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 
17 package android.nfc;
18 
19 import android.annotation.NonNull;
20 import android.annotation.RequiresPermission;
21 import android.annotation.SdkConstant;
22 import android.annotation.SdkConstant.SdkConstantType;
23 import android.annotation.SystemApi;
24 import android.annotation.UnsupportedAppUsage;
25 import android.app.Activity;
26 import android.app.ActivityThread;
27 import android.app.OnActivityPausedListener;
28 import android.app.PendingIntent;
29 import android.content.Context;
30 import android.content.IntentFilter;
31 import android.content.pm.IPackageManager;
32 import android.content.pm.PackageManager;
33 import android.net.Uri;
34 import android.nfc.tech.MifareClassic;
35 import android.nfc.tech.Ndef;
36 import android.nfc.tech.NfcA;
37 import android.nfc.tech.NfcF;
38 import android.os.Bundle;
39 import android.os.Handler;
40 import android.os.IBinder;
41 import android.os.RemoteException;
42 import android.os.ServiceManager;
43 import android.util.Log;
44 
45 import java.io.IOException;
46 import java.util.ArrayList;
47 import java.util.HashMap;
48 import java.util.List;
49 
50 /**
51  * Represents the local NFC adapter.
52  * <p>
53  * Use the helper {@link #getDefaultAdapter(Context)} to get the default NFC
54  * adapter for this Android device.
55  *
56  * <div class="special reference">
57  * <h3>Developer Guides</h3>
58  * <p>For more information about using NFC, read the
59  * <a href="{@docRoot}guide/topics/nfc/index.html">Near Field Communication</a> developer guide.</p>
60  * <p>To perform basic file sharing between devices, read
61  * <a href="{@docRoot}training/beam-files/index.html">Sharing Files with NFC</a>.
62  * </div>
63  */
64 public final class NfcAdapter {
65     static final String TAG = "NFC";
66 
67     /**
68      * Intent to start an activity when a tag with NDEF payload is discovered.
69      *
70      * <p>The system inspects the first {@link NdefRecord} in the first {@link NdefMessage} and
71      * looks for a URI, SmartPoster, or MIME record. If a URI or SmartPoster record is found the
72      * intent will contain the URI in its data field. If a MIME record is found the intent will
73      * contain the MIME type in its type field. This allows activities to register
74      * {@link IntentFilter}s targeting specific content on tags. Activities should register the
75      * most specific intent filters possible to avoid the activity chooser dialog, which can
76      * disrupt the interaction with the tag as the user interacts with the screen.
77      *
78      * <p>If the tag has an NDEF payload this intent is started before
79      * {@link #ACTION_TECH_DISCOVERED}. If any activities respond to this intent neither
80      * {@link #ACTION_TECH_DISCOVERED} or {@link #ACTION_TAG_DISCOVERED} will be started.
81      *
82      * <p>The MIME type or data URI of this intent are normalized before dispatch -
83      * so that MIME, URI scheme and URI host are always lower-case.
84      */
85     @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION)
86     public static final String ACTION_NDEF_DISCOVERED = "android.nfc.action.NDEF_DISCOVERED";
87 
88     /**
89      * Intent to start an activity when a tag is discovered and activities are registered for the
90      * specific technologies on the tag.
91      *
92      * <p>To receive this intent an activity must include an intent filter
93      * for this action and specify the desired tech types in a
94      * manifest <code>meta-data</code> entry. Here is an example manfiest entry:
95      * <pre>
96      * &lt;activity android:name=".nfc.TechFilter" android:label="NFC/TechFilter"&gt;
97      *     &lt;!-- Add a technology filter --&gt;
98      *     &lt;intent-filter&gt;
99      *         &lt;action android:name="android.nfc.action.TECH_DISCOVERED" /&gt;
100      *     &lt;/intent-filter&gt;
101      *
102      *     &lt;meta-data android:name="android.nfc.action.TECH_DISCOVERED"
103      *         android:resource="@xml/filter_nfc"
104      *     /&gt;
105      * &lt;/activity&gt;</pre>
106      *
107      * <p>The meta-data XML file should contain one or more <code>tech-list</code> entries
108      * each consisting or one or more <code>tech</code> entries. The <code>tech</code> entries refer
109      * to the qualified class name implementing the technology, for example "android.nfc.tech.NfcA".
110      *
111      * <p>A tag matches if any of the
112      * <code>tech-list</code> sets is a subset of {@link Tag#getTechList() Tag.getTechList()}. Each
113      * of the <code>tech-list</code>s is considered independently and the
114      * activity is considered a match is any single <code>tech-list</code> matches the tag that was
115      * discovered. This provides AND and OR semantics for filtering desired techs. Here is an
116      * example that will match any tag using {@link NfcF} or any tag using {@link NfcA},
117      * {@link MifareClassic}, and {@link Ndef}:
118      *
119      * <pre>
120      * &lt;resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2"&gt;
121      *     &lt;!-- capture anything using NfcF --&gt;
122      *     &lt;tech-list&gt;
123      *         &lt;tech&gt;android.nfc.tech.NfcF&lt;/tech&gt;
124      *     &lt;/tech-list&gt;
125      *
126      *     &lt;!-- OR --&gt;
127      *
128      *     &lt;!-- capture all MIFARE Classics with NDEF payloads --&gt;
129      *     &lt;tech-list&gt;
130      *         &lt;tech&gt;android.nfc.tech.NfcA&lt;/tech&gt;
131      *         &lt;tech&gt;android.nfc.tech.MifareClassic&lt;/tech&gt;
132      *         &lt;tech&gt;android.nfc.tech.Ndef&lt;/tech&gt;
133      *     &lt;/tech-list&gt;
134      * &lt;/resources&gt;</pre>
135      *
136      * <p>This intent is started after {@link #ACTION_NDEF_DISCOVERED} and before
137      * {@link #ACTION_TAG_DISCOVERED}. If any activities respond to {@link #ACTION_NDEF_DISCOVERED}
138      * this intent will not be started. If any activities respond to this intent
139      * {@link #ACTION_TAG_DISCOVERED} will not be started.
140      */
141     @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION)
142     public static final String ACTION_TECH_DISCOVERED = "android.nfc.action.TECH_DISCOVERED";
143 
144     /**
145      * Intent to start an activity when a tag is discovered.
146      *
147      * <p>This intent will not be started when a tag is discovered if any activities respond to
148      * {@link #ACTION_NDEF_DISCOVERED} or {@link #ACTION_TECH_DISCOVERED} for the current tag.
149      */
150     @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION)
151     public static final String ACTION_TAG_DISCOVERED = "android.nfc.action.TAG_DISCOVERED";
152 
153     /**
154      * Broadcast Action: Intent to notify an application that an transaction event has occurred
155      * on the Secure Element.
156      *
157      * <p>This intent will only be sent if the application has requested permission for
158      * {@link android.Manifest.permission#NFC_TRANSACTION_EVENT} and if the application has the
159      * necessary access to Secure Element which witnessed the particular event.
160      */
161     @RequiresPermission(android.Manifest.permission.NFC_TRANSACTION_EVENT)
162     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
163     public static final String ACTION_TRANSACTION_DETECTED =
164             "android.nfc.action.TRANSACTION_DETECTED";
165 
166     /**
167      * Broadcast to only the activity that handles ACTION_TAG_DISCOVERED
168      * @hide
169      */
170     public static final String ACTION_TAG_LEFT_FIELD = "android.nfc.action.TAG_LOST";
171 
172     /**
173      * Mandatory extra containing the {@link Tag} that was discovered for the
174      * {@link #ACTION_NDEF_DISCOVERED}, {@link #ACTION_TECH_DISCOVERED}, and
175      * {@link #ACTION_TAG_DISCOVERED} intents.
176      */
177     public static final String EXTRA_TAG = "android.nfc.extra.TAG";
178 
179     /**
180      * Extra containing an array of {@link NdefMessage} present on the discovered tag.<p>
181      * This extra is mandatory for {@link #ACTION_NDEF_DISCOVERED} intents,
182      * and optional for {@link #ACTION_TECH_DISCOVERED}, and
183      * {@link #ACTION_TAG_DISCOVERED} intents.<p>
184      * When this extra is present there will always be at least one
185      * {@link NdefMessage} element. Most NDEF tags have only one NDEF message,
186      * but we use an array for future compatibility.
187      */
188     public static final String EXTRA_NDEF_MESSAGES = "android.nfc.extra.NDEF_MESSAGES";
189 
190     /**
191      * Optional extra containing a byte array containing the ID of the discovered tag for
192      * the {@link #ACTION_NDEF_DISCOVERED}, {@link #ACTION_TECH_DISCOVERED}, and
193      * {@link #ACTION_TAG_DISCOVERED} intents.
194      */
195     public static final String EXTRA_ID = "android.nfc.extra.ID";
196 
197     /**
198      * Broadcast Action: The state of the local NFC adapter has been
199      * changed.
200      * <p>For example, NFC has been turned on or off.
201      * <p>Always contains the extra field {@link #EXTRA_ADAPTER_STATE}
202      */
203     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
204     public static final String ACTION_ADAPTER_STATE_CHANGED =
205             "android.nfc.action.ADAPTER_STATE_CHANGED";
206 
207     /**
208      * Used as an int extra field in {@link #ACTION_ADAPTER_STATE_CHANGED}
209      * intents to request the current power state. Possible values are:
210      * {@link #STATE_OFF},
211      * {@link #STATE_TURNING_ON},
212      * {@link #STATE_ON},
213      * {@link #STATE_TURNING_OFF},
214      */
215     public static final String EXTRA_ADAPTER_STATE = "android.nfc.extra.ADAPTER_STATE";
216 
217     /**
218      * Mandatory byte[] extra field in {@link #ACTION_TRANSACTION_DETECTED}
219      */
220     public static final String EXTRA_AID = "android.nfc.extra.AID";
221 
222     /**
223      * Optional byte[] extra field in {@link #ACTION_TRANSACTION_DETECTED}
224      */
225     public static final String EXTRA_DATA = "android.nfc.extra.DATA";
226 
227     /**
228      * Mandatory String extra field in {@link #ACTION_TRANSACTION_DETECTED}
229      * Indicates the Secure Element on which the transaction occurred.
230      * eSE1...eSEn for Embedded Secure Elements, SIM1...SIMn for UICC, etc.
