com.github.jknack.css.CSS.java Source code

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Here is the source code for com.github.jknack.css.CSS.java

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/**
 * Copyright (c) 2012-2013 Edgar Espina
 *
 * This file is part of css.java.
 *
 * 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.github.jknack.css;

import java.util.BitSet;

import org.antlr.v4.runtime.ANTLRErrorListener;
import org.antlr.v4.runtime.ANTLRInputStream;
import org.antlr.v4.runtime.CommonToken;
import org.antlr.v4.runtime.CommonTokenStream;
import org.antlr.v4.runtime.Parser;
import org.antlr.v4.runtime.RecognitionException;
import org.antlr.v4.runtime.Recognizer;
import org.antlr.v4.runtime.Token;
import org.antlr.v4.runtime.atn.ATNConfigSet;
import org.antlr.v4.runtime.dfa.DFA;
import org.antlr.v4.runtime.misc.ParseCancellationException;

import com.github.jknack.css.internal.CssLexer;
import com.github.jknack.css.internal.CssParser;
import com.github.jknack.css.internal.CssParser.StyleSheetContext;

public class CSS {

    private static class ErrorReporter implements ANTLRErrorListener {

        @Override
        public void syntaxError(final Recognizer<?, ?> recognizer, final Object offendingSymbol, final int line,
                final int charPositionInLine, final String msg, final RecognitionException e) {
            throw new ParseCancellationException(msg, e);
        }

        @Override
        public void reportAmbiguity(final Parser recognizer, final DFA dfa, final int startIndex,
                final int stopIndex, final BitSet ambigAlts, final ATNConfigSet configs) {
        }

        @Override
        public void reportAttemptingFullContext(final Parser recognizer, final DFA dfa, final int startIndex,
                final int stopIndex, final ATNConfigSet configs) {
        }

        @Override
        public void reportContextSensitivity(final Parser recognizer, final DFA dfa, final int startIndex,
                final int stopIndex, final ATNConfigSet configs) {
        }

    }

    public static boolean debug = false;

    public CSS() {
        // TODO Auto-generated constructor stub
    }

    public StyleSheet parse(final String content) {
        CssLexer lexer = new CssLexer(new ANTLRInputStream(content));
        //    lexer.removeErrorListeners();
        if (!debug) {
            lexer.addErrorListener(new ErrorReporter());
        }
        CommonTokenStream tokens = new CommonTokenStream(lexer);

        tokens.fill();
        CssParser parser = new CssParser(tokens);
        //    parser.setErrorHandler(new BailErrorStrategy());
        //    parser.removeParseListeners();
        if (!debug) {
            parser.addErrorListener(new ErrorReporter());
        }
        if (debug) {
            for (Token tok : tokens.getTokens()) {
                CommonToken ct = (CommonToken) tok;
                String[] tokenNames = lexer.getTokenNames();
                int type = ct.getType();
                System.out.println((type > 0 ? tokenNames[type] : "EOF") + "(" + ct.getText() + ")");
            }
        }
        StyleSheetContext tree = parser.styleSheet();
        if (debug) {
            System.out.println(tree.toStringTree(parser));
        }
        CSSBuilder builder = new CSSBuilder();
        return (StyleSheet) builder.visit(tree);
    }
}