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.ErrorCodes;
20import android.nfc.Tag;
21import android.os.Bundle;
22import android.os.RemoteException;
23import android.util.Log;
24
25import java.io.IOException;
26
27/**
28 * Provides access to NFC-F (JIS 6319-4) properties and I/O operations on a {@link Tag}.
29 *
30 * <p>Acquire a {@link NfcF} object using {@link #get}.
31 * <p>The primary NFC-F I/O operation is {@link #transceive}. Applications must
32 * implement their own protocol stack on top of {@link #transceive}.
33 *
34 * <p class="note"><strong>Note:</strong> Methods that perform I/O operations
35 * require the {@link android.Manifest.permission#NFC} permission.
36 */
37public final class NfcF extends BasicTagTechnology {
38    private static final String TAG = "NFC";
39
40    /** @hide */
41    public static final String EXTRA_SC = "systemcode";
42    /** @hide */
43    public static final String EXTRA_PMM = "pmm";
44
45    private byte[] mSystemCode = null;
46    private byte[] mManufacturer = null;
47
48    /**
49     * Get an instance of {@link NfcF} for the given tag.
50     * <p>Returns null if {@link NfcF} was not enumerated in {@link Tag#getTechList}.
51     * This indicates the tag does not support NFC-F.
52     * <p>Does not cause any RF activity and does not block.
53     *
54     * @param tag an NFC-F compatible tag
55     * @return NFC-F object
56     */
57    public static NfcF get(Tag tag) {
58        if (!tag.hasTech(TagTechnology.NFC_F)) return null;
59        try {
60            return new NfcF(tag);
61        } catch (RemoteException e) {
62            return null;
63        }
64    }
65
66    /** @hide */
67    public NfcF(Tag tag) throws RemoteException {
68        super(tag, TagTechnology.NFC_F);
69        Bundle extras = tag.getTechExtras(TagTechnology.NFC_F);
70        if (extras != null) {
71            mSystemCode = extras.getByteArray(EXTRA_SC);
72            mManufacturer = extras.getByteArray(EXTRA_PMM);
73        }
74    }
75
76    /**
77     * Return the System Code bytes from tag discovery.
78     *
79     * <p>Does not cause any RF activity and does not block.
80     *
81     * @return System Code bytes
82     */
83    public byte[] getSystemCode() {
84      return mSystemCode;
85    }
86
87    /**
88     * Return the Manufacturer bytes from tag discovery.
89     *
90     * <p>Does not cause any RF activity and does not block.
91     *
92     * @return Manufacturer bytes
93     */
94    public byte[] getManufacturer() {
95      return mManufacturer;
96    }
97
98    /**
99     * Send raw NFC-F commands to the tag and receive the response.
100     *
101     * <p>Applications must not prefix the SoD (preamble and sync code)
102     * and/or append the EoD (CRC) to the payload, it will be automatically calculated.
103     *
104     * <p>A typical NFC-F frame for this method looks like:
105     * <pre>
106     * LENGTH (1 byte) --- CMD (1 byte) -- IDm (8 bytes) -- PARAMS (LENGTH - 10 bytes)
107     * </pre>
108     *
109     * <p>Use {@link #getMaxTransceiveLength} to retrieve the maximum amount of bytes
110     * that can be sent with {@link #transceive}.
111     *
112     * <p>This is an I/O operation and will block until complete. It must
113     * not be called from the main application thread. A blocked call will be canceled with
114     * {@link IOException} if {@link #close} is called from another thread.
115     *
116     * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
117     *
118     * @param data bytes to send
119     * @return bytes received in response
120     * @throws TagLostException if the tag leaves the field
121     * @throws IOException if there is an I/O failure, or this operation is canceled
122     */
123    public byte[] transceive(byte[] data) throws IOException {
124        return transceive(data, true);
125    }
126
127    /**
128     * Return the maximum number of bytes that can be sent with {@link #transceive}.
129     * @return the maximum number of bytes that can be sent with {@link #transceive}.
130     */
131    public int getMaxTransceiveLength() {
132        return getMaxTransceiveLengthInternal();
133    }
134
135    /**
136     * Set the {@link #transceive} timeout in milliseconds.
137     *
138     * <p>The timeout only applies to {@link #transceive} on this object,
139     * and is reset to a default value when {@link #close} is called.
140     *
141     * <p>Setting a longer timeout may be useful when performing
142     * transactions that require a long processing time on the tag
143     * such as key generation.
144     *
145     * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
146     *
147     * @param timeout timeout value in milliseconds
148     */
149    public void setTimeout(int timeout) {
150        try {
151            int err = mTag.getTagService().setTimeout(TagTechnology.NFC_F, timeout);
152            if (err != ErrorCodes.SUCCESS) {
153                throw new IllegalArgumentException("The supplied timeout is not valid");
154            }
155        } catch (RemoteException e) {
156            Log.e(TAG, "NFC service dead", e);
157        }
158    }
159
160    /**
161     * Get the current {@link #transceive} timeout in milliseconds.
162     *
163     * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
164     *
165     * @return timeout value in milliseconds
166     */
167    public int getTimeout() {
168        try {
169            return mTag.getTagService().getTimeout(TagTechnology.NFC_F);
170        } catch (RemoteException e) {
171            Log.e(TAG, "NFC service dead", e);
172            return 0;
173        }
174    }
175}
176