DocumentationDelegateProvider.java

/*
 * Copyright 2000-2016 JetBrains s.r.o.
 *
 * 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.intellij.codeInsight.javadoc;

import com.intellij.openapi.extensions.ExtensionPointName;
import com.intellij.psi.PsiDocCommentOwner;
import com.intellij.psi.PsiMember;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

public abstract class DocumentationDelegateProvider {

  public static final ExtensionPointName<DocumentationDelegateProvider> EP_NAME = ExtensionPointName.create(
    "com.intellij.documentationDelegateProvider"
  );

  /**
   * <p>
   * Computes PsiDocCommentOwner to get documentation from.
   * </p>
   * <p>
   * Suppose there is a {@code Foo#bar()} with doc and {@code Baz#bar()} without doc:
   * <pre>
   * class Foo {
   *   /**
   *   * Some javadoc
   *   */
   *   void bar() {}
   * }
   * class Baz {
   *   void bar() {}
   * }
   * </pre>
   * If it is needed to display doc from {@code Foo#bar()} when doc for {@code Baz#bar()} is queried
   * then this method should return PsiMethod corresponding to {@code Foo#bar()} for PsiMethod corresponding to {@code Baz#bar()}.
   * <br>
   * The copied documentation will include <i>Description copied from</i> link.
   * </p>
   *
   * @param member method to search delegate for.
   * @return delegate PsiDocCommentOwner instance.
   */
  @Nullable
  public abstract PsiDocCommentOwner computeDocumentationDelegate(@NotNull PsiMember member);

  @Nullable
  public static PsiDocCommentOwner findDocumentationDelegate(@NotNull PsiMember method) {
    for (DocumentationDelegateProvider delegator : EP_NAME.getExtensions()) {
      PsiDocCommentOwner type = delegator.computeDocumentationDelegate(method);
      if (type != null) {
        return type;
      }
    }
    return null;
  }
}