platform/vcs-api/src/com/intellij/openapi/vcs/changes/ChangeRequestChain.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.openapi.vcs.changes;

import com.intellij.openapi.diff.DiffRequest;
import com.intellij.openapi.vcs.changes.actions.DiffRequestPresentable;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

import java.util.List;

public interface ChangeRequestChain {
  boolean canMoveForward();

  boolean canMoveBack();

  @Nullable
  DiffRequest moveForward();

  @Nullable
  DiffRequest moveBack();

  @NotNull
  List<DiffRequestPresentable> getAllRequests();

  @Nullable
  DiffRequest moveTo(DiffRequestPresentable request);

  /**
   * Returns the diff request which is currently shown in the diff dialog.
   */
  @Nullable
  DiffRequestPresentable getCurrentRequest();
}