com.google.common.css.compiler.ast.CssTree.java Source code

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Here is the source code for com.google.common.css.compiler.ast.CssTree.java

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/*
 * Copyright 2008 Google Inc.
 *
 * 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.google.common.css.compiler.ast;

import com.google.common.collect.Sets;
import com.google.common.css.SourceCode;

import java.util.Collection;
import java.util.LinkedHashSet;

import javax.annotation.Nullable;

/**
 * A mutable abstract syntax tree that corresponds to a CSS input file.
 *
 * @author oana@google.com (Oana Florescu)
 */
public class CssTree {
    /** The root of the tree. */
    private final CssRootNode root;
    /** The source code corresponding to the tree. */
    private final SourceCode sourceCode;
    /** A reference to the collection of ruleset nodes to remove. */
    private RulesetNodesToRemove rulesetNodesToRemove;

    // TODO(oana): Maybe make this part of some generic information we want to
    // store for the tree.
    public static class RulesetNodesToRemove {
        private final LinkedHashSet<CssRulesetNode> rulesetNodes = Sets.newLinkedHashSet();

        public void addRulesetNode(CssRulesetNode node) {
            rulesetNodes.add(node);
        }

        public Collection<CssRulesetNode> getRulesetNodes() {
            return rulesetNodes;
        }
    }

    /**
     * Constructor of a tree.
     *
     * @param sourceCode the source location associated with the tree (probably
     *     the start of the file)
     * @param root the root node of the tree
     */
    public CssTree(SourceCode sourceCode, CssRootNode root) {
        this.root = root;
        this.sourceCode = sourceCode;
        this.rulesetNodesToRemove = new RulesetNodesToRemove();
    }

    /**
     * Constructor of a tree.
     *
     * @param sourceCode the source location associated with the tree (probably
     *     the start of the file). Can be {@code null}.
     */
    public CssTree(@Nullable SourceCode sourceCode) {
        this(sourceCode, new CssRootNode());
    }

    /**
     * Copy constructor. This also copies the ruleset nodes to remove. The
     * collection of ruleset node to remove can be cleared if it is not desired
     * without affecting the original tree.
     *
     * @param tree the tree to copy. Must not be {@code null}.
     */
    public CssTree(CssTree tree) {
        root = tree.root.deepCopy();
        sourceCode = tree.sourceCode;
        rulesetNodesToRemove = new RulesetNodesToRemove();
        rulesetNodesToRemove.rulesetNodes.addAll(tree.rulesetNodesToRemove.rulesetNodes);
    }

    public CssRootNode getRoot() {
        return root;
    }

    public SourceCode getSourceCode() {
        return sourceCode;
    }

    public RulesetNodesToRemove getRulesetNodesToRemove() {
        return rulesetNodesToRemove;
    }

    public void resetRulesetNodesToRemove() {
        this.rulesetNodesToRemove = new RulesetNodesToRemove();
    }

    public MutatingVisitController getMutatingVisitController() {
        return new DefaultVisitController(this, true /* allowMutating */);
    }

    public VisitController getVisitController() {
        return new DefaultVisitController(this, false /* allowMutating */);
    }

    // TODO(user): Add a method that merges two trees and produces a new one as
    //     a result. This method might belong to a compiler pass.
}