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.ErrorCodes;
  import android.nfc.Tag;
  import android.os.Bundle;
  import android.os.RemoteException;
  import android.util.Log;
  
  import java.io.IOException;
  
  /**
   * Provides access to ISO-DEP (ISO 14443-4) properties and I/O operations on a {@link Tag}.
   *
   * <p>Acquire an {@link IsoDep} object using {@link #get}.
   * <p>The primary ISO-DEP I/O operation is {@link #transceive}. Applications must
   * implement their own protocol stack on top of {@link #transceive}.
   * <p>Tags that enumerate the {@link IsoDep} technology in {@link Tag#getTechList}
   * will also enumerate
   * {@link NfcA} or {@link NfcB} (since IsoDep builds on top of either of these).
   *
   * <p class="note"><strong>Note:</strong> Methods that perform I/O operations
   * require the {@link android.Manifest.permission#NFC} permission.
   */
  public final class IsoDep extends BasicTagTechnology {
      private static final String TAG = "NFC";
  
      /** @hide */
      public static final String EXTRA_HI_LAYER_RESP = "hiresp";
      /** @hide */
      public static final String EXTRA_HIST_BYTES = "histbytes";
  
      private byte[] mHiLayerResponse = null;
      private byte[] mHistBytes = null;
  
      /**
       * Get an instance of {@link IsoDep} for the given tag.
       * <p>Does not cause any RF activity and does not block.
       * <p>Returns null if {@link IsoDep} was not enumerated in {@link Tag#getTechList}.
       * This indicates the tag does not support ISO-DEP.
       *
       * @param tag an ISO-DEP compatible tag
       * @return ISO-DEP object
       */
      public static IsoDep get(Tag tag) {
          if (!tag.hasTech(TagTechnology.ISO_DEP)) return null;
          try {
              return new IsoDep(tag);
          } catch (RemoteException e) {
              return null;
          }
      }
  
      /** @hide */
      public IsoDep(Tag tag)
              throws RemoteException {
          super(tag, TagTechnology.ISO_DEP);
          Bundle extras = tag.getTechExtras(TagTechnology.ISO_DEP);
          if (extras != null) {
              mHiLayerResponse = extras.getByteArray(EXTRA_HI_LAYER_RESP);
              mHistBytes = extras.getByteArray(EXTRA_HIST_BYTES);
          }
      }
  
      /**
       * Set the timeout of {@link #transceive} in milliseconds.
       * <p>The timeout only applies to ISO-DEP {@link #transceive}, and is
       * reset to a default value when {@link #close} is called.
       * <p>Setting a longer timeout may be useful when performing
       * transactions that require a long processing time on the tag
       * such as key generation.
       *
       * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
       *
       * @param timeout timeout value in milliseconds
       */
      public void setTimeout(int timeout) {
          try {
              int err = mTag.getTagService().setTimeout(TagTechnology.ISO_DEP, timeout);
              if (err != ErrorCodes.SUCCESS) {
                  throw new IllegalArgumentException("The supplied timeout is not valid");
              }
          } catch (RemoteException e) {
              Log.e(TAG, "NFC service dead", e);
          }
      }
  
      /**
       * Get the current timeout for {@link #transceive} in milliseconds.
       *
       * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
       *
       * @return timeout value in milliseconds
       */
      public int getTimeout() {
          try {
              return mTag.getTagService().getTimeout(TagTechnology.ISO_DEP);
          } catch (RemoteException e) {
              Log.e(TAG, "NFC service dead", e);
              return 0;
          }
      }
  
      /**
       * Return the ISO-DEP historical bytes for {@link NfcA} tags.
       * <p>Does not cause any RF activity and does not block.
       * <p>The historical bytes can be used to help identify a tag. They are present
       * only on {@link IsoDep} tags that are based on {@link NfcA} RF technology.
       * If this tag is not {@link NfcA} then null is returned.
       * <p>In ISO 14443-4 terminology, the historical bytes are a subset of the RATS
       * response.
       *
       * @return ISO-DEP historical bytes, or null if this is not a {@link NfcA} tag
       */
      public byte[] getHistoricalBytes() {
          return mHistBytes;
      }
  
      /**
       * Return the higher layer response bytes for {@link NfcB} tags.
       * <p>Does not cause any RF activity and does not block.
       * <p>The higher layer response bytes can be used to help identify a tag.
       * They are present only on {@link IsoDep} tags that are based on {@link NfcB}
       * RF technology. If this tag is not {@link NfcB} then null is returned.
       * <p>In ISO 14443-4 terminology, the higher layer bytes are a subset of the
       * ATTRIB response.
       *
       * @return ISO-DEP historical bytes, or null if this is not a {@link NfcB} tag
       */
      public byte[] getHiLayerResponse() {
          return mHiLayerResponse;
      }
  
      /**
       * Send raw ISO-DEP data to the tag and receive the response.
       *
       * <p>Applications must only send the INF payload, and not the start of frame and
       * end of frame indicators. Applications do not need to fragment the payload, it
       * will be automatically fragmented and defragmented by {@link #transceive} if
       * it exceeds FSD/FSC limits.
       *
       * <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 command bytes to send, must not be null
       * @return response bytes received, will not be null
       * @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();
      }
  
      /**
       * <p>Standard APDUs have a 1-byte length field, allowing a maximum of
       * 255 payload bytes, which results in a maximum APDU length of 261 bytes.
       *
       * <p>Extended length APDUs have a 3-byte length field, allowing 65535
       * payload bytes.
       *
       * <p>Some NFC adapters, like the one used in the Nexus S and the Galaxy Nexus
       * do not support extended length APDUs. They are expected to be well-supported
       * in the future though. Use this method to check for extended length APDU
       * support.
       *
       * @return whether the NFC adapter on this device supports extended length APDUs.
       */
      public boolean isExtendedLengthApduSupported() {
          try {
              return mTag.getTagService().getExtendedLengthApdusSupported();
          } catch (RemoteException e) {
              Log.e(TAG, "NFC service dead", e);
              return false;
          }
      }
  }
  