com.streamsets.pipeline.api.base.BaseEnumChooserValues Maven / Gradle / Ivy

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/*
 * Copyright 2017 StreamSets Inc.
 *
 * 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 com.streamsets.pipeline.api.base;

import com.streamsets.pipeline.api.ChooserValues;
import com.streamsets.pipeline.api.Label;
import com.streamsets.pipeline.api.impl.Utils;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * Base {@link ChooserValues} implementation for enums.
 */
public abstract class BaseEnumChooserValues implements ChooserValues {
  private String resourceBundle;
  private List values;
  private List labels;

  /**
   * Creates a ChooserValues with all the enum values of the given enum class.
   *
   * @param klass enum class.
   */
  @SuppressWarnings("unchecked")
  public BaseEnumChooserValues(Class klass) {
    this((T[])klass.getEnumConstants());
  }

  /**
   * Creates a ChooserValues with the specified enum values.
   *
   * @param enums enums for the ChooserValues.
   */
  @SuppressWarnings("unchecked")
  public BaseEnumChooserValues(T ... enums) {
    Utils.checkNotNull(enums, "enums");
    Utils.checkArgument(enums.length > 0, "array enum cannot have zero elements");
    resourceBundle = enums[0].getClass().getName() + "-bundle";
    boolean isEnumWithLabels = enums[0] instanceof Label;
    values = new ArrayList<>(enums.length);
    labels = new ArrayList<>(enums.length);
    for (T e : enums) {
      String value = e.name();
      values.add(value);
      String label = isEnumWithLabels ? ((Label)e).getLabel() : value;
      labels.add(label);
    }
    values = Collections.unmodifiableList(values);
    labels = Collections.unmodifiableList(labels);
  }

  @Override
  public String getResourceBundle() {
    return resourceBundle;
  }

  @Override
  public List getValues() {
    return values;
  }

  @Override
  public List getLabels() {
    return labels;
  }
}