1/*
2 * Copyright (C) 2017 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.android.bluetooth.opp;
17
18import android.content.BroadcastReceiver;
19import android.content.Context;
20import android.content.Intent;
21import android.content.IntentFilter;
22import android.content.pm.ProviderInfo;
23import android.net.Uri;
24import android.os.UserHandle;
25import android.os.UserManager;
26import android.support.v4.content.FileProvider;
27import android.util.Log;
28import java.io.File;
29
30/**
31 * A FileProvider for files received by Bluetooth share
32 */
33public class BluetoothOppFileProvider extends FileProvider {
34    private static final String TAG = "BluetoothOppFileProvider";
35
36    private Context mContext = null;
37    private ProviderInfo mProviderInfo = null;
38    private boolean mRegisteredReceiver = false;
39    private boolean mInitialized = false;
40
41    /** Broadcast receiver that attach FileProvider info when user unlocks the phone for the
42     *  first time after reboot and the credential-encrypted storage is available.
43     */
44    private final BroadcastReceiver mBroadcastReceiver = new BroadcastReceiver() {
45        @Override
46        public void onReceive(final Context context, Intent intent) {
47            if (Intent.ACTION_USER_UNLOCKED.equals(intent.getAction())) {
48                attachInfo(mContext, mProviderInfo);
49            }
50        }
51    };
52
53    /**
54     * After the FileProvider is instantiated, this method is called to provide the system with
55     * information about the provider. The actual initialization is delayed until user unlock the
56     * device
57     *
58     * @param context A {@link Context} for the current component.
59     * @param info A {@link ProviderInfo} for the new provider.
60     */
61    @Override
62    public void attachInfo(Context context, ProviderInfo info) {
63        synchronized (this) {
64            mContext = context;
65            mProviderInfo = info;
66            if (!mRegisteredReceiver) {
67                IntentFilter userFilter = new IntentFilter();
68                userFilter.addAction(Intent.ACTION_USER_UNLOCKED);
69                mContext.registerReceiverAsUser(
70                        mBroadcastReceiver, UserHandle.CURRENT, userFilter, null, null);
71                mRegisteredReceiver = true;
72            }
73            UserManager userManager = (UserManager) mContext.getSystemService(Context.USER_SERVICE);
74            if (userManager.isUserUnlocked()) {
75                if (!mInitialized) {
76                    if (Constants.DEBUG) Log.d(TAG, "Initialized");
77                    super.attachInfo(mContext, mProviderInfo);
78                    mInitialized = true;
79                }
80                if (mRegisteredReceiver) {
81                    mContext.unregisterReceiver(mBroadcastReceiver);
82                    mRegisteredReceiver = false;
83                }
84            }
85        }
86    }
87
88    /**
89     * Return a content URI for a given {@link File}. Specific temporary
90     * permissions for the content URI can be set with
91     * {@link Context#grantUriPermission(String, Uri, int)}, or added
92     * to an {@link Intent} by calling {@link Intent#setData(Uri) setData()} and then
93     * {@link Intent#setFlags(int) setFlags()}; in both cases, the applicable flags are
94     * {@link Intent#FLAG_GRANT_READ_URI_PERMISSION} and
95     * {@link Intent#FLAG_GRANT_WRITE_URI_PERMISSION}. A FileProvider can only return a
96     * <code>content</code> {@link Uri} for file paths defined in their <code>&lt;paths&gt;</code>
97     * meta-data element. See the Class Overview for more information.
98     *
99     * @param context A {@link Context} for the current component.
100     * @param authority The authority of a {@link FileProvider} defined in a
101     *            {@code <provider>} element in your app's manifest.
102     * @param file A {@link File} pointing to the filename for which you want a
103     * <code>content</code> {@link Uri}.
104     * @return A content URI for the file. Null if the user hasn't unlock the phone
105     * @throws IllegalArgumentException When the given {@link File} is outside
106     * the paths supported by the provider.
107     */
108    public static Uri getUriForFile(Context context, String authority, File file) {
109        UserManager userManager = (UserManager) context.getSystemService(Context.USER_SERVICE);
110        if (!userManager.isUserUnlocked()) {
111            return null;
112        }
113        context = context.createCredentialProtectedStorageContext();
114        return FileProvider.getUriForFile(context, authority, file);
115    }
116}
117