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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.app.Activity;
25 import android.app.ActivityThread;
26 import android.app.OnActivityPausedListener;
27 import android.app.PendingIntent;
28 import android.compat.annotation.UnsupportedAppUsage;
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 a 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 Action: Intent to notify if the preferred payment service changed.
168      *
169      * <p>This intent will only be sent to the application has requested permission for
170      * {@link android.Manifest.permission#NFC_PREFERRED_PAYMENT_INFO} and if the application
171      * has the necessary access to Secure Element which witnessed the particular event.
172      */
173     @RequiresPermission(android.Manifest.permission.NFC_PREFERRED_PAYMENT_INFO)
174     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
175     public static final String ACTION_PREFERRED_PAYMENT_CHANGED =
176             "android.nfc.action.PREFERRED_PAYMENT_CHANGED";
177 
178     /**
179      * Broadcast to only the activity that handles ACTION_TAG_DISCOVERED
180      * @hide
181      */
182     public static final String ACTION_TAG_LEFT_FIELD = "android.nfc.action.TAG_LOST";
183 
184     /**
185      * Mandatory extra containing the {@link Tag} that was discovered for the
186      * {@link #ACTION_NDEF_DISCOVERED}, {@link #ACTION_TECH_DISCOVERED}, and
187      * {@link #ACTION_TAG_DISCOVERED} intents.
188      */
189     public static final String EXTRA_TAG = "android.nfc.extra.TAG";
190 
191     /**
192      * Extra containing an array of {@link NdefMessage} present on the discovered tag.<p>
193      * This extra is mandatory for {@link #ACTION_NDEF_DISCOVERED} intents,
194      * and optional for {@link #ACTION_TECH_DISCOVERED}, and
195      * {@link #ACTION_TAG_DISCOVERED} intents.<p>
196      * When this extra is present there will always be at least one
197      * {@link NdefMessage} element. Most NDEF tags have only one NDEF message,
198      * but we use an array for future compatibility.
199      */
200     public static final String EXTRA_NDEF_MESSAGES = "android.nfc.extra.NDEF_MESSAGES";
201 
202     /**
203      * Optional extra containing a byte array containing the ID of the discovered tag for
204      * the {@link #ACTION_NDEF_DISCOVERED}, {@link #ACTION_TECH_DISCOVERED}, and
205      * {@link #ACTION_TAG_DISCOVERED} intents.
206      */
207     public static final String EXTRA_ID = "android.nfc.extra.ID";
208 
209     /**
210      * Broadcast Action: The state of the local NFC adapter has been
211      * changed.
212      * <p>For example, NFC has been turned on or off.
213      * <p>Always contains the extra field {@link #EXTRA_ADAPTER_STATE}
214      */
215     @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION)
216     public static final String ACTION_ADAPTER_STATE_CHANGED =
217             "android.nfc.action.ADAPTER_STATE_CHANGED";
218 
219     /**
220      * Used as an int extra field in {@link #ACTION_ADAPTER_STATE_CHANGED}
221      * intents to request the current power state. Possible values are:
222      * {@link #STATE_OFF},
223      * {@link #STATE_TURNING_ON},
224      * {@link #STATE_ON},
225      * {@link #STATE_TURNING_OFF},
226      */
227     public static final String EXTRA_ADAPTER_STATE = "android.nfc.extra.ADAPTER_STATE";
228 
229     /**
230      * Mandatory byte[] extra field in {@link #ACTION_TRANSACTION_DETECTED}
231      */
232     public static final String EXTRA_AID = "android.nfc.extra.AID";
233 
234     /**
235      * Optional byte[] extra field in {@link #ACTION_TRANSACTION_DETECTED}
236      */
237     public static final String EXTRA_DATA = "android.nfc.extra.DATA";
238 
239     /**
240      * Mandatory String extra field in {@link #ACTION_TRANSACTION_DETECTED}
241      * Indicates the Secure Element on which the transaction occurred.
242      * eSE1...eSEn for Embedded Secure Elements, SIM1...SIMn for UICC, etc.
243      */
244     public static final String EXTRA_SECURE_ELEMENT_NAME = "android.nfc.extra.SECURE_ELEMENT_NAME";
245 
246     /**
247      * Mandatory String extra field in {@link #ACTION_PREFERRED_PAYMENT_CHANGED}
248      * Indicates the condition when trigger this event. Possible values are:
249      * {@link #PREFERRED_PAYMENT_LOADED},
250      * {@link #PREFERRED_PAYMENT_CHANGED},
251      * {@link #PREFERRED_PAYMENT_UPDATED},
252      */
253     public static final String EXTRA_PREFERRED_PAYMENT_CHANGED_REASON =
254             "android.nfc.extra.PREFERRED_PAYMENT_CHANGED_REASON";
255     /**
256      * Nfc is enabled and the preferred payment aids are registered.
257      */
258     public static final int PREFERRED_PAYMENT_LOADED = 1;
259     /**
260      * User selected another payment application as the preferred payment.
261      */
262     public static final int PREFERRED_PAYMENT_CHANGED = 2;
263     /**
264      * Current preferred payment has issued an update (registered/unregistered new aids or has been
265      * updated itself).
266      */
267     public static final int PREFERRED_PAYMENT_UPDATED = 3;
268 
269     public static final int STATE_OFF = 1;
270     public static final int STATE_TURNING_ON = 2;
271     public static final int STATE_ON = 3;
272     public static final int STATE_TURNING_OFF = 4;
273 
274     /**
275      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
276      * <p>
277      * Setting this flag enables polling for Nfc-A technology.
278      */
279     public static final int FLAG_READER_NFC_A = 0x1;
280 
281     /**
282      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
283      * <p>
284      * Setting this flag enables polling for Nfc-B technology.
285      */
286     public static final int FLAG_READER_NFC_B = 0x2;
287 
288     /**
289      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
290      * <p>
291      * Setting this flag enables polling for Nfc-F technology.
292      */
293     public static final int FLAG_READER_NFC_F = 0x4;
294 
295     /**
296      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
297      * <p>
298      * Setting this flag enables polling for Nfc-V (ISO15693) technology.
299      */
300     public static final int FLAG_READER_NFC_V = 0x8;
301 
302     /**
303      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
304      * <p>
305      * Setting this flag enables polling for NfcBarcode technology.
306      */
307     public static final int FLAG_READER_NFC_BARCODE = 0x10;
308 
309     /**
310      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
311      * <p>
312      * Setting this flag allows the caller to prevent the
313      * platform from performing an NDEF check on the tags it
314      * finds.
315      */
316     public static final int FLAG_READER_SKIP_NDEF_CHECK = 0x80;
317 
318     /**
319      * Flag for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
320      * <p>
321      * Setting this flag allows the caller to prevent the
322      * platform from playing sounds when it discovers a tag.
323      */
324     public static final int FLAG_READER_NO_PLATFORM_SOUNDS = 0x100;
325 
326     /**
327      * Int Extra for use with {@link #enableReaderMode(Activity, ReaderCallback, int, Bundle)}.
328      * <p>
329      * Setting this integer extra allows the calling application to specify
330      * the delay that the platform will use for performing presence checks
331      * on any discovered tag.
332      */
333     public static final String EXTRA_READER_PRESENCE_CHECK_DELAY = "presence";
334 
335     /** @hide */
336     @SystemApi
337     public static final int FLAG_NDEF_PUSH_NO_CONFIRM = 0x1;
338 
339     /** @hide */
340     public static final String ACTION_HANDOVER_TRANSFER_STARTED =
341             "android.nfc.action.HANDOVER_TRANSFER_STARTED";
342 
343     /** @hide */
344     public static final String ACTION_HANDOVER_TRANSFER_DONE =
345             "android.nfc.action.HANDOVER_TRANSFER_DONE";
346 
347     /** @hide */
348     public static final String EXTRA_HANDOVER_TRANSFER_STATUS =
349             "android.nfc.extra.HANDOVER_TRANSFER_STATUS";
350 
351     /** @hide */
352     public static final int HANDOVER_TRANSFER_STATUS_SUCCESS = 0;
353     /** @hide */
354     public static final int HANDOVER_TRANSFER_STATUS_FAILURE = 1;
355 
356     /** @hide */
357     public static final String EXTRA_HANDOVER_TRANSFER_URI =
358             "android.nfc.extra.HANDOVER_TRANSFER_URI";
359 
360     // Guarded by NfcAdapter.class
361     static boolean sIsInitialized = false;
362     static boolean sHasNfcFeature;
363     static boolean sHasBeamFeature;
364 
365     // Final after first constructor, except for
366     // attemptDeadServiceRecovery() when NFC crashes - we accept a best effort
367     // recovery
368     @UnsupportedAppUsage
369     static INfcAdapter sService;
370     static INfcTag sTagService;
371     static INfcCardEmulation sCardEmulationService;
372     static INfcFCardEmulation sNfcFCardEmulationService;
373 
374     /**
375      * The NfcAdapter object for each application context.
