ANTLR is a powerful parser generator for multiple programming languages including Java.

ANTLR contains 2 major modules:

• Runtime - For building and executing parsers/lexers generated in Java.
• Tool (The Parser Generator) - For generating parsers/lexers Java class.

ANTLR Runtime Source Code files are provided in the distribution packge (antlr4-4.10.1.zip). You can download them at ANTLR Website.

You can also browse the source code below:

⏎ org/antlr/v4/runtime/tree/ParseTreeListener.java

/*
 * Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
 * Use of this file is governed by the BSD 3-clause license that
 * can be found in the LICENSE.txt file in the project root.
 */

package org.antlr.v4.runtime.tree;

import org.antlr.v4.runtime.ParserRuleContext;

/** This interface describes the minimal core of methods triggered
 *  by {@link ParseTreeWalker}. E.g.,
 *
 *  	ParseTreeWalker walker = new ParseTreeWalker();
 *		walker.walk(myParseTreeListener, myParseTree); <-- triggers events in your listener
 *
 *  If you want to trigger events in multiple listeners during a single
 *  tree walk, you can use the ParseTreeDispatcher object available at
 *
 * 		https://github.com/antlr/antlr4/issues/841
 */
public interface ParseTreeListener {
	void visitTerminal(TerminalNode node);
	void visitErrorNode(ErrorNode node);
    void enterEveryRule(ParserRuleContext ctx);
    void exitEveryRule(ParserRuleContext ctx);
}

⏎ org/antlr/v4/runtime/tree/ParseTreeListener.java

Or download all of them as a single archive file:

File name: antlr-runtime-4.10.1-sources.jar
File size: 308953 bytes
Release date: 2022-04-15
Download 

⇒ ANTLR Tool Source Code

⇐ What Is ANTLR Parser Generator

⇑ Download and Review ANTLR Parser Generator

⇑⇑ FAQ for ANTLR Parser Generator