Re: Newbie on JtextArea swing component

From:

Rico <richard.copeman@lauterbach.co.uk>

Newsgroups:

comp.lang.java.help

Date:

Wed, 01 Aug 2007 04:38:18 -0700

Message-ID:

<1185968298.121749.49600@g4g2000hsf.googlegroups.com>

On 31 Jul, 21:20, Roedy Green <see_webs...@mindprod.com.invalid>
wrote:

I want to be able to set an arbitrary line as the top
visible line in the GUI and have the line highlighted.

seehttp://mindprod.com/jgloss/jscrollpane.html
andhttp://mindprod.com/jgloss/jtextarea.html
There is a gotcha. Strangely you need SwingUtilities.invokeLater even
when you have only one thread.
--
Roedy Green Canadian Mind Products
The Java Glossaryhttp://mindprod.com

Thanks for the info. I took a look and it made some sense to me (so I
must be learning something :-) )

I found a workaround which doesn't quite do what I expected: My code
looks like this:

try
{
    FileInputStream fstream = new FileInputStream(SrcFile);
    BufferedReader in = new BufferedReader(new
InputStreamReader(fstream));

    String thisline;
    sline = 1;
    schar = 0;
    while ( (thisline = in.readLine()) != null)
    {
        jT_SourceCode.append(thisline+"\n");
        schar += (thisline.length()+1); //don't forget CR that has
been added
        if(sline == SrcLine)
        {
            System.out.println("Found source line "+SrcLine+" "+sline
+" "+schar);
            System.out.println("Lines -
"+jT_SourceCode.getLineCount());
            System.out.println("Char offset -
"+jT_SourceCode.getLineStartOffset(sline));

jT_SourceCode.setCaretPosition(jT_SourceCode.getLineStartOffset(sline));
        }//if found source line
        sline++;
    }
    in.close();
}//try

The numbers that are printed out by the System.out.println()'s are
correct (I counted the lines and characters in a separate text editor)
but the text in the JTextArea is not placed at the correct place. Does
the JTextArea convert tabs to spaces? How does it handle newlines/
Carriage returns?

TIA,

Richard.