376      * There is a 1-1 relationship between application context and
377      * NfcAdapter object.
378      */
379     static HashMap<Context, NfcAdapter> sNfcAdapters = new HashMap(); //guard by NfcAdapter.class
380 
381     /**
382      * NfcAdapter used with a null context. This ctor was deprecated but we have
383      * to support it for backwards compatibility. New methods that require context
384      * might throw when called on the null-context NfcAdapter.
385      */
386     static NfcAdapter sNullContextNfcAdapter;  // protected by NfcAdapter.class
387 
388     final NfcActivityManager mNfcActivityManager;
389     final Context mContext;
390     final HashMap<NfcUnlockHandler, INfcUnlockHandler> mNfcUnlockHandlers;
391     final Object mLock;
392 
393     ITagRemovedCallback mTagRemovedListener; // protected by mLock
394 
395     /**
396      * A callback to be invoked when the system finds a tag while the foreground activity is
397      * operating in reader mode.
398      * <p>Register your {@code ReaderCallback} implementation with {@link
399      * NfcAdapter#enableReaderMode} and disable it with {@link
400      * NfcAdapter#disableReaderMode}.
401      * @see NfcAdapter#enableReaderMode
402      */
403     public interface ReaderCallback {
onTagDiscovered(Tag tag)404         public void onTagDiscovered(Tag tag);
405     }
406 
407     /**
408      * A callback to be invoked when the system successfully delivers your {@link NdefMessage}
409      * to another device.
410      * @see #setOnNdefPushCompleteCallback
411      * @deprecated this feature is deprecated. File sharing can work using other technology like
412      * Bluetooth.
413      */
414     @java.lang.Deprecated
415     public interface OnNdefPushCompleteCallback {
416         /**
417          * Called on successful NDEF push.
418          *
419          * <p>This callback is usually made on a binder thread (not the UI thread).
420          *
421          * @param event {@link NfcEvent} with the {@link NfcEvent#nfcAdapter} field set
422          * @see #setNdefPushMessageCallback
423          */
onNdefPushComplete(NfcEvent event)424         public void onNdefPushComplete(NfcEvent event);
425     }
426 
427     /**
428      * A callback to be invoked when another NFC device capable of NDEF push (Android Beam)
429      * is within range.
430      * <p>Implement this interface and pass it to {@link
431      * NfcAdapter#setNdefPushMessageCallback setNdefPushMessageCallback()} in order to create an
432      * {@link NdefMessage} at the moment that another device is within range for NFC. Using this
433      * callback allows you to create a message with data that might vary based on the
434      * content currently visible to the user. Alternatively, you can call {@link
435      * #setNdefPushMessage setNdefPushMessage()} if the {@link NdefMessage} always contains the
436      * same data.
437      * @deprecated this feature is deprecated. File sharing can work using other technology like
438      * Bluetooth.
439      */
440     @java.lang.Deprecated
441     public interface CreateNdefMessageCallback {
442         /**
443          * Called to provide a {@link NdefMessage} to push.
444          *
445          * <p>This callback is usually made on a binder thread (not the UI thread).
446          *
447          * <p>Called when this device is in range of another device
448          * that might support NDEF push. It allows the application to
449          * create the NDEF message only when it is required.
450          *
451          * <p>NDEF push cannot occur until this method returns, so do not
452          * block for too long.
453          *
454          * <p>The Android operating system will usually show a system UI
455          * on top of your activity during this time, so do not try to request
456          * input from the user to complete the callback, or provide custom NDEF
457          * push UI. The user probably will not see it.
458          *
459          * @param event {@link NfcEvent} with the {@link NfcEvent#nfcAdapter} field set
460          * @return NDEF message to push, or null to not provide a message
461          */
createNdefMessage(NfcEvent event)462         public NdefMessage createNdefMessage(NfcEvent event);
463     }
464 
465 
466      /**
467      * @deprecated this feature is deprecated. File sharing can work using other technology like
468      * Bluetooth.
469      */
470     @java.lang.Deprecated
471     public interface CreateBeamUrisCallback {
createBeamUris(NfcEvent event)472         public Uri[] createBeamUris(NfcEvent event);
473     }
474 
475     /**
476      * A callback that is invoked when a tag is removed from the field.
477      * @see NfcAdapter#ignore
478      */
479     public interface OnTagRemovedListener {
onTagRemoved()480         void onTagRemoved();
481     }
482 
483     /**
484      * A callback to be invoked when an application has registered as a
485      * handler to unlock the device given an NFC tag at the lockscreen.
486      * @hide
487      */
488     @SystemApi
489     public interface NfcUnlockHandler {
490         /**
491          * Called at the lock screen to attempt to unlock the device with the given tag.
492          * @param tag the detected tag, to be used to unlock the device
493          * @return true if the device was successfully unlocked
494          */
onUnlockAttempted(Tag tag)495         public boolean onUnlockAttempted(Tag tag);
496     }
497 
498     /**
499      * Helper to check if this device has FEATURE_NFC_BEAM, but without using
500      * a context.
501      * Equivalent to
502      * context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_NFC_BEAM)
503      */
hasBeamFeature()504     private static boolean hasBeamFeature() {
505         IPackageManager pm = ActivityThread.getPackageManager();
506         if (pm == null) {
507             Log.e(TAG, "Cannot get package manager, assuming no Android Beam feature");
508             return false;
509         }
510         try {
511             return pm.hasSystemFeature(PackageManager.FEATURE_NFC_BEAM, 0);
512         } catch (RemoteException e) {
513             Log.e(TAG, "Package manager query failed, assuming no Android Beam feature", e);
514             return false;
515         }
516     }
517 
518     /**
519      * Helper to check if this device has FEATURE_NFC, but without using
520      * a context.
521      * Equivalent to
522      * context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_NFC)
523      */
hasNfcFeature()524     private static boolean hasNfcFeature() {
525         IPackageManager pm = ActivityThread.getPackageManager();
526         if (pm == null) {
527             Log.e(TAG, "Cannot get package manager, assuming no NFC feature");
528             return false;
529         }
530         try {
531             return pm.hasSystemFeature(PackageManager.FEATURE_NFC, 0);
532         } catch (RemoteException e) {
533             Log.e(TAG, "Package manager query failed, assuming no NFC feature", e);
534             return false;
535         }
536     }
537 
538     /**
539      * Helper to check if this device is NFC HCE capable, by checking for
540      * FEATURE_NFC_HOST_CARD_EMULATION and/or FEATURE_NFC_HOST_CARD_EMULATION_NFCF,
541      * but without using a context.
542      */
hasNfcHceFeature()543     private static boolean hasNfcHceFeature() {
544         IPackageManager pm = ActivityThread.getPackageManager();
545         if (pm == null) {
546             Log.e(TAG, "Cannot get package manager, assuming no NFC feature");
547             return false;
548         }
549         try {
550             return pm.hasSystemFeature(PackageManager.FEATURE_NFC_HOST_CARD_EMULATION, 0)
551                 || pm.hasSystemFeature(PackageManager.FEATURE_NFC_HOST_CARD_EMULATION_NFCF, 0);
552         } catch (RemoteException e) {
553             Log.e(TAG, "Package manager query failed, assuming no NFC feature", e);
554             return false;
555         }
556     }
557 
558     /**
559      * Return list of Secure Elements which support off host card emulation.
560      *
561      * @return List<String> containing secure elements on the device which supports
562      *                      off host card emulation. eSE for Embedded secure element,
563      *                      SIM for UICC and so on.
564      * @hide
565      */
getSupportedOffHostSecureElements()566     public @NonNull List<String> getSupportedOffHostSecureElements() {
567         List<String> offHostSE = new ArrayList<String>();
568         IPackageManager pm = ActivityThread.getPackageManager();
569         if (pm == null) {
570             Log.e(TAG, "Cannot get package manager, assuming no off-host CE feature");
571             return offHostSE;
572         }
573         try {
574             if (pm.hasSystemFeature(PackageManager.FEATURE_NFC_OFF_HOST_CARD_EMULATION_UICC, 0)) {
575                 offHostSE.add("SIM");
576             }
577             if (pm.hasSystemFeature(PackageManager.FEATURE_NFC_OFF_HOST_CARD_EMULATION_ESE, 0)) {
578                 offHostSE.add("eSE");
579             }
580         } catch (RemoteException e) {
581             Log.e(TAG, "Package manager query failed, assuming no off-host CE feature", e);
582             offHostSE.clear();
583             return offHostSE;
584         }
585         return offHostSE;
586     }
587 
588     /**
589      * Returns the NfcAdapter for application context,
590      * or throws if NFC is not available.
