确定JTextArea行换行时的文本偏移量

Question

我正在尝试确定文本区域中文本行的边界。我知道我可以确定偏移量的边界，这意味着我需要知道该行的开始和结束的偏移量。

所以我想我会尝试使用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); 
    } 
} 

它突出显示的是文本的整个段落，但我只想包含我正在搜索的术语的那一行。

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)); 
    } 
}