platform/lang-api/src/com/intellij/ide/hierarchy/HierarchyProvider.java

/*
 * Copyright 2000-2009 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.ide.hierarchy;

import com.intellij.lang.LanguageExtensionPoint;
import com.intellij.openapi.actionSystem.DataContext;
import com.intellij.openapi.extensions.ExtensionPointName;
import com.intellij.psi.PsiElement;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

/**
 * Implement this interface to provide hierarchy browsing actions (Type Hierarchy, Method Hierarchy,
 * Call Hierarchy) for a custom language.
 *
 * @author yole
 */
public interface HierarchyProvider {
  ExtensionPointName<LanguageExtensionPoint> TYPE_EP_NAME = ExtensionPointName.create("com.intellij.typeHierarchyProvider");
  ExtensionPointName<LanguageExtensionPoint> METHOD_EP_NAME = ExtensionPointName.create("com.intellij.methodHierarchyProvider");

  /**
   * Returns the element for which the hierarchy should be displayed.
   *
   * @param dataContext the data context for the action invocation.
   * @return the target element, or null if the action is not applicable in this context.
   */
  @Nullable
  PsiElement getTarget(@NotNull DataContext dataContext);

  /**
   * Creates a browser for viewing the hierarchy of the specified element.
   *
   * @param target the element to view the hierarchy for.
   * @return the browser instance.
   */
  @NotNull
  HierarchyBrowser createHierarchyBrowser(final PsiElement target);

  /**
   * Notifies that the toolwindow has been shown and the specified browser is currently being displayed.
   *
   * @param hierarchyBrowser the browser instance created by {@link #createHierarchyBrowser(com.intellij.psi.PsiElement)}.
   */
  void browserActivated(@NotNull HierarchyBrowser hierarchyBrowser);
}