591      * @hide
592      */
593     @UnsupportedAppUsage
getNfcAdapter(Context context)594     public static synchronized NfcAdapter getNfcAdapter(Context context) {
595         if (!sIsInitialized) {
596             sHasNfcFeature = hasNfcFeature();
597             sHasBeamFeature = hasBeamFeature();
598             boolean hasHceFeature = hasNfcHceFeature();
599             /* is this device meant to have NFC */
600             if (!sHasNfcFeature && !hasHceFeature) {
601                 Log.v(TAG, "this device does not have NFC support");
602                 throw new UnsupportedOperationException();
603             }
604             sService = getServiceInterface();
605             if (sService == null) {
606                 Log.e(TAG, "could not retrieve NFC service");
607                 throw new UnsupportedOperationException();
608             }
609             if (sHasNfcFeature) {
610                 try {
611                     sTagService = sService.getNfcTagInterface();
612                 } catch (RemoteException e) {
613                     Log.e(TAG, "could not retrieve NFC Tag service");
614                     throw new UnsupportedOperationException();
615                 }
616             }
617             if (hasHceFeature) {
618                 try {
619                     sNfcFCardEmulationService = sService.getNfcFCardEmulationInterface();
620                 } catch (RemoteException e) {
621                     Log.e(TAG, "could not retrieve NFC-F card emulation service");
622                     throw new UnsupportedOperationException();
623                 }
624                 try {
625                     sCardEmulationService = sService.getNfcCardEmulationInterface();
626                 } catch (RemoteException e) {
627                     Log.e(TAG, "could not retrieve card emulation service");
628                     throw new UnsupportedOperationException();
629                 }
630             }
631 
632             sIsInitialized = true;
633         }
634         if (context == null) {
635             if (sNullContextNfcAdapter == null) {
636                 sNullContextNfcAdapter = new NfcAdapter(null);
637             }
638             return sNullContextNfcAdapter;
639         }
640         NfcAdapter adapter = sNfcAdapters.get(context);
641         if (adapter == null) {
642             adapter = new NfcAdapter(context);
643             sNfcAdapters.put(context, adapter);
644         }
645         return adapter;
646     }
647 
648     /** get handle to NFC service interface */
getServiceInterface()649     private static INfcAdapter getServiceInterface() {
650         /* get a handle to NFC service */
651         IBinder b = ServiceManager.getService("nfc");
652         if (b == null) {
653             return null;
654         }
655         return INfcAdapter.Stub.asInterface(b);
656     }
657 
658     /**
659      * Helper to get the default NFC Adapter.
660      * <p>
661      * Most Android devices will only have one NFC Adapter (NFC Controller).
662      * <p>
663      * This helper is the equivalent of:
664      * <pre>
665      * NfcManager manager = (NfcManager) context.getSystemService(Context.NFC_SERVICE);
666      * NfcAdapter adapter = manager.getDefaultAdapter();</pre>
667      * @param context the calling application's context
668      *
669      * @return the default NFC adapter, or null if no NFC adapter exists
670      */
getDefaultAdapter(Context context)671     public static NfcAdapter getDefaultAdapter(Context context) {
672         if (context == null) {
673             throw new IllegalArgumentException("context cannot be null");
674         }
675         context = context.getApplicationContext();
676         if (context == null) {
677             throw new IllegalArgumentException(
678                     "context not associated with any application (using a mock context?)");
679         }
680 
681         if (getServiceInterface() == null) {
682             // NFC is not available
683             return null;
684         }
685 
686         /* use getSystemService() for consistency */
687         NfcManager manager = (NfcManager) context.getSystemService(Context.NFC_SERVICE);
688         if (manager == null) {
689             // NFC not available
690             return null;
691         }
692         return manager.getDefaultAdapter();
693     }
694 
695     /**
696      * Legacy NfcAdapter getter, always use {@link #getDefaultAdapter(Context)} instead.<p>
697      * This method was deprecated at API level 10 (Gingerbread MR1) because a context is required
698      * for many NFC API methods. Those methods will fail when called on an NfcAdapter
699      * object created from this method.<p>
700      * @deprecated use {@link #getDefaultAdapter(Context)}
701      * @hide
702      */
703     @Deprecated
704     @UnsupportedAppUsage
getDefaultAdapter()705     public static NfcAdapter getDefaultAdapter() {
706         // introduced in API version 9 (GB 2.3)
707         // deprecated in API version 10 (GB 2.3.3)
708         // removed from public API in version 16 (ICS MR2)
709         // should maintain as a hidden API for binary compatibility for a little longer
710         Log.w(TAG, "WARNING: NfcAdapter.getDefaultAdapter() is deprecated, use " +
711                 "NfcAdapter.getDefaultAdapter(Context) instead", new Exception());
712 
713         return NfcAdapter.getNfcAdapter(null);
714     }
715 
NfcAdapter(Context context)716     NfcAdapter(Context context) {
717         mContext = context;
718         mNfcActivityManager = new NfcActivityManager(this);
719         mNfcUnlockHandlers = new HashMap<NfcUnlockHandler, INfcUnlockHandler>();
720         mTagRemovedListener = null;
721         mLock = new Object();
722     }
723 
724     /**
725      * @hide
726      */
727     @UnsupportedAppUsage
getContext()728     public Context getContext() {
729         return mContext;
730     }
731 
732     /**
733      * Returns the binder interface to the service.
734      * @hide
735      */
736     @UnsupportedAppUsage
getService()737     public INfcAdapter getService() {
738         isEnabled();  // NOP call to recover sService if it is stale
739         return sService;
740     }
741 
742     /**
743      * Returns the binder interface to the tag service.
744      * @hide
745      */
getTagService()746     public INfcTag getTagService() {
747         isEnabled();  // NOP call to recover sTagService if it is stale
748         return sTagService;
749     }
750 
751     /**
752      * Returns the binder interface to the card emulation service.
753      * @hide
754      */
getCardEmulationService()755     public INfcCardEmulation getCardEmulationService() {
756         isEnabled();
757         return sCardEmulationService;
758     }
759 
760     /**
761      * Returns the binder interface to the NFC-F card emulation service.
762      * @hide
763      */
getNfcFCardEmulationService()764     public INfcFCardEmulation getNfcFCardEmulationService() {
765         isEnabled();
766         return sNfcFCardEmulationService;
767     }
768 
769     /**
770      * Returns the binder interface to the NFC-DTA test interface.
771      * @hide
772      */
getNfcDtaInterface()773     public INfcDta getNfcDtaInterface() {
774         if (mContext == null) {
775             throw new UnsupportedOperationException("You need a context on NfcAdapter to use the "
776                     + " NFC extras APIs");
777         }
778         try {
779             return sService.getNfcDtaInterface(mContext.getPackageName());
780         } catch (RemoteException e) {
781             attemptDeadServiceRecovery(e);
782             return null;
783         }
784     }
785 
786     /**
787      * NFC service dead - attempt best effort recovery
788      * @hide
789      */
790     @UnsupportedAppUsage
attemptDeadServiceRecovery(Exception e)791     public void attemptDeadServiceRecovery(Exception e) {
792         Log.e(TAG, "NFC service dead - attempting to recover", e);
793         INfcAdapter service = getServiceInterface();
794         if (service == null) {
795             Log.e(TAG, "could not retrieve NFC service during service recovery");
796             // nothing more can be done now, sService is still stale, we'll hit
797             // this recovery path again later
798             return;
799         }
800         // assigning to sService is not thread-safe, but this is best-effort code
801         // and on a well-behaved system should never happen
802         sService = service;
803         try {
804             sTagService = service.getNfcTagInterface();
805         } catch (RemoteException ee) {
806             Log.e(TAG, "could not retrieve NFC tag service during service recovery");
807             // nothing more can be done now, sService is still stale, we'll hit
808             // this recovery path again later
809             return;
810         }
811 
812         try {
813             sCardEmulationService = service.getNfcCardEmulationInterface();
814         } catch (RemoteException ee) {
815             Log.e(TAG, "could not retrieve NFC card emulation service during service recovery");
816         }
817 
818         try {
819             sNfcFCardEmulationService = service.getNfcFCardEmulationInterface();
820         } catch (RemoteException ee) {
821             Log.e(TAG, "could not retrieve NFC-F card emulation service during service recovery");
822         }
823 
824         return;
825     }
826 
827     /**
828      * Return true if this NFC Adapter has any features enabled.
829      *
830      * <p>If this method returns false, the NFC hardware is guaranteed not to
831      * generate or respond to any NFC communication over its NFC radio.
