NfcHandler.java revision e5b15cd3c8450c935ce43ca9be83a23bcdd565a2 
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.email.activity;
18
19import com.android.emailcommon.provider.Account;
20
21import android.app.Activity;
22import android.content.Context;
23import android.nfc.NdefMessage;
24import android.nfc.NdefRecord;
25import android.nfc.NfcAdapter;
26import android.text.TextUtils;
27import android.util.Log;
28
29import java.io.UnsupportedEncodingException;
30import java.net.URLEncoder;
31
32/**
33  * This class implements sharing the e-mail address of the
34  * active account to another device using NFC. NFC sharing is only
35  * enabled when the activity is in the foreground and resumed.
36  * When an NFC link is established, {@link #createMessage}
37  * will be called to create the data to be sent over the link,
38  * which is a vCard in this case.
39  */
40public class NfcHandler implements NfcAdapter.NdefPushCallback {
41    private NfcAdapter mNfcAdapter;
42    private UIControllerBase mUiController;
43    private Activity mActivity;
44    private String mCurrentEmail;
45    private static final String TAG = "ContactsNfcHandler";
46
47    public NfcHandler(UIControllerBase controller, Activity
48            activity) {
49        mUiController = controller;
50        mActivity = activity;
51        mNfcAdapter = NfcAdapter.getDefaultAdapter(mActivity);
52    }
53
54    public void onAccountChanged() {
55        if (mUiController.isActualAccountSelected()) {
56            final long accountId = mUiController.getActualAccountId();
57            final Account account = Account.restoreAccountWithId(
58                    mActivity, accountId);
59            mCurrentEmail = account.mEmailAddress;
60        } else {
61            mCurrentEmail = null;
62        }
63
64    }
65
66    public void onPause() {
67        if (mNfcAdapter != null) {
68            mNfcAdapter.disableForegroundNdefPush(
69                    mActivity);
70        }
71    }
72
73    public void onResume() {
74        if (mNfcAdapter != null) {
75            mNfcAdapter.enableForegroundNdefPush(
76                    mActivity, this);
77            onAccountChanged(); // Fetch current account
78        }
79    }
80
81    private static NdefMessage buildMailtoNdef(String address) {
82        if (TextUtils.isEmpty(address)) {
83            return null;
84        }
85        byte[] accountBytes;
86        try {
87            accountBytes = URLEncoder.encode(address, "UTF-8")
88                    .getBytes("UTF-8");
89        } catch (UnsupportedEncodingException e) {
90            return null;
91        }
92        byte[] recordBytes = new byte[accountBytes.length + 1];
93        recordBytes[0] = 0x06; // NDEF mailto: prefix
94        System.arraycopy(accountBytes, 0, recordBytes, 1, accountBytes.length);
95        NdefRecord mailto = new NdefRecord(NdefRecord.TNF_WELL_KNOWN, NdefRecord.RTD_URI,
96                new byte[0], recordBytes);
97        return new NdefMessage(new NdefRecord[] { mailto });
98    }
99
100    @Override
101    public NdefMessage createMessage() {
102        if (mCurrentEmail != null) {
103            return buildMailtoNdef(mCurrentEmail);
104        } else {
105            return null;
106        }
107    }
108
109    @Override
110    public void onMessagePushed() {
111    }
112}
113