code: // Licensed to the Software Freedom Conservancy (SFC) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The SFC licenses this file
  // to you under the Apache License, Version 2.0 (the
  // "License"); you may not use this file except in compliance
  // with the License.  You may obtain a copy of the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing,
  // software distributed under the License is distributed on an
  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, either express or implied.  See the License for the
  // specific language governing permissions and limitations
  // under the License.
  
  package org.openqa.selenium.devtools.events;
  
  import static java.nio.charset.StandardCharsets.UTF_8;
  import static org.openqa.selenium.json.Json.MAP_TYPE;
  
  import com.google.common.io.Resources;
  import java.io.IOException;
  import java.net.URL;
  import java.util.List;
  import java.util.Map;
  import java.util.function.Consumer;
  import org.openqa.selenium.By;
  import org.openqa.selenium.JavascriptExecutor;
  import org.openqa.selenium.WebDriver;
  import org.openqa.selenium.WebElement;
  import org.openqa.selenium.devtools.DevTools;
  import org.openqa.selenium.devtools.HasDevTools;
  import org.openqa.selenium.internal.Require;
  import org.openqa.selenium.json.Json;
  import org.openqa.selenium.logging.EventType;
  
  public class CdpEventTypes {
  
    private static final Json JSON = new Json();
  
    private CdpEventTypes() {
      // Utility class.
    }
  
    public static EventType<ConsoleEvent> consoleEvent(Consumer<ConsoleEvent> handler) {
      Require.nonNull("Handler", handler);
  
      return new EventType<ConsoleEvent>() {
        public void consume(ConsoleEvent event) {
          handler.accept(event);
        }
  
        @Override
        public void initializeListener(WebDriver webDriver) {
          Require.precondition(
              webDriver instanceof HasDevTools, "Loggable must implement HasDevTools");
  
          DevTools tools = ((HasDevTools) webDriver).getDevTools();
          tools.createSessionIfThereIsNotOne(webDriver.getWindowHandle());
  
          tools.getDomains().events().addConsoleListener(handler);
        }
      };
    }
  
    public static EventType<Void> domMutation(Consumer<DomMutationEvent> handler) {
      Require.nonNull("Handler", handler);
  
      URL url = CdpEventTypes.class.getResource("/org/openqa/selenium/devtools/mutation-listener.js");
      if (url == null) {
        throw new IllegalStateException("Unable to find helper script");
      }
      String script;
      try {
        script = Resources.toString(url, UTF_8);
      } catch (IOException e) {
        throw new IllegalStateException("Unable to read helper script");
      }
  
      return new EventType<Void>() {
        @Override
        public void consume(Void event) {
          handler.accept(null);
        }
  
        @Override
        public void initializeListener(WebDriver driver) {
          Require.precondition(driver instanceof HasDevTools, "Loggable must implement HasDevTools");
  
          DevTools tools = ((HasDevTools) driver).getDevTools();
          tools.createSessionIfThereIsNotOne(driver.getWindowHandle());
  
          tools.getDomains().javascript().pin("__webdriver_attribute", script);
  
          // And add the script to the current page
          ((JavascriptExecutor) driver).executeScript(script);
  
          tools
              .getDomains()
              .javascript()
              .addBindingCalledListener(
                  json -> {
                    Map<String, Object> values = JSON.toType(json, MAP_TYPE);
                    String id = (String) values.get("target");
  
                    List<WebElement> elements =
                        driver.findElements(
                            By.cssSelector(String.format("*[data-__webdriver_id='%s']", id)));
  
                    if (!elements.isEmpty()) {
                      DomMutationEvent event =
                          new DomMutationEvent(
                              elements.get(0),
                              String.valueOf(values.get("name")),
                              String.valueOf(values.get("value")),
                              String.valueOf(values.get("oldValue")));
                      handler.accept(event);
                    }
                  });
        }
      };
    }
  }
  