832      * <p>Applications can use this to check if NFC is enabled. Applications
833      * can request Settings UI allowing the user to toggle NFC using:
834      * <p><pre>startActivity(new Intent(Settings.ACTION_NFC_SETTINGS))</pre>
835      *
836      * @see android.provider.Settings#ACTION_NFC_SETTINGS
837      * @return true if this NFC Adapter has any features enabled
838      */
isEnabled()839     public boolean isEnabled() {
840         try {
841             return sService.getState() == STATE_ON;
842         } catch (RemoteException e) {
843             attemptDeadServiceRecovery(e);
844             return false;
845         }
846     }
847 
848     /**
849      * Return the state of this NFC Adapter.
850      *
851      * <p>Returns one of {@link #STATE_ON}, {@link #STATE_TURNING_ON},
852      * {@link #STATE_OFF}, {@link #STATE_TURNING_OFF}.
853      *
854      * <p>{@link #isEnabled()} is equivalent to
855      * <code>{@link #getAdapterState()} == {@link #STATE_ON}</code>
856      *
857      * @return the current state of this NFC adapter
858      *
859      * @hide
860      */
861     @UnsupportedAppUsage
getAdapterState()862     public int getAdapterState() {
863         try {
864             return sService.getState();
865         } catch (RemoteException e) {
866             attemptDeadServiceRecovery(e);
867             return NfcAdapter.STATE_OFF;
868         }
869     }
870 
871     /**
872      * Enable NFC hardware.
873      *
874      * <p>This call is asynchronous. Listen for
875      * {@link #ACTION_ADAPTER_STATE_CHANGED} broadcasts to find out when the
876      * operation is complete.
877      *
878      * <p>If this returns true, then either NFC is already on, or
879      * a {@link #ACTION_ADAPTER_STATE_CHANGED} broadcast will be sent
880      * to indicate a state transition. If this returns false, then
881      * there is some problem that prevents an attempt to turn
882      * NFC on (for example we are in airplane mode and NFC is not
883      * toggleable in airplane mode on this platform).
884      *
885      * @hide
886      */
887     @SystemApi
888     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
enable()889     public boolean enable() {
890         try {
891             return sService.enable();
892         } catch (RemoteException e) {
893             attemptDeadServiceRecovery(e);
894             return false;
895         }
896     }
897 
898     /**
899      * Disable NFC hardware.
900      *
901      * <p>No NFC features will work after this call, and the hardware
902      * will not perform or respond to any NFC communication.
903      *
904      * <p>This call is asynchronous. Listen for
905      * {@link #ACTION_ADAPTER_STATE_CHANGED} broadcasts to find out when the
906      * operation is complete.
907      *
908      * <p>If this returns true, then either NFC is already off, or
909      * a {@link #ACTION_ADAPTER_STATE_CHANGED} broadcast will be sent
910      * to indicate a state transition. If this returns false, then
911      * there is some problem that prevents an attempt to turn
912      * NFC off.
913      *
914      * @hide
915      */
916     @SystemApi
917     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
disable()918     public boolean disable() {
919         try {
920             return sService.disable(true);
921         } catch (RemoteException e) {
922             attemptDeadServiceRecovery(e);
923             return false;
924         }
925     }
926 
927     /**
928      * Disable NFC hardware.
929      * @hide
930     */
931     @SystemApi
932     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
disable(boolean persist)933     public boolean disable(boolean persist) {
934         try {
935             return sService.disable(persist);
936         } catch (RemoteException e) {
937             attemptDeadServiceRecovery(e);
938             return false;
939         }
940     }
941 
942     /**
943      * Pauses polling for a {@code timeoutInMs} millis. If polling must be resumed before timeout,
944      * use {@link #resumePolling()}.
945      * @hide
946      */
pausePolling(int timeoutInMs)947     public void pausePolling(int timeoutInMs) {
948         try {
949             sService.pausePolling(timeoutInMs);
950         } catch (RemoteException e) {
951             attemptDeadServiceRecovery(e);
952         }
953     }
954 
955     /**
956      * Resumes default polling for the current device state if polling is paused. Calling
957      * this while polling is not paused is a no-op.
958      *
959      * @hide
960      */
resumePolling()961     public void resumePolling() {
962         try {
963             sService.resumePolling();
964         } catch (RemoteException e) {
965             attemptDeadServiceRecovery(e);
966         }
967     }
968 
969     /**
970      * Set one or more {@link Uri}s to send using Android Beam (TM). Every
971      * Uri you provide must have either scheme 'file' or scheme 'content'.
972      *
973      * <p>For the data provided through this method, Android Beam tries to
974      * switch to alternate transports such as Bluetooth to achieve a fast
975      * transfer speed. Hence this method is very suitable
976      * for transferring large files such as pictures or songs.
977      *
978      * <p>The receiving side will store the content of each Uri in
979      * a file and present a notification to the user to open the file
980      * with a {@link android.content.Intent} with action
981      * {@link android.content.Intent#ACTION_VIEW}.
982      * If multiple URIs are sent, the {@link android.content.Intent} will refer
983      * to the first of the stored files.
984      *
985      * <p>This method may be called at any time before {@link Activity#onDestroy},
986      * but the URI(s) are only made available for Android Beam when the
987      * specified activity(s) are in resumed (foreground) state. The recommended
988      * approach is to call this method during your Activity's
989      * {@link Activity#onCreate} - see sample
990      * code below. This method does not immediately perform any I/O or blocking work,
991      * so is safe to call on your main thread.
992      *
993      * <p>{@link #setBeamPushUris} and {@link #setBeamPushUrisCallback}
994      * have priority over both {@link #setNdefPushMessage} and
995      * {@link #setNdefPushMessageCallback}.
996      *
997      * <p>If {@link #setBeamPushUris} is called with a null Uri array,
998      * and/or {@link #setBeamPushUrisCallback} is called with a null callback,
999      * then the Uri push will be completely disabled for the specified activity(s).
1000      *
1001      * <p>Code example:
1002      * <pre>
1003      * protected void onCreate(Bundle savedInstanceState) {
1004      *     super.onCreate(savedInstanceState);
1005      *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
1006      *     if (nfcAdapter == null) return;  // NFC not available on this device
1007      *     nfcAdapter.setBeamPushUris(new Uri[] {uri1, uri2}, this);
1008      * }</pre>
1009      * And that is it. Only one call per activity is necessary. The Android
1010      * OS will automatically release its references to the Uri(s) and the
1011      * Activity object when it is destroyed if you follow this pattern.
1012      *
1013      * <p>If your Activity wants to dynamically supply Uri(s),
1014      * then set a callback using {@link #setBeamPushUrisCallback} instead
1015      * of using this method.
1016      *
1017      * <p class="note">Do not pass in an Activity that has already been through
1018      * {@link Activity#onDestroy}. This is guaranteed if you call this API
1019      * during {@link Activity#onCreate}.
1020      *
1021      * <p class="note">If this device does not support alternate transports
1022      * such as Bluetooth or WiFI, calling this method does nothing.
1023      *
1024      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1025      *
1026      * @param uris an array of Uri(s) to push over Android Beam
1027      * @param activity activity for which the Uri(s) will be pushed
1028      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1029      * @deprecated this feature is deprecated. File sharing can work using other technology like
1030      * Bluetooth.
1031      */
1032     @java.lang.Deprecated
setBeamPushUris(Uri[] uris, Activity activity)1033     public void setBeamPushUris(Uri[] uris, Activity activity) {
1034         synchronized (NfcAdapter.class) {
1035             if (!sHasNfcFeature) {
1036                 throw new UnsupportedOperationException();
1037             }
1038             if (!sHasBeamFeature) {
1039                 return;
1040             }
1041         }
1042         if (activity == null) {
1043             throw new NullPointerException("activity cannot be null");
1044         }
1045         if (uris != null) {
1046             for (Uri uri : uris) {
1047                 if (uri == null) throw new NullPointerException("Uri not " +
1048                         "allowed to be null");
1049                 String scheme = uri.getScheme();
1050                 if (scheme == null || (!scheme.equalsIgnoreCase("file") &&
1051                         !scheme.equalsIgnoreCase("content"))) {
1052                     throw new IllegalArgumentException("URI needs to have " +
1053                             "either scheme file or scheme content");
1054                 }
1055             }
1056         }
1057         mNfcActivityManager.setNdefPushContentUri(activity, uris);
1058     }
1059 
1060     /**
1061      * Set a callback that will dynamically generate one or more {@link Uri}s
1062      * to send using Android Beam (TM). Every Uri the callback provides
1063      * must have either scheme 'file' or scheme 'content'.