231      */
232     public static final String EXTRA_SECURE_ELEMENT_NAME = "android.nfc.extra.SECURE_ELEMENT_NAME";
233 
234     public static final int STATE_OFF = 1;
235     public static final int STATE_TURNING_ON = 2;
236     public static final int STATE_ON = 3;
237     public static final int STATE_TURNING_OFF = 4;
238 
239     /**
240      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
241      * <p>
242      * Setting this flag enables polling for Nfc-A technology.
243      */
244     public static final int FLAG_READER_NFC_A = 0x1;
245 
246     /**
247      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
248      * <p>
249      * Setting this flag enables polling for Nfc-B technology.
250      */
251     public static final int FLAG_READER_NFC_B = 0x2;
252 
253     /**
254      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
255      * <p>
256      * Setting this flag enables polling for Nfc-F technology.
257      */
258     public static final int FLAG_READER_NFC_F = 0x4;
259 
260     /**
261      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
262      * <p>
263      * Setting this flag enables polling for Nfc-V (ISO15693) technology.
264      */
265     public static final int FLAG_READER_NFC_V = 0x8;
266 
267     /**
268      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
269      * <p>
270      * Setting this flag enables polling for NfcBarcode technology.
271      */
272     public static final int FLAG_READER_NFC_BARCODE = 0x10;
273 
274     /**
275      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
276      * <p>
277      * Setting this flag allows the caller to prevent the
278      * platform from performing an NDEF check on the tags it
279      * finds.
280      */
281     public static final int FLAG_READER_SKIP_NDEF_CHECK = 0x80;
282 
283     /**
284      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
285      * <p>
286      * Setting this flag allows the caller to prevent the
287      * platform from playing sounds when it discovers a tag.
288      */
289     public static final int FLAG_READER_NO_PLATFORM_SOUNDS = 0x100;
290 
291     /**
292      * Int Extra for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
293      * <p>
294      * Setting this integer extra allows the calling application to specify
295      * the delay that the platform will use for performing presence checks
296      * on any discovered tag.
297      */
298     public static final String EXTRA_READER_PRESENCE_CHECK_DELAY = "presence";
299 
300     /** @hide */
301     @SystemApi
302     public static final int FLAG_NDEF_PUSH_NO_CONFIRM = 0x1;
303 
304     /** @hide */
305     public static final String ACTION_HANDOVER_TRANSFER_STARTED =
306             "android.nfc.action.HANDOVER_TRANSFER_STARTED";
307 
308     /** @hide */
309     public static final String ACTION_HANDOVER_TRANSFER_DONE =
310             "android.nfc.action.HANDOVER_TRANSFER_DONE";
311 
312     /** @hide */
313     public static final String EXTRA_HANDOVER_TRANSFER_STATUS =
314             "android.nfc.extra.HANDOVER_TRANSFER_STATUS";
315 
316     /** @hide */
317     public static final int HANDOVER_TRANSFER_STATUS_SUCCESS = 0;
318     /** @hide */
319     public static final int HANDOVER_TRANSFER_STATUS_FAILURE = 1;
320 
321     /** @hide */
322     public static final String EXTRA_HANDOVER_TRANSFER_URI =
323             "android.nfc.extra.HANDOVER_TRANSFER_URI";
324 
325     // Guarded by NfcAdapter.class
326     static boolean sIsInitialized = false;
327     static boolean sHasNfcFeature;
328     static boolean sHasBeamFeature;
329 
330     // Final after first constructor, except for
331     // attemptDeadServiceRecovery() when NFC crashes - we accept a best effort
332     // recovery
333     @UnsupportedAppUsage
334     static INfcAdapter sService;
335     static INfcTag sTagService;
336     static INfcCardEmulation sCardEmulationService;
337     static INfcFCardEmulation sNfcFCardEmulationService;
338 
339     /**
340      * The NfcAdapter object for each application context.
341      * There is a 1-1 relationship between application context and
342      * NfcAdapter object.
343      */
344     static HashMap<Context, NfcAdapter> sNfcAdapters = new HashMap(); //guard by NfcAdapter.class
345 
346     /**
347      * NfcAdapter used with a null context. This ctor was deprecated but we have
348      * to support it for backwards compatibility. New methods that require context
349      * might throw when called on the null-context NfcAdapter.
350      */
351     static NfcAdapter sNullContextNfcAdapter;  // protected by NfcAdapter.class
352 
353     final NfcActivityManager mNfcActivityManager;
354     final Context mContext;
355     final HashMap<NfcUnlockHandler, INfcUnlockHandler> mNfcUnlockHandlers;
356     final Object mLock;
357 
358     ITagRemovedCallback mTagRemovedListener; // protected by mLock
359 
360     /**
361      * A callback to be invoked when the system finds a tag while the foreground activity is
362      * operating in reader mode.
363      * <p>Register your {@code ReaderCallback} implementation with {@link
364      * NfcAdapter#enableReaderMode} and disable it with {@link
365      * NfcAdapter#disableReaderMode}.
366      * @see NfcAdapter#enableReaderMode
367      */
368     public interface ReaderCallback {
onTagDiscovered(Tag tag)369         public void onTagDiscovered(Tag tag);
370     }
371 
372     /**
373      * A callback to be invoked when the system successfully delivers your {@link NdefMessage}
374      * to another device.
375      * @see #setOnNdefPushCompleteCallback
376      * @deprecated this feature is deprecated. File sharing can work using other technology like
377      * Bluetooth.
378      */
379     @java.lang.Deprecated
380     public interface OnNdefPushCompleteCallback {
381         /**
382          * Called on successful NDEF push.
383          *
384          * <p>This callback is usually made on a binder thread (not the UI thread).
385          *
386          * @param event {@link NfcEvent} with the {@link NfcEvent#nfcAdapter} field set
387          * @see #setNdefPushMessageCallback
388          */
onNdefPushComplete(NfcEvent event)389         public void onNdefPushComplete(NfcEvent event);
390     }
391 
392     /**
393      * A callback to be invoked when another NFC device capable of NDEF push (Android Beam)
394      * is within range.
395      * <p>Implement this interface and pass it to {@link
396      * NfcAdapter#setNdefPushMessageCallback setNdefPushMessageCallback()} in order to create an
397      * {@link NdefMessage} at the moment that another device is within range for NFC. Using this
398      * callback allows you to create a message with data that might vary based on the
399      * content currently visible to the user. Alternatively, you can call {@link
400      * #setNdefPushMessage setNdefPushMessage()} if the {@link NdefMessage} always contains the
401      * same data.
402      * @deprecated this feature is deprecated. File sharing can work using other technology like
403      * Bluetooth.
404      */
405     @java.lang.Deprecated
406     public interface CreateNdefMessageCallback {
407         /**
408          * Called to provide a {@link NdefMessage} to push.
409          *
410          * <p>This callback is usually made on a binder thread (not the UI thread).
411          *
412          * <p>Called when this device is in range of another device
413          * that might support NDEF push. It allows the application to
414          * create the NDEF message only when it is required.
415          *
416          * <p>NDEF push cannot occur until this method returns, so do not
417          * block for too long.
418          *
419          * <p>The Android operating system will usually show a system UI
420          * on top of your activity during this time, so do not try to request
421          * input from the user to complete the callback, or provide custom NDEF
422          * push UI. The user probably will not see it.
423          *
424          * @param event {@link NfcEvent} with the {@link NfcEvent#nfcAdapter} field set
425          * @return NDEF message to push, or null to not provide a message
426          */
createNdefMessage(NfcEvent event)427         public NdefMessage createNdefMessage(NfcEvent event);
428     }
429 
430 
431      /**
432      * @deprecated this feature is deprecated. File sharing can work using other technology like
433      * Bluetooth.
434      */
435     @java.lang.Deprecated
436     public interface CreateBeamUrisCallback {
createBeamUris(NfcEvent event)437         public Uri[] createBeamUris(NfcEvent event);
438     }
439 
440     /**
441      * A callback that is invoked when a tag is removed from the field.
442      * @see NfcAdapter#ignore
443      */
444     public interface OnTagRemovedListener {
onTagRemoved()445         void onTagRemoved();
446     }
447 
448     /**
449      * A callback to be invoked when an application has registered as a
450      * handler to unlock the device given an NFC tag at the lockscreen.
451      * @hide
452      */
453     @SystemApi
454     public interface NfcUnlockHandler {
455         /**
456          * Called at the lock screen to attempt to unlock the device with the given tag.
457          * @param tag the detected tag, to be used to unlock the device
458          * @return true if the device was successfully unlocked
459          */
onUnlockAttempted(Tag tag)460         public boolean onUnlockAttempted(Tag tag);
461     }
462 
463     /**
464      * Helper to check if this device has FEATURE_NFC_BEAM, but without using
465      * a context.
466      * Equivalent to
467      * context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_NFC_BEAM)
468      */
hasBeamFeature()469     private static boolean hasBeamFeature() {
470         IPackageManager pm = ActivityThread.getPackageManager();
471         if (pm == null) {
472             Log.e(TAG, "Cannot get package manager, assuming no Android Beam feature");
473             return false;
474         }
475         try {
476             return pm.hasSystemFeature(PackageManager.FEATURE_NFC_BEAM, 0);
477         } catch (RemoteException e) {
478             Log.e(TAG, "Package manager query failed, assuming no Android Beam feature", e);
479             return false;
480         }
481     }
482 
483     /**
484      * Helper to check if this device has FEATURE_NFC, but without using
485      * a context.
486      * Equivalent to
487      * context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_NFC)
488      */
hasNfcFeature()489     private static boolean hasNfcFeature() {
490         IPackageManager pm = ActivityThread.getPackageManager();
491         if (pm == null) {
492             Log.e(TAG, "Cannot get package manager, assuming no NFC feature");
493             return false;
494         }
495         try {
496             return pm.hasSystemFeature(PackageManager.FEATURE_NFC, 0);
497         } catch (RemoteException e) {
498             Log.e(TAG, "Package manager query failed, assuming no NFC feature", e);
499             return false;
500         }
501     }
502 
503     /**
504      * Helper to check if this device is NFC HCE capable, by checking for
505      * FEATURE_NFC_HOST_CARD_EMULATION and/or FEATURE_NFC_HOST_CARD_EMULATION_NFCF,
506      * but without using a context.
