java - 迭代使用 DocumentFilter

Question

我正在尝试运行此代码:

How to change the color of specific words in a JTextPane?

private final class CustomDocumentFilter extends DocumentFilter
{
        private final StyledDocument styledDocument = yourTextPane.getStyledDocument();

    private final StyleContext styleContext = StyleContext.getDefaultStyleContext();
    private final AttributeSet greenAttributeSet = styleContext.addAttribute(styleContext.getEmptySet(), StyleConstants.Foreground, Color.GREEN);
    private final AttributeSet blackAttributeSet = styleContext.addAttribute(styleContext.getEmptySet(), StyleConstants.Foreground, Color.BLACK);

// Use a regular expression to find the words you are looking for
Pattern pattern = buildPattern();

@Override
public void insertString(FilterBypass fb, int offset, String text, AttributeSet attributeSet) throws BadLocationException {
    super.insertString(fb, offset, text, attributeSet);

    handleTextChanged();
}

@Override
public void remove(FilterBypass fb, int offset, int length) throws BadLocationException {
    super.remove(fb, offset, length);

    handleTextChanged();
}

@Override
public void replace(FilterBypass fb, int offset, int length, String text, AttributeSet attributeSet) throws BadLocationException {
    super.replace(fb, offset, length, text, attributeSet);

    handleTextChanged();
}

/**
 * Runs your updates later, not during the event notification.
 */
private void handleTextChanged()
{
    SwingUtilities.invokeLater(new Runnable() {
        @Override
        public void run() {
            updateTextStyles();
        }
    });
}

/**
 * Build the regular expression that looks for the whole word of each word that you wish to find.  The "\\b" is the beginning or end of a word boundary.  The "|" is a regex "or" operator.
 * @return
 */
private Pattern buildPattern()
{
    StringBuilder sb = new StringBuilder();
    for (String token : ALL_WORDS_THAT_YOU_WANT_TO_FIND) {
        sb.append("\\b"); // Start of word boundary
        sb.append(token);
        sb.append("\\b|"); // End of word boundary and an or for the next word
    }
    if (sb.length() > 0) {
        sb.deleteCharAt(sb.length() - 1); // Remove the trailing "|"
    }

    Pattern p = Pattern.compile(sb.toString());

    return p;
}


private void updateTextStyles()
{
    // Clear existing styles
    styledDocument.setCharacterAttributes(0, yourTextPane.getText().length(), blackAttributeSet, true);

    // Look for tokens and highlight them
    Matcher matcher = pattern.matcher(yourTextPane.getText());
    while (matcher.find()) {
        // Change the color of recognized tokens
        styledDocument.setCharacterAttributes(matcher.start(), matcher.end() - matcher.start(), greenAttributeSet, false);
    }
}
}

还有

((AbstractDocument) yourTextPane.getDocument()).setDocumentFilter(new CustomDocumentFilter());

我想迭代地使用它，也就是说，任何新字符串ALL_WORDS_THAT_YOU_WANT_TO_FIND都会自动着色。我想到了删除

styledDocument.setCharacterAttributes(0, yourTextPane.getText().length(), blackAttributeSet, true);

(即不破坏之前的彩色单词)，但它不起作用:它只保留上次迭代时给出的输入单词的颜色。我怎样才能做到这一点？

Answer 1

编辑:在评论中提出两个问题后更新

您想将单词添加到列表中并更新 JTextPane 吗？在这种情况下，您需要确保每次 updateTextStyles 方法运行时都会更新并使用该列表。

您可以使用多个单词列表，这些单词列表可以对文本应用独特的格式。您开始使用的代码使用正则表达式，您可以将其扩展为多个正则表达式。您还可以搜索子字符串(或文本片段)的区分大小写的精确匹配项，而无需查看单词边界，如下面的代码中所使用的那样。

这意味着某些文本的格式可能会因不同组的匹配而多次更改。您搜索的顺序将决定最终结果。例如，这个小示例允许您填充文本 Pane 并将新单词添加到三个突出显示组(颜色为红色、橙色和蓝色):

以下是示例中三个类的代码(使用 Java 8):

IterativeDocumentFilter.java:

import java.awt.*;
import java.util.List;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.text.*;

public class IterativeDocumentFilter {
    public static void main(String[] arguments) {
        SwingUtilities.invokeLater(
                () -> new IterativeDocumentFilter().createAndShowGui()
        );
    }

    private void createAndShowGui() {
        JFrame frame = new JFrame("Stack Overflow");
        frame.setBounds(100, 100, 1000, 600);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        JPanel mainPanel = new JPanel(new BorderLayout());

        JTextPane textPane = new JTextPane(new DefaultStyledDocument());
        CustomDocumentFilter documentFilter = new CustomDocumentFilter(textPane);
        textPane.setBorder(new LineBorder(Color.BLACK, 1));
        enlargeFont(textPane);

        mainPanel.add(textPane, BorderLayout.CENTER);
        mainPanel.add(createBottomPanels(documentFilter), BorderLayout.PAGE_END);

