Java by API/javax.swing.text/DefaultHighlighter

DefaultHighlighter.DefaultPainter

 


import java.awt.BorderLayout;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.text.DefaultHighlighter;
import javax.swing.text.Highlighter;
public class Main {
  public static void main(String args[]) throws Exception {
    JFrame frame = new JFrame("MultiHighlight");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    JTextArea comp = new JTextArea(5, 20);
    comp.setText("this is a test");
    frame.getContentPane().add(new JScrollPane(comp), BorderLayout.CENTER);
    String charsToHighlight = "a";
    Highlighter h = comp.getHighlighter();
    h.removeAllHighlights();
    String text = comp.getText().toUpperCase();
    for (int j = 0; j < text.length(); j += 1) {
      char ch = text.charAt(j);
      if (charsToHighlight.indexOf(ch) >= 0)
        h.addHighlight(j, j + 1, DefaultHighlighter.DefaultPainter);
    }
    frame.pack();
    frame.setVisible(true);
  }
}