content: /*
   * Copyright (C) 2012 The Android Open Source Project
   *
   * Licensed 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 androidx.test.internal.runner;
  
  import androidx.annotation.Nullable;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.LinkedHashMap;
  import java.util.List;
  import java.util.Map;
  import org.junit.runner.Runner;
  import org.junit.runners.model.RunnerBuilder;
  
  /**
   * An abstract class for loading JUnit3 and JUnit4 test classes given a set of potential class
   * names.
   */
  public abstract class TestLoader {
  
    /** Factory for {@link TestLoader} */
    public static class Factory {
  
      private Factory() {}
  
      public static TestLoader create(
          @Nullable ClassLoader classLoader, RunnerBuilder runnerBuilder, boolean scanningPath) {
  
        if (classLoader == null) {
          classLoader = TestLoader.class.getClassLoader();
        }
  
        if (scanningPath) {
          return new ScanningTestLoader(classLoader, runnerBuilder);
        } else {
          return new DirectTestLoader(classLoader, runnerBuilder);
        }
      }
    }
  
    protected abstract Runner doCreateRunner(String className);
  
    /**
     * Get the {@link Collection) of {@link Runner runners}.
     */
    public List<Runner> getRunnersFor(Collection<String> classNames) {
      final Map<String, Runner> runnersMap = new LinkedHashMap<>();
  
      for (String className : classNames) {
        if (!runnersMap.containsKey(className)) {
          Runner runner = doCreateRunner(className);
          if (runner != null) {
            runnersMap.put(className, runner);
          }
        }
      }
      return new ArrayList<>(runnersMap.values());
    }
  }
  