        frame.getContentPane().add(mainPanel);
        frame.setVisible(true);
    }

    private JPanel createBottomPanels(CustomDocumentFilter documentFilter) {
        JPanel bottomPanels = new JPanel();
        bottomPanels.setLayout(new BoxLayout(bottomPanels, BoxLayout.PAGE_AXIS));
        for (HighlightGroup highlightGroup : documentFilter.getHighlightGroups()) {
            List<String> textFragments = highlightGroup.getTextFragments();
            JPanel groupPanel = new JPanel(new FlowLayout(FlowLayout.LEADING));
            JLabel textFragmentsLabel = new JLabel("Current text fragments: "
                                                   + textFragments);
            textFragmentsLabel.setForeground(highlightGroup.getColor());
            JLabel addTextFragmentLabel = new JLabel("Additional text fragment:");
            addTextFragmentLabel.setForeground(highlightGroup.getColor());
            JTextField addTextFragmentTextField = new JTextField(28);
            JButton addTextFragmentButton = new JButton("Add text fragment");
            addTextFragmentButton.setForeground(highlightGroup.getColor());

            addTextFragmentButton.addActionListener(actionEvent -> {
                String newTextFragment = addTextFragmentTextField.getText().trim();
                if (!textFragments.contains(newTextFragment)) {
                    textFragments.add(newTextFragment);
                    documentFilter.handleTextChanged();
                    textFragmentsLabel.setText("Current text fragments: "
                                               + textFragments);
                }
                addTextFragmentTextField.setText("");
            });

            groupPanel.add(addTextFragmentLabel);
            groupPanel.add(addTextFragmentTextField);
            groupPanel.add(addTextFragmentButton);
            textFragmentsLabel.setBorder(new EmptyBorder(0, 42, 0, 0));
            groupPanel.add(textFragmentsLabel);

            enlargeFont(addTextFragmentLabel);
            enlargeFont(addTextFragmentTextField);
            enlargeFont(addTextFragmentButton);
            enlargeFont(textFragmentsLabel);

            bottomPanels.add(groupPanel);
        }

        return bottomPanels;
    }

    private void enlargeFont(Component component) {
        component.setFont(component.getFont().deriveFont(16f));
    }
}

CustomDocumentFilter.java:

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

public class CustomDocumentFilter extends DocumentFilter
{
    private final JTextPane textPane;
    private final List<HighlightGroup> highlightGroups;

    private final StyleContext styleContext = StyleContext.getDefaultStyleContext();
    private final AttributeSet blackAttributeSet
            = styleContext.addAttribute(styleContext.getEmptySet(),
                                        StyleConstants.Foreground, Color.BLACK);

    public CustomDocumentFilter(JTextPane textPane) {
        this.textPane = textPane;

        highlightGroups = createHighlightGroups();
        ((AbstractDocument) textPane.getDocument()).setDocumentFilter(this);
    }

    private List<HighlightGroup> createHighlightGroups() {
        List<HighlightGroup> groups = new ArrayList<>();
        groups.add(new HighlightGroup(Arrays.asList("one", "two", "three"), Color.RED));
        groups.add(new HighlightGroup(Arrays.asList("a", "the"), Color.ORANGE));
        groups.add(new HighlightGroup(Arrays.asList("th", "o"), Color.BLUE));
        return groups;
    }

    public List<HighlightGroup> getHighlightGroups() {
        return highlightGroups;
    }

    @Override
    public void insertString(FilterBypass fb, int offset, String text,
                             AttributeSet attributeSet) throws BadLocationException {
        super.insertString(fb, offset, text, attributeSet);

        handleTextChanged();
    }

    @Override
    public void remove(FilterBypass fb, int offset, int length)
            throws BadLocationException {
        super.remove(fb, offset, length);

        handleTextChanged();
    }

    @Override
    public void replace(FilterBypass fb, int offset, int length, String text,
                        AttributeSet attributeSet) throws BadLocationException {
        super.replace(fb, offset, length, text, attributeSet);

        handleTextChanged();
    }

    /**
     * Runs your updates later, not during the event notification.
     */
    public void handleTextChanged()
    {
        SwingUtilities.invokeLater(this::updateTextStyles);
    }

    private void updateTextStyles()
    {
        // Reset the existing styles by using the default black style for all text.
        StyledDocument document = textPane.getStyledDocument();
        document.setCharacterAttributes(0, textPane.getText().length(),
                                        blackAttributeSet, true);

        // Apply styling for the different groups (the order of the groups is relevant).
        for (HighlightGroup highlightGroup : highlightGroups) {
            highlightGroup.highlightWords(textPane);
        }
    }
}

HighlightGroup.java:

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

public class HighlightGroup {
    private final List<String> textFragments;
    private final Color color;
    private final AttributeSet attributeSet;

    public HighlightGroup(List<String> textFragments, Color color) {
        this.textFragments = new ArrayList<>(textFragments);
        this.color = color;

        StyleContext styleContext = StyleContext.getDefaultStyleContext();
        this.attributeSet = styleContext.addAttribute(styleContext.getEmptySet(),
                                                      StyleConstants.Foreground,
                                                      color);
    }

    public List<String> getTextFragments() {
        return textFragments;
    }

    public Color getColor() {
        return color;
    }

    public void highlightWords(JTextPane textPane) {
        String text = textPane.getText();
        StyledDocument styledDocument = textPane.getStyledDocument();
        for (String textFragment : textFragments) {
            int fromIndex = 0;
            int startIndex = text.indexOf(textFragment, fromIndex);
            while (startIndex != -1) {
                // Change the color of recognized text fragments.
                styledDocument.setCharacterAttributes(startIndex, textFragment.length(),
                                                      attributeSet, false);

                fromIndex = startIndex + textFragment.length();
                startIndex = text.indexOf(textFragment, fromIndex);
            }
        }
    }
}