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.contacts;
18
19import android.app.Activity;
20import android.content.ContentResolver;
21import android.content.Context;
22import android.net.Uri;
23import android.nfc.NdefMessage;
24import android.nfc.NdefRecord;
25import android.nfc.NfcAdapter;
26import android.nfc.NfcEvent;
27import android.provider.ContactsContract.Contacts;
28import android.provider.ContactsContract.Profile;
29import android.util.Log;
30
31import java.io.ByteArrayOutputStream;
32import java.io.IOException;
33import java.io.InputStream;
34
35/**
36  * This class implements sharing the currently displayed
37  * contact to another device using NFC. NFC sharing is only
38  * enabled when the activity is in the foreground and resumed.
39  * When an NFC link is established, {@link #createMessage}
40  * will be called to create the data to be sent over the link,
41  * which is a vCard in this case.
42  */
43public class NfcHandler implements NfcAdapter.CreateNdefMessageCallback {
44
45    private static final String TAG = "ContactNfcHandler";
46    private static final String PROFILE_LOOKUP_KEY = "profile";
47    private final Context mContext;
48    private final Uri mContactUri;
49
50    /* Register NFC handler. This should be called in activities' onCreate(), or similar methods */
51    public static void register(Activity activity, Uri contactUri) {
52        NfcAdapter adapter = NfcAdapter.getDefaultAdapter(activity.getApplicationContext());
53        if (adapter == null) {
54            return;  // NFC not available on this device
55        }
56        adapter.setNdefPushMessageCallback(new NfcHandler(activity, contactUri), activity);
57    }
58
59    public NfcHandler(Context context, Uri contactUri) {
60        mContext = context;
61        mContactUri = contactUri;
62    }
63
64    @Override
65    public NdefMessage createNdefMessage(NfcEvent event) {
66        ContentResolver resolver = mContext.getContentResolver();
67        if (mContactUri != null) {
68            final String lookupKey = Uri.encode(mContactUri.getPathSegments().get(2));
69            final Uri shareUri;
70            // TODO find out where to get this constant from, or find another way
71            // of determining this.
72            if (lookupKey.equals(PROFILE_LOOKUP_KEY)) {
73                shareUri = Profile.CONTENT_VCARD_URI.buildUpon().
74                appendQueryParameter(Contacts.QUERY_PARAMETER_VCARD_NO_PHOTO, "true").
75                build();
76            } else {
77                shareUri = Contacts.CONTENT_VCARD_URI.buildUpon().
78                appendPath(lookupKey).
79                appendQueryParameter(Contacts.QUERY_PARAMETER_VCARD_NO_PHOTO, "true").
80                build();
81            }
82            ByteArrayOutputStream ndefBytes = new ByteArrayOutputStream();
83            byte[] buffer = new byte[1024];
84            int r;
85            try {
86                InputStream vcardInputStream = resolver.openInputStream(shareUri);
87                while ((r = vcardInputStream.read(buffer)) > 0) {
88                    ndefBytes.write(buffer, 0, r);
89                }
90
91                NdefRecord record = NdefRecord.createMime("text/x-vcard", ndefBytes.toByteArray());
92                return new NdefMessage(record);
93            } catch (IOException e) {
94                Log.e(TAG, "IOException creating vcard.");
95                return null;
96            }
97        } else {
98            Log.w(TAG, "No contact URI to share.");
99            return null;
100        }
101    }
102}
103