507      */
hasNfcHceFeature()508     private static boolean hasNfcHceFeature() {
509         IPackageManager pm = ActivityThread.getPackageManager();
510         if (pm == null) {
511             Log.e(TAG, "Cannot get package manager, assuming no NFC feature");
512             return false;
513         }
514         try {
515             return pm.hasSystemFeature(PackageManager.FEATURE_NFC_HOST_CARD_EMULATION, 0)
516                 || pm.hasSystemFeature(PackageManager.FEATURE_NFC_HOST_CARD_EMULATION_NFCF, 0);
517         } catch (RemoteException e) {
518             Log.e(TAG, "Package manager query failed, assuming no NFC feature", e);
519             return false;
520         }
521     }
522 
523     /**
524      * Return list of Secure Elements which support off host card emulation.
525      *
526      * @return List<String> containing secure elements on the device which supports
527      *                      off host card emulation. eSE for Embedded secure element,
528      *                      SIM for UICC and so on.
529      * @hide
530      */
getSupportedOffHostSecureElements()531     public @NonNull List<String> getSupportedOffHostSecureElements() {
532         List<String> offHostSE = new ArrayList<String>();
533         IPackageManager pm = ActivityThread.getPackageManager();
534         if (pm == null) {
535             Log.e(TAG, "Cannot get package manager, assuming no off-host CE feature");
536             return offHostSE;
537         }
538         try {
539             if (pm.hasSystemFeature(PackageManager.FEATURE_NFC_OFF_HOST_CARD_EMULATION_UICC, 0)) {
540                 offHostSE.add("SIM");
541             }
542             if (pm.hasSystemFeature(PackageManager.FEATURE_NFC_OFF_HOST_CARD_EMULATION_ESE, 0)) {
543                 offHostSE.add("eSE");
544             }
545         } catch (RemoteException e) {
546             Log.e(TAG, "Package manager query failed, assuming no off-host CE feature", e);
547             offHostSE.clear();
548             return offHostSE;
549         }
550         return offHostSE;
551     }
552 
553     /**
554      * Returns the NfcAdapter for application context,
555      * or throws if NFC is not available.
556      * @hide
557      */
558     @UnsupportedAppUsage
getNfcAdapter(Context context)559     public static synchronized NfcAdapter getNfcAdapter(Context context) {
560         if (!sIsInitialized) {
561             sHasNfcFeature = hasNfcFeature();
562             sHasBeamFeature = hasBeamFeature();
563             boolean hasHceFeature = hasNfcHceFeature();
564             /* is this device meant to have NFC */
565             if (!sHasNfcFeature && !hasHceFeature) {
566                 Log.v(TAG, "this device does not have NFC support");
567                 throw new UnsupportedOperationException();
568             }
569             sService = getServiceInterface();
570             if (sService == null) {
571                 Log.e(TAG, "could not retrieve NFC service");
572                 throw new UnsupportedOperationException();
573             }
574             if (sHasNfcFeature) {
575                 try {
576                     sTagService = sService.getNfcTagInterface();
577                 } catch (RemoteException e) {
578                     Log.e(TAG, "could not retrieve NFC Tag service");
579                     throw new UnsupportedOperationException();
580                 }
581             }
582             if (hasHceFeature) {
583                 try {
584                     sNfcFCardEmulationService = sService.getNfcFCardEmulationInterface();
585                 } catch (RemoteException e) {
586                     Log.e(TAG, "could not retrieve NFC-F card emulation service");
587                     throw new UnsupportedOperationException();
588                 }
589                 try {
590                     sCardEmulationService = sService.getNfcCardEmulationInterface();
591                 } catch (RemoteException e) {
592                     Log.e(TAG, "could not retrieve card emulation service");
593                     throw new UnsupportedOperationException();
594                 }
595             }
596 
597             sIsInitialized = true;
598         }
599         if (context == null) {
600             if (sNullContextNfcAdapter == null) {
601                 sNullContextNfcAdapter = new NfcAdapter(null);
602             }
603             return sNullContextNfcAdapter;
604         }
605         NfcAdapter adapter = sNfcAdapters.get(context);
606         if (adapter == null) {
607             adapter = new NfcAdapter(context);
608             sNfcAdapters.put(context, adapter);
609         }
610         return adapter;
611     }
612 
613     /** get handle to NFC service interface */
getServiceInterface()614     private static INfcAdapter getServiceInterface() {
615         /* get a handle to NFC service */
616         IBinder b = ServiceManager.getService("nfc");
617         if (b == null) {
618             return null;
619         }
620         return INfcAdapter.Stub.asInterface(b);
621     }
622 
623     /**
624      * Helper to get the default NFC Adapter.
625      * <p>
626      * Most Android devices will only have one NFC Adapter (NFC Controller).
627      * <p>
628      * This helper is the equivalent of:
629      * <pre>
630      * NfcManager manager = (NfcManager) context.getSystemService(Context.NFC_SERVICE);
631      * NfcAdapter adapter = manager.getDefaultAdapter();</pre>
632      * @param context the calling application's context
633      *
634      * @return the default NFC adapter, or null if no NFC adapter exists
635      */
getDefaultAdapter(Context context)636     public static NfcAdapter getDefaultAdapter(Context context) {
637         if (context == null) {
638             throw new IllegalArgumentException("context cannot be null");
639         }
640         context = context.getApplicationContext();
641         if (context == null) {
642             throw new IllegalArgumentException(
643                     "context not associated with any application (using a mock context?)");
644         }
645         /* use getSystemService() for consistency */
646         NfcManager manager = (NfcManager) context.getSystemService(Context.NFC_SERVICE);
647         if (manager == null) {
648             // NFC not available
649             return null;
650         }
651         return manager.getDefaultAdapter();
652     }
653 
654     /**
655      * Legacy NfcAdapter getter, always use {@link #getDefaultAdapter(Context)} instead.<p>
656      * This method was deprecated at API level 10 (Gingerbread MR1) because a context is required
657      * for many NFC API methods. Those methods will fail when called on an NfcAdapter
658      * object created from this method.<p>
659      * @deprecated use {@link #getDefaultAdapter(Context)}
660      * @hide
661      */
662     @Deprecated
663     @UnsupportedAppUsage
getDefaultAdapter()664     public static NfcAdapter getDefaultAdapter() {
665         // introduced in API version 9 (GB 2.3)
666         // deprecated in API version 10 (GB 2.3.3)
667         // removed from public API in version 16 (ICS MR2)
668         // should maintain as a hidden API for binary compatibility for a little longer
669         Log.w(TAG, "WARNING: NfcAdapter.getDefaultAdapter() is deprecated, use " +
670                 "NfcAdapter.getDefaultAdapter(Context) instead", new Exception());
671 
672         return NfcAdapter.getNfcAdapter(null);
673     }
674 
NfcAdapter(Context context)675     NfcAdapter(Context context) {
676         mContext = context;
677         mNfcActivityManager = new NfcActivityManager(this);
678         mNfcUnlockHandlers = new HashMap<NfcUnlockHandler, INfcUnlockHandler>();
679         mTagRemovedListener = null;
680         mLock = new Object();
681     }
682 
683     /**
684      * @hide
685      */
686     @UnsupportedAppUsage
getContext()687     public Context getContext() {
688         return mContext;
689     }
690 
691     /**
692      * Returns the binder interface to the service.
693      * @hide
694      */
695     @UnsupportedAppUsage
getService()696     public INfcAdapter getService() {
697         isEnabled();  // NOP call to recover sService if it is stale
698         return sService;
699     }
700 
701     /**
702      * Returns the binder interface to the tag service.
703      * @hide
704      */
getTagService()705     public INfcTag getTagService() {
706         isEnabled();  // NOP call to recover sTagService if it is stale
707         return sTagService;
708     }
709 
710     /**
711      * Returns the binder interface to the card emulation service.
712      * @hide
713      */
getCardEmulationService()714     public INfcCardEmulation getCardEmulationService() {
715         isEnabled();
716         return sCardEmulationService;
717     }
718 
719     /**
720      * Returns the binder interface to the NFC-F card emulation service.
721      * @hide
722      */
getNfcFCardEmulationService()723     public INfcFCardEmulation getNfcFCardEmulationService() {
724         isEnabled();
725         return sNfcFCardEmulationService;
726     }
727 
728     /**
729      * Returns the binder interface to the NFC-DTA test interface.
730      * @hide
731      */
getNfcDtaInterface()732     public INfcDta getNfcDtaInterface() {
733         if (mContext == null) {
734             throw new UnsupportedOperationException("You need a context on NfcAdapter to use the "
735                     + " NFC extras APIs");
736         }
737         try {
738             return sService.getNfcDtaInterface(mContext.getPackageName());
739         } catch (RemoteException e) {
740             attemptDeadServiceRecovery(e);
741             return null;
742         }
743     }
744 
745     /**
746      * NFC service dead - attempt best effort recovery
747      * @hide
748      */
749     @UnsupportedAppUsage
attemptDeadServiceRecovery(Exception e)750     public void attemptDeadServiceRecovery(Exception e) {
751         Log.e(TAG, "NFC service dead - attempting to recover", e);
752         INfcAdapter service = getServiceInterface();
753         if (service == null) {
754             Log.e(TAG, "could not retrieve NFC service during service recovery");
755             // nothing more can be done now, sService is still stale, we'll hit
756             // this recovery path again later
757             return;
758         }
759         // assigning to sService is not thread-safe, but this is best-effort code
760         // and on a well-behaved system should never happen
761         sService = service;
762         try {
763             sTagService = service.getNfcTagInterface();
764         } catch (RemoteException ee) {
765             Log.e(TAG, "could not retrieve NFC tag service during service recovery");
766             // nothing more can be done now, sService is still stale, we'll hit
767             // this recovery path again later
768             return;
769         }
770 
771         try {
772             sCardEmulationService = service.getNfcCardEmulationInterface();
773         } catch (RemoteException ee) {
774             Log.e(TAG, "could not retrieve NFC card emulation service during service recovery");
775         }
776 
777         try {
778             sNfcFCardEmulationService = service.getNfcFCardEmulationInterface();
779         } catch (RemoteException ee) {
780             Log.e(TAG, "could not retrieve NFC-F card emulation service during service recovery");
781         }
782 
783         return;
784     }
785 
786     /**
787      * Return true if this NFC Adapter has any features enabled.
788      *
789      * <p>If this method returns false, the NFC hardware is guaranteed not to
790      * generate or respond to any NFC communication over its NFC radio.
