content: /*
   * Copyright (C) 2010 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package android.nfc.tech;
  
  import android.nfc.Tag;
  import android.os.Bundle;
  import android.os.RemoteException;
  
  import java.io.IOException;
  
  /**
   * Provides access to NFC-B (ISO 14443-3B) properties and I/O operations on a {@link Tag}.
   *
   * <p>Acquire a {@link NfcB} object using {@link #get}.
   * <p>The primary NFC-B I/O operation is {@link #transceive}. Applications must
   * implement their own protocol stack on top of {@link #transceive}.
   *
   * <p class="note"><strong>Note:</strong> Methods that perform I/O operations
   * require the {@link android.Manifest.permission#NFC} permission.
   */
  public final class NfcB extends BasicTagTechnology {
      /** @hide */
      public static final String EXTRA_APPDATA = "appdata";
      /** @hide */
      public static final String EXTRA_PROTINFO = "protinfo";
  
      private byte[] mAppData;
      private byte[] mProtInfo;
  
      /**
       * Get an instance of {@link NfcB} for the given tag.
       * <p>Returns null if {@link NfcB} was not enumerated in {@link Tag#getTechList}.
       * This indicates the tag does not support NFC-B.
       * <p>Does not cause any RF activity and does not block.
       *
       * @param tag an NFC-B compatible tag
       * @return NFC-B object
       */
      public static NfcB get(Tag tag) {
          if (!tag.hasTech(TagTechnology.NFC_B)) return null;
          try {
              return new NfcB(tag);
          } catch (RemoteException e) {
              return null;
          }
      }
  
      /** @hide */
      public NfcB(Tag tag) throws RemoteException {
          super(tag, TagTechnology.NFC_B);
          Bundle extras = tag.getTechExtras(TagTechnology.NFC_B);
          mAppData = extras.getByteArray(EXTRA_APPDATA);
          mProtInfo = extras.getByteArray(EXTRA_PROTINFO);
      }
  
      /**
       * Return the Application Data bytes from ATQB/SENSB_RES at tag discovery.
       *
       * <p>Does not cause any RF activity and does not block.
       *
       * @return Application Data bytes from ATQB/SENSB_RES bytes
       */
      public byte[] getApplicationData() {
          return mAppData;
      }
  
      /**
       * Return the Protocol Info bytes from ATQB/SENSB_RES at tag discovery.
       *
       * <p>Does not cause any RF activity and does not block.
       *
       * @return Protocol Info bytes from ATQB/SENSB_RES bytes
       */
      public byte[] getProtocolInfo() {
          return mProtInfo;
      }
  
      /**
       * Send raw NFC-B commands to the tag and receive the response.
       *
       * <p>Applications must not append the EoD (CRC) to the payload,
       * it will be automatically calculated.
       * <p>Applications must not send commands that manage the polling
       * loop and initialization (SENSB_REQ, SLOT_MARKER etc).
       *
       * <p>Use {@link #getMaxTransceiveLength} to retrieve the maximum number of bytes
       * that can be sent with {@link #transceive}.
       *
       * <p>This is an I/O operation and will block until complete. It must
       * not be called from the main application thread. A blocked call will be canceled with
       * {@link IOException} if {@link #close} is called from another thread.
       *
       * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
       *
       * @param data bytes to send
       * @return bytes received in response
       * @throws TagLostException if the tag leaves the field
       * @throws IOException if there is an I/O failure, or this operation is canceled
       */
      public byte[] transceive(byte[] data) throws IOException {
          return transceive(data, true);
      }
  
      /**
       * Return the maximum number of bytes that can be sent with {@link #transceive}.
       * @return the maximum number of bytes that can be sent with {@link #transceive}.
       */
      public int getMaxTransceiveLength() {
          return getMaxTransceiveLengthInternal();
      }
  }
  