001    /*
002     * Sonar, open source software quality management tool.
003     * Copyright (C) 2009 SonarSource SA
004     * mailto:contact AT sonarsource DOT com
005     *
006     * Sonar is free software; you can redistribute it and/or
007     * modify it under the terms of the GNU Lesser General Public
008     * License as published by the Free Software Foundation; either
009     * version 3 of the License, or (at your option) any later version.
010     *
011     * Sonar is distributed in the hope that it will be useful,
012     * but WITHOUT ANY WARRANTY; without even the implied warranty of
013     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014     * Lesser General Public License for more details.
015     *
016     * You should have received a copy of the GNU Lesser General Public
017     * License along with Sonar; if not, write to the Free Software
018     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
019     */
020    package org.sonar.java.ast.visitor;
021    
022    import java.util.Arrays;
023    import java.util.List;
024    
025    import org.sonar.squid.api.SourceCode;
026    import org.sonar.squid.measures.Metric;
027    
028    import antlr.collections.AST;
029    
030    import com.puppycrawl.tools.checkstyle.api.DetailAST;
031    import com.puppycrawl.tools.checkstyle.api.Scope;
032    import com.puppycrawl.tools.checkstyle.api.TokenTypes;
033    
034    public class PublicApiVisitor extends AstVisitor {
035    
036      final static String OVERRIDE_ANNOTATION_KEYWORD = "Override";
037    
038      private static final List<Integer> TOKENS = Arrays.asList(TokenTypes.CLASS_DEF, TokenTypes.INTERFACE_DEF, TokenTypes.METHOD_DEF,
039          TokenTypes.CTOR_DEF, TokenTypes.ANNOTATION_DEF, TokenTypes.ANNOTATION_FIELD_DEF, TokenTypes.VARIABLE_DEF);
040    
041      public PublicApiVisitor() {
042      }
043    
044      @Override
045      public List<Integer> getWantedTokens() {
046        return TOKENS;
047      }
048    
049      @Override
050      public void visitToken(DetailAST ast) {
051        SourceCode currentResource = peekResource();
052        if (isPublic(ast) && !isStaticFinalVariable(ast) && !isMethodWithOverrideAnnotation(ast) && !isEmptyDefaultConstructor(ast)) {
053          currentResource.add(Metric.PUBLIC_API, 1);
054          if (isDocumentedApi(ast)) {
055            currentResource.add(Metric.PUBLIC_DOC_API, 1);
056          }
057        }
058      }
059    
060      private boolean isEmptyDefaultConstructor(DetailAST ast) {
061        return (isConstructorWithoutParameters(ast)) && (ast.getLastChild().getChildCount() == 1);
062      }
063    
064      private boolean isConstructorWithoutParameters(DetailAST ast) {
065        return ast.getType() == TokenTypes.CTOR_DEF && ast.findFirstToken(TokenTypes.PARAMETERS).getChildCount() == 0;
066      }
067    
068      private boolean isMethodWithOverrideAnnotation(DetailAST ast) {
069        if (isMethod(ast)) {
070          DetailAST modifier = ast.findFirstToken(TokenTypes.MODIFIERS);
071          for (AST annotation = modifier.getFirstChild(); annotation != null; annotation = annotation.getNextSibling()) {
072            if (isAnnotation(annotation) && ((DetailAST) annotation).findFirstToken(TokenTypes.IDENT) != null) {
073              String name = ((DetailAST) annotation).findFirstToken(TokenTypes.IDENT).getText();
074              return OVERRIDE_ANNOTATION_KEYWORD.equals(name);
075            }
076          }
077        }
078        return false;
079      }
080    
081      private boolean isAnnotation(AST annotation) {
082        return annotation.getType() == TokenTypes.ANNOTATION;
083      }
084    
085      private boolean isMethod(DetailAST ast) {
086        return ast.getType() == TokenTypes.METHOD_DEF;
087      }
088    
089      private boolean isPublic(DetailAST ast) {
090        return (AstUtils.isScope(AstUtils.getScope(ast), Scope.PUBLIC) || AstUtils.isType(ast, TokenTypes.ANNOTATION_FIELD_DEF));
091      }
092    
093      private boolean isDocumentedApi(DetailAST ast) {
094        return getFileContents().getJavadocBefore(ast.getLineNo()) != null;
095      }
096    
097      private boolean isStaticFinalVariable(DetailAST ast) {
098        return (AstUtils.isClassVariable(ast) || AstUtils.isInterfaceVariable(ast)) && AstUtils.isFinal(ast) && AstUtils.isStatic(ast);
099      }
100    }