1064      *
1065      * <p>For the data provided through this callback, Android Beam tries to
1066      * switch to alternate transports such as Bluetooth to achieve a fast
1067      * transfer speed. Hence this method is very suitable
1068      * for transferring large files such as pictures or songs.
1069      *
1070      * <p>The receiving side will store the content of each Uri in
1071      * a file and present a notification to the user to open the file
1072      * with a {@link android.content.Intent} with action
1073      * {@link android.content.Intent#ACTION_VIEW}.
1074      * If multiple URIs are sent, the {@link android.content.Intent} will refer
1075      * to the first of the stored files.
1076      *
1077      * <p>This method may be called at any time before {@link Activity#onDestroy},
1078      * but the URI(s) are only made available for Android Beam when the
1079      * specified activity(s) are in resumed (foreground) state. The recommended
1080      * approach is to call this method during your Activity's
1081      * {@link Activity#onCreate} - see sample
1082      * code below. This method does not immediately perform any I/O or blocking work,
1083      * so is safe to call on your main thread.
1084      *
1085      * <p>{@link #setBeamPushUris} and {@link #setBeamPushUrisCallback}
1086      * have priority over both {@link #setNdefPushMessage} and
1087      * {@link #setNdefPushMessageCallback}.
1088      *
1089      * <p>If {@link #setBeamPushUris} is called with a null Uri array,
1090      * and/or {@link #setBeamPushUrisCallback} is called with a null callback,
1091      * then the Uri push will be completely disabled for the specified activity(s).
1092      *
1093      * <p>Code example:
1094      * <pre>
1095      * protected void onCreate(Bundle savedInstanceState) {
1096      *     super.onCreate(savedInstanceState);
1097      *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
1098      *     if (nfcAdapter == null) return;  // NFC not available on this device
1099      *     nfcAdapter.setBeamPushUrisCallback(callback, this);
1100      * }</pre>
1101      * And that is it. Only one call per activity is necessary. The Android
1102      * OS will automatically release its references to the Uri(s) and the
1103      * Activity object when it is destroyed if you follow this pattern.
1104      *
1105      * <p class="note">Do not pass in an Activity that has already been through
1106      * {@link Activity#onDestroy}. This is guaranteed if you call this API
1107      * during {@link Activity#onCreate}.
1108      *
1109      * <p class="note">If this device does not support alternate transports
1110      * such as Bluetooth or WiFI, calling this method does nothing.
1111      *
1112      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1113      *
1114      * @param callback callback, or null to disable
1115      * @param activity activity for which the Uri(s) will be pushed
1116      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1117      * @deprecated this feature is deprecated. File sharing can work using other technology like
1118      * Bluetooth.
1119      */
1120     @java.lang.Deprecated
setBeamPushUrisCallback(CreateBeamUrisCallback callback, Activity activity)1121     public void setBeamPushUrisCallback(CreateBeamUrisCallback callback, Activity activity) {
1122         synchronized (NfcAdapter.class) {
1123             if (!sHasNfcFeature) {
1124                 throw new UnsupportedOperationException();
1125             }
1126             if (!sHasBeamFeature) {
1127                 return;
1128             }
1129         }
1130         if (activity == null) {
1131             throw new NullPointerException("activity cannot be null");
1132         }
1133         mNfcActivityManager.setNdefPushContentUriCallback(activity, callback);
1134     }
1135 
1136     /**
1137      * Set a static {@link NdefMessage} to send using Android Beam (TM).
1138      *
1139      * <p>This method may be called at any time before {@link Activity#onDestroy},
1140      * but the NDEF message is only made available for NDEF push when the
1141      * specified activity(s) are in resumed (foreground) state. The recommended
1142      * approach is to call this method during your Activity's
1143      * {@link Activity#onCreate} - see sample
1144      * code below. This method does not immediately perform any I/O or blocking work,
1145      * so is safe to call on your main thread.
1146      *
1147      * <p>Only one NDEF message can be pushed by the currently resumed activity.
1148      * If both {@link #setNdefPushMessage} and
1149      * {@link #setNdefPushMessageCallback} are set, then
1150      * the callback will take priority.
1151      *
1152      * <p>If neither {@link #setNdefPushMessage} or
1153      * {@link #setNdefPushMessageCallback} have been called for your activity, then
1154      * the Android OS may choose to send a default NDEF message on your behalf,
1155      * such as a URI for your application.
1156      *
1157      * <p>If {@link #setNdefPushMessage} is called with a null NDEF message,
1158      * and/or {@link #setNdefPushMessageCallback} is called with a null callback,
1159      * then NDEF push will be completely disabled for the specified activity(s).
1160      * This also disables any default NDEF message the Android OS would have
1161      * otherwise sent on your behalf for those activity(s).
1162      *
1163      * <p>If you want to prevent the Android OS from sending default NDEF
1164      * messages completely (for all activities), you can include a
1165      * {@code <meta-data>} element inside the {@code <application>}
1166      * element of your AndroidManifest.xml file, like this:
1167      * <pre>
1168      * &lt;application ...>
1169      *     &lt;meta-data android:name="android.nfc.disable_beam_default"
1170      *         android:value="true" />
1171      * &lt;/application></pre>
1172      *
1173      * <p>The API allows for multiple activities to be specified at a time,
1174      * but it is strongly recommended to just register one at a time,
1175      * and to do so during the activity's {@link Activity#onCreate}. For example:
1176      * <pre>
1177      * protected void onCreate(Bundle savedInstanceState) {
1178      *     super.onCreate(savedInstanceState);
1179      *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
1180      *     if (nfcAdapter == null) return;  // NFC not available on this device
1181      *     nfcAdapter.setNdefPushMessage(ndefMessage, this);
1182      * }</pre>
1183      * And that is it. Only one call per activity is necessary. The Android
1184      * OS will automatically release its references to the NDEF message and the
1185      * Activity object when it is destroyed if you follow this pattern.
1186      *
1187      * <p>If your Activity wants to dynamically generate an NDEF message,
1188      * then set a callback using {@link #setNdefPushMessageCallback} instead
1189      * of a static message.
1190      *
1191      * <p class="note">Do not pass in an Activity that has already been through
1192      * {@link Activity#onDestroy}. This is guaranteed if you call this API
1193      * during {@link Activity#onCreate}.
1194      *
1195      * <p class="note">For sending large content such as pictures and songs,
1196      * consider using {@link #setBeamPushUris}, which switches to alternate transports
1197      * such as Bluetooth to achieve a fast transfer rate.
1198      *
1199      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1200      *
1201      * @param message NDEF message to push over NFC, or null to disable
1202      * @param activity activity for which the NDEF message will be pushed
1203      * @param activities optional additional activities, however we strongly recommend
1204      *        to only register one at a time, and to do so in that activity's
1205      *        {@link Activity#onCreate}
1206      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1207      * @deprecated this feature is deprecated. File sharing can work using other technology like
1208      * Bluetooth.
1209      */
1210     @java.lang.Deprecated
setNdefPushMessage(NdefMessage message, Activity activity, Activity ... activities)1211     public void setNdefPushMessage(NdefMessage message, Activity activity,
1212             Activity ... activities) {
1213         synchronized (NfcAdapter.class) {
1214             if (!sHasNfcFeature) {
1215                 throw new UnsupportedOperationException();
1216             }
1217             if (!sHasBeamFeature) {
1218                 return;
1219             }
1220         }
1221         int targetSdkVersion = getSdkVersion();
1222         try {
1223             if (activity == null) {
1224                 throw new NullPointerException("activity cannot be null");
1225             }
1226             mNfcActivityManager.setNdefPushMessage(activity, message, 0);
1227             for (Activity a : activities) {
1228                 if (a == null) {
1229                     throw new NullPointerException("activities cannot contain null");
1230                 }
1231                 mNfcActivityManager.setNdefPushMessage(a, message, 0);
1232             }
1233         } catch (IllegalStateException e) {
1234             if (targetSdkVersion < android.os.Build.VERSION_CODES.JELLY_BEAN) {
1235                 // Less strict on old applications - just log the error
1236                 Log.e(TAG, "Cannot call API with Activity that has already " +
1237                         "been destroyed", e);
1238             } else {
1239                 // Prevent new applications from making this mistake, re-throw
1240                 throw(e);
1241             }
1242         }
1243     }
1244 
1245     /**
1246      * @hide
1247      */
1248     @SystemApi
setNdefPushMessage(NdefMessage message, Activity activity, int flags)1249     public void setNdefPushMessage(NdefMessage message, Activity activity, int flags) {
1250         synchronized (NfcAdapter.class) {
1251             if (!sHasNfcFeature) {
1252                 throw new UnsupportedOperationException();
1253             }
1254         }
1255         if (activity == null) {
1256             throw new NullPointerException("activity cannot be null");
1257         }
1258         mNfcActivityManager.setNdefPushMessage(activity, message, flags);
1259     }
1260 
1261     /**
1262      * Set a callback that dynamically generates NDEF messages to send using Android Beam (TM).
