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      1 /*
      2  * Copyright (C) 2012 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 
     17 package android.nfc.tech;
     18 
     19 import android.nfc.Tag;
     20 import android.os.Bundle;
     21 import android.os.RemoteException;
     22 
     23 /**
     24  * Provides access to tags containing just a barcode.
     25  *
     26  * <p>Acquire an {@link NfcBarcode} object using {@link #get}.
     27  *
     28  */
     29 public final class NfcBarcode extends BasicTagTechnology {
     30 
     31     /** Kovio Tags */
     32     public static final int TYPE_KOVIO = 1;
     33     public static final int TYPE_UNKNOWN = -1;
     34 
     35     /** @hide */
     36     public static final String EXTRA_BARCODE_TYPE = "barcodetype";
     37 
     38     private int mType;
     39 
     40     /**
     41      * Get an instance of {@link NfcBarcode} for the given tag.
     42      *
     43      * <p>Returns null if {@link NfcBarcode} was not enumerated in {@link Tag#getTechList}.
     44      *
     45      * <p>Does not cause any RF activity and does not block.
     46      *
     47      * @param tag an NfcBarcode compatible tag
     48      * @return NfcBarcode object
     49      */
     50     public static NfcBarcode get(Tag tag) {
     51         if (!tag.hasTech(TagTechnology.NFC_BARCODE)) return null;
     52         try {
     53             return new NfcBarcode(tag);
     54         } catch (RemoteException e) {
     55             return null;
     56         }
     57     }
     58 
     59     /**
     60      * Internal constructor, to be used by NfcAdapter
     61      * @hide
     62      */
     63     public NfcBarcode(Tag tag) throws RemoteException {
     64         super(tag, TagTechnology.NFC_BARCODE);
     65         Bundle extras = tag.getTechExtras(TagTechnology.NFC_BARCODE);
     66         if (extras != null) {
     67             mType = extras.getInt(EXTRA_BARCODE_TYPE);
     68         } else {
     69             throw new NullPointerException("NfcBarcode tech extras are null.");
     70         }
     71     }
     72 
     73     /**
     74      * Returns the NFC Barcode tag type.
     75      *
     76      * <p>Currently only one of {@link #TYPE_KOVIO} or {@link #TYPE_UNKNOWN}.
     77      *
     78      * <p>Does not cause any RF activity and does not block.
     79      *
     80      * @return the NFC Barcode tag type
     81      */
     82     public int getType() {
     83         return mType;
     84     }
     85 
     86     /**
     87      * Returns the barcode of an NfcBarcode tag.
     88      *
     89      * <p> Tags of {@link #TYPE_KOVIO} return 16 bytes:
     90      *     <ul>
     91      *     <p> The first byte is 0x80 ORd with a manufacturer ID, corresponding
     92      *       to ISO/IEC 7816-6.
     93      *     <p> The second byte describes the payload data format. Defined data
     94      *       format types include the following:<ul>
     95      *       <li>0x00: Reserved for manufacturer assignment</li>
     96      *       <li>0x01: 96-bit URL with "http://www." prefix</li>
     97      *       <li>0x02: 96-bit URL with "https://www." prefix</li>
     98      *       <li>0x03: 96-bit URL with "http://" prefix</li>
     99      *       <li>0x04: 96-bit URL with "https://" prefix</li>
    100      *       <li>0x05: 96-bit GS1 EPC</li>
    101      *       <li>0x06-0xFF: reserved</li>
    102      *       </ul>
    103      *     <p>The following 12 bytes are payload:<ul>
    104      *       <li> In case of a URL payload, the payload is encoded in US-ASCII,
    105      *            following the limitations defined in RFC3987.
    106      *            {@see <a href="http://www.ietf.org/rfc/rfc3987.txt">RFC 3987</a>}</li>
    107      *       <li> In case of GS1 EPC data, see <a href="http://www.gs1.org/gsmp/kc/epcglobal/tds/">
    108      *            GS1 Electronic Product Code (EPC) Tag Data Standard (TDS)</a> for more details.
    109      *       </li>
    110      *     </ul>
    111      *     <p>The last 2 bytes comprise the CRC.
    112      *     </ul>
    113      * <p>Does not cause any RF activity and does not block.
    114      *
    115      * @return a byte array containing the barcode
    116      * @see <a href="http://www.thinfilm.no/docs/thinfilm-nfc-barcode-datasheet.pdf">
    117      *      Thinfilm NFC Barcode tag specification (previously Kovio NFC Barcode)</a>
    118      * @see <a href="http://www.thinfilm.no/docs/thinfilm-nfc-barcode-data-format.pdf">
    119      *      Thinfilm NFC Barcode data format (previously Kovio NFC Barcode)</a>
    120      */
    121     public byte[] getBarcode() {
    122         switch (mType) {
    123             case TYPE_KOVIO:
    124                 // For Kovio tags the barcode matches the ID
    125                 return mTag.getId();
    126             default:
    127                 return null;
    128         }
    129     }
    130 }
    131