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 */
16package com.google.currysrc.processors;
17
18import com.google.common.collect.Lists;
19import com.google.currysrc.api.process.Context;
20import com.google.currysrc.api.process.Processor;
21import com.google.currysrc.api.process.Reporter;
22
23import org.eclipse.jdt.core.dom.Comment;
24import org.eclipse.jdt.core.dom.CompilationUnit;
25import org.eclipse.jface.text.BadLocationException;
26import org.eclipse.jface.text.Document;
27
28import java.util.List;
29
30/**
31 * A base-class for general comment processors. All comments of all types in a
32 * {@link CompilationUnit} are considered. Subclasses determine whether to make a complete comment
33 * replacement.
34 */
35public abstract class BaseModifyCommentScanner implements Processor {
36
37  @Override
38  public final void process(Context context, CompilationUnit cu) {
39    Document document = context.document();
40    Reporter reporter = context.reporter();
41    List<Comment> comments = cu.getCommentList();
42    try {
43      for (Comment comment : Lists.reverse(comments)) {
44        String commentText = document.get(comment.getStartPosition(), comment.getLength());
45        String newCommentText = processComment(reporter, comment, commentText);
46        if (newCommentText != null) {
47          document.replace(comment.getStartPosition(), comment.getLength(), newCommentText);
48        }
49      }
50    } catch (BadLocationException e) {
51      throw new AssertionError(e);
52    }
53  }
54
55  /**
56   * Generates new text for the comment, or returns {@code null} if there is nothing to change.
57   * Comments are passed in the reverse order that they appear in source code to ensure that
58   * document offsets remain valid.
59   */
60  protected abstract String processComment(Reporter reporter, Comment commentNode,
61      String commentText);
62}
63