1263      *
1264      * <p>This method may be called at any time before {@link Activity#onDestroy},
1265      * but the NDEF message callback can only occur when the
1266      * specified activity(s) are in resumed (foreground) state. The recommended
1267      * approach is to call this method during your Activity's
1268      * {@link Activity#onCreate} - see sample
1269      * code below. This method does not immediately perform any I/O or blocking work,
1270      * so is safe to call on your main thread.
1271      *
1272      * <p>Only one NDEF message can be pushed by the currently resumed activity.
1273      * If both {@link #setNdefPushMessage} and
1274      * {@link #setNdefPushMessageCallback} are set, then
1275      * the callback will take priority.
1276      *
1277      * <p>If neither {@link #setNdefPushMessage} or
1278      * {@link #setNdefPushMessageCallback} have been called for your activity, then
1279      * the Android OS may choose to send a default NDEF message on your behalf,
1280      * such as a URI for your application.
1281      *
1282      * <p>If {@link #setNdefPushMessage} is called with a null NDEF message,
1283      * and/or {@link #setNdefPushMessageCallback} is called with a null callback,
1284      * then NDEF push will be completely disabled for the specified activity(s).
1285      * This also disables any default NDEF message the Android OS would have
1286      * otherwise sent on your behalf for those activity(s).
1287      *
1288      * <p>If you want to prevent the Android OS from sending default NDEF
1289      * messages completely (for all activities), you can include a
1290      * {@code <meta-data>} element inside the {@code <application>}
1291      * element of your AndroidManifest.xml file, like this:
1292      * <pre>
1293      * &lt;application ...>
1294      *     &lt;meta-data android:name="android.nfc.disable_beam_default"
1295      *         android:value="true" />
1296      * &lt;/application></pre>
1297      *
1298      * <p>The API allows for multiple activities to be specified at a time,
1299      * but it is strongly recommended to just register one at a time,
1300      * and to do so during the activity's {@link Activity#onCreate}. For example:
1301      * <pre>
1302      * protected void onCreate(Bundle savedInstanceState) {
1303      *     super.onCreate(savedInstanceState);
1304      *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
1305      *     if (nfcAdapter == null) return;  // NFC not available on this device
1306      *     nfcAdapter.setNdefPushMessageCallback(callback, this);
1307      * }</pre>
1308      * And that is it. Only one call per activity is necessary. The Android
1309      * OS will automatically release its references to the callback and the
1310      * Activity object when it is destroyed if you follow this pattern.
1311      *
1312      * <p class="note">Do not pass in an Activity that has already been through
1313      * {@link Activity#onDestroy}. This is guaranteed if you call this API
1314      * during {@link Activity#onCreate}.
1315      * <p class="note">For sending large content such as pictures and songs,
1316      * consider using {@link #setBeamPushUris}, which switches to alternate transports
1317      * such as Bluetooth to achieve a fast transfer rate.
1318      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1319      *
1320      * @param callback callback, or null to disable
1321      * @param activity activity for which the NDEF message will be pushed
1322      * @param activities optional additional activities, however we strongly recommend
1323      *        to only register one at a time, and to do so in that activity's
1324      *        {@link Activity#onCreate}
1325      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1326      * @deprecated this feature is deprecated. File sharing can work using other technology like
1327      * Bluetooth.
1328      */
1329     @java.lang.Deprecated
setNdefPushMessageCallback(CreateNdefMessageCallback callback, Activity activity, Activity ... activities)1330     public void setNdefPushMessageCallback(CreateNdefMessageCallback callback, Activity activity,
1331             Activity ... activities) {
1332         synchronized (NfcAdapter.class) {
1333             if (!sHasNfcFeature) {
1334                 throw new UnsupportedOperationException();
1335             }
1336             if (!sHasBeamFeature) {
1337                 return;
1338             }
1339         }
1340         int targetSdkVersion = getSdkVersion();
1341         try {
1342             if (activity == null) {
1343                 throw new NullPointerException("activity cannot be null");
1344             }
1345             mNfcActivityManager.setNdefPushMessageCallback(activity, callback, 0);
1346             for (Activity a : activities) {
1347                 if (a == null) {
1348                     throw new NullPointerException("activities cannot contain null");
1349                 }
1350                 mNfcActivityManager.setNdefPushMessageCallback(a, callback, 0);
1351             }
1352         } catch (IllegalStateException e) {
1353             if (targetSdkVersion < android.os.Build.VERSION_CODES.JELLY_BEAN) {
1354                 // Less strict on old applications - just log the error
1355                 Log.e(TAG, "Cannot call API with Activity that has already " +
1356                         "been destroyed", e);
1357             } else {
1358                 // Prevent new applications from making this mistake, re-throw
1359                 throw(e);
1360             }
1361         }
1362     }
1363 
1364     /**
1365      * @hide
1366      */
1367     @UnsupportedAppUsage
setNdefPushMessageCallback(CreateNdefMessageCallback callback, Activity activity, int flags)1368     public void setNdefPushMessageCallback(CreateNdefMessageCallback callback, Activity activity,
1369             int flags) {
1370         if (activity == null) {
1371             throw new NullPointerException("activity cannot be null");
1372         }
1373         mNfcActivityManager.setNdefPushMessageCallback(activity, callback, flags);
1374     }
1375 
1376     /**
1377      * Set a callback on successful Android Beam (TM).
1378      *
1379      * <p>This method may be called at any time before {@link Activity#onDestroy},
1380      * but the callback can only occur when the
1381      * specified activity(s) are in resumed (foreground) state. The recommended
1382      * approach is to call this method during your Activity's
1383      * {@link Activity#onCreate} - see sample
1384      * code below. This method does not immediately perform any I/O or blocking work,
1385      * so is safe to call on your main thread.
1386      *
1387      * <p>The API allows for multiple activities to be specified at a time,
1388      * but it is strongly recommended to just register one at a time,
1389      * and to do so during the activity's {@link Activity#onCreate}. For example:
1390      * <pre>
1391      * protected void onCreate(Bundle savedInstanceState) {
1392      *     super.onCreate(savedInstanceState);
1393      *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
1394      *     if (nfcAdapter == null) return;  // NFC not available on this device
1395      *     nfcAdapter.setOnNdefPushCompleteCallback(callback, this);
1396      * }</pre>
1397      * And that is it. Only one call per activity is necessary. The Android
1398      * OS will automatically release its references to the callback and the
1399      * Activity object when it is destroyed if you follow this pattern.
1400      *
1401      * <p class="note">Do not pass in an Activity that has already been through
1402      * {@link Activity#onDestroy}. This is guaranteed if you call this API
1403      * during {@link Activity#onCreate}.
1404      *
1405      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1406      *
1407      * @param callback callback, or null to disable
1408      * @param activity activity for which the NDEF message will be pushed
1409      * @param activities optional additional activities, however we strongly recommend
1410      *        to only register one at a time, and to do so in that activity's
1411      *        {@link Activity#onCreate}
1412      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1413      * @deprecated this feature is deprecated. File sharing can work using other technology like
1414      * Bluetooth.
1415      */
1416     @java.lang.Deprecated
setOnNdefPushCompleteCallback(OnNdefPushCompleteCallback callback, Activity activity, Activity ... activities)1417     public void setOnNdefPushCompleteCallback(OnNdefPushCompleteCallback callback,
1418             Activity activity, Activity ... activities) {
1419         synchronized (NfcAdapter.class) {
1420             if (!sHasNfcFeature) {
1421                 throw new UnsupportedOperationException();
1422             }
1423             if (!sHasBeamFeature) {
1424                 return;
1425             }
1426         }
1427         int targetSdkVersion = getSdkVersion();
1428         try {
1429             if (activity == null) {
1430                 throw new NullPointerException("activity cannot be null");
1431             }
1432             mNfcActivityManager.setOnNdefPushCompleteCallback(activity, callback);
1433             for (Activity a : activities) {
1434                 if (a == null) {
1435                     throw new NullPointerException("activities cannot contain null");
1436                 }
1437                 mNfcActivityManager.setOnNdefPushCompleteCallback(a, callback);
1438             }
1439         } catch (IllegalStateException e) {
1440             if (targetSdkVersion < android.os.Build.VERSION_CODES.JELLY_BEAN) {
1441                 // Less strict on old applications - just log the error
1442                 Log.e(TAG, "Cannot call API with Activity that has already " +
1443                         "been destroyed", e);
1444             } else {
1445                 // Prevent new applications from making this mistake, re-throw
1446                 throw(e);
1447             }
1448         }
1449     }
1450 
1451     /**
1452      * Enable foreground dispatch to the given Activity.
