1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.databinding.tool;
18
19import org.antlr.v4.runtime.ANTLRInputStream;
20import org.antlr.v4.runtime.BaseErrorListener;
21import org.antlr.v4.runtime.CommonTokenStream;
22import org.antlr.v4.runtime.ParserRuleContext;
23import org.antlr.v4.runtime.RecognitionException;
24import org.antlr.v4.runtime.Recognizer;
25import org.antlr.v4.runtime.Token;
26import org.antlr.v4.runtime.tree.ErrorNode;
27import org.antlr.v4.runtime.tree.ParseTreeListener;
28import org.antlr.v4.runtime.tree.TerminalNode;
29
30import android.databinding.parser.BindingExpressionLexer;
31import android.databinding.parser.BindingExpressionParser;
32import android.databinding.tool.expr.Expr;
33import android.databinding.tool.expr.ExprModel;
34import android.databinding.tool.processing.ErrorMessages;
35import android.databinding.tool.store.Location;
36import android.databinding.tool.util.L;
37import android.databinding.tool.util.Preconditions;
38
39import com.android.annotations.Nullable;
40
41import java.util.ArrayList;
42import java.util.List;
43
44public class ExpressionParser {
45    final ExprModel mModel;
46    final ExpressionVisitor visitor;
47
48    public ExpressionParser(ExprModel model) {
49        mModel = model;
50        visitor = new ExpressionVisitor(mModel);
51    }
52
53    public Expr parse(String input, @Nullable Location locationInFile, BindingTarget target) {
54        ANTLRInputStream inputStream = new ANTLRInputStream(input);
55        BindingExpressionLexer lexer = new BindingExpressionLexer(inputStream);
56        CommonTokenStream tokenStream = new CommonTokenStream(lexer);
57        final BindingExpressionParser parser = new BindingExpressionParser(tokenStream);
58        visitor.setBindingTarget(target);
59        parser.addErrorListener(new BaseErrorListener() {
60            @Override
61            public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol, int line,
62                    int charPositionInLine, String msg, RecognitionException e) {
63                L.e(ErrorMessages.SYNTAX_ERROR, msg);
64            }
65        });
66        BindingExpressionParser.BindingSyntaxContext root = parser.bindingSyntax();
67        try {
68            mModel.setCurrentLocationInFile(locationInFile);
69            visitor.setParseTreeListener(new ParseTreeListener() {
70                List<ParserRuleContext> mStack = new ArrayList<ParserRuleContext>();
71                @Override
72                public void visitTerminal(TerminalNode node) {
73                }
74
75                @Override
76                public void visitErrorNode(ErrorNode node) {
77                }
78
79                @Override
80                public void enterEveryRule(ParserRuleContext ctx) {
81                    mStack.add(ctx);
82                    mModel.setCurrentParserContext(ctx);
83                }
84
85                @Override
86                public void exitEveryRule(ParserRuleContext ctx) {
87                    Preconditions.check(ctx == mStack.get(mStack.size() - 1),
88                            "Inconsistent exit from context. Received %s, expecting %s",
89                            ctx.toInfoString(parser),
90                            mStack.get(mStack.size() - 1).toInfoString(parser));
91                    mStack.remove(mStack.size() - 1);
92                    if (mStack.size() > 0) {
93                        mModel.setCurrentParserContext(mStack.get(mStack.size() - 1));
94                    } else {
95                        mModel.setCurrentParserContext(null);
96                    }
97                }
98            });
99            return root.accept(visitor);
100        } finally {
101            mModel.setCurrentLocationInFile(null);
102        }
103    }
104
105    public ExprModel getModel() {
106        return mModel;
107    }
108}
109