1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.nfc.tech;
18
19import android.nfc.ErrorCodes;
20import android.nfc.Tag;
21import android.nfc.TransceiveResult;
22import android.os.RemoteException;
23import android.util.Log;
24
25import java.io.IOException;
26
27/**
28 * A base class for tag technologies that are built on top of transceive().
29 */
30abstract class BasicTagTechnology implements TagTechnology {
31    private static final String TAG = "NFC";
32
33    final Tag mTag;
34
35    boolean mIsConnected;
36    int mSelectedTechnology;
37
38    BasicTagTechnology(Tag tag, int tech) throws RemoteException {
39        mTag = tag;
40        mSelectedTechnology = tech;
41    }
42
43    @Override
44    public Tag getTag() {
45        return mTag;
46    }
47
48    /** Internal helper to throw IllegalStateException if the technology isn't connected */
49    void checkConnected() {
50       if ((mTag.getConnectedTechnology() != mSelectedTechnology) ||
51               (mTag.getConnectedTechnology() == -1)) {
52           throw new IllegalStateException("Call connect() first!");
53       }
54    }
55
56    @Override
57    public boolean isConnected() {
58        if (!mIsConnected) {
59            return false;
60        }
61
62        try {
63            return mTag.getTagService().isPresent(mTag.getServiceHandle());
64        } catch (RemoteException e) {
65            Log.e(TAG, "NFC service dead", e);
66            return false;
67        }
68    }
69
70    @Override
71    public void connect() throws IOException {
72        try {
73            int errorCode = mTag.getTagService().connect(mTag.getServiceHandle(),
74                    mSelectedTechnology);
75
76            if (errorCode == ErrorCodes.SUCCESS) {
77                // Store this in the tag object
78                mTag.setConnectedTechnology(mSelectedTechnology);
79                mIsConnected = true;
80            } else if (errorCode == ErrorCodes.ERROR_NOT_SUPPORTED) {
81                throw new UnsupportedOperationException("Connecting to " +
82                        "this technology is not supported by the NFC " +
83                        "adapter.");
84            } else {
85                throw new IOException();
86            }
87        } catch (RemoteException e) {
88            Log.e(TAG, "NFC service dead", e);
89            throw new IOException("NFC service died");
90        }
91    }
92
93    /** @hide */
94    @Override
95    public void reconnect() throws IOException {
96        if (!mIsConnected) {
97            throw new IllegalStateException("Technology not connected yet");
98        }
99
100        try {
101            int errorCode = mTag.getTagService().reconnect(mTag.getServiceHandle());
102
103            if (errorCode != ErrorCodes.SUCCESS) {
104                mIsConnected = false;
105                mTag.setTechnologyDisconnected();
106                throw new IOException();
107            }
108        } catch (RemoteException e) {
109            mIsConnected = false;
110            mTag.setTechnologyDisconnected();
111            Log.e(TAG, "NFC service dead", e);
112            throw new IOException("NFC service died");
113        }
114    }
115
116    @Override
117    public void close() throws IOException {
118        try {
119            /* Note that we don't want to physically disconnect the tag,
120             * but just reconnect to it to reset its state
121             */
122            mTag.getTagService().resetTimeouts();
123            mTag.getTagService().reconnect(mTag.getServiceHandle());
124        } catch (RemoteException e) {
125            Log.e(TAG, "NFC service dead", e);
126        } finally {
127            mIsConnected = false;
128            mTag.setTechnologyDisconnected();
129        }
130    }
131
132    /** Internal getMaxTransceiveLength() */
133    int getMaxTransceiveLengthInternal() {
134        try {
135            return mTag.getTagService().getMaxTransceiveLength(mSelectedTechnology);
136        } catch (RemoteException e) {
137            Log.e(TAG, "NFC service dead", e);
138            return 0;
139        }
140    }
141    /** Internal transceive */
142    byte[] transceive(byte[] data, boolean raw) throws IOException {
143        checkConnected();
144
145        try {
146            TransceiveResult result = mTag.getTagService().transceive(mTag.getServiceHandle(),
147                    data, raw);
148            if (result == null) {
149                throw new IOException("transceive failed");
150            } else {
151                return result.getResponseOrThrow();
152            }
153        } catch (RemoteException e) {
154            Log.e(TAG, "NFC service dead", e);
155            throw new IOException("NFC service died");
156        }
157    }
158}
159