1453      *
1454      * <p>This will give priority to the foreground activity when
1455      * dispatching a discovered {@link Tag} to an application.
1456      *
1457      * <p>If any IntentFilters are provided to this method they are used to match dispatch Intents
1458      * for both the {@link NfcAdapter#ACTION_NDEF_DISCOVERED} and
1459      * {@link NfcAdapter#ACTION_TAG_DISCOVERED}. Since {@link NfcAdapter#ACTION_TECH_DISCOVERED}
1460      * relies on meta data outside of the IntentFilter matching for that dispatch Intent is handled
1461      * by passing in the tech lists separately. Each first level entry in the tech list represents
1462      * an array of technologies that must all be present to match. If any of the first level sets
1463      * match then the dispatch is routed through the given PendingIntent. In other words, the second
1464      * level is ANDed together and the first level entries are ORed together.
1465      *
1466      * <p>If you pass {@code null} for both the {@code filters} and {@code techLists} parameters
1467      * that acts a wild card and will cause the foreground activity to receive all tags via the
1468      * {@link NfcAdapter#ACTION_TAG_DISCOVERED} intent.
1469      *
1470      * <p>This method must be called from the main thread, and only when the activity is in the
1471      * foreground (resumed). Also, activities must call {@link #disableForegroundDispatch} before
1472      * the completion of their {@link Activity#onPause} callback to disable foreground dispatch
1473      * after it has been enabled.
1474      *
1475      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1476      *
1477      * @param activity the Activity to dispatch to
1478      * @param intent the PendingIntent to start for the dispatch
1479      * @param filters the IntentFilters to override dispatching for, or null to always dispatch
1480      * @param techLists the tech lists used to perform matching for dispatching of the
1481      *      {@link NfcAdapter#ACTION_TECH_DISCOVERED} intent
1482      * @throws IllegalStateException if the Activity is not currently in the foreground
1483      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1484      */
enableForegroundDispatch(Activity activity, PendingIntent intent, IntentFilter[] filters, String[][] techLists)1485     public void enableForegroundDispatch(Activity activity, PendingIntent intent,
1486             IntentFilter[] filters, String[][] techLists) {
1487         synchronized (NfcAdapter.class) {
1488             if (!sHasNfcFeature) {
1489                 throw new UnsupportedOperationException();
1490             }
1491         }
1492         if (activity == null || intent == null) {
1493             throw new NullPointerException();
1494         }
1495         if (!activity.isResumed()) {
1496             throw new IllegalStateException("Foreground dispatch can only be enabled " +
1497                     "when your activity is resumed");
1498         }
1499         try {
1500             TechListParcel parcel = null;
1501             if (techLists != null && techLists.length > 0) {
1502                 parcel = new TechListParcel(techLists);
1503             }
1504             ActivityThread.currentActivityThread().registerOnActivityPausedListener(activity,
1505                     mForegroundDispatchListener);
1506             sService.setForegroundDispatch(intent, filters, parcel);
1507         } catch (RemoteException e) {
1508             attemptDeadServiceRecovery(e);
1509         }
1510     }
1511 
1512     /**
1513      * Disable foreground dispatch to the given activity.
1514      *
1515      * <p>After calling {@link #enableForegroundDispatch}, an activity
1516      * must call this method before its {@link Activity#onPause} callback
1517      * completes.
1518      *
1519      * <p>This method must be called from the main thread.
1520      *
1521      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1522      *
1523      * @param activity the Activity to disable dispatch to
1524      * @throws IllegalStateException if the Activity has already been paused
1525      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1526      */
disableForegroundDispatch(Activity activity)1527     public void disableForegroundDispatch(Activity activity) {
1528         synchronized (NfcAdapter.class) {
1529             if (!sHasNfcFeature) {
1530                 throw new UnsupportedOperationException();
1531             }
1532         }
1533         ActivityThread.currentActivityThread().unregisterOnActivityPausedListener(activity,
1534                 mForegroundDispatchListener);
1535         disableForegroundDispatchInternal(activity, false);
1536     }
1537 
1538     OnActivityPausedListener mForegroundDispatchListener = new OnActivityPausedListener() {
1539         @Override
1540         public void onPaused(Activity activity) {
1541             disableForegroundDispatchInternal(activity, true);
1542         }
1543     };
1544 
disableForegroundDispatchInternal(Activity activity, boolean force)1545     void disableForegroundDispatchInternal(Activity activity, boolean force) {
1546         try {
1547             sService.setForegroundDispatch(null, null, null);
1548             if (!force && !activity.isResumed()) {
1549                 throw new IllegalStateException("You must disable foreground dispatching " +
1550                         "while your activity is still resumed");
1551             }
1552         } catch (RemoteException e) {
1553             attemptDeadServiceRecovery(e);
1554         }
1555     }
1556 
1557     /**
1558      * Limit the NFC controller to reader mode while this Activity is in the foreground.
1559      *
1560      * <p>In this mode the NFC controller will only act as an NFC tag reader/writer,
1561      * thus disabling any peer-to-peer (Android Beam) and card-emulation modes of
1562      * the NFC adapter on this device.
1563      *
1564      * <p>Use {@link #FLAG_READER_SKIP_NDEF_CHECK} to prevent the platform from
1565      * performing any NDEF checks in reader mode. Note that this will prevent the
1566      * {@link Ndef} tag technology from being enumerated on the tag, and that
1567      * NDEF-based tag dispatch will not be functional.
1568      *
1569      * <p>For interacting with tags that are emulated on another Android device
1570      * using Android's host-based card-emulation, the recommended flags are
1571      * {@link #FLAG_READER_NFC_A} and {@link #FLAG_READER_SKIP_NDEF_CHECK}.
1572      *
1573      * @param activity the Activity that requests the adapter to be in reader mode
1574      * @param callback the callback to be called when a tag is discovered
1575      * @param flags Flags indicating poll technologies and other optional parameters
1576      * @param extras Additional extras for configuring reader mode.
1577      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1578      */
enableReaderMode(Activity activity, ReaderCallback callback, int flags, Bundle extras)1579     public void enableReaderMode(Activity activity, ReaderCallback callback, int flags,
1580             Bundle extras) {
1581         synchronized (NfcAdapter.class) {
1582             if (!sHasNfcFeature) {
1583                 throw new UnsupportedOperationException();
1584             }
1585         }
1586         mNfcActivityManager.enableReaderMode(activity, callback, flags, extras);
1587     }
1588 
1589     /**
1590      * Restore the NFC adapter to normal mode of operation: supporting
1591      * peer-to-peer (Android Beam), card emulation, and polling for
1592      * all supported tag technologies.
1593      *
1594      * @param activity the Activity that currently has reader mode enabled
1595      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1596      */
disableReaderMode(Activity activity)1597     public void disableReaderMode(Activity activity) {
1598         synchronized (NfcAdapter.class) {
1599             if (!sHasNfcFeature) {
1600                 throw new UnsupportedOperationException();
1601             }
1602         }
1603         mNfcActivityManager.disableReaderMode(activity);
1604     }
1605 
1606     /**
1607      * Manually invoke Android Beam to share data.
1608      *
1609      * <p>The Android Beam animation is normally only shown when two NFC-capable
1610      * devices come into range.
1611      * By calling this method, an Activity can invoke the Beam animation directly
1612      * even if no other NFC device is in range yet. The Beam animation will then
1613      * prompt the user to tap another NFC-capable device to complete the data
1614      * transfer.
1615      *
1616      * <p>The main advantage of using this method is that it avoids the need for the
1617      * user to tap the screen to complete the transfer, as this method already
1618      * establishes the direction of the transfer and the consent of the user to
1619      * share data. Callers are responsible for making sure that the user has
1620      * consented to sharing data on NFC tap.
1621      *
1622      * <p>Note that to use this method, the passed in Activity must have already
1623      * set data to share over Beam by using method calls such as
1624      * {@link #setNdefPushMessageCallback} or
1625      * {@link #setBeamPushUrisCallback}.
1626      *
1627      * @param activity the current foreground Activity that has registered data to share
1628      * @return whether the Beam animation was successfully invoked
1629      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1630      * @deprecated this feature is deprecated. File sharing can work using other technology like
1631      * Bluetooth.