791      * <p>Applications can use this to check if NFC is enabled. Applications
792      * can request Settings UI allowing the user to toggle NFC using:
793      * <p><pre>startActivity(new Intent(Settings.ACTION_NFC_SETTINGS))</pre>
794      *
795      * @see android.provider.Settings#ACTION_NFC_SETTINGS
796      * @return true if this NFC Adapter has any features enabled
797      */
isEnabled()798     public boolean isEnabled() {
799         try {
800             return sService.getState() == STATE_ON;
801         } catch (RemoteException e) {
802             attemptDeadServiceRecovery(e);
803             return false;
804         }
805     }
806 
807     /**
808      * Return the state of this NFC Adapter.
809      *
810      * <p>Returns one of {@link #STATE_ON}, {@link #STATE_TURNING_ON},
811      * {@link #STATE_OFF}, {@link #STATE_TURNING_OFF}.
812      *
813      * <p>{@link #isEnabled()} is equivalent to
814      * <code>{@link #getAdapterState()} == {@link #STATE_ON}</code>
815      *
816      * @return the current state of this NFC adapter
817      *
818      * @hide
819      */
820     @UnsupportedAppUsage
getAdapterState()821     public int getAdapterState() {
822         try {
823             return sService.getState();
824         } catch (RemoteException e) {
825             attemptDeadServiceRecovery(e);
826             return NfcAdapter.STATE_OFF;
827         }
828     }
829 
830     /**
831      * Enable NFC hardware.
832      *
833      * <p>This call is asynchronous. Listen for
834      * {@link #ACTION_ADAPTER_STATE_CHANGED} broadcasts to find out when the
835      * operation is complete.
836      *
837      * <p>If this returns true, then either NFC is already on, or
838      * a {@link #ACTION_ADAPTER_STATE_CHANGED} broadcast will be sent
839      * to indicate a state transition. If this returns false, then
840      * there is some problem that prevents an attempt to turn
841      * NFC on (for example we are in airplane mode and NFC is not
842      * toggleable in airplane mode on this platform).
843      *
844      * @hide
845      */
846     @SystemApi
847     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
enable()848     public boolean enable() {
849         try {
850             return sService.enable();
851         } catch (RemoteException e) {
852             attemptDeadServiceRecovery(e);
853             return false;
854         }
855     }
856 
857     /**
858      * Disable NFC hardware.
859      *
860      * <p>No NFC features will work after this call, and the hardware
861      * will not perform or respond to any NFC communication.
862      *
863      * <p>This call is asynchronous. Listen for
864      * {@link #ACTION_ADAPTER_STATE_CHANGED} broadcasts to find out when the
865      * operation is complete.
866      *
867      * <p>If this returns true, then either NFC is already off, or
868      * a {@link #ACTION_ADAPTER_STATE_CHANGED} broadcast will be sent
869      * to indicate a state transition. If this returns false, then
870      * there is some problem that prevents an attempt to turn
871      * NFC off.
872      *
873      * @hide
874      */
875     @SystemApi
876     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
disable()877     public boolean disable() {
878         try {
879             return sService.disable(true);
880         } catch (RemoteException e) {
881             attemptDeadServiceRecovery(e);
882             return false;
883         }
884     }
885 
886     /**
887      * Disable NFC hardware.
888      * @hide
889     */
890     @SystemApi
891     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
disable(boolean persist)892     public boolean disable(boolean persist) {
893         try {
894             return sService.disable(persist);
895         } catch (RemoteException e) {
896             attemptDeadServiceRecovery(e);
897             return false;
898         }
899     }
900 
901     /**
902      * Pauses polling for a {@code timeoutInMs} millis. If polling must be resumed before timeout,
903      * use {@link #resumePolling()}.
904      * @hide
905      */
pausePolling(int timeoutInMs)906     public void pausePolling(int timeoutInMs) {
907         try {
908             sService.pausePolling(timeoutInMs);
909         } catch (RemoteException e) {
910             attemptDeadServiceRecovery(e);
911         }
912     }
913 
914     /**
915      * Resumes default polling for the current device state if polling is paused. Calling
916      * this while polling is not paused is a no-op.
917      *
918      * @hide
919      */
resumePolling()920     public void resumePolling() {
921         try {
922             sService.resumePolling();
923         } catch (RemoteException e) {
924             attemptDeadServiceRecovery(e);
925         }
926     }
927 
928     /**
929      * Set one or more {@link Uri}s to send using Android Beam (TM). Every
930      * Uri you provide must have either scheme 'file' or scheme 'content'.
931      *
932      * <p>For the data provided through this method, Android Beam tries to
933      * switch to alternate transports such as Bluetooth to achieve a fast
934      * transfer speed. Hence this method is very suitable
935      * for transferring large files such as pictures or songs.
936      *
937      * <p>The receiving side will store the content of each Uri in
938      * a file and present a notification to the user to open the file
939      * with a {@link android.content.Intent} with action
940      * {@link android.content.Intent#ACTION_VIEW}.
941      * If multiple URIs are sent, the {@link android.content.Intent} will refer
942      * to the first of the stored files.
943      *
944      * <p>This method may be called at any time before {@link Activity#onDestroy},
945      * but the URI(s) are only made available for Android Beam when the
946      * specified activity(s) are in resumed (foreground) state. The recommended
947      * approach is to call this method during your Activity's
948      * {@link Activity#onCreate} - see sample
949      * code below. This method does not immediately perform any I/O or blocking work,
950      * so is safe to call on your main thread.
951      *
952      * <p>{@link #setBeamPushUris} and {@link #setBeamPushUrisCallback}
953      * have priority over both {@link #setNdefPushMessage} and
954      * {@link #setNdefPushMessageCallback}.
955      *
956      * <p>If {@link #setBeamPushUris} is called with a null Uri array,
957      * and/or {@link #setBeamPushUrisCallback} is called with a null callback,
958      * then the Uri push will be completely disabled for the specified activity(s).
959      *
960      * <p>Code example:
961      * <pre>
962      * protected void onCreate(Bundle savedInstanceState) {
963      *     super.onCreate(savedInstanceState);
964      *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
965      *     if (nfcAdapter == null) return;  // NFC not available on this device
966      *     nfcAdapter.setBeamPushUris(new Uri[] {uri1, uri2}, this);
967      * }</pre>
968      * And that is it. Only one call per activity is necessary. The Android
969      * OS will automatically release its references to the Uri(s) and the
970      * Activity object when it is destroyed if you follow this pattern.
971      *
972      * <p>If your Activity wants to dynamically supply Uri(s),
973      * then set a callback using {@link #setBeamPushUrisCallback} instead
974      * of using this method.
975      *
976      * <p class="note">Do not pass in an Activity that has already been through
977      * {@link Activity#onDestroy}. This is guaranteed if you call this API
978      * during {@link Activity#onCreate}.
979      *
980      * <p class="note">If this device does not support alternate transports
981      * such as Bluetooth or WiFI, calling this method does nothing.
982      *
983      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
984      *
985      * @param uris an array of Uri(s) to push over Android Beam
986      * @param activity activity for which the Uri(s) will be pushed
987      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
988      * @deprecated this feature is deprecated. File sharing can work using other technology like
989      * Bluetooth.
990      */
991     @java.lang.Deprecated
setBeamPushUris(Uri[] uris, Activity activity)992     public void setBeamPushUris(Uri[] uris, Activity activity) {
993         synchronized (NfcAdapter.class) {
994             if (!sHasNfcFeature) {
995                 throw new UnsupportedOperationException();
996             }
997             if (!sHasBeamFeature) {
998                 return;
999             }
1000         }
1001         if (activity == null) {
1002             throw new NullPointerException("activity cannot be null");
1003         }
1004         if (uris != null) {
1005             for (Uri uri : uris) {
1006                 if (uri == null) throw new NullPointerException("Uri not " +
1007                         "allowed to be null");
1008                 String scheme = uri.getScheme();
1009                 if (scheme == null || (!scheme.equalsIgnoreCase("file") &&
1010                         !scheme.equalsIgnoreCase("content"))) {
1011                     throw new IllegalArgumentException("URI needs to have " +
1012                             "either scheme file or scheme content");
1013                 }
1014             }
1015         }
1016         mNfcActivityManager.setNdefPushContentUri(activity, uris);
1017     }
1018 
1019     /**
1020      * Set a callback that will dynamically generate one or more {@link Uri}s
1021      * to send using Android Beam (TM). Every Uri the callback provides
1022      * must have either scheme 'file' or scheme 'content'.
1023      *
1024      * <p>For the data provided through this callback, Android Beam tries to
1025      * switch to alternate transports such as Bluetooth to achieve a fast
1026      * transfer speed. Hence this method is very suitable
1027      * for transferring large files such as pictures or songs.
1028      *
1029      * <p>The receiving side will store the content of each Uri in
1030      * a file and present a notification to the user to open the file
1031      * with a {@link android.content.Intent} with action
1032      * {@link android.content.Intent#ACTION_VIEW}.
1033      * If multiple URIs are sent, the {@link android.content.Intent} will refer
1034      * to the first of the stored files.
1035      *
1036      * <p>This method may be called at any time before {@link Activity#onDestroy},
1037      * but the URI(s) are only made available for Android Beam when the
1038      * specified activity(s) are in resumed (foreground) state. The recommended
1039      * approach is to call this method during your Activity's
1040      * {@link Activity#onCreate} - see sample
1041      * code below. This method does not immediately perform any I/O or blocking work,
1042      * so is safe to call on your main thread.
1043      *
1044      * <p>{@link #setBeamPushUris} and {@link #setBeamPushUrisCallback}
1045      * have priority over both {@link #setNdefPushMessage} and
1046      * {@link #setNdefPushMessageCallback}.
1047      *
1048      * <p>If {@link #setBeamPushUris} is called with a null Uri array,
1049      * and/or {@link #setBeamPushUrisCallback} is called with a null callback,
1050      * then the Uri push will be completely disabled for the specified activity(s).
1051      *
1052      * <p>Code example:
1053      * <pre>
1054      * protected void onCreate(Bundle savedInstanceState) {
1055      *     super.onCreate(savedInstanceState);
1056      *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
1057      *     if (nfcAdapter == null) return;  // NFC not available on this device
1058      *     nfcAdapter.setBeamPushUrisCallback(callback, this);
1059      * }</pre>
1060      * And that is it. Only one call per activity is necessary. The Android
1061      * OS will automatically release its references to the Uri(s) and the
1062      * Activity object when it is destroyed if you follow this pattern.
1063      *
1064      * <p class="note">Do not pass in an Activity that has already been through
1065      * {@link Activity#onDestroy}. This is guaranteed if you call this API
1066      * during {@link Activity#onCreate}.
