1/*
2 * Copyright (C) 2011 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.inputmethod.latin;
18
19import java.io.File;
20
21/**
22 * Immutable class to hold the address of an asset.
23 * As opposed to a normal file, an asset is usually represented as a contiguous byte array in
24 * the package file. Open it correctly thus requires the name of the package it is in, but
25 * also the offset in the file and the length of this data. This class encapsulates these three.
26 */
27final class AssetFileAddress {
28    public final String mFilename;
29    public final long mOffset;
30    public final long mLength;
31
32    public AssetFileAddress(final String filename, final long offset, final long length) {
33        mFilename = filename;
34        mOffset = offset;
35        mLength = length;
36    }
37
38    public static AssetFileAddress makeFromFile(final File file) {
39        if (!file.isFile()) return null;
40        return new AssetFileAddress(file.getAbsolutePath(), 0L, file.length());
41    }
42
43    public static AssetFileAddress makeFromFileName(final String filename) {
44        if (null == filename) return null;
45        return makeFromFile(new File(filename));
46    }
47
48    public static AssetFileAddress makeFromFileNameAndOffset(final String filename,
49            final long offset, final long length) {
50        if (null == filename) return null;
51        final File f = new File(filename);
52        if (!f.isFile()) return null;
53        return new AssetFileAddress(filename, offset, length);
54    }
55}
56