Allow the remote server to handle relative locators

This avoids the need to send a large amount of JS across the wire, and
should make using the relative locators with the Selenium server more
efficient.

java/src/org/openqa/selenium/support/locators/BUILD.bazel

@@ -13,8 +13,9 @@ java_library(
         "//java/test/org/openqa/selenium/support/locators:__pkg__",
     ],
     deps = [
-        "//java/src/org/openqa/selenium:core",
+        "//java:auto-service",
         "//java/src/org/openqa/selenium/json",
+        "//java/src/org/openqa/selenium/remote",
         artifact("com.google.guava:guava"),
     ],
 )

java/src/org/openqa/selenium/support/locators/RelativeLocator.java

@@ -36,6 +36,7 @@
 import java.util.Map;
 
 import static org.openqa.selenium.json.Json.MAP_TYPE;
+import static org.openqa.selenium.support.locators.RelativeLocatorScript.FIND_ELEMENTS;
 
 /**
  * Used for finding elements by their location on a page, rather than their
@@ -71,23 +72,6 @@
 public class RelativeLocator {
 
   private static final Json JSON = new Json();
-  private static final String FIND_ELEMENTS;
-
-  static {
-    try {
-      String location = String.format(
-        "/%s/%s",
-        RelativeLocator.class.getPackage().getName().replace(".", "/"),
-        "findElements.js");
-
-      URL url = RelativeLocator.class.getResource(location);
-
-      String rawFunction = Resources.toString(url, StandardCharsets.UTF_8);
-      FIND_ELEMENTS = String.format("return (%s).apply(null, arguments);", rawFunction);
-    } catch (IOException e) {
-      throw new UncheckedIOException(e);
-    }
-  }
 
   private static final int CLOSE_IN_PIXELS = 100;
 

java/src/org/openqa/selenium/support/locators/RelativeLocatorScript.java

@@ -0,0 +1,51 @@
+// 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.support.locators;
+
+import com.google.common.io.Resources;
+
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+
+class RelativeLocatorScript {
+
+  static final String FIND_ELEMENTS;
+
+  static {
+    try {
+      String location = String.format(
+        "/%s/%s",
+        RelativeLocator.class.getPackage().getName().replace(".", "/"),
+        "findElements.js");
+
+      URL url = RelativeLocator.class.getResource(location);
+
+      String rawFunction = Resources.toString(url, StandardCharsets.UTF_8);
+      FIND_ELEMENTS = String.format("return (%s).apply(null, arguments);", rawFunction);
+    } catch (IOException e) {
+      throw new UncheckedIOException(e);
+    }
+  }
+
+  private RelativeLocatorScript() {
+    // Utility class.
+  }
+
+}

java/src/org/openqa/selenium/support/locators/RelativeLocatorServerSide.java

@@ -0,0 +1,74 @@
+// 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.support.locators;
+
+import com.google.auto.service.AutoService;
+import com.google.common.collect.ImmutableMap;
+import org.openqa.selenium.By;
+import org.openqa.selenium.InvalidArgumentException;
+import org.openqa.selenium.JavascriptExecutor;
+import org.openqa.selenium.SearchContext;
+import org.openqa.selenium.WebDriver;
+import org.openqa.selenium.WebElement;
+import org.openqa.selenium.internal.Require;
+import org.openqa.selenium.remote.JsonToWebElementConverter;
+import org.openqa.selenium.remote.RemoteWebDriver;
+import org.openqa.selenium.remote.locators.CustomLocator;
+
+import java.util.List;
+
+import static org.openqa.selenium.support.locators.RelativeLocatorScript.FIND_ELEMENTS;
+
+@AutoService(CustomLocator.class)
+public class RelativeLocatorServerSide implements CustomLocator {
+  @Override
+  public String getLocatorName() {
+    return "relative";
+  }
+
+  @Override
+  public By createBy(Object usingParameter) {
+    Require.nonNull("Using", usingParameter);
+    return new RemoteRelative(usingParameter);
+  }
+
+  private static class RemoteRelative extends By {
+    private final Object using;
+
+    private RemoteRelative(Object usingParameter) {
+      using = usingParameter;
+    }
+
+    @Override
+    public List<WebElement> findElements(SearchContext context) {
+      JavascriptExecutor js = getJavascriptExecutor(context);
+
+      WebDriver driver = getWebDriver(context);
+
+      if (driver instanceof RemoteWebDriver) {
+        Object converted = new JsonToWebElementConverter((RemoteWebDriver) driver).apply(using);
+
+        @SuppressWarnings("unchecked")
+        List<WebElement> elements = (List<WebElement>) js.executeScript(FIND_ELEMENTS, ImmutableMap.of("relative", converted));
+        return elements;
+      }
+
+      throw new InvalidArgumentException("Unable to find element");
+    }
+  }
+}

java/test/org/openqa/selenium/chrome/BUILD.bazel

@@ -23,7 +23,7 @@ java_selenium_test_suite(
         artifact("org.mockito:mockito-core"),
     ],
     javacopts = [
-            "--release",
-            "11",
-        ],
+        "--release",
+        "11",
+    ],
 )

java/test/org/openqa/selenium/support/locators/BUILD.bazel

@@ -10,6 +10,9 @@ java_selenium_test_suite(
         "--release",
         "11",
     ],
+    tags = [
+        "selenium-remote",
+    ],
     deps = [
         "//java/src/org/openqa/selenium:core",
         "//java/src/org/openqa/selenium/remote",

java/test/org/openqa/selenium/support/locators/RelativeLocatorTest.java

@@ -19,8 +19,11 @@
 
 import org.junit.Test;
 import org.openqa.selenium.By;
+import org.openqa.selenium.ImmutableCapabilities;
+import org.openqa.selenium.WebDriver;
 import org.openqa.selenium.WebElement;
 import org.openqa.selenium.environment.webserver.Page;
+import org.openqa.selenium.remote.RemoteWebDriver;
 import org.openqa.selenium.testing.JUnit4TestBase;
 
 import java.util.List;