Find the offset to a String in a JTextPane

问题:

I'm looking for a quick way to find a String in a JTextPane and change the style there, so it gets highlighted. What I currently have is something like this (tpOutput is the JTextPane in question, strSearch the String to be searched.. duh):

int index = tpOutput.getText().indexOf(strSearch);
StyledDocument doc = tpOutput.getStyledDocument();
doc.setCharacterAttributes(i, strSearch.length(), doc.getStyle("exampleStyle") , false);

However, as beautiful as that would be if it worked, it counts wrong on newline characters, so if I search the text "foobar" in

foobarTTT
abcd123
abcd123

it would highlight "foobar" in the first line correctly. However, in

abcd123
abcd123
foobarTTT

it would highlight "obarTT" (and the following 2 whitespaces if they exist)

I'm probably doing the whole thing wrong, trying to get the offset easy using just the text. Anyone know the proper way to do this?

回答1:

You can also use a Highlighter, discussed in How to Use Text Fields: Another Example: TextFieldDemo.

回答2:

IndexOutOfBounds is maybe from doc.getStyle("exampleStyle"), by using MutableAttributeSet works for me,

can you demonstrated your issue with IndexOutOfBounds by using this SSCCE

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

public class TextPaneAttributes extends JFrame {

    private static final long serialVersionUID = 1L;

    public TextPaneAttributes() {
        final JTextPane textPane = new JTextPane();
        StyledDocument doc = textPane.getStyledDocument();
        final MutableAttributeSet standard = new SimpleAttributeSet();
        StyleConstants.setAlignment(standard, StyleConstants.ALIGN_CENTER);
        doc.setParagraphAttributes(0, 0, standard, true);
        MutableAttributeSet keyWord = new SimpleAttributeSet();
        StyleConstants.setForeground(keyWord, Color.red);
        StyleConstants.setItalic(keyWord, true);
        textPane.setText("one\ntwo\nthree\nfour\nfive\nsix\nseven\neight\n");
        doc.setCharacterAttributes(0, 3, keyWord, false);
        doc.setCharacterAttributes(19, 4, keyWord, false);
        try {
            doc.insertString(0, "Start of text\n", null);
            doc.insertString(doc.getLength(), "End of text\n", keyWord);
        } catch (Exception e) {
        }
        final MutableAttributeSet selWord = new SimpleAttributeSet();
        StyleConstants.setForeground(selWord, Color.blue);
        StyleConstants.setItalic(selWord, true);
        JScrollPane scrollPane = new JScrollPane(textPane);
        scrollPane.setPreferredSize(new Dimension(200, 200));
        add(scrollPane);

        JToggleButton toggleButton = new JToggleButton("where is 'four'");
        toggleButton.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent actionEvent) {
                //AbstractButton abstractButton = (AbstractButton) actionEvent.getSource();
                //boolean selected = abstractButton.getModel().isSelected();
                int index = textPane.getText().indexOf("four");
                StyledDocument doc = textPane.getStyledDocument();
                doc.setCharacterAttributes(index, 4, selWord, false);
            }
        });
        add(toggleButton, BorderLayout.SOUTH);
    }

    public static void main(String[] args) {
        Runnable doRun = new Runnable() {

            @Override
            public void run() {
                TextPaneAttributes frame = new TextPaneAttributes();
                frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
                frame.pack();
                frame.setVisible(true);
            }
        };
        SwingUtilities.invokeLater(doRun);
    }
}

回答3:

my guess: maybe there's a difference in what newline characters are used in JTextPane and StyledDocument, let's say JTextPane uses \n and StyledDocument uses \r\n

回答4:

I observed the same thing and I used this code to adjustment:

  private int countCarrierReturns(StringBuilder sb, int end) {
        final String cr = "\r";
        int lines = 0;
        int init = sb.indexOf(cr, 0);

        if (init == -1) {
            return 0;
        }

        while (init < end) {
            lines++;

            init = sb.indexOf(cr, init + 1);
        }

        return lines;
    }

the 'int end' is my first char to apply style.