gradle-master/subprojects/dependency-management/src/main/java/org/gradle/api/internal/artifacts/ivyservice/resolveengine/graph/ResolvedGraphDependency.java
/*
 * Copyright 2016 the original author or authors.
 *
 * 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 org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph;

import org.gradle.api.artifacts.component.ComponentSelector;
import org.gradle.api.artifacts.result.ComponentSelectionReason;
import org.gradle.internal.resolve.ModuleVersionResolveException;

import javax.annotation.Nullable;

/**
 * The final representation of a dependency in the resolved dependency graph.
 * This is the type that is serialized on resolve and deserialized when we later need to build a `ResolutionResult`.
 */
public interface ResolvedGraphDependency {

    ComponentSelector getRequested();

    @Nullable
    ModuleVersionResolveException getFailure();

    /**
     * Returns the simple id of the selected component, as per {@link ResolvedGraphComponent#getResultId()}.
     */
    @Nullable
    Long getSelected();

    /**
     * Not null only when failure is not null.
     */
    @Nullable
    ComponentSelectionReason getReason();

    boolean isConstraint();

    /**
     * Returns the simple id of the source variant, as per {@link ResolvedGraphVariant#getNodeId()}.
     */
    Long getFromVariant();

    /**
     * Returns the simple id of the selected variant, as per {@link ResolvedGraphVariant#getNodeId()}.
     */
    @Nullable
    Long getSelectedVariant();
}
