dagger.internal.codegen.MissingBindingSuggestions.java Source code

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Here is the source code for dagger.internal.codegen.MissingBindingSuggestions.java

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/*
 * Copyright (C) 2015 The Dagger 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 dagger.internal.codegen;

import com.google.common.collect.ImmutableList;
import java.util.ArrayDeque;
import java.util.Deque;

/**
 * Utility code that looks for bindings matching a key in all subcomponents in a binding graph so
 * that a user is advised that a binding exists elsewhere when it is not found in the current
 * subgraph. If a binding matching a key exists in a sub- or sibling component, that is often what
 * the user actually wants to use.
 */
class MissingBindingSuggestions {
    /**
     * Searches the entire binding graph from the top-level graph for a binding matching
     * {@code key}.
     */
    static ImmutableList<String> forKey(BindingGraph topLevelGraph, BindingKey key) {
        ImmutableList.Builder<String> resolutions = new ImmutableList.Builder<>();
        Deque<BindingGraph> graphsToTry = new ArrayDeque<>();

        graphsToTry.add(topLevelGraph);
        do {
            BindingGraph graph = graphsToTry.removeLast();
            ResolvedBindings bindings = graph.resolvedBindings().get(key);
            if ((bindings == null) || bindings.bindings().isEmpty()) {
                graphsToTry.addAll(graph.subgraphs());
            } else {
                resolutions.add("A binding with matching key exists in component: "
                        + graph.componentType().getQualifiedName());
            }
        } while (!graphsToTry.isEmpty());

        return resolutions.build();
    }

    private MissingBindingSuggestions() {
    }
}