1067      *
1068      * <p class="note">If this device does not support alternate transports
1069      * such as Bluetooth or WiFI, calling this method does nothing.
1070      *
1071      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1072      *
1073      * @param callback callback, or null to disable
1074      * @param activity activity for which the Uri(s) will be pushed
1075      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1076      * @deprecated this feature is deprecated. File sharing can work using other technology like
1077      * Bluetooth.
1078      */
1079     @java.lang.Deprecated
setBeamPushUrisCallback(CreateBeamUrisCallback callback, Activity activity)1080     public void setBeamPushUrisCallback(CreateBeamUrisCallback callback, Activity activity) {
1081         synchronized (NfcAdapter.class) {
1082             if (!sHasNfcFeature) {
1083                 throw new UnsupportedOperationException();
1084             }
1085             if (!sHasBeamFeature) {
1086                 return;
1087             }
1088         }
1089         if (activity == null) {
1090             throw new NullPointerException("activity cannot be null");
1091         }
1092         mNfcActivityManager.setNdefPushContentUriCallback(activity, callback);
1093     }
1094 
1095     /**
1096      * Set a static {@link NdefMessage} to send using Android Beam (TM).
1097      *
1098      * <p>This method may be called at any time before {@link Activity#onDestroy},
1099      * but the NDEF message is only made available for NDEF push when the
1100      * specified activity(s) are in resumed (foreground) state. The recommended
1101      * approach is to call this method during your Activity's
1102      * {@link Activity#onCreate} - see sample
1103      * code below. This method does not immediately perform any I/O or blocking work,
1104      * so is safe to call on your main thread.
1105      *
1106      * <p>Only one NDEF message can be pushed by the currently resumed activity.
1107      * If both {@link #setNdefPushMessage} and
1108      * {@link #setNdefPushMessageCallback} are set, then
1109      * the callback will take priority.
1110      *
1111      * <p>If neither {@link #setNdefPushMessage} or
1112      * {@link #setNdefPushMessageCallback} have been called for your activity, then
1113      * the Android OS may choose to send a default NDEF message on your behalf,
1114      * such as a URI for your application.
1115      *
1116      * <p>If {@link #setNdefPushMessage} is called with a null NDEF message,
1117      * and/or {@link #setNdefPushMessageCallback} is called with a null callback,
1118      * then NDEF push will be completely disabled for the specified activity(s).
1119      * This also disables any default NDEF message the Android OS would have
1120      * otherwise sent on your behalf for those activity(s).
1121      *
1122      * <p>If you want to prevent the Android OS from sending default NDEF
1123      * messages completely (for all activities), you can include a
1124      * {@code <meta-data>} element inside the {@code <application>}
1125      * element of your AndroidManifest.xml file, like this:
1126      * <pre>
1127      * &lt;application ...>
1128      *     &lt;meta-data android:name="android.nfc.disable_beam_default"
1129      *         android:value="true" />
1130      * &lt;/application></pre>
1131      *
1132      * <p>The API allows for multiple activities to be specified at a time,
1133      * but it is strongly recommended to just register one at a time,
1134      * and to do so during the activity's {@link Activity#onCreate}. For example:
1135      * <pre>
1136      * protected void onCreate(Bundle savedInstanceState) {
1137      *     super.onCreate(savedInstanceState);
1138      *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
1139      *     if (nfcAdapter == null) return;  // NFC not available on this device
1140      *     nfcAdapter.setNdefPushMessage(ndefMessage, this);
1141      * }</pre>
1142      * And that is it. Only one call per activity is necessary. The Android
1143      * OS will automatically release its references to the NDEF message and the
1144      * Activity object when it is destroyed if you follow this pattern.
1145      *
1146      * <p>If your Activity wants to dynamically generate an NDEF message,
1147      * then set a callback using {@link #setNdefPushMessageCallback} instead
1148      * of a static message.
1149      *
1150      * <p class="note">Do not pass in an Activity that has already been through
1151      * {@link Activity#onDestroy}. This is guaranteed if you call this API
1152      * during {@link Activity#onCreate}.
1153      *
1154      * <p class="note">For sending large content such as pictures and songs,
1155      * consider using {@link #setBeamPushUris}, which switches to alternate transports
1156      * such as Bluetooth to achieve a fast transfer rate.
1157      *
1158      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1159      *
1160      * @param message NDEF message to push over NFC, or null to disable
1161      * @param activity activity for which the NDEF message will be pushed
1162      * @param activities optional additional activities, however we strongly recommend
1163      *        to only register one at a time, and to do so in that activity's
1164      *        {@link Activity#onCreate}
1165      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1166      * @deprecated this feature is deprecated. File sharing can work using other technology like
1167      * Bluetooth.
1168      */
1169     @java.lang.Deprecated
setNdefPushMessage(NdefMessage message, Activity activity, Activity ... activities)1170     public void setNdefPushMessage(NdefMessage message, Activity activity,
1171             Activity ... activities) {
1172         synchronized (NfcAdapter.class) {
1173             if (!sHasNfcFeature) {
1174                 throw new UnsupportedOperationException();
1175             }
1176             if (!sHasBeamFeature) {
1177                 return;
1178             }
1179         }
1180         int targetSdkVersion = getSdkVersion();
1181         try {
1182             if (activity == null) {
1183                 throw new NullPointerException("activity cannot be null");
1184             }
1185             mNfcActivityManager.setNdefPushMessage(activity, message, 0);
1186             for (Activity a : activities) {
1187                 if (a == null) {
1188                     throw new NullPointerException("activities cannot contain null");
1189                 }
1190                 mNfcActivityManager.setNdefPushMessage(a, message, 0);
1191             }
1192         } catch (IllegalStateException e) {
1193             if (targetSdkVersion < android.os.Build.VERSION_CODES.JELLY_BEAN) {
1194                 // Less strict on old applications - just log the error
1195                 Log.e(TAG, "Cannot call API with Activity that has already " +
1196                         "been destroyed", e);
1197             } else {
1198                 // Prevent new applications from making this mistake, re-throw
1199                 throw(e);
1200             }
1201         }
1202     }
1203 
1204     /**
1205      * @hide
1206      */
1207     @SystemApi
setNdefPushMessage(NdefMessage message, Activity activity, int flags)1208     public void setNdefPushMessage(NdefMessage message, Activity activity, int flags) {
1209         synchronized (NfcAdapter.class) {
1210             if (!sHasNfcFeature) {
1211                 throw new UnsupportedOperationException();
1212             }
1213         }
1214         if (activity == null) {
1215             throw new NullPointerException("activity cannot be null");
1216         }
1217         mNfcActivityManager.setNdefPushMessage(activity, message, flags);
1218     }
1219 
1220     /**
1221      * Set a callback that dynamically generates NDEF messages to send using Android Beam (TM).
1222      *
1223      * <p>This method may be called at any time before {@link Activity#onDestroy},
1224      * but the NDEF message callback can only occur when the
1225      * specified activity(s) are in resumed (foreground) state. The recommended
1226      * approach is to call this method during your Activity's
1227      * {@link Activity#onCreate} - see sample
1228      * code below. This method does not immediately perform any I/O or blocking work,
1229      * so is safe to call on your main thread.
1230      *
1231      * <p>Only one NDEF message can be pushed by the currently resumed activity.
1232      * If both {@link #setNdefPushMessage} and
1233      * {@link #setNdefPushMessageCallback} are set, then
1234      * the callback will take priority.
1235      *
1236      * <p>If neither {@link #setNdefPushMessage} or
1237      * {@link #setNdefPushMessageCallback} have been called for your activity, then
1238      * the Android OS may choose to send a default NDEF message on your behalf,
1239      * such as a URI for your application.
1240      *
1241      * <p>If {@link #setNdefPushMessage} is called with a null NDEF message,
1242      * and/or {@link #setNdefPushMessageCallback} is called with a null callback,
1243      * then NDEF push will be completely disabled for the specified activity(s).
1244      * This also disables any default NDEF message the Android OS would have
1245      * otherwise sent on your behalf for those activity(s).
1246      *
1247      * <p>If you want to prevent the Android OS from sending default NDEF
1248      * messages completely (for all activities), you can include a
1249      * {@code <meta-data>} element inside the {@code <application>}
1250      * element of your AndroidManifest.xml file, like this:
1251      * <pre>
1252      * &lt;application ...>
1253      *     &lt;meta-data android:name="android.nfc.disable_beam_default"
1254      *         android:value="true" />
1255      * &lt;/application></pre>
1256      *
1257      * <p>The API allows for multiple activities to be specified at a time,
1258      * but it is strongly recommended to just register one at a time,
1259      * and to do so during the activity's {@link Activity#onCreate}. For example:
1260      * <pre>
1261      * protected void onCreate(Bundle savedInstanceState) {
1262      *     super.onCreate(savedInstanceState);
1263      *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
1264      *     if (nfcAdapter == null) return;  // NFC not available on this device
1265      *     nfcAdapter.setNdefPushMessageCallback(callback, this);
1266      * }</pre>
1267      * And that is it. Only one call per activity is necessary. The Android
1268      * OS will automatically release its references to the callback and the
1269      * Activity object when it is destroyed if you follow this pattern.
1270      *
1271      * <p class="note">Do not pass in an Activity that has already been through
1272      * {@link Activity#onDestroy}. This is guaranteed if you call this API
1273      * during {@link Activity#onCreate}.
1274      * <p class="note">For sending large content such as pictures and songs,
1275      * consider using {@link #setBeamPushUris}, which switches to alternate transports
1276      * such as Bluetooth to achieve a fast transfer rate.
1277      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1278      *
1279      * @param callback callback, or null to disable
1280      * @param activity activity for which the NDEF message will be pushed
1281      * @param activities optional additional activities, however we strongly recommend
1282      *        to only register one at a time, and to do so in that activity's
1283      *        {@link Activity#onCreate}
1284      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1285      * @deprecated this feature is deprecated. File sharing can work using other technology like
1286      * Bluetooth.
