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 java.io.Closeable;
  import java.io.IOException;
  
  /**
   * {@link TagTechnology} is an interface to a technology in a {@link Tag}.
   * <p>
   * Obtain a {@link TagTechnology} implementation by calling the static method <code>get()</code>
   * on the implementation class.
   * <p>
   * NFC tags are based on a number of independently developed technologies and offer a
   * wide range of capabilities. The
   * {@link TagTechnology} implementations provide access to these different
   * technologies and capabilities. Some sub-classes map to technology
   * specification (for example {@link NfcA}, {@link IsoDep}, others map to
   * pseudo-technologies or capabilities (for example {@link Ndef}, {@link NdefFormatable}).
   * <p>
   * It is mandatory for all Android NFC devices to provide the following
   * {@link TagTechnology} implementations.
   * <ul>
   * <li>{@link NfcA} (also known as ISO 14443-3A)
   * <li>{@link NfcB} (also known as ISO 14443-3B)
   * <li>{@link NfcF} (also known as JIS 6319-4)
   * <li>{@link NfcV} (also known as ISO 15693)
   * <li>{@link IsoDep}
   * <li>{@link Ndef} on NFC Forum Type 1, Type 2, Type 3 or Type 4 compliant tags
   * </ul>
   * It is optional for Android NFC devices to provide the following
   * {@link TagTechnology} implementations. If it is not provided, the
   * Android device will never enumerate that class via {@link Tag#getTechList}.
   * <ul>
   * <li>{@link MifareClassic}
   * <li>{@link MifareUltralight}
   * <li>{@link NfcBarcode}
   * <li>{@link NdefFormatable} must only be enumerated on tags for which this Android device
   * is capable of formatting. Proprietary knowledge is often required to format a tag
   * to make it NDEF compatible.
   * </ul>
   * <p>
   * {@link TagTechnology} implementations provide methods that fall into two classes:
   * <em>cached getters</em> and <em>I/O operations</em>.
   * <h4>Cached getters</h4>
   * These methods (usually prefixed by <code>get</code> or <code>is</code>) return
   * properties of the tag, as determined at discovery time. These methods will never
   * block or cause RF activity, and do not require {@link #connect} to have been called.
   * They also never update, for example if a property is changed by an I/O operation with a tag
   * then the cached getter will still return the result from tag discovery time.
   * <h4>I/O operations</h4>
   * I/O operations may require RF activity, and may block. They have the following semantics.
   * <ul>
   * <li>{@link #connect} must be called before using any other I/O operation.
   * <li>{@link #close} must be called after completing I/O operations with a
   * {@link TagTechnology}, and it will cancel all other blocked I/O operations on other threads
   * (including {@link #connect} with {@link IOException}.
   * <li>Only one {@link TagTechnology} can be connected at a time. Other calls to
   * {@link #connect} will return {@link IOException}.
   * <li>I/O operations may block, and should never be called on the main application
   * thread.
   * </ul>
   *
   * <p class="note"><strong>Note:</strong> Methods that perform I/O operations
   * require the {@link android.Manifest.permission#NFC} permission.
   */
  public interface TagTechnology extends Closeable {
      /**
       * This technology is an instance of {@link NfcA}.
       * <p>Support for this technology type is mandatory.
       * @hide
       */
      public static final int NFC_A = 1;
  
      /**
       * This technology is an instance of {@link NfcB}.
       * <p>Support for this technology type is mandatory.
       * @hide
       */
      public static final int NFC_B = 2;
  
      /**
       * This technology is an instance of {@link IsoDep}.
       * <p>Support for this technology type is mandatory.
       * @hide
       */
      public static final int ISO_DEP = 3;
  
      /**
       * This technology is an instance of {@link NfcF}.
       * <p>Support for this technology type is mandatory.
       * @hide
       */
      public static final int NFC_F = 4;
  
      /**
       * This technology is an instance of {@link NfcV}.
       * <p>Support for this technology type is mandatory.
       * @hide
       */
      public static final int NFC_V = 5;
  
      /**
       * This technology is an instance of {@link Ndef}.
       * <p>Support for this technology type is mandatory.
       * @hide
       */
      public static final int NDEF = 6;
  
      /**
       * This technology is an instance of {@link NdefFormatable}.
       * <p>Support for this technology type is mandatory.
       * @hide
       */
      public static final int NDEF_FORMATABLE = 7;
  
      /**
       * This technology is an instance of {@link MifareClassic}.
       * <p>Support for this technology type is optional. If a stack doesn't support this technology
       * type tags using it must still be discovered and present the lower level radio interface
       * technologies in use.
       * @hide
       */
      public static final int MIFARE_CLASSIC = 8;
  
      /**
       * This technology is an instance of {@link MifareUltralight}.
       * <p>Support for this technology type is optional. If a stack doesn't support this technology
       * type tags using it must still be discovered and present the lower level radio interface
       * technologies in use.
       * @hide
       */
      public static final int MIFARE_ULTRALIGHT = 9;
  
      /**
       * This technology is an instance of {@link NfcBarcode}.
       * <p>Support for this technology type is optional. If a stack doesn't support this technology
       * type tags using it must still be discovered and present the lower level radio interface
       * technologies in use.
       * @hide
       */
      public static final int NFC_BARCODE = 10;
  
      /**
       * Get the {@link Tag} object backing this {@link TagTechnology} object.
       * @return the {@link Tag} backing this {@link TagTechnology} object.
       */
      public Tag getTag();
  
      /**
       * Enable I/O operations to the tag from this {@link TagTechnology} object.
       * <p>May cause RF activity and may block. Must not be called
       * from the main application thread. A blocked call will be canceled with
       * {@link IOException} by calling {@link #close} from another thread.
       * <p>Only one {@link TagTechnology} object can be connected to a {@link Tag} at a time.
       * <p>Applications must call {@link #close} when I/O operations are complete.
       *
       * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
       *
       * @see #close()
       * @throws TagLostException if the tag leaves the field
       * @throws IOException if there is an I/O failure, or connect is canceled
       */
      public void connect() throws IOException;
  
      /**
       * Re-connect to the {@link Tag} associated with this connection. Reconnecting to a tag can be
       * used to reset the state of the tag itself.
       *
       * <p>May cause RF activity and may block. Must not be called
       * from the main application thread. A blocked call will be canceled with
       * {@link IOException} by calling {@link #close} from another thread.
       *
       * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
       *
       * @see #connect()
       * @see #close()
       * @throws TagLostException if the tag leaves the field
       * @throws IOException if there is an I/O failure, or connect is canceled
       * @hide
       */
      public void reconnect() throws IOException;
  
      /**
       * Disable I/O operations to the tag from this {@link TagTechnology} object, and release resources.
       * <p>Also causes all blocked I/O operations on other thread to be canceled and
       * return with {@link IOException}.
       *
       * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
       *
       * @see #connect()
       */
      public void close() throws IOException;
  
      /**
       * Helper to indicate if I/O operations should be possible.
       *
       * <p>Returns true if {@link #connect} has completed, and {@link #close} has not been
       * called, and the {@link Tag} is not known to be out of range.
       * <p>Does not cause RF activity, and does not block.
       *
       * @return true if I/O operations should be possible
       */
      public boolean isConnected();
  }
  