确定换行时 JTextArea 行的文本偏移量

Question

我正在尝试确定文本区域中一行文本的边界。我知道我可以确定偏移量的界限，这意味着我需要知道行的开头和结尾的偏移量。

所以我想尝试使用 getLine* 方法，但它没有给出我预期的结果。

import java.awt.BorderLayout;
import java.awt.Color;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.text.DefaultHighlighter;

public class TextAreaLineBoundsTest
{
    public static void main(String[] args) throws Exception
    {
        String string = "Lorem ipsum eum putant gubergren evertitur in, no assueverit vituperatoribus eum. Ea cibo offendit vim, est et vivendum qualisque prodesset. Vis doctus expetenda contentiones an, no ius mazim epicuri expetendis, saperet salutandi forensibus ne usu. Ex fugit alterum usu. His ignota cotidieque in, augue erroribus eam no.";
        JTextArea textArea = new JTextArea(string);
        textArea.setLineWrap(true);
        textArea.setWrapStyleWord(true);

        String term = "qualisque";
        int termOffset = string.indexOf(term);

        int termLine = textArea.getLineOfOffset(termOffset);
        int termLineStartOffset = textArea.getLineStartOffset(termLine);
        int termLineEndOffset = textArea.getLineEndOffset(termLine);

        textArea.getHighlighter().addHighlight(termLineStartOffset, termLineEndOffset, new DefaultHighlighter.DefaultHighlightPainter(Color.YELLOW));

        JScrollPane textAreaScroll = new JScrollPane(textArea);

        JFrame frame = new JFrame();
        frame.setLayout(new BorderLayout());
        frame.add(textAreaScroll, BorderLayout.CENTER);
        frame.setSize(400, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
}

它突出显示的是整个文本段落，但我只想要包含我正在搜索的术语的行。

Answer 1

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

public class TextAreaLine
{
    public static void main(String[] args) throws Exception
    {
        String string = "Lorem ipsum eum putant gubergren evertitur in, no assueverit vituperatoribus eum. Ea cibo offendit vim, est et vivendum qualisque prodesset. Vis doctus expetenda contentiones an, no ius mazim epicuri expetendis, saperet salutandi forensibus ne usu. Ex fugit alterum usu. His ignota cotidieque in, augue erroribus eam no.";
        JTextArea textArea = new JTextArea(string);
        textArea.setLineWrap(true);
        textArea.setWrapStyleWord(true);
        JScrollPane textAreaScroll = new JScrollPane(textArea);

        JFrame frame = new JFrame();
        frame.setLayout(new BorderLayout());
        frame.add(textAreaScroll, BorderLayout.CENTER);
        frame.setSize(400, 300);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);

        String term = "qualisque";
        int termOffset = string.indexOf(term);
        Rectangle view = textArea.modelToView(termOffset);
        int startOffset = textArea.viewToModel(new Point(0, view.y));
        int endOffset = textArea.viewToModel(new Point(textArea.getSize().width, view.y) );
        textArea.getHighlighter().addHighlight(startOffset, endOffset, new DefaultHighlighter.DefaultHighlightPainter(Color.YELLOW));
    }
}