1287      */
1288     @java.lang.Deprecated
setNdefPushMessageCallback(CreateNdefMessageCallback callback, Activity activity, Activity ... activities)1289     public void setNdefPushMessageCallback(CreateNdefMessageCallback callback, Activity activity,
1290             Activity ... activities) {
1291         synchronized (NfcAdapter.class) {
1292             if (!sHasNfcFeature) {
1293                 throw new UnsupportedOperationException();
1294             }
1295             if (!sHasBeamFeature) {
1296                 return;
1297             }
1298         }
1299         int targetSdkVersion = getSdkVersion();
1300         try {
1301             if (activity == null) {
1302                 throw new NullPointerException("activity cannot be null");
1303             }
1304             mNfcActivityManager.setNdefPushMessageCallback(activity, callback, 0);
1305             for (Activity a : activities) {
1306                 if (a == null) {
1307                     throw new NullPointerException("activities cannot contain null");
1308                 }
1309                 mNfcActivityManager.setNdefPushMessageCallback(a, callback, 0);
1310             }
1311         } catch (IllegalStateException e) {
1312             if (targetSdkVersion < android.os.Build.VERSION_CODES.JELLY_BEAN) {
1313                 // Less strict on old applications - just log the error
1314                 Log.e(TAG, "Cannot call API with Activity that has already " +
1315                         "been destroyed", e);
1316             } else {
1317                 // Prevent new applications from making this mistake, re-throw
1318                 throw(e);
1319             }
1320         }
1321     }
1322 
1323     /**
1324      * @hide
1325      */
1326     @UnsupportedAppUsage
setNdefPushMessageCallback(CreateNdefMessageCallback callback, Activity activity, int flags)1327     public void setNdefPushMessageCallback(CreateNdefMessageCallback callback, Activity activity,
1328             int flags) {
1329         if (activity == null) {
1330             throw new NullPointerException("activity cannot be null");
1331         }
1332         mNfcActivityManager.setNdefPushMessageCallback(activity, callback, flags);
1333     }
1334 
1335     /**
1336      * Set a callback on successful Android Beam (TM).
1337      *
1338      * <p>This method may be called at any time before {@link Activity#onDestroy},
1339      * but the callback can only occur when the
1340      * specified activity(s) are in resumed (foreground) state. The recommended
1341      * approach is to call this method during your Activity's
1342      * {@link Activity#onCreate} - see sample
1343      * code below. This method does not immediately perform any I/O or blocking work,
1344      * so is safe to call on your main thread.
1345      *
1346      * <p>The API allows for multiple activities to be specified at a time,
1347      * but it is strongly recommended to just register one at a time,
1348      * and to do so during the activity's {@link Activity#onCreate}. For example:
1349      * <pre>
1350      * protected void onCreate(Bundle savedInstanceState) {
1351      *     super.onCreate(savedInstanceState);
1352      *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
1353      *     if (nfcAdapter == null) return;  // NFC not available on this device
1354      *     nfcAdapter.setOnNdefPushCompleteCallback(callback, this);
1355      * }</pre>
1356      * And that is it. Only one call per activity is necessary. The Android
1357      * OS will automatically release its references to the callback and the
1358      * Activity object when it is destroyed if you follow this pattern.
1359      *
1360      * <p class="note">Do not pass in an Activity that has already been through
1361      * {@link Activity#onDestroy}. This is guaranteed if you call this API
1362      * during {@link Activity#onCreate}.
1363      *
1364      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1365      *
1366      * @param callback callback, or null to disable
1367      * @param activity activity for which the NDEF message will be pushed
1368      * @param activities optional additional activities, however we strongly recommend
1369      *        to only register one at a time, and to do so in that activity's
1370      *        {@link Activity#onCreate}
1371      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1372      * @deprecated this feature is deprecated. File sharing can work using other technology like
1373      * Bluetooth.
1374      */
1375     @java.lang.Deprecated
setOnNdefPushCompleteCallback(OnNdefPushCompleteCallback callback, Activity activity, Activity ... activities)1376     public void setOnNdefPushCompleteCallback(OnNdefPushCompleteCallback callback,
1377             Activity activity, Activity ... activities) {
1378         synchronized (NfcAdapter.class) {
1379             if (!sHasNfcFeature) {
1380                 throw new UnsupportedOperationException();
1381             }
1382             if (!sHasBeamFeature) {
1383                 return;
1384             }
1385         }
1386         int targetSdkVersion = getSdkVersion();
1387         try {
1388             if (activity == null) {
1389                 throw new NullPointerException("activity cannot be null");
1390             }
1391             mNfcActivityManager.setOnNdefPushCompleteCallback(activity, callback);
1392             for (Activity a : activities) {
1393                 if (a == null) {
1394                     throw new NullPointerException("activities cannot contain null");
1395                 }
1396                 mNfcActivityManager.setOnNdefPushCompleteCallback(a, callback);
1397             }
1398         } catch (IllegalStateException e) {
1399             if (targetSdkVersion < android.os.Build.VERSION_CODES.JELLY_BEAN) {
1400                 // Less strict on old applications - just log the error
1401                 Log.e(TAG, "Cannot call API with Activity that has already " +
1402                         "been destroyed", e);
1403             } else {
1404                 // Prevent new applications from making this mistake, re-throw
1405                 throw(e);
1406             }
1407         }
1408     }
1409 
1410     /**
1411      * Enable foreground dispatch to the given Activity.
1412      *
1413      * <p>This will give give priority to the foreground activity when
1414      * dispatching a discovered {@link Tag} to an application.
1415      *
1416      * <p>If any IntentFilters are provided to this method they are used to match dispatch Intents
1417      * for both the {@link NfcAdapter#ACTION_NDEF_DISCOVERED} and
1418      * {@link NfcAdapter#ACTION_TAG_DISCOVERED}. Since {@link NfcAdapter#ACTION_TECH_DISCOVERED}
1419      * relies on meta data outside of the IntentFilter matching for that dispatch Intent is handled
1420      * by passing in the tech lists separately. Each first level entry in the tech list represents
1421      * an array of technologies that must all be present to match. If any of the first level sets
1422      * match then the dispatch is routed through the given PendingIntent. In other words, the second
1423      * level is ANDed together and the first level entries are ORed together.
1424      *
1425      * <p>If you pass {@code null} for both the {@code filters} and {@code techLists} parameters
1426      * that acts a wild card and will cause the foreground activity to receive all tags via the
1427      * {@link NfcAdapter#ACTION_TAG_DISCOVERED} intent.
1428      *
1429      * <p>This method must be called from the main thread, and only when the activity is in the
1430      * foreground (resumed). Also, activities must call {@link #disableForegroundDispatch} before
1431      * the completion of their {@link Activity#onPause} callback to disable foreground dispatch
1432      * after it has been enabled.
1433      *
1434      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1435      *
1436      * @param activity the Activity to dispatch to
1437      * @param intent the PendingIntent to start for the dispatch
1438      * @param filters the IntentFilters to override dispatching for, or null to always dispatch
1439      * @param techLists the tech lists used to perform matching for dispatching of the
1440      *      {@link NfcAdapter#ACTION_TECH_DISCOVERED} intent
1441      * @throws IllegalStateException if the Activity is not currently in the foreground
1442      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1443      */
enableForegroundDispatch(Activity activity, PendingIntent intent, IntentFilter[] filters, String[][] techLists)1444     public void enableForegroundDispatch(Activity activity, PendingIntent intent,
1445             IntentFilter[] filters, String[][] techLists) {
1446         synchronized (NfcAdapter.class) {
1447             if (!sHasNfcFeature) {
1448                 throw new UnsupportedOperationException();
1449             }
1450         }
1451         if (activity == null || intent == null) {
1452             throw new NullPointerException();
1453         }
1454         if (!activity.isResumed()) {
1455             throw new IllegalStateException("Foreground dispatch can only be enabled " +
1456                     "when your activity is resumed");
1457         }
1458         try {
1459             TechListParcel parcel = null;
1460             if (techLists != null && techLists.length > 0) {
1461                 parcel = new TechListParcel(techLists);
1462             }
1463             ActivityThread.currentActivityThread().registerOnActivityPausedListener(activity,
1464                     mForegroundDispatchListener);
1465             sService.setForegroundDispatch(intent, filters, parcel);
1466         } catch (RemoteException e) {
1467             attemptDeadServiceRecovery(e);
1468         }
1469     }
1470 
1471     /**
1472      * Disable foreground dispatch to the given activity.
1473      *
1474      * <p>After calling {@link #enableForegroundDispatch}, an activity
1475      * must call this method before its {@link Activity#onPause} callback
1476      * completes.
1477      *
1478      * <p>This method must be called from the main thread.
1479      *
1480      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1481      *
1482      * @param activity the Activity to disable dispatch to
1483      * @throws IllegalStateException if the Activity has already been paused
1484      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1485      */
disableForegroundDispatch(Activity activity)1486     public void disableForegroundDispatch(Activity activity) {
1487         synchronized (NfcAdapter.class) {
1488             if (!sHasNfcFeature) {
1489                 throw new UnsupportedOperationException();
1490             }
1491         }
1492         ActivityThread.currentActivityThread().unregisterOnActivityPausedListener(activity,
1493                 mForegroundDispatchListener);
1494         disableForegroundDispatchInternal(activity, false);
1495     }
1496 
1497     OnActivityPausedListener mForegroundDispatchListener = new OnActivityPausedListener() {
1498         @Override
1499         public void onPaused(Activity activity) {
1500             disableForegroundDispatchInternal(activity, true);
1501         }
1502     };
1503 
disableForegroundDispatchInternal(Activity activity, boolean force)1504     void disableForegroundDispatchInternal(Activity activity, boolean force) {
1505         try {
1506             sService.setForegroundDispatch(null, null, null);
1507             if (!force && !activity.isResumed()) {
1508                 throw new IllegalStateException("You must disable foreground dispatching " +
1509                         "while your activity is still resumed");
1510             }
1511         } catch (RemoteException e) {
1512             attemptDeadServiceRecovery(e);
1513         }
1514     }
1515 
1516     /**
1517      * Limit the NFC controller to reader mode while this Activity is in the foreground.
1518      *
1519      * <p>In this mode the NFC controller will only act as an NFC tag reader/writer,
1520      * thus disabling any peer-to-peer (Android Beam) and card-emulation modes of
1521      * the NFC adapter on this device.
1522      *
1523      * <p>Use {@link #FLAG_READER_SKIP_NDEF_CHECK} to prevent the platform from
1524      * performing any NDEF checks in reader mode. Note that this will prevent the
1525      * {@link Ndef} tag technology from being enumerated on the tag, and that
1526      * NDEF-based tag dispatch will not be functional.
1527      *
1528      * <p>For interacting with tags that are emulated on another Android device
1529      * using Android's host-based card-emulation, the recommended flags are
1530      * {@link #FLAG_READER_NFC_A} and {@link #FLAG_READER_SKIP_NDEF_CHECK}.
