wriring code for an EDITOR big problem??

[vikky agrawal]

Hi, i am developing code for an editor like tool. as we work in some IDE`S like eclipse or netbeans or even any editor like edit plus or notepad++ etc. whenever we write any keyword for specified language that keyword changes it`s attributes eg change in color etc.. i`ve tried my best to do that but it`s not working....
here is the code for that stuff .. actually m is an object for frame and t is JTextPane associated with it
it changes the color of selected text but after updating caret the text changes again it`s color..

 import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
import javax.swing.text.rtf.*;

public class EditorPane extends JTextPane implements CaretListener,KeyListener
{
	private String[] KEY_WORDS={"class","public","void","static"};
	String str="";
	Font f;
	Mymenu m;
	protected RTFEditorKit m_kit;
	static int count=0;
	static int edit=0;
	
	EditorPane()
	{
		
	}
	EditorPane(Mymenu m,String text)
	{
		super();
		this.setText(text);
		this.m_kit=new RTFEditorKit();
		this.m=m;
		//this.setEditorKit(this.m_kit);
		
		JScrollPane ps = new JScrollPane(this);
		//m.getContentPane().add(ps, BorderLayout.CENTER);
		
		m.getContentPane().add(ps);		//not working,,...
		
		
		this.str=this.getText();
		f=new Font("Dialog",Font.PLAIN,15);
		setFont(f);
		
		this.addCaretListener(this);
		
		this.addKeyListener(this);
		repaint();
		
	}
	
	

	public void caretUpdate(CaretEvent ce) 
	{
		int i=this.getCaretPosition();
		if(i>0)
		{
			count=i;
		}
	}
	
	String[] parse(String text)
	{
		String[] tokens=text.split("\\s");
		return tokens;
	}
	
	
	public void keyPressed(KeyEvent arg0) {
		// TODO Auto-generated method stub
		
	}
	public void keyReleased(KeyEvent arg0) {
		// TODO Auto-generated method stub
		
	}
	public void keyTyped(KeyEvent ke) 
	{
	   char c=ke.getKeyChar();
	   ke.getKeyLocation();
	  
		Thread thread=new Thread(){
			public void run()
			{
				EditorPane obj=new EditorPane();
				try
				{
					String text=m.t.getText();
					String[] tokens=obj.parse(text);
					int i=0;
					for(String tok:tokens)
					{
						int j=i;
						i=i+tok.length();
						for(String KEY_WORD:obj.KEY_WORDS)
						{
							if(tok.equals(KEY_WORD))
							{
								int caret=m.t.getCaretPosition();
								m.t.select(j, i+1);
								System.out.println(m.t.getSelectedText());
								//Font f=new Font(Font.DIALOG,Font.BOLD,20);
								m.t.setSelectedTextColor(Color.RED);
								
							}
						}
					}
					
				}
				catch(Exception ex)
				{
					ex.printStackTrace();
				}
			}
		};
		if(c==' ')
			thread.start();
		
	}

}
   

if you will try this code in a frame after changing some code it will show you what`s happening ...
now i do need a solution for this problem please help me...

[Rob Prime]

You should make all updates to the GUI in the Event Dispatcher Thread. You can use EventQueue.invokeAndWait and EventQueue.invokeLater for that, or SwingWorker if you're using Java 6.

A quick attempt:

public void keyTyped(KeyEvent ke)    
{   
    char c = ke.getKeyChar();   
    ke.getKeyLocation();   
    if (c == ' ') // perhaps change this to Character.isWhitespace(c) to also handle tabs and enters
    {
        class Selection
        {
            int start;
            int end;
        }

        final String text = m.t.getText();   
        SwingWorker<Void,Selection> worker = new SwingWorker<Void,Selection>()
        {
            @Override
            protected Void doInBackGround()
            {
                String[] tokens = parse(text); // use this instance!
                int i=0;   
                for(String tok: tokens)   
                {   
                    int j=i;   
                    i = i + tok.length();   
                    for (String KEY_WORD: KEY_WORDS) // again, this instance
                    {   
                        if (tok.equals(KEY_WORD))   
                        {   
                            Selection selection = new Selection();
                            selection.start = j;
                            selection.end = i + 1;
                            publish(selection);
                        }   
                    }   
                }   
                return null;
            }

            @Override
            protected void process(List<Selection> chunks)
            {
                for (Selection selection: chunks)
                {
                    int caret = m.t.getCaretPosition();   
                    m.t.select(selection.start, selection.end);
                    System.out.println(m.t.getSelectedText());   
                    //Font f=new Font(Font.DIALOG,Font.BOLD,20);   
                    m.t.setSelectedTextColor(Color.RED);   
                }
            }
        };
        worker.execute();
    }
}

Disclaimer: not tested.

A SwingWorker executes its doInBackGround method in the background. When publish is called, those objects are gathered and eventually process is called on the Event Dispatcher Thread with all gathered objects so far. At the end, done is called on the Event Dispatcher Thread again.


Also, why do you create a thread if c != ' '? Wouldn't it be more efficient to move the thread creation inside the if-statement?

if(c==' ')
{
    Thread thread = ...
    thread.start();   
}

[Rob Camick]

it changes the color of selected text but after updating caret the text changes again it`s color..

Yes, text "selection" is temporary. You need to change the attributes of the text. Read the JTextPane API and follow the "Using Text Components" link for more information. I then suggest you search the web using "syntax highlighting" to find some ideas. What you want to do is not easy.

[Rob Prime]

Each JTextComponent has an optional Highlighter (using JTextComponent.getHighlighter()) you can use for this:

Highlighter highlighter = getHighlighter();
if (highlighter == null)
{
    highlighter = new DefaultHighlighter();
    setHighlighter(highlighter);
}
// use highlighter.addHighlight(...)

[Gregg Bolinger]

Just use this and be done with it.

http://code.google.com/p/jsyntaxpane/

[vikky agrawal]

@
Rob Prime

thanks for your reply...
actually your code is working properly but what do i need is to change the attribute of that selected text then after it should reflect the changes made but what`s happening is that after updating caret the selected text becomes same again ..that is temporary...how to make it(the changes i made) permanent..
is there any class in API to do that ???
i want to highlight selected text with changing it`s color and it should remain permanent after updating caret..

[Rob Prime]

Have you even read the 3(!) posts above yours?