如何在Java Swing TextArea中更改突出显示颜色？并且，更改与突出显示位置对应的文本的开头

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问题描述

问题1：通过使用defaulthighlighter，我可以使聚焦的线条变为蓝色。 现在我想将其更改为其他颜色。有谁知道如何更改此参数？ ---已解决

Problem 1: BY using defaulthighlighter, I can make the focused lines change to blue. Now I want to change it to other colors. Do anyone know how to change this parameter? --- solved

问题2：pos是我想要突出显示的子字符串的起始索引。我用setCaretPosition（pos）;更新显示内容。但它总是出现在窗口的底部。我想把它放在最顶层。有人可以告诉我如何处理它吗？

Problem 2: pos is the beginning index of my substring which I want to highlight. I use setCaretPosition(pos); to update the showing content. But it always appears at the bottom of the window. I want to have it at the top. Could anyone tell me how to deal with that?

我用一个演示来表明我的问题：

I use one demo to show my problem:

import java.awt.Color;
import java.net.MalformedURLException;

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

public class Test {
    public static void main(final String[] args) throws MalformedURLException {
        SwingUtilities.invokeLater(new Runnable() {

        @Override
        public void run() {
            try {
                init();
            } catch (BadLocationException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }
    });
}

private static void init() throws BadLocationException {
    JFrame frame = new JFrame();
    final JTextArea textArea = new JTextArea();
    JScrollPane pane = new JScrollPane(textArea);
    textArea.setText("Something. Something else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Samething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Sbmething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Scmething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Sdmething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Semething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Sfmething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Sgmething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n");
    textArea.setSelectionColor(Color.RED);
    frame.add(pane);
    frame.setSize(300, 120);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);

    String turnToString2 = "Sdmething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla";
    int pos2 = textArea.getText().indexOf(turnToString2);
    textArea.getHighlighter().addHighlight(pos2,
            pos2 + turnToString2.length(),
            new DefaultHighlighter.DefaultHighlightPainter(Color.yellow));
    textArea.setCaretPosition(pos2);

结果是：

The result is :

我希望它在在屏幕的右上角，但在此代码中，它显示在滚动窗格的底部。任何人都可以知道如何改变这个？
谢谢。

I want it to be at the right top of the screen but in this code, it is shown at the bottom of the scrollpane. Can anyone know how to change this?THanks.

推荐答案

你可以实现这一点，虽然不是直接的，因为你必须保存对突出显示您已添加到所述行，因此您必须遍历所有要点以删除所需的那个，看看附加的程序，可能会这样帮助你达到你想要的目标：

You can achieve this, though not directly, since you have to save the reference to the Highlight that you had added to the said line, hence you have to traverse through all the Highlights to remove the one you want, have a look at the program attached, might be this will help you to attain what you so desire :

最新编辑：新代码，删除了一些错误，并添加了与设置CARET相关的所需功能位置

LATEST EDIT : NEW CODE, REMOVED SOME BUGS AND SEEMS LIKE ADDED THE DESIRED FUNCTIONALITY RELATED TO SETTING CARET POSITION

import java.awt.*;
import java.awt.event.*;
import java.util.Map;
import java.util.HashMap;
import javax.swing.*;
import javax.swing.text.*;

public class TextHighlight
{
    private JTextArea tarea;
    private JComboBox cbox;
    private JTextField lineField;
    private String[] colourNames = {"RED", "ORANGE", "CYAN"};

    private Highlighter.HighlightPainter redPainter;
    private Highlighter.HighlightPainter orangePainter;
    private Highlighter.HighlightPainter cyanPainter;

    private int firstUpdateIndex;
    private int counter;

    private Map<Integer, Highlighter.Highlight> highlights = new HashMap<Integer, Highlighter.Highlight>();

    public TextHighlight()
    {
        redPainter = new DefaultHighlighter.DefaultHighlightPainter(Color.RED);
        orangePainter = new DefaultHighlighter.DefaultHighlightPainter(Color.ORANGE);
        cyanPainter = new DefaultHighlighter.DefaultHighlightPainter(Color.CYAN);

        firstUpdateIndex = -1;
        counter = 0;
    }

    private void createAndDisplayGUI()
    {
        final JFrame frame = new JFrame("Text HIGHLIGHT");
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);

        JPanel contentPane = new JPanel();
        contentPane.setBorder(BorderFactory.createTitledBorder(
                BorderFactory.createEmptyBorder(5, 5, 5, 5), "Highlighter JTextArea"));

        tarea = new JTextArea(10, 10);
        JScrollPane scrollPane = new JScrollPane(tarea);
        contentPane.add(scrollPane);

        JButton remHighButton = new JButton("REMOVE HIGHLIGHT");
        remHighButton.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent ae)
            {
                String input = JOptionPane.showInputDialog(frame, "Please Enter Start Index : "
                                                        , "Highlighting Options : "
                                                        , JOptionPane.PLAIN_MESSAGE);

                if (input != null && (highlights.size() > 0))
                {
                    int startIndex = Integer.parseInt(input.trim());
                    Highlighter highlighter = tarea.getHighlighter();
                    highlighter.removeHighlight(highlights.get(startIndex));
                    tarea.setCaretPosition(startIndex);
                    tarea.requestFocusInWindow();
                    highlights.remove(startIndex);
                }
            }
        });

