com.google.api.codegen.configgen.NodeFinder.java Source code

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Here is the source code for com.google.api.codegen.configgen.NodeFinder.java

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/* Copyright 2017 Google LLC
 *
 * 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
 *
 *      https://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.google.api.codegen.configgen;

import com.google.api.codegen.configgen.nodes.ConfigNode;
import com.google.api.codegen.configgen.nodes.ListItemConfigNode;
import com.google.api.codegen.configgen.nodes.NullConfigNode;
import com.google.common.collect.Iterables;
import java.util.Iterator;
import java.util.NoSuchElementException;

/** Utilities for finding and traversing ConfigNodes. */
public class NodeFinder {
    public static ConfigNode findByValue(ConfigNode parentNode, String value) {
        for (ConfigNode childNode : getChildren(parentNode)) {
            if (value.equals(childNode.getText())) {
                return childNode;
            }
        }

        return new NullConfigNode();
    }

    /**
     * Returns true if the given node has text content. If the node is a list item, checks its child.
     */
    public static boolean hasContent(ConfigNode node) {
        if (!node.getText().isEmpty()) {
            return true;
        }

        if (!(node instanceof ListItemConfigNode)) {
            return false;
        }

        return hasContent(node.getChild());
    }

    public static int getNextLine(ConfigNode node) {
        return node.getChild().isPresent() ? getNextLine(node.getChild()) : node.getStartLine() + 1;
    }

    public static ConfigNode getLastChild(ConfigNode parentNode) {
        return Iterables.getLast(getChildren(parentNode));
    }

    public static Iterable<ConfigNode> getChildren(final ConfigNode parentNode) {
        return () -> new NodeIterator(parentNode.getChild());
    }

    private static class NodeIterator implements Iterator<ConfigNode> {
        private ConfigNode cursor;

        private NodeIterator(ConfigNode start) {
            cursor = start;
        }

        @Override
        public boolean hasNext() {
            return cursor.isPresent();
        }

        @Override
        public ConfigNode next() {
            if (!hasNext()) {
                throw new NoSuchElementException();
            }

            ConfigNode current = cursor;
            cursor = cursor.getNext();
            return current;
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }
    }
}