1531      *
1532      * @param activity the Activity that requests the adapter to be in reader mode
1533      * @param callback the callback to be called when a tag is discovered
1534      * @param flags Flags indicating poll technologies and other optional parameters
1535      * @param extras Additional extras for configuring reader mode.
1536      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1537      */
enableReaderMode(Activity activity, ReaderCallback callback, int flags, Bundle extras)1538     public void enableReaderMode(Activity activity, ReaderCallback callback, int flags,
1539             Bundle extras) {
1540         synchronized (NfcAdapter.class) {
1541             if (!sHasNfcFeature) {
1542                 throw new UnsupportedOperationException();
1543             }
1544         }
1545         mNfcActivityManager.enableReaderMode(activity, callback, flags, extras);
1546     }
1547 
1548     /**
1549      * Restore the NFC adapter to normal mode of operation: supporting
1550      * peer-to-peer (Android Beam), card emulation, and polling for
1551      * all supported tag technologies.
1552      *
1553      * @param activity the Activity that currently has reader mode enabled
1554      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1555      */
disableReaderMode(Activity activity)1556     public void disableReaderMode(Activity activity) {
1557         synchronized (NfcAdapter.class) {
1558             if (!sHasNfcFeature) {
1559                 throw new UnsupportedOperationException();
1560             }
1561         }
1562         mNfcActivityManager.disableReaderMode(activity);
1563     }
1564 
1565     /**
1566      * Manually invoke Android Beam to share data.
1567      *
1568      * <p>The Android Beam animation is normally only shown when two NFC-capable
1569      * devices come into range.
1570      * By calling this method, an Activity can invoke the Beam animation directly
1571      * even if no other NFC device is in range yet. The Beam animation will then
1572      * prompt the user to tap another NFC-capable device to complete the data
1573      * transfer.
1574      *
1575      * <p>The main advantage of using this method is that it avoids the need for the
1576      * user to tap the screen to complete the transfer, as this method already
1577      * establishes the direction of the transfer and the consent of the user to
1578      * share data. Callers are responsible for making sure that the user has
1579      * consented to sharing data on NFC tap.
1580      *
1581      * <p>Note that to use this method, the passed in Activity must have already
1582      * set data to share over Beam by using method calls such as
1583      * {@link #setNdefPushMessageCallback} or
1584      * {@link #setBeamPushUrisCallback}.
1585      *
1586      * @param activity the current foreground Activity that has registered data to share
1587      * @return whether the Beam animation was successfully invoked
1588      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1589      * @deprecated this feature is deprecated. File sharing can work using other technology like
1590      * Bluetooth.
1591      */
1592     @java.lang.Deprecated
invokeBeam(Activity activity)1593     public boolean invokeBeam(Activity activity) {
1594         synchronized (NfcAdapter.class) {
1595             if (!sHasNfcFeature) {
1596                 throw new UnsupportedOperationException();
1597             }
1598             if (!sHasBeamFeature) {
1599                 return false;
1600             }
1601         }
1602         if (activity == null) {
1603             throw new NullPointerException("activity may not be null.");
1604         }
1605         enforceResumed(activity);
1606         try {
1607             sService.invokeBeam();
1608             return true;
1609         } catch (RemoteException e) {
1610             Log.e(TAG, "invokeBeam: NFC process has died.");
1611             attemptDeadServiceRecovery(e);
1612             return false;
1613         }
1614     }
1615 
1616     /**
1617      * @hide
1618      */
invokeBeam(BeamShareData shareData)1619     public boolean invokeBeam(BeamShareData shareData) {
1620         try {
1621             Log.e(TAG, "invokeBeamInternal()");
1622             sService.invokeBeamInternal(shareData);
1623             return true;
1624         } catch (RemoteException e) {
1625             Log.e(TAG, "invokeBeam: NFC process has died.");
1626             attemptDeadServiceRecovery(e);
1627             return false;
1628         }
1629     }
1630 
1631     /**
1632      * Enable NDEF message push over NFC while this Activity is in the foreground.
1633      *
1634      * <p>You must explicitly call this method every time the activity is
1635      * resumed, and you must call {@link #disableForegroundNdefPush} before
1636      * your activity completes {@link Activity#onPause}.
1637      *
1638      * <p>Strongly recommend to use the new {@link #setNdefPushMessage}
1639      * instead: it automatically hooks into your activity life-cycle,
1640      * so you do not need to call enable/disable in your onResume/onPause.
1641      *
1642      * <p>For NDEF push to function properly the other NFC device must
1643      * support either NFC Forum's SNEP (Simple Ndef Exchange Protocol), or
1644      * Android's "com.android.npp" (Ndef Push Protocol). This was optional
1645      * on Gingerbread level Android NFC devices, but SNEP is mandatory on
1646      * Ice-Cream-Sandwich and beyond.
1647      *
1648      * <p>This method must be called from the main thread.
1649      *
1650      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1651      *
1652      * @param activity foreground activity
1653      * @param message a NDEF Message to push over NFC
1654      * @throws IllegalStateException if the activity is not currently in the foreground
1655      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1656      * @deprecated use {@link #setNdefPushMessage} instead
1657      */
1658     @Deprecated
enableForegroundNdefPush(Activity activity, NdefMessage message)1659     public void enableForegroundNdefPush(Activity activity, NdefMessage message) {
1660         synchronized (NfcAdapter.class) {
1661             if (!sHasNfcFeature) {
1662                 throw new UnsupportedOperationException();
1663             }
1664             if (!sHasBeamFeature) {
1665                 return;
1666             }
1667         }
1668         if (activity == null || message == null) {
1669             throw new NullPointerException();
1670         }
1671         enforceResumed(activity);
1672         mNfcActivityManager.setNdefPushMessage(activity, message, 0);
1673     }
1674 
1675     /**
1676      * Disable NDEF message push over P2P.
1677      *
1678      * <p>After calling {@link #enableForegroundNdefPush}, an activity
1679      * must call this method before its {@link Activity#onPause} callback
1680      * completes.
1681      *
1682      * <p>Strongly recommend to use the new {@link #setNdefPushMessage}
1683      * instead: it automatically hooks into your activity life-cycle,
1684      * so you do not need to call enable/disable in your onResume/onPause.
1685      *
1686      * <p>This method must be called from the main thread.
1687      *
1688      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1689      *
1690      * @param activity the Foreground activity
1691      * @throws IllegalStateException if the Activity has already been paused
1692      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1693      * @deprecated use {@link #setNdefPushMessage} instead
1694      */
1695     @Deprecated
disableForegroundNdefPush(Activity activity)1696     public void disableForegroundNdefPush(Activity activity) {
1697         synchronized (NfcAdapter.class) {
1698             if (!sHasNfcFeature) {
1699                 throw new UnsupportedOperationException();
1700             }
1701             if (!sHasBeamFeature) {
1702                 return;
1703             }
1704         }
1705         if (activity == null) {
1706             throw new NullPointerException();
1707         }
1708         enforceResumed(activity);
1709         mNfcActivityManager.setNdefPushMessage(activity, null, 0);
1710         mNfcActivityManager.setNdefPushMessageCallback(activity, null, 0);
1711         mNfcActivityManager.setOnNdefPushCompleteCallback(activity, null);
1712     }
1713 
1714     /**
1715      * Sets Secure NFC feature.
1716      * <p>This API is for the Settings application.
1717      * @return True if successful
1718      * @hide
1719      */
1720     @SystemApi
1721     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
enableSecureNfc(boolean enable)1722     public boolean enableSecureNfc(boolean enable) {
1723         if (!sHasNfcFeature) {
1724             throw new UnsupportedOperationException();
1725         }
1726         try {
1727             return sService.setNfcSecure(enable);
1728         } catch (RemoteException e) {
1729             attemptDeadServiceRecovery(e);
1730             return false;
1731         }
1732     }
1733 
1734     /**
1735      * Checks if the device supports Secure NFC functionality.
1736      *
1737      * @return True if device supports Secure NFC, false otherwise
1738      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1739      */
isSecureNfcSupported()1740     public boolean isSecureNfcSupported() {
1741         if (!sHasNfcFeature) {
1742             throw new UnsupportedOperationException();
1743         }
1744         try {
1745             return sService.deviceSupportsNfcSecure();
1746         } catch (RemoteException e) {
1747             attemptDeadServiceRecovery(e);
1748             return false;
1749         }
1750     }
1751 
1752     /**
1753      * Checks Secure NFC feature is enabled.
1754      *
1755      * @return True if Secure NFC is enabled, false otherwise
1756      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1757      * @throws UnsupportedOperationException if device doesn't support
1758      *         Secure NFC functionality. {@link #isSecureNfcSupported}
1759      */
isSecureNfcEnabled()1760     public boolean isSecureNfcEnabled() {
1761         if (!sHasNfcFeature) {
1762             throw new UnsupportedOperationException();
1763         }
1764         try {
1765             return sService.isNfcSecureEnabled();
1766         } catch (RemoteException e) {
1767             attemptDeadServiceRecovery(e);
1768             return false;
1769         }
1770     }
1771 
1772     /**
1773      * Enable NDEF Push feature.
1774      * <p>This API is for the Settings application.
1775      * @hide
1776      */
1777     @SystemApi
1778     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
enableNdefPush()1779     public boolean enableNdefPush() {
1780         if (!sHasNfcFeature) {
1781             throw new UnsupportedOperationException();
1782         }
1783         try {
1784             return sService.enableNdefPush();
1785         } catch (RemoteException e) {
1786             attemptDeadServiceRecovery(e);
1787             return false;
1788         }
1789     }
1790 
1791     /**
1792      * Disable NDEF Push feature.
1793      * <p>This API is for the Settings application.
1794      * @hide
1795      */
1796     @SystemApi
1797     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
disableNdefPush()1798     public boolean disableNdefPush() {
1799         synchronized (NfcAdapter.class) {
1800             if (!sHasNfcFeature) {
1801                 throw new UnsupportedOperationException();
1802             }
1803         }
1804         try {
1805             return sService.disableNdefPush();
1806         } catch (RemoteException e) {
1807             attemptDeadServiceRecovery(e);
1808             return false;
1809         }
1810     }
1811 
1812     /**
1813      * Return true if the NDEF Push (Android Beam) feature is enabled.
1814      * <p>This function will return true only if both NFC is enabled, and the
1815      * NDEF Push feature is enabled.
