Change text selection type in a JTextArea

Question

In most of the text editors, I have seen that when text is selected, all the line changes the color to the selection color.

But in JTextArea, during the selection only the text color is changed during selection.

How can I achieve the above mentioned selection type in JTextArea where all the area under selection is colored? I cannot find any method that would do the job.

Answer 1

Maybe the DefaultHighlighter#setDrawsLayeredHighlights(false) will work:

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

public class SelectionTypeTest {
  public JComponent makeUI() {
    JTextArea textArea = new JTextArea();
    DefaultHighlighter hl = (DefaultHighlighter) textArea.getHighlighter();
    System.out.println(hl.getDrawsLayeredHighlights());
    hl.setDrawsLayeredHighlights(false);
    textArea.setSelectionColor(Color.RED);
    textArea.setSelectedTextColor(Color.WHITE);
    try (Reader reader = new BufferedReader(new InputStreamReader(
          new FileInputStream("SelectionTypeTest.java"), "UTF-8"))) {
      textArea.read(reader, "");
    } catch (Exception ex) {
      ex.printStackTrace();
    }
    return new JScrollPane(textArea);
  }
  public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
      @Override public void run() {
        createAndShowGUI();
      }
    });
  }
  public static void createAndShowGUI() {
    JFrame f = new JFrame();
    f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    f.getContentPane().add(new SelectionTypeTest().makeUI());
    f.setSize(320, 240);
    f.setLocationRelativeTo(null);
    f.setVisible(true);
  }
}