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/*
* 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}.
*
* Acquire a {@link NfcV} object using {@link #get}.
*
The primary NFC-V I/O operation is {@link #transceive}. Applications must
* implement their own protocol stack on top of {@link #transceive}.
*
*
Note: 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.
*
Returns null if {@link NfcV} was not enumerated in {@link Tag#getTechList}.
* This indicates the tag does not support NFC-V.
*
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.
*
*
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.
*
*
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.
*
*
Applications must not append the CRC to the payload,
* it will be automatically calculated. The application does
* provide FLAGS, CMD and PARAMETER bytes.
*
*
Use {@link #getMaxTransceiveLength} to retrieve the maximum amount of bytes
* that can be sent with {@link #transceive}.
*
*
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.
*
*
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();
}
}