Change appearance of lines in a JTextArea

[blackbird]

I have a JTextArea that will send its contents over a socket one line at a time. As the lines are sent, I want them to change appearance, perhaps by going from black font to gray, or changing background/foreground color.

Is there a common "GUI pattern" for this?

I will be looping through the JTextArea, so right after sending the line off into the ether, I should be able to tweak its representation. I'm thinking something like this (pseudocode - "outgoing" is the name of the JTextArea):

				for (int i = 0, i < outgoing.size, ++) {
					writer.println(outgoing[i].getText());
					outgoing[i].background = Color.black;
					outgoing[i].foreground = Color.white;
					sleep(10);
				}

Does this makes sense/is it the way to do it/is it possible to do it similar to this?

[Norm]

JTextAreas are pretty plain. Everything is displayed the same.
For individual character by character formatting, see the JTextPane class for example.

[blackbird]

JTextAreas are pretty plain. Everything is displayed the same.
For individual character by character formatting, see the JTextPane class for example.

OK, I'll czech that out.

Is it possible, though, to change the JTextArea at all to give certain lines at least a slightly different look?

This pseudocode is closer, but I still don't know how to refer to a particular line/row in the JTextArea

for (int i = 0; i < outgoing.getLineCount(); i++) {
  writer.println(outgoing.getLine(i));
  outgoing[i].setBackground = Color.black;
  outgoing[i].setForeground = Color.white;
  Thread.sleep(100);
}

[Norm]

give certain lines at least a slightly different look

Make some lines all capital letters, otherwise
JTextAreas are pretty plain. Everything is displayed the same.

how to refer to a particular line/row in the JTextArea

Read the API doc to see what methods are available.

[camickr]

A JList might be a better solution. You can use a custom renderer.

See: How to Use Lists (The Java™ Tutorials > Creating a GUI With JFC/Swing > Using Swing Components)

Otherwise you would need to use a JTextPane which does support different fonts and colors:

See: Text Component Features (The Java™ Tutorials > Creating a GUI With JFC/Swing > Using Swing Components)

[blackbird]

Make some lines all capital letters, otherwise
[I]JTextAreas are pretty plain. Everything is displayed the same.

That's an idea; it doesn't have to be fancy.

Read the API doc to see what methods are available.

I looked through all of the possible values in the editor and none looked all that likely.

[Norm]

Another simple idea: put a line of **********s before and after the line

[blackbird]

Another simple idea: put a line of **********s before and after the line

Okay, once I figure out how to access a specific line...

[Norm]

Lines end with the newline character. You either keep track as you add them, or count them starting at the beginning.

[DarrylBurke]

Use a Highlighter. See the example here: How to Use Text Fields (The Java™ Tutorials > Creating a GUI With JFC/Swing > Using Swing Components)

db

[Norm]

Thanks db. Learning new things every day.

[blackbird]

The "Example: Getting and setting all lines sequentially" section here: Java: JTextArea seems to be purt near what the non-doctor ordered:

    String text = inputArea.getText();
    int totalLines = inputArea.getLineCount();
    for (int i=0; i < totalLines; i++) {
        int start = inputArea.getLineStartOffset(i);
        int end   = inputArea.getLineEndOffset(i);
        String line = text.substring(start, end);
        
        outputArea.append(line + "\n");
    }