core/java/android/nfc/Tag.java

/*
 * 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;

import android.os.Parcel;
import android.os.Parcelable;

/**
 * Immutable data class, represents a discovered tag.
 * <p>
 * A tag is a passive NFC element, such as NFC Forum Tag's, Mifare class Tags,
 * Sony Felica Tags.
 * <p>
 * Tag's have a type and usually have a UID.
 * <p>
 * Tag objects are passed to applications via the NfcAdapter.EXTRA_TAG extra
 * in NfcAdapter.ACTION_TAG_DISCOVERED intents. The Tag object is immutable
 * and represents the state of the Tag at the time of discovery. It can be
 * directly queried for its UID and Type, or used to create a TagConnection
 * (NfcAdapter.createTagConnection()).
 * <p>
 * This Tag object can only be used to create a TagConnection while it is in
 * range. If it is removed and then returned to range then the most recent
 * Tag object (in ACTION_TAG_DISCOVERED) should be used to create a
 * TagConnection.
 */
public class Tag implements Parcelable {

    /**
     * @hide
     */
    public static final int NFC_TAG_ISO14443_A = 1; /* phNfc_eISO14443_A_PICC */

    /**
     * @hide
     */
    public static final int NFC_TAG_ISO14443_4A = 2; /* phNfc_eISO14443_4A_PICC */

    /**
     * @hide
     */
    public static final int NFC_TAG_ISO14443_3A = 3; /* phNfc_eISO14443_3A_PICC */

    /**
     * @hide
     */
    public static final int NFC_TAG_MIFARE = 4; /* phNfc_eMifare_PICC */

    /**
     * @hide
     */
    public static final int NFC_TAG_ISO14443_B = 5; /* phNfc_eISO14443_B_PICC */

    /**
     * @hide
     */
    public static final int NFC_TAG_ISO14443_4B = 6; /* phNfc_eISO14443_4B_PICC */

    /**
     * @hide
     */
    public static final int NFC_TAG_ISO14443_B_PRIME = 7; /* phNfc_eISO14443_BPrime_PICC */

    /**
     * @hide
     */
    public static final int NFC_TAG_FELICA = 8; /* phNfc_eFelica_PICC */

    /**
     * @hide
     */
    public static final int NFC_TAG_JEWEL = 9; /* phNfc_eJewel_PICC */

    /**
     * @hide
     */
    public static final int NFC_TAG_ISO15693 = 10; /* phNfc_eISO15693_PICC */

    /**
     * @hide
     */
    public static final int NFC_TAG_OTHER = 11; /* phNfc_ePICC_DevType */


    public static final String TARGET_ISO_14443_3A = "iso14443_3a";

    public static final String TARGET_ISO_14443_3B = "iso14443_3b";

    public static final String TARGET_ISO_14443_3B_PRIME = "iso14443_3b";

    public static final String TARGET_ISO_14443_4 = "iso14443_4";

    public static final String TARGET_ISO_15693 = "iso15693";

    public static final String TARGET_JIS_X_6319_4 = "jis_x_6319_4";

    public static final String TARGET_TOPAZ = "topaz";

    public static final String TARGET_OTHER = "other";

    /*package*/ final int mType;
    /*package*/ final boolean mIsNdef;
    /*package*/ final byte[] mUid;
    /*package*/ final int mNativeHandle;

    /**
     * Hidden constructor to be used by NFC service only.
     * @hide
     */
    public Tag(int type, boolean isNdef, byte[] uid, int nativeHandle) {
        mType = type;
        mIsNdef = isNdef;
        mUid = uid.clone();
        mNativeHandle = nativeHandle;
    }

    /**
     * For use by NfcService only.
     * @hide
     */
    public int getHandle() {
        return mNativeHandle;
    }

    /**
     * Return the available targets that this NFC adapter can use to create
     * a RawTagConnection.
     *
     * @return
     */
    public String[] getRawTargets() {
        //TODO
        throw new UnsupportedOperationException();
    }

    /**
     * Get the Tag type.
     * <p>
     * The Tag type is one of the NFC_TAG constants. It is read at discovery
     * time and this method does not cause any further RF activity and does not
     * block.
     *
     * @return a NFC_TAG constant
     * @hide
     */
    public int getType() {
        return mType;
    }

    /**
     * Get the Tag Identifier (if it has one).
     * <p>
     * Tag ID is usually a serial number for the tag.
     * <p>
     * The Tag ID is read at discovery time and this method does not cause any
     * further RF activity and does not block.
     *
     * @return ID, or null if it does not exist
     */
    public byte[] getId() {
        if (mUid.length > 0) {
            return mUid.clone();
        } else {
            return null;
        }
    }

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        boolean[] booleans = new boolean[] {mIsNdef};
        dest.writeInt(mType);
        dest.writeBooleanArray(booleans);
        dest.writeInt(mUid.length);
        dest.writeByteArray(mUid);
        dest.writeInt(mNativeHandle);
    }

    public static final Parcelable.Creator<Tag> CREATOR =
            new Parcelable.Creator<Tag>() {
        public Tag createFromParcel(Parcel in) {
            boolean[] booleans = new boolean[1];
            int type = in.readInt();
            in.readBooleanArray(booleans);
            boolean isNdef = booleans[0];
            int uidLength = in.readInt();
            byte[] uid = new byte[uidLength];
            in.readByteArray(uid);
            int nativeHandle = in.readInt();

            return new Tag(type, isNdef, uid, nativeHandle);
        }
        public Tag[] newArray(int size) {
            return new Tag[size];
        }
    };
}