1/*
2 * Copyright (C) 2010 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 android.nfc.tech;
18
19import android.nfc.Tag;
20import android.os.Bundle;
21import android.os.RemoteException;
22
23import java.io.IOException;
24
25/**
26 * Provides access to NFC-B (ISO 14443-3B) properties and I/O operations on a {@link Tag}.
27 *
28 * <p>Acquire a {@link NfcB} object using {@link #get}.
29 * <p>The primary NFC-B I/O operation is {@link #transceive}. Applications must
30 * implement their own protocol stack on top of {@link #transceive}.
31 *
32 * <p class="note"><strong>Note:</strong> Methods that perform I/O operations
33 * require the {@link android.Manifest.permission#NFC} permission.
34 */
35public final class NfcB extends BasicTagTechnology {
36    /** @hide */
37    public static final String EXTRA_APPDATA = "appdata";
38    /** @hide */
39    public static final String EXTRA_PROTINFO = "protinfo";
40
41    private byte[] mAppData;
42    private byte[] mProtInfo;
43
44    /**
45     * Get an instance of {@link NfcB} for the given tag.
46     * <p>Returns null if {@link NfcB} was not enumerated in {@link Tag#getTechList}.
47     * This indicates the tag does not support NFC-B.
48     * <p>Does not cause any RF activity and does not block.
49     *
50     * @param tag an NFC-B compatible tag
51     * @return NFC-B object
52     */
53    public static NfcB get(Tag tag) {
54        if (!tag.hasTech(TagTechnology.NFC_B)) return null;
55        try {
56            return new NfcB(tag);
57        } catch (RemoteException e) {
58            return null;
59        }
60    }
61
62    /** @hide */
63    public NfcB(Tag tag) throws RemoteException {
64        super(tag, TagTechnology.NFC_B);
65        Bundle extras = tag.getTechExtras(TagTechnology.NFC_B);
66        mAppData = extras.getByteArray(EXTRA_APPDATA);
67        mProtInfo = extras.getByteArray(EXTRA_PROTINFO);
68    }
69
70    /**
71     * Return the Application Data bytes from ATQB/SENSB_RES at tag discovery.
72     *
73     * <p>Does not cause any RF activity and does not block.
74     *
75     * @return Application Data bytes from ATQB/SENSB_RES bytes
76     */
77    public byte[] getApplicationData() {
78        return mAppData;
79    }
80
81    /**
82     * Return the Protocol Info bytes from ATQB/SENSB_RES at tag discovery.
83     *
84     * <p>Does not cause any RF activity and does not block.
85     *
86     * @return Protocol Info bytes from ATQB/SENSB_RES bytes
87     */
88    public byte[] getProtocolInfo() {
89        return mProtInfo;
90    }
91
92    /**
93     * Send raw NFC-B commands to the tag and receive the response.
94     *
95     * <p>Applications must not append the EoD (CRC) to the payload,
96     * it will be automatically calculated.
97     * <p>Applications must not send commands that manage the polling
98     * loop and initialization (SENSB_REQ, SLOT_MARKER etc).
99     *
100     * <p>Use {@link #getMaxTransceiveLength} to retrieve the maximum number of bytes
101     * that can be sent with {@link #transceive}.
102     *
103     * <p>This is an I/O operation and will block until complete. It must
104     * not be called from the main application thread. A blocked call will be canceled with
105     * {@link IOException} if {@link #close} is called from another thread.
106     *
107     * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
108     *
109     * @param data bytes to send
110     * @return bytes received in response
111     * @throws TagLostException if the tag leaves the field
112     * @throws IOException if there is an I/O failure, or this operation is canceled
113     */
114    public byte[] transceive(byte[] data) throws IOException {
115        return transceive(data, true);
116    }
117
118    /**
119     * Return the maximum number of bytes that can be sent with {@link #transceive}.
120     * @return the maximum number of bytes that can be sent with {@link #transceive}.
121     */
122    public int getMaxTransceiveLength() {
123        return getMaxTransceiveLengthInternal();
124    }
125}
126