        JButton button = new JButton("HIGHLIGHT TEXT");
        button.addActionListener(new ActionListener()
        {
            public void actionPerformed(ActionEvent ae)
            {
                String text = null;
                text = tarea.getSelectedText();
                if (text != null && text.length() > 0)
                {
                    int startIndex = tarea.getText().indexOf(text);
                    int endIndex = startIndex + text.length();
                    Highlighter highlighter = tarea.getHighlighter();

                    int selection = JOptionPane.showConfirmDialog(
                                            frame, getOptionPanel(), "Highlight Colour : "
                                                , JOptionPane.OK_CANCEL_OPTION
                                                , JOptionPane.PLAIN_MESSAGE);

                    System.out.println("TEXT : " + text);
                    System.out.println("START INDEX : " + startIndex);
                    System.out.println("END INDEX : " + endIndex);

                    if (selection == JOptionPane.OK_OPTION)
                    {
                        String colour = (String) cbox.getSelectedItem();
                        try
                        {
                            if (colour == colourNames[0])
                            {
                                System.out.println("Colour Selected : " + colour);
                                highlighter.addHighlight(startIndex, endIndex, redPainter);
                            }
                            else if (colour == colourNames[1])
                            {
                                System.out.println("Colour Selected : " + colour);
                                highlighter.addHighlight(startIndex, endIndex, orangePainter);
                            }
                            else if (colour == colourNames[2])
                            {
                                System.out.println("Colour Selected : " + colour);
                                highlighter.addHighlight(startIndex, endIndex, cyanPainter);
                            }
                            Highlighter.Highlight[] highlightIndex = highlighter.getHighlights();
                            System.out.println("Lengh of Highlights used : " + highlightIndex.length);
                            highlights.put(startIndex, highlightIndex[highlightIndex.length - 1]);
                        }
                        catch(BadLocationException ble)
                        {
                            ble.printStackTrace();
                        }
                    }
                    else if (selection == JOptionPane.CANCEL_OPTION)
                    {
                        System.out.println("CANCEL BUTTON PRESSED.");
                    }
                    else if (selection == JOptionPane.CLOSED_OPTION)
                    {
                        System.out.println("JOPTIONPANE CLOSED DELIBERATELY.");
                    }
                }
            }
        });

        frame.add(remHighButton, BorderLayout.PAGE_START);
        frame.add(contentPane, BorderLayout.CENTER);
        frame.add(button, BorderLayout.PAGE_END);

        frame.pack();
        frame.setLocationByPlatform(true);
        frame.setVisible(true);
    }

    private JPanel getOptionPanel()
    {
        JPanel panel = new JPanel();
        panel.setBorder(BorderFactory.createTitledBorder(
                        BorderFactory.createLineBorder(Color.DARK_GRAY, 2), "COLOUR SELECTION"));
        panel.setLayout(new GridLayout(0, 2, 5, 5));

        JLabel colourLabel = new JLabel("Select One Colour : ");
        cbox = new JComboBox(colourNames);

        panel.add(colourLabel);
        panel.add(cbox);

        return panel;
    }

    public static void main(String... args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                new TextHighlight().createAndDisplayGUI();
            }
        });
    }
}

输出：

BEGIN：

亮点第一行 第二行

REMOVED HIGHLIGHT

突出显示不同颜色的相同

最新编辑与问题中的样本代码一致

import java.awt.*;
import java.net.MalformedURLException;

import javax.swing.*;
import javax.swing.text.*;

public class Test {
    public static void main(final String[] args) throws MalformedURLException {
        SwingUtilities.invokeLater(new Runnable() {

        @Override
        public void run() {
            try {
                init();
            } catch (BadLocationException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

        }
    });
}

private static void init() throws BadLocationException {
    JFrame frame = new JFrame();
    final JTextArea textArea = new JTextArea();
    JScrollPane pane = new JScrollPane(textArea);
    textArea.setText("Something. Something else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Samething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Sbmething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Scmething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Sdmething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Semething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Sfmething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nSomething. Sgmething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla\nBlabla\n");
    textArea.setSelectionColor(Color.RED);
    frame.add(pane);
    frame.setSize(300, 120);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);

    String turnToString2 = "Sdmething else.\nA second line\na third line"
            + "Blabla\nBlabla\nBlabla\nBlabla\nBlabla";
    int pos2 = textArea.getText().indexOf(turnToString2);
    Rectangle startIndex = textArea.modelToView(pos2);
    textArea.getHighlighter().addHighlight(pos2,
            pos2 + turnToString2.length(),
            new DefaultHighlighter.DefaultHighlightPainter(Color.yellow));
    int y = startIndex.y + (pane.getHeight() - 10);
    System.out.println("Pane Height : " + pane.getHeight());
    System.out.println("X : " + startIndex.x);
    System.out.println("Y : " + y);
    System.out.println("Y (pos2) : " + startIndex.y);
    textArea.setCaretPosition(textArea.viewToModel(new Point(startIndex.x, y)));
    pane.scrollRectToVisible(new Rectangle(startIndex.x, y));
    }
}

这是OUTPUT：

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