Path.java revision dd9eb897ee7c7b507cbdcf80263bb4b5de6966bf 
1/*
2 * Copyright 2012 Sebastian Annies, Hamburg
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.googlecode.mp4parser.util;
17
18
19import com.coremedia.iso.IsoFile;
20import com.coremedia.iso.boxes.Box;
21import com.coremedia.iso.boxes.ContainerBox;
22
23import java.util.Collections;
24import java.util.LinkedList;
25import java.util.List;
26import java.util.regex.Matcher;
27import java.util.regex.Pattern;
28
29public class Path {
30
31    private Path() {
32    }
33
34    static Pattern component = Pattern.compile("(....|\\.\\.)(\\[(.*)\\])?");
35
36    public static String createPath(Box box) {
37        return createPath(box, "");
38    }
39
40    private static String createPath(Box box, String path) {
41        if (box instanceof IsoFile) {
42            return path;
43        } else {
44            List<?> boxesOfBoxType = box.getParent().getBoxes(box.getClass());
45            int index = boxesOfBoxType.indexOf(box);
46            path = String.format("/%s[%d]", box.getType(), index) + path;
47
48            return createPath(box.getParent(), path);
49        }
50    }
51
52    public static Box getPath(Box box, String path) {
53        List<Box> all = getPaths(box, path);
54        return all.isEmpty() ? null : all.get(0);
55    }
56
57
58    public static List<Box> getPaths(Box box, String path) {
59        if (path.startsWith("/")) {
60            Box isoFile = box;
61            while (isoFile.getParent() != null) {
62                isoFile = isoFile.getParent();
63            }
64            assert isoFile instanceof IsoFile : isoFile.getType() + " has no parent";
65            return getPaths(isoFile, path.substring(1));
66        } else if (path.isEmpty()) {
67            return Collections.singletonList(box);
68        } else {
69            String later;
70            String now;
71            if (path.contains("/")) {
72                later = path.substring(path.indexOf('/') + 1);
73                now = path.substring(0, path.indexOf('/'));
74            } else {
75                now = path;
76                later = "";
77            }
78
79            Matcher m = component.matcher(now);
80            if (m.matches()) {
81                String type = m.group(1);
82                if ("..".equals(type)) {
83                    return getPaths(box.getParent(), later);
84                } else {
85                    int index = -1;
86                    if (m.group(2) != null) {
87                        // we have a specific index
88                        String indexString = m.group(3);
89                        index = Integer.parseInt(indexString);
90                    }
91                    List<Box> children = new LinkedList<Box>();
92                    int currentIndex = 0;
93                    for (Box box1 : ((ContainerBox) box).getBoxes()) {
94                        if (box1.getType().matches(type)) {
95                            if (index == -1 || index == currentIndex) {
96                                children.addAll(getPaths(box1, later));
97                            }
98                            currentIndex++;
99                        }
100                    }
101                    return children;
102                }
103            } else {
104                throw new RuntimeException(now + " is invalid path.");
105            }
106        }
107
108    }
109
110
111    public static boolean isContained(Box box, String path) {
112        assert path.startsWith("/") : "Absolute path required";
113        return getPaths(box, path).contains(box);
114    }
115}
116