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-V (ISO 15693) properties and I/O operations on a {@link Tag}.
   *
   * <p>Acquire a {@link NfcV} object using {@link #get}.
   * <p>The primary NFC-V 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 NfcV extends BasicTagTechnology {
      /** @hide */
      public static final String EXTRA_RESP_FLAGS = "respflags";
  
      /** @hide */
      public static final String EXTRA_DSFID = "dsfid";
  
      private byte mRespFlags;
      private byte mDsfId;
  
      /**
       * Get an instance of {@link NfcV} for the given tag.
       * <p>Returns null if {@link NfcV} was not enumerated in {@link Tag#getTechList}.
       * This indicates the tag does not support NFC-V.
       * <p>Does not cause any RF activity and does not block.
       *
       * @param tag an NFC-V compatible tag
       * @return NFC-V object
       */
      public static NfcV get(Tag tag) {
          if (!tag.hasTech(TagTechnology.NFC_V)) return null;
          try {
              return new NfcV(tag);
          } catch (RemoteException e) {
              return null;
          }
      }
  
      /** @hide */
      public NfcV(Tag tag) throws RemoteException {
          super(tag, TagTechnology.NFC_V);
          Bundle extras = tag.getTechExtras(TagTechnology.NFC_V);
          mRespFlags = extras.getByte(EXTRA_RESP_FLAGS);
          mDsfId = extras.getByte(EXTRA_DSFID);
      }
  
      /**
       * Return the Response Flag bytes from tag discovery.
       *
       * <p>Does not cause any RF activity and does not block.
       *
       * @return Response Flag bytes
       */
      public byte getResponseFlags() {
          return mRespFlags;
      }
  
      /**
       * Return the DSF ID bytes from tag discovery.
       *
       * <p>Does not cause any RF activity and does not block.
       *
       * @return DSF ID bytes
       */
      public byte getDsfId() {
          return mDsfId;
      }
  
      /**
       * Send raw NFC-V commands to the tag and receive the response.
       *
       * <p>Applications must not append the CRC to the payload,
       * it will be automatically calculated. The application does
       * provide FLAGS, CMD and PARAMETER bytes.
       *
       * <p>Use {@link #getMaxTransceiveLength} to retrieve the maximum amount 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();
      }
  }
  