st.getCurrPosition();

  file://设置关键字显示属性
  m_doc.setCharacterAttributes(start+xStart, s.length(),
  keyAttr, false);
  }
  inputAttributes.addAttributes(normalAttr);
  } catch (Exception ex) {
  ex.printStackTrace();
  }
  }

  public static void main(String[] args) {
  JFrame frame = new JFrame("test text pane");
  frame.getContentPane().add(new MyTextPane());
  WindowListener wndCloser = new WindowAdapter() {
  public void windowClosing(WindowEvent e) {
  System.exit(0);
  }
  };
  frame.addWindowListener(wndCloser);
  final int inset = 50;
  Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
  frame.setBounds ( inset, inset, screenSize.width - inset*2, screenSize.height - inset*2 );
  frame.show();
  }
}

/*在分析字符串的同时，记录每个token所在的位置
*
*/
class MyStringTokenizer extends StringTokenizer{
  String sval = " ";
  String oldStr,str;
  int m_currPosition = 0,m_beginPosition=0;
  MyStringTokenizer(String str) {
  super(str," ");
  this.oldStr = str;
  this.str = str;
  }

  public String nextToken() {
  try {
  String s = super.nextToken();
  int pos = -1;

  if (oldStr.equals(s)) {
  return s;
  }

  pos = str.indexOf(s + sval);
  if ( pos == -1) {
  pos = str.indexOf(sval + s);
  if ( pos == -1)
  return null;
  else pos += 1;
  }

  int xBegin = pos + s.length();
  str = str.substring(xBegin);

  m_currPosition = m_beginPosition + pos;
  m_beginPosition = m_beginPosition + xBegin;
  return s;
  } catch (java.util.NoSuchElementException ex) {
  ex.printStackTrace();
  return null;
  }
  }

  file://返回token在字符串中的位置
  public int getCurrPosition() {
  return m_currPosition;
  }
}

来自 “ ITPUB博客 ” ，链接：http://blog.itpub.net/10752043/viewspace-991528/，如需转载，请注明出处，否则将追究法律责任。

转载于:http://blog.itpub.net/10752043/viewspace-991528/