1/*
2 * Copyright (C) 2007 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 com.android.dx.dex.file;
18
19import com.android.dx.rop.cst.CstUtf8;
20import com.android.dx.util.AnnotatedOutput;
21import com.android.dx.util.Hex;
22
23/**
24 * Representation of a string inside a Dalvik file.
25 */
26public final class StringIdItem
27        extends IndexedItem implements Comparable {
28    /** size of instances when written out to a file, in bytes */
29    public static final int WRITE_SIZE = 4;
30
31    /** {@code non-null;} the string value */
32    private final CstUtf8 value;
33
34    /** {@code null-ok;} associated string data object, if known */
35    private StringDataItem data;
36
37    /**
38     * Constructs an instance.
39     *
40     * @param value {@code non-null;} the string value
41     */
42    public StringIdItem(CstUtf8 value) {
43        if (value == null) {
44            throw new NullPointerException("value == null");
45        }
46
47        this.value = value;
48        this.data = null;
49    }
50
51    /** {@inheritDoc} */
52    @Override
53    public boolean equals(Object other) {
54        if (!(other instanceof StringIdItem)) {
55            return false;
56        }
57
58        StringIdItem otherString = (StringIdItem) other;
59        return value.equals(otherString.value);
60    }
61
62    /** {@inheritDoc} */
63    @Override
64    public int hashCode() {
65        return value.hashCode();
66    }
67
68    /** {@inheritDoc} */
69    public int compareTo(Object other) {
70        StringIdItem otherString = (StringIdItem) other;
71        return value.compareTo(otherString.value);
72    }
73
74    /** {@inheritDoc} */
75    @Override
76    public ItemType itemType() {
77        return ItemType.TYPE_STRING_ID_ITEM;
78    }
79
80    /** {@inheritDoc} */
81    @Override
82    public int writeSize() {
83        return WRITE_SIZE;
84    }
85
86    /** {@inheritDoc} */
87    @Override
88    public void addContents(DexFile file) {
89        if (data == null) {
90            // The string data hasn't yet been added, so add it.
91            MixedItemSection stringData = file.getStringData();
92            data = new StringDataItem(value);
93            stringData.add(data);
94        }
95    }
96
97    /** {@inheritDoc} */
98    @Override
99    public void writeTo(DexFile file, AnnotatedOutput out) {
100        int dataOff = data.getAbsoluteOffset();
101
102        if (out.annotates()) {
103            out.annotate(0, indexString() + ' ' + value.toQuoted(100));
104            out.annotate(4, "  string_data_off: " + Hex.u4(dataOff));
105        }
106
107        out.writeInt(dataOff);
108    }
109
110    /**
111     * Gets the string value.
112     *
113     * @return {@code non-null;} the value
114     */
115    public CstUtf8 getValue() {
116        return value;
117    }
118
119    /**
120     * Gets the associated data object for this instance, if known.
121     *
122     * @return {@code null-ok;} the associated data object or {@code null}
123     * if not yet known
124     */
125    public StringDataItem getData() {
126        return data;
127    }
128}
129