com.google.common.css.compiler.passes.HandleUnknownAtRuleNodes.java Source code

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Here is the source code for com.google.common.css.compiler.passes.HandleUnknownAtRuleNodes.java

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/*
 * Copyright 2009 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.passes;

import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableSet;
import com.google.common.css.compiler.ast.*;

import java.util.Set;

/**
 * Compiler pass that handles remaining {@link CssUnknownAtRuleNode} instances
 * by optionally reporting them as errors and optionally removing
 * them.
 *
 */
public class HandleUnknownAtRuleNodes extends DefaultTreeVisitor implements CssCompilerPass {
    static final String unknownAtRuleErrorMessage = "unknown @ rule";

    private final MutatingVisitController visitController;
    private final ErrorManager errorManager;
    private final Set<String> additionalAtRules;
    private final boolean report;
    private final boolean remove;

    public HandleUnknownAtRuleNodes(MutatingVisitController visitController, ErrorManager errorManager,
            boolean report, boolean remove) {
        this(visitController, errorManager, ImmutableSet.<String>of(), report, remove);
    }

    public HandleUnknownAtRuleNodes(MutatingVisitController visitController, ErrorManager errorManager,
            Set<String> additionalAtRules, boolean report, boolean remove) {
        Preconditions.checkArgument(!report || errorManager != null);
        this.visitController = visitController;
        this.errorManager = errorManager;
        this.additionalAtRules = additionalAtRules;
        this.report = report;
        this.remove = remove;
    }

    @Override
    public boolean enterUnknownAtRule(CssUnknownAtRuleNode node) {
        if (node.isOkWithoutProcessing() || additionalAtRules.contains(node.getName().getValue())) {
            return true;
        }

        if (report) {
            errorManager.report(new GssError(unknownAtRuleErrorMessage, node.getSourceCodeLocation()));
        }
        if (remove) {
            visitController.removeCurrentNode();
            return false;
        } else {
            return true;
        }
    }

    @Override
    public void runPass() {
        if (report || remove) {
            visitController.startVisit(this);
        }
    }
}