Highlighting for programmer but not user

Question

I'm making a program where I need to be able to edit the highlighting feature of a JTextArea via my code, but I dont want the user to be able to highlight via the mouse. That, or I need some way of being able to paint over the JTextArea manually (to look like highlighting).

I don't really have anything going code wise for this yet because I have no idea how to implement it.

Edit: I know how to paint over the text, but I need the painting to be transparent like highlighting.

[maybe usage of JTextPane and Highlighter will better....](http://stackoverflow.com/a/9022901/714968) — mKorbel, Mar 18 '13 at 22:02
also see [Highlight one specific row/line in JTextArea](http://stackoverflow.com/q/10191723/1048330) — tenorsax, Mar 18 '13 at 22:03

score 3 · Answer 1 · answered Mar 18 '13 at 22:27

You could start by this code. It finds a word given by the user in String findstr and highlights this word in entire text area. You could use it to find and highlight a certain word multiple times in a text area till it reaches the end of text area content.

String findstr = findTextField.getText().toUpperCase(); // User Input Word to find
int findstrLength = findstr.length();                   
String findtextarea = textarea.getText().toUpperCase(); // TextArea Content
Highlighter h = textarea.getHighlighter();
h.removeAllHighlights();
try
    {
        int index=0;
         while(index>=0) {
        index = findtextarea.indexOf(findstr,index);
        if (index > 0) {
           h.addHighlight(index,index+findstrLength, DefaultHighlighter.DefaultPainter);
        }
        index++; // try adding this to allow you to look for the next index.
    }
    }

score 3 · Answer 2 · answered Mar 18 '13 at 23:35

I dont want the user to be able to highlight via the mouse

That is referred to as "selection". You can disable this on a text component by using a custom Caret:

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

public class NoTextSelectionCaret extends DefaultCaret
{
    public NoTextSelectionCaret(JTextComponent textComponent)
    {
        setBlinkRate( textComponent.getCaret().getBlinkRate() );
        textComponent.setHighlighter( null );
    }

    @Override
    public int getMark()
    {
        return getDot();
    }

    private static void createAndShowUI()
    {
        JTextField textField1 = new JTextField("No Text Selection Allowed");
        textField1.setCaret( new NoTextSelectionCaret( textField1 ) );
        textField1.setEditable(false);

        JTextField textField2 = new JTextField("Text Selection Allowed");

        JFrame frame = new JFrame("No Text Selection Caret");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(textField1, BorderLayout.NORTH);
        frame.add(textField2, BorderLayout.SOUTH);
        frame.pack();
        frame.setLocationByPlatform( true );
        frame.setVisible( true );
    }

    public static void main(String[] args)
    {
        EventQueue.invokeLater(new Runnable()
        {
            public void run()
            {
                createAndShowUI();
            }
        });
    }
}

score 1 · Answer 3 · answered Mar 18 '13 at 22:06

1

See the Highlighter.HighlightPainter interface, that easily (questionable), allows you to change the appearance of the highlight.

There are some concrete implementations, but you can define your own.

answered Mar 18 '13 at 22:06

Mordechai

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Highlighting for programmer but not user

3 Answers3