| /* |
| * 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.technology; |
| |
| import java.io.IOException; |
| |
| import android.nfc.INfcAdapter; |
| import android.nfc.INfcTag; |
| import android.nfc.NfcAdapter; |
| import android.nfc.Tag; |
| import android.nfc.ErrorCodes; |
| import android.os.RemoteException; |
| import android.util.Log; |
| |
| /** |
| * A base class for tag technologies that are built on top of transceive(). |
| */ |
| /* package */ abstract class BasicTagTechnology implements TagTechnology { |
| private static final String TAG = "NFC"; |
| |
| /*package*/ final Tag mTag; |
| /*package*/ boolean mIsConnected; |
| /*package*/ int mSelectedTechnology; |
| private final NfcAdapter mAdapter; |
| /*package*/ final INfcAdapter mService; |
| /*package*/ final INfcTag mTagService; |
| |
| /** |
| * @hide |
| */ |
| public BasicTagTechnology(NfcAdapter adapter, Tag tag, int tech) throws RemoteException { |
| int[] techList = tag.getTechnologyList(); |
| int i; |
| |
| // Check target validity |
| for (i = 0; i < techList.length; i++) { |
| if (tech == techList[i]) { |
| break; |
| } |
| } |
| if (i >= techList.length) { |
| // Technology not found |
| throw new IllegalArgumentException("Technology " + tech + " not present on tag " + tag); |
| } |
| |
| mAdapter = adapter; |
| mService = mAdapter.getService(); |
| mTagService = mAdapter.getTagService(); |
| mTag = tag; |
| mSelectedTechnology = tech; |
| } |
| |
| /** |
| * @hide |
| */ |
| public BasicTagTechnology(NfcAdapter adapter, Tag tag) throws RemoteException { |
| this(adapter, tag, tag.getTechnologyList()[0]); |
| } |
| |
| /** |
| * Get the {@link Tag} this connection is associated with. |
| * <p>Requires {@link android.Manifest.permission#NFC} permission. |
| */ |
| @Override |
| public Tag getTag() { |
| return mTag; |
| } |
| |
| public void checkConnected() { |
| if ((mTag.getConnectedTechnology() != getTechnologyId()) || |
| (mTag.getConnectedTechnology() == -1)) { |
| throw new IllegalStateException("Call connect() first!"); |
| } |
| } |
| |
| /** |
| * <p>Requires {@link android.Manifest.permission#NFC} permission. |
| */ |
| @Override |
| public int getTechnologyId() { |
| return mSelectedTechnology; |
| } |
| |
| /** |
| * Helper to indicate if {@link #transceive transceive()} calls might succeed. |
| * <p> |
| * Does not cause RF activity, and does not block. |
| * <p>Requires {@link android.Manifest.permission#NFC} permission. |
| * @return true if {@link #connect} has completed successfully and the {@link Tag} is believed |
| * to be within range. Applications must still handle {@link java.io.IOException} |
| * while using {@link #transceive transceive()}, in case connection is lost after this method |
| * returns true. |
| */ |
| public boolean isConnected() { |
| if (!mIsConnected) { |
| return false; |
| } |
| |
| try { |
| return mTagService.isPresent(mTag.getServiceHandle()); |
| } catch (RemoteException e) { |
| Log.e(TAG, "NFC service dead", e); |
| return false; |
| } |
| } |
| |
| /** |
| * Connect to the {@link Tag} associated with this connection. |
| * <p> |
| * This method blocks until the connection is established. |
| * <p> |
| * {@link #close} can be called from another thread to cancel this connection |
| * attempt. |
| * <p>Requires {@link android.Manifest.permission#NFC} permission. |
| * @throws IOException if the target is lost, or connect canceled |
| */ |
| @Override |
| public void connect() throws IOException { |
| try { |
| int errorCode = mTagService.connect(mTag.getServiceHandle(), getTechnologyId()); |
| |
| if (errorCode == ErrorCodes.SUCCESS) { |
| // Store this in the tag object |
| mTag.setConnectedTechnology(getTechnologyId()); |
| mIsConnected = true; |
| } else { |
| throw new IOException(); |
| } |
| } catch (RemoteException e) { |
| Log.e(TAG, "NFC service dead", e); |
| throw new IOException("NFC service died"); |
| } |
| } |
| |
| /** |
| * Re-connect to the {@link Tag} associated with this connection. |
| * <p> |
| * Reconnecting to a tag can be used to reset the state of the tag itself. |
| * This method blocks until the connection is re-established. |
| * <p> |
| * {@link #close} can be called from another thread to cancel this connection |
| * attempt. |
| * <p>Requires {@link android.Manifest.permission#NFC} permission. |
| * @throws IOException if the target is lost, or connect canceled |
| */ |
| @Override |
| public void reconnect() throws IOException { |
| if (!mIsConnected) { |
| throw new IllegalStateException("Technology not connected yet"); |
| } |
| |
| try { |
| int errorCode = mTagService.reconnect(mTag.getServiceHandle()); |
| |
| if (errorCode != ErrorCodes.SUCCESS) { |
| mIsConnected = false; |
| mTag.setTechnologyDisconnected(); |
| throw new IOException(); |
| } |
| } catch (RemoteException e) { |
| mIsConnected = false; |
| mTag.setTechnologyDisconnected(); |
| Log.e(TAG, "NFC service dead", e); |
| throw new IOException("NFC service died"); |
| } |
| } |
| |
| /** |
| * Close this connection. |
| * <p> |
| * Causes blocking operations such as {@link #transceive transceive()} or {@link #connect} to |
| * be canceled and immediately throw {@link java.io.IOException}. |
| * <p> |
| * Once this method is called, this object cannot be re-used and should be discarded. Further |
| * calls to {@link #transceive transceive()} or {@link #connect} will fail. |
| * <p>Requires {@link android.Manifest.permission#NFC} permission. |
| */ |
| @Override |
| public void close() { |
| try { |
| /* Note that we don't want to physically disconnect the tag, |
| * but just reconnect to it to reset its state |
| */ |
| mTagService.reconnect(mTag.getServiceHandle()); |
| } catch (RemoteException e) { |
| Log.e(TAG, "NFC service dead", e); |
| } finally { |
| mIsConnected = false; |
| mTag.setTechnologyDisconnected(); |
| } |
| } |
| |
| /** internal transceive */ |
| /*package*/ byte[] transceive(byte[] data, boolean raw) throws IOException { |
| checkConnected(); |
| |
| try { |
| byte[] response = mTagService.transceive(mTag.getServiceHandle(), data, raw); |
| if (response == null) { |
| throw new IOException("transceive failed"); |
| } |
| return response; |
| } catch (RemoteException e) { |
| Log.e(TAG, "NFC service dead", e); |
| throw new IOException("NFC service died"); |
| } |
| } |
| |
| /** |
| * Send data to a tag and receive the response. |
| * <p> |
| * This method will block until the response is received. It can be canceled |
| * with {@link #close}. |
| * <p>Requires {@link android.Manifest.permission#NFC} permission. |
| * |
| * @param data bytes to send |
| * @return bytes received in response |
| * @throws IOException if the target is lost or connection closed |
| */ |
| public byte[] transceive(byte[] data) throws IOException { |
| return transceive(data, true); |
| } |
| } |