1816      * <p>Note that if NFC is enabled but NDEF Push is disabled then this
1817      * device can still <i>receive</i> NDEF messages, it just cannot send them.
1818      * <p>Applications cannot directly toggle the NDEF Push feature, but they
1819      * can request Settings UI allowing the user to toggle NDEF Push using
1820      * <code>startActivity(new Intent(Settings.ACTION_NFCSHARING_SETTINGS))</code>
1821      * <p>Example usage in an Activity that requires NDEF Push:
1822      * <p><pre>
1823      * protected void onResume() {
1824      *     super.onResume();
1825      *     if (!nfcAdapter.isEnabled()) {
1826      *         startActivity(new Intent(Settings.ACTION_NFC_SETTINGS));
1827      *     } else if (!nfcAdapter.isNdefPushEnabled()) {
1828      *         startActivity(new Intent(Settings.ACTION_NFCSHARING_SETTINGS));
1829      *     }
1830      * }</pre>
1831      *
1832      * @see android.provider.Settings#ACTION_NFCSHARING_SETTINGS
1833      * @return true if NDEF Push feature is enabled
1834      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1835      * @deprecated this feature is deprecated. File sharing can work using other technology like
1836      * Bluetooth.
1837      */
1838     @java.lang.Deprecated
1839 
isNdefPushEnabled()1840     public boolean isNdefPushEnabled() {
1841         synchronized (NfcAdapter.class) {
1842             if (!sHasNfcFeature) {
1843                 throw new UnsupportedOperationException();
1844             }
1845             if (!sHasBeamFeature) {
1846                 return false;
1847             }
1848         }
1849         try {
1850             return sService.isNdefPushEnabled();
1851         } catch (RemoteException e) {
1852             attemptDeadServiceRecovery(e);
1853             return false;
1854         }
1855     }
1856 
1857     /**
1858      * Signals that you are no longer interested in communicating with an NFC tag
1859      * for as long as it remains in range.
1860      *
1861      * All future attempted communication to this tag will fail with {@link IOException}.
1862      * The NFC controller will be put in a low-power polling mode, allowing the device
1863      * to save power in cases where it's "attached" to a tag all the time (e.g. a tag in
1864      * car dock).
1865      *
1866      * Additionally the debounceMs parameter allows you to specify for how long the tag needs
1867      * to have gone out of range, before it will be dispatched again.
1868      *
1869      * Note: the NFC controller typically polls at a pretty slow interval (100 - 500 ms).
1870      * This means that if the tag repeatedly goes in and out of range (for example, in
1871      * case of a flaky connection), and the controller happens to poll every time the
1872      * tag is out of range, it *will* re-dispatch the tag after debounceMs, despite the tag
1873      * having been "in range" during the interval.
1874      *
1875      * Note 2: if a tag with another UID is detected after this API is called, its effect
1876      * will be cancelled; if this tag shows up before the amount of time specified in
1877      * debounceMs, it will be dispatched again.
1878      *
1879      * Note 3: some tags have a random UID, in which case this API won't work reliably.
1880      *
1881      * @param tag        the {@link android.nfc.Tag Tag} to ignore.
1882      * @param debounceMs minimum amount of time the tag needs to be out of range before being
1883      *                   dispatched again.
1884      * @param tagRemovedListener listener to be called when the tag is removed from the field.
1885      *                           Note that this will only be called if the tag has been out of range
1886      *                           for at least debounceMs, or if another tag came into range before
1887      *                           debounceMs. May be null in case you don't want a callback.
1888      * @param handler the {@link android.os.Handler Handler} that will be used for delivering
1889      *                the callback. if the handler is null, then the thread used for delivering
1890      *                the callback is unspecified.
1891      * @return false if the tag couldn't be found (or has already gone out of range), true otherwise
1892      */
ignore(final Tag tag, int debounceMs, final OnTagRemovedListener tagRemovedListener, final Handler handler)1893     public boolean ignore(final Tag tag, int debounceMs,
1894                           final OnTagRemovedListener tagRemovedListener, final Handler handler) {
1895         ITagRemovedCallback.Stub iListener = null;
1896         if (tagRemovedListener != null) {
1897             iListener = new ITagRemovedCallback.Stub() {
1898                 @Override
1899                 public void onTagRemoved() throws RemoteException {
1900                     if (handler != null) {
1901                         handler.post(new Runnable() {
1902                             @Override
1903                             public void run() {
1904                                 tagRemovedListener.onTagRemoved();
1905                             }
1906                         });
1907                     } else {
1908                         tagRemovedListener.onTagRemoved();
1909                     }
1910                     synchronized (mLock) {
1911                         mTagRemovedListener = null;
1912                     }
1913                 }
1914             };
1915         }
1916         synchronized (mLock) {
1917             mTagRemovedListener = iListener;
1918         }
1919         try {
1920             return sService.ignore(tag.getServiceHandle(), debounceMs, iListener);
1921         } catch (RemoteException e) {
1922             return false;
1923         }
1924     }
1925 
1926     /**
1927      * Inject a mock NFC tag.<p>
1928      * Used for testing purposes.
1929      * <p class="note">Requires the
1930      * {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} permission.
1931      * @hide
1932      */
dispatch(Tag tag)1933     public void dispatch(Tag tag) {
1934         if (tag == null) {
1935             throw new NullPointerException("tag cannot be null");
1936         }
1937         try {
1938             sService.dispatch(tag);
1939         } catch (RemoteException e) {
1940             attemptDeadServiceRecovery(e);
1941         }
1942     }
1943 
1944     /**
1945      * @hide
1946      */
setP2pModes(int initiatorModes, int targetModes)1947     public void setP2pModes(int initiatorModes, int targetModes) {
1948         try {
1949             sService.setP2pModes(initiatorModes, targetModes);
1950         } catch (RemoteException e) {
1951             attemptDeadServiceRecovery(e);
1952         }
1953     }
1954 
1955     /**
1956      * Registers a new NFC unlock handler with the NFC service.
1957      *
1958      * <p />NFC unlock handlers are intended to unlock the keyguard in the presence of a trusted
1959      * NFC device. The handler should return true if it successfully authenticates the user and
1960      * unlocks the keyguard.
1961      *
1962      * <p /> The parameter {@code tagTechnologies} determines which Tag technologies will be polled for
1963      * at the lockscreen. Polling for less tag technologies reduces latency, and so it is
1964      * strongly recommended to only provide the Tag technologies that the handler is expected to
1965      * receive. There must be at least one tag technology provided, otherwise the unlock handler
1966      * is ignored.
1967      *
1968      * @hide
1969      */
1970     @SystemApi
1971     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
addNfcUnlockHandler(final NfcUnlockHandler unlockHandler, String[] tagTechnologies)1972     public boolean addNfcUnlockHandler(final NfcUnlockHandler unlockHandler,
1973                                        String[] tagTechnologies) {
1974         synchronized (NfcAdapter.class) {
1975             if (!sHasNfcFeature) {
1976                 throw new UnsupportedOperationException();
1977             }
1978         }
1979         // If there are no tag technologies, don't bother adding unlock handler
1980         if (tagTechnologies.length == 0) {
1981             return false;
1982         }
1983 
1984         try {
1985             synchronized (mLock) {
1986                 if (mNfcUnlockHandlers.containsKey(unlockHandler)) {
1987                     // update the tag technologies
1988                     sService.removeNfcUnlockHandler(mNfcUnlockHandlers.get(unlockHandler));
1989                     mNfcUnlockHandlers.remove(unlockHandler);
1990                 }
1991 
1992                 INfcUnlockHandler.Stub iHandler = new INfcUnlockHandler.Stub() {
1993                     @Override
1994                     public boolean onUnlockAttempted(Tag tag) throws RemoteException {
1995                         return unlockHandler.onUnlockAttempted(tag);
1996                     }
1997                 };
1998 
1999                 sService.addNfcUnlockHandler(iHandler,
2000                         Tag.getTechCodesFromStrings(tagTechnologies));
2001                 mNfcUnlockHandlers.put(unlockHandler, iHandler);
2002             }
2003         } catch (RemoteException e) {
2004             attemptDeadServiceRecovery(e);
2005             return false;
2006         } catch (IllegalArgumentException e) {
2007             Log.e(TAG, "Unable to register LockscreenDispatch", e);
2008             return false;
2009         }
2010 
2011         return true;
2012     }
2013 
2014     /**
2015      * Removes a previously registered unlock handler. Also removes the tag technologies
2016      * associated with the removed unlock handler.
2017      *
2018      * @hide
2019      */
2020     @SystemApi
2021     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
removeNfcUnlockHandler(NfcUnlockHandler unlockHandler)2022     public boolean removeNfcUnlockHandler(NfcUnlockHandler unlockHandler) {
2023         synchronized (NfcAdapter.class) {
2024             if (!sHasNfcFeature) {
2025                 throw new UnsupportedOperationException();
2026             }
2027         }
2028         try {
2029             synchronized (mLock) {
2030                 if (mNfcUnlockHandlers.containsKey(unlockHandler)) {
2031                     sService.removeNfcUnlockHandler(mNfcUnlockHandlers.remove(unlockHandler));
2032                 }
2033 
2034                 return true;
2035             }
2036         } catch (RemoteException e) {
2037             attemptDeadServiceRecovery(e);
2038             return false;
2039         }
2040     }
2041 
2042     /**
2043      * @hide
2044      */
2045     @UnsupportedAppUsage
getNfcAdapterExtrasInterface()2046     public INfcAdapterExtras getNfcAdapterExtrasInterface() {
2047         if (mContext == null) {
2048             throw new UnsupportedOperationException("You need a context on NfcAdapter to use the "
2049                     + " NFC extras APIs");
2050         }
2051         try {
2052             return sService.getNfcAdapterExtrasInterface(mContext.getPackageName());
2053         } catch (RemoteException e) {
2054             attemptDeadServiceRecovery(e);
2055             return null;
2056         }
2057     }
2058 
enforceResumed(Activity activity)2059     void enforceResumed(Activity activity) {
2060         if (!activity.isResumed()) {
2061             throw new IllegalStateException("API cannot be called while activity is paused");
2062         }
2063     }
2064 
getSdkVersion()2065     int getSdkVersion() {
2066         if (mContext == null) {
2067             return android.os.Build.VERSION_CODES.GINGERBREAD; // best guess
2068         } else {
2069             return mContext.getApplicationInfo().targetSdkVersion;
2070         }
2071     }
2072 }
2073