How to change the color of the text in a Jtextpane?

Question

I’m developing a chat and he uses a JTextPane to display messages in different colors for each user. However, I don’t know how to change the colors of the text of this component.

Example:
We have two people (John and Peter), when I receive a message from Peter for the first time the chat chooses a color and then will use this color for all of John’s messages, while giving another color to Peter’s messages, but they all appeared in the same JTextPane, users are identified by their IP address.

Something like this:

Answer 1

From a taken example of this link, made an example where it is possible to change the text at runtime, using the classes StyleContext and AttributeSet. To use, simply adapt the component ColorPane in your code, and pass the desired color along with the text in the method append, as the user who is typing.

Follows the code:

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

public class ChangeColorPaneTest extends JFrame {

    JTextField field;
    ColorPane pane;
    boolean alternate = true;

    public void startFrame() {
        pane = new ColorPane();
        pane.setBackground(new Color(245, 245, 245));

        field = new JTextField();
        field.setPreferredSize(new Dimension(getSize().width, 25));
        field.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                //action apenas para fins de exemplificação
                Color textColor = alternate ? Color.red : Color.BLUE;
                pane.append(textColor, field.getText());
                alternate = !alternate;
                field.setText("");
            }
        });

        JScrollPane scrollpane = new JScrollPane(pane);
        scrollpane.setPreferredSize(new Dimension(400, 200));
        setTitle("ColorPane example");

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        add(scrollpane, BorderLayout.CENTER);
        add(field, BorderLayout.PAGE_END);
        field.requestFocusInWindow();
        pack();
        setVisible(true);
    }

    class ColorPane extends JTextPane {

        public void append(Color c, String s) {
            //implementação utilizando StyleContext
            StyleContext sc = StyleContext.getDefaultStyleContext();
            AttributeSet aset = sc.addAttribute(SimpleAttributeSet.EMPTY,
                    StyleConstants.Foreground, c);

            // tamanho do texto já no component
            int len = getDocument().getLength(); 
            // altera a posicao do cursor para o fim(se não houver seleção)
            setCaretPosition(len); 
            setCharacterAttributes(aset, false);
            //O \n é apenas para o texto ser quebrado
            //para fins de demonstracao
            //se não houver seleção, adiciona o texto no fim
            replaceSelection(s.concat("\n")); 
        }

    }

    public static void main(String argv[]) {

        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                ChangeColorPaneTest pane = new ChangeColorPaneTest();
                pane.startFrame();
            }
        });
    }
}

Upshot:

Reference:

How to Use Editor Panes and Text Panes(Documentation)

Answer 2

If you only want to change the color of the text, do so:

textPane.setForeground(Color.RED);

And if you want to change the background color (background), do so:

textPane.setBackground(Color.BLACK);

And don’t forget to import the class Color:

import java.awt.Color;

Answer 3

First of all you create the object to be able to modify it

private jTextPane1 = new javax.swing.JTextPane();

then you can access it to modify the following ways.

You might be putting right into the constructor for example:

    public NovoJFrame() {
      initComponents();
      //use setForeground para mudar a cor e Color pra colocar o código rgb da cor
      jTextPane1.setForeground(new Color(255,0,0));

}

or you can put it in some function like for example:

public mudaCor(){
//use setForeground para mudar a cor e Color pra colocar o código rgb da cor
  jTextPane1.setForeground(new Color(255,0,0));
}

Answer 4

Just as an alternative, if you are going to learn try using Javafx. It is much simpler and much more dynamic, in it you would use only label1.setTextFill(Color.web("#0076a3"));, actually has even an editor called Scene Builder it does everything. Look what to create. You can even create games so perfect and does not take up any space.