为程序内功能创建语法

Question

在 Java 中，我正在尝试制作一个具有输入文本区域的程序，该区域将对我之前定义的某些语法做出反应。每当我在其他单词中写关键字时它应该突出显示并且应该按照我的命令执行。

我的问题是如何创建这样的语法？如何让程序对这些词做出反应？在哪里保存这些关键字（在数组中？）？

谢谢

Answer 1

很好用TextDemo as a starting point here is a naive solution using DocumentListener

要点在这个函数上：

public void search() {
    hilit.removeAllHighlights();
    for (String s : keywords) {
        String content = textArea.getText();
        Pattern p = Pattern.compile("\b"+s+"\b");

        Matcher m = p.matcher(content);
        while (m.find()) {
            int index = m.start();
            int end = index + s.length();
            try {
                hilit.addHighlight(index, end, painter);
            } catch (BadLocationException ex) {
            }

        }
    }

}

我在数组上设置的关键字

private final String[] keywords = {"public", "final", "static"};

然后在 DocumentListener 函数中调用 search：

 @Override
 public void insertUpdate(DocumentEvent ev) {
    search();
 }

 @Override
 public void removeUpdate(DocumentEvent ev) {
    search();
 }

完整代码：

import java.awt.Color;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.swing.*;
import javax.swing.text.*;
import javax.swing.event.*;
import javax.swing.GroupLayout.*;

public class HighLightDemo extends JFrame implements DocumentListener {

    private final String[] keywords = {"public", "final", "static"};
    private JScrollPane jScrollPane1;
    private JTextArea textArea;

    final static Color HILIT_COLOR = Color.GREEN;
    final Highlighter hilit;
    final Highlighter.HighlightPainter painter;

    public HighLightDemo() {
        initComponents();
        hilit = new DefaultHighlighter();
        painter = new DefaultHighlighter.DefaultHighlightPainter(HILIT_COLOR);
        textArea.setHighlighter(hilit);
        textArea.getDocument().addDocumentListener(this);
    }

    private void initComponents() {
        textArea = new JTextArea();
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setTitle("HighlightDemo");

        textArea.setColumns(20);
        textArea.setLineWrap(true);
        textArea.setRows(5);
        textArea.setWrapStyleWord(true);
        jScrollPane1 = new JScrollPane(textArea);

        GroupLayout layout = new GroupLayout(getContentPane());
        getContentPane().setLayout(layout);

        //Create a parallel group for the horizontal axis
        ParallelGroup hGroup = layout.createParallelGroup(GroupLayout.Alignment.LEADING);

        //Create a sequential and a parallel groups
        SequentialGroup h1 = layout.createSequentialGroup();
        ParallelGroup h2 = layout.createParallelGroup(GroupLayout.Alignment.TRAILING);

        //Add a container gap to the sequential group h1
        h1.addContainerGap();

        //Add a scroll pane and a label to the parallel group h2
        h2.addComponent(jScrollPane1, GroupLayout.Alignment.LEADING, GroupLayout.DEFAULT_SIZE, 450, Short.MAX_VALUE);
        h1.addGroup(h2);

        h1.addContainerGap();

        //Add the group h1 to the hGroup
        hGroup.addGroup(GroupLayout.Alignment.TRAILING, h1);
        //Create the horizontal group
        layout.setHorizontalGroup(hGroup);

        //Create a parallel group for the vertical axis
        ParallelGroup vGroup = layout.createParallelGroup(GroupLayout.Alignment.LEADING);
        //Create a sequential group v1
        SequentialGroup v1 = layout.createSequentialGroup();
        //Add a container gap to the sequential group v1
        v1.addContainerGap();
        //Create a parallel group v2
        ParallelGroup v2 = layout.createParallelGroup(GroupLayout.Alignment.BASELINE);

        //Add the group v2 tp the group v1
        v1.addGroup(v2);
        v1.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED);
        v1.addComponent(jScrollPane1, GroupLayout.DEFAULT_SIZE, 233, Short.MAX_VALUE);
        v1.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED);
        v1.addContainerGap();

        //Add the group v1 to the group vGroup
        vGroup.addGroup(v1);
        //Create the vertical group
        layout.setVerticalGroup(vGroup);
        pack();
    }

    public void search() {
        hilit.removeAllHighlights();


        for (String s : keywords) {
            String content = textArea.getText();
            Pattern p = Pattern.compile("\b"+s+"\b");

            Matcher m = p.matcher(content);
            while (m.find()) {
                int index = m.start();
                int end = index + s.length();
                try {
                    hilit.addHighlight(index, end, painter);
                } catch (BadLocationException ex) {
                }

            }
        }

    }

    @Override
    public void insertUpdate(DocumentEvent ev) {
        search();
    }

    @Override
    public void removeUpdate(DocumentEvent ev) {
        search();
    }

    @Override
    public void changedUpdate(DocumentEvent ev) {
    }

    public static void main(String args[]) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new HighLightDemo().setVisible(true);
            }
        });
    }

}

为程序内功能创建语法

Creating a syntax for the in-program functionality

java

syntax

syntax-highlighting