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.browser;
18
19import android.app.Activity;
20import android.nfc.NdefMessage;
21import android.nfc.NdefRecord;
22import android.nfc.NfcAdapter;
23import android.nfc.NfcEvent;
24import android.os.Handler;
25import android.os.Message;
26import android.util.Log;
27
28import java.util.concurrent.CountDownLatch;
29
30/** This class implements sharing the URL of the currently
31  * shown browser page over NFC. Sharing is only active
32  * when the activity is in the foreground and resumed.
33  * Incognito tabs will not be shared over NFC.
34  */
35public class NfcHandler implements NfcAdapter.CreateNdefMessageCallback {
36    static final String TAG = "BrowserNfcHandler";
37    static final int GET_PRIVATE_BROWSING_STATE_MSG = 100;
38
39    final Controller mController;
40
41    Tab mCurrentTab;
42    boolean mIsPrivate;
43    CountDownLatch mPrivateBrowsingSignal;
44
45    public static void register(Activity activity, Controller controller) {
46        NfcAdapter adapter = NfcAdapter.getDefaultAdapter(activity.getApplicationContext());
47        if (adapter == null) {
48            return;  // NFC not available on this device
49        }
50        NfcHandler handler = null;
51        if (controller != null) {
52            handler = new NfcHandler(controller);
53        }
54
55        adapter.setNdefPushMessageCallback(handler, activity);
56    }
57
58    public static void unregister(Activity activity) {
59        // Passing a null controller causes us to disable
60        // the callback and release the ref to out activity.
61        register(activity, null);
62    }
63
64    public NfcHandler(Controller controller) {
65        mController = controller;
66    }
67
68    final Handler mHandler = new Handler() {
69        @Override
70        public void handleMessage(Message msg) {
71            if (msg.what == GET_PRIVATE_BROWSING_STATE_MSG) {
72                mIsPrivate = mCurrentTab.getWebView().isPrivateBrowsingEnabled();
73                mPrivateBrowsingSignal.countDown();
74            }
75        }
76    };
77
78    @Override
79    public NdefMessage createNdefMessage(NfcEvent event) {
80        mCurrentTab = mController.getCurrentTab();
81        if ((mCurrentTab != null) && (mCurrentTab.getWebView() != null)) {
82            // We can only read the WebView state on the UI thread, so post
83            // a message and wait.
84            mPrivateBrowsingSignal = new CountDownLatch(1);
85            mHandler.sendMessage(mHandler.obtainMessage(GET_PRIVATE_BROWSING_STATE_MSG));
86            try {
87                mPrivateBrowsingSignal.await();
88            } catch (InterruptedException e) {
89                return null;
90            }
91        }
92
93        if ((mCurrentTab == null) || mIsPrivate) {
94            return null;
95        }
96
97        String currentUrl = mCurrentTab.getUrl();
98        if (currentUrl != null) {
99            try {
100                return new NdefMessage(NdefRecord.createUri(currentUrl));
101            } catch (IllegalArgumentException e) {
102                Log.e(TAG, "IllegalArgumentException creating URI NdefRecord", e);
103                return null;
104            }
105        } else {
106            return null;
107        }
108    }
109}
110