1632      */
1633     @java.lang.Deprecated
invokeBeam(Activity activity)1634     public boolean invokeBeam(Activity activity) {
1635         synchronized (NfcAdapter.class) {
1636             if (!sHasNfcFeature) {
1637                 throw new UnsupportedOperationException();
1638             }
1639             if (!sHasBeamFeature) {
1640                 return false;
1641             }
1642         }
1643         if (activity == null) {
1644             throw new NullPointerException("activity may not be null.");
1645         }
1646         enforceResumed(activity);
1647         try {
1648             sService.invokeBeam();
1649             return true;
1650         } catch (RemoteException e) {
1651             Log.e(TAG, "invokeBeam: NFC process has died.");
1652             attemptDeadServiceRecovery(e);
1653             return false;
1654         }
1655     }
1656 
1657     /**
1658      * @hide
1659      */
invokeBeam(BeamShareData shareData)1660     public boolean invokeBeam(BeamShareData shareData) {
1661         try {
1662             Log.e(TAG, "invokeBeamInternal()");
1663             sService.invokeBeamInternal(shareData);
1664             return true;
1665         } catch (RemoteException e) {
1666             Log.e(TAG, "invokeBeam: NFC process has died.");
1667             attemptDeadServiceRecovery(e);
1668             return false;
1669         }
1670     }
1671 
1672     /**
1673      * Enable NDEF message push over NFC while this Activity is in the foreground.
1674      *
1675      * <p>You must explicitly call this method every time the activity is
1676      * resumed, and you must call {@link #disableForegroundNdefPush} before
1677      * your activity completes {@link Activity#onPause}.
1678      *
1679      * <p>Strongly recommend to use the new {@link #setNdefPushMessage}
1680      * instead: it automatically hooks into your activity life-cycle,
1681      * so you do not need to call enable/disable in your onResume/onPause.
1682      *
1683      * <p>For NDEF push to function properly the other NFC device must
1684      * support either NFC Forum's SNEP (Simple Ndef Exchange Protocol), or
1685      * Android's "com.android.npp" (Ndef Push Protocol). This was optional
1686      * on Gingerbread level Android NFC devices, but SNEP is mandatory on
1687      * Ice-Cream-Sandwich and beyond.
1688      *
1689      * <p>This method must be called from the main thread.
1690      *
1691      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1692      *
1693      * @param activity foreground activity
1694      * @param message a NDEF Message to push over NFC
1695      * @throws IllegalStateException if the activity is not currently in the foreground
1696      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1697      * @deprecated use {@link #setNdefPushMessage} instead
1698      */
1699     @Deprecated
enableForegroundNdefPush(Activity activity, NdefMessage message)1700     public void enableForegroundNdefPush(Activity activity, NdefMessage message) {
1701         synchronized (NfcAdapter.class) {
1702             if (!sHasNfcFeature) {
1703                 throw new UnsupportedOperationException();
1704             }
1705             if (!sHasBeamFeature) {
1706                 return;
1707             }
1708         }
1709         if (activity == null || message == null) {
1710             throw new NullPointerException();
1711         }
1712         enforceResumed(activity);
1713         mNfcActivityManager.setNdefPushMessage(activity, message, 0);
1714     }
1715 
1716     /**
1717      * Disable NDEF message push over P2P.
1718      *
1719      * <p>After calling {@link #enableForegroundNdefPush}, an activity
1720      * must call this method before its {@link Activity#onPause} callback
1721      * completes.
1722      *
1723      * <p>Strongly recommend to use the new {@link #setNdefPushMessage}
1724      * instead: it automatically hooks into your activity life-cycle,
1725      * so you do not need to call enable/disable in your onResume/onPause.
1726      *
1727      * <p>This method must be called from the main thread.
1728      *
1729      * <p class="note">Requires the {@link android.Manifest.permission#NFC} permission.
1730      *
1731      * @param activity the Foreground activity
1732      * @throws IllegalStateException if the Activity has already been paused
1733      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1734      * @deprecated use {@link #setNdefPushMessage} instead
1735      */
1736     @Deprecated
disableForegroundNdefPush(Activity activity)1737     public void disableForegroundNdefPush(Activity activity) {
1738         synchronized (NfcAdapter.class) {
1739             if (!sHasNfcFeature) {
1740                 throw new UnsupportedOperationException();
1741             }
1742             if (!sHasBeamFeature) {
1743                 return;
1744             }
1745         }
1746         if (activity == null) {
1747             throw new NullPointerException();
1748         }
1749         enforceResumed(activity);
1750         mNfcActivityManager.setNdefPushMessage(activity, null, 0);
1751         mNfcActivityManager.setNdefPushMessageCallback(activity, null, 0);
1752         mNfcActivityManager.setOnNdefPushCompleteCallback(activity, null);
1753     }
1754 
1755     /**
1756      * Sets Secure NFC feature.
1757      * <p>This API is for the Settings application.
1758      * @return True if successful
1759      * @hide
1760      */
1761     @SystemApi
1762     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
enableSecureNfc(boolean enable)1763     public boolean enableSecureNfc(boolean enable) {
1764         if (!sHasNfcFeature) {
1765             throw new UnsupportedOperationException();
1766         }
1767         try {
1768             return sService.setNfcSecure(enable);
1769         } catch (RemoteException e) {
1770             attemptDeadServiceRecovery(e);
1771             return false;
1772         }
1773     }
1774 
1775     /**
1776      * Checks if the device supports Secure NFC functionality.
1777      *
1778      * @return True if device supports Secure NFC, false otherwise
1779      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1780      */
isSecureNfcSupported()1781     public boolean isSecureNfcSupported() {
1782         if (!sHasNfcFeature) {
1783             throw new UnsupportedOperationException();
1784         }
1785         try {
1786             return sService.deviceSupportsNfcSecure();
1787         } catch (RemoteException e) {
1788             attemptDeadServiceRecovery(e);
1789             return false;
1790         }
1791     }
1792 
1793     /**
1794      * Checks Secure NFC feature is enabled.
1795      *
1796      * @return True if Secure NFC is enabled, false otherwise
1797      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1798      * @throws UnsupportedOperationException if device doesn't support
1799      *         Secure NFC functionality. {@link #isSecureNfcSupported}
1800      */
isSecureNfcEnabled()1801     public boolean isSecureNfcEnabled() {
1802         if (!sHasNfcFeature) {
1803             throw new UnsupportedOperationException();
1804         }
1805         try {
1806             return sService.isNfcSecureEnabled();
1807         } catch (RemoteException e) {
1808             attemptDeadServiceRecovery(e);
1809             return false;
1810         }
1811     }
1812 
1813     /**
1814      * Enable NDEF Push feature.
1815      * <p>This API is for the Settings application.
1816      * @hide
1817      */
1818     @SystemApi
1819     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
enableNdefPush()1820     public boolean enableNdefPush() {
1821         if (!sHasNfcFeature) {
1822             throw new UnsupportedOperationException();
1823         }
1824         try {
1825             return sService.enableNdefPush();
1826         } catch (RemoteException e) {
1827             attemptDeadServiceRecovery(e);
1828             return false;
1829         }
1830     }
1831 
1832     /**
1833      * Disable NDEF Push feature.
1834      * <p>This API is for the Settings application.
1835      * @hide
1836      */
1837     @SystemApi
1838     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
disableNdefPush()1839     public boolean disableNdefPush() {
1840         synchronized (NfcAdapter.class) {
1841             if (!sHasNfcFeature) {
1842                 throw new UnsupportedOperationException();
1843             }
1844         }
1845         try {
1846             return sService.disableNdefPush();
1847         } catch (RemoteException e) {
1848             attemptDeadServiceRecovery(e);
1849             return false;
1850         }
1851     }
1852 
1853     /**
1854      * Return true if the NDEF Push (Android Beam) feature is enabled.
1855      * <p>This function will return true only if both NFC is enabled, and the
1856      * NDEF Push feature is enabled.
1857      * <p>Note that if NFC is enabled but NDEF Push is disabled then this
1858      * device can still <i>receive</i> NDEF messages, it just cannot send them.
1859      * <p>Applications cannot directly toggle the NDEF Push feature, but they
1860      * can request Settings UI allowing the user to toggle NDEF Push using
1861      * <code>startActivity(new Intent(Settings.ACTION_NFCSHARING_SETTINGS))</code>
1862      * <p>Example usage in an Activity that requires NDEF Push:
1863      * <p><pre>
1864      * protected void onResume() {
1865      *     super.onResume();
1866      *     if (!nfcAdapter.isEnabled()) {
1867      *         startActivity(new Intent(Settings.ACTION_NFC_SETTINGS));
1868      *     } else if (!nfcAdapter.isNdefPushEnabled()) {
1869      *         startActivity(new Intent(Settings.ACTION_NFCSHARING_SETTINGS));
1870      *     }
1871      * }</pre>
1872      *
1873      * @see android.provider.Settings#ACTION_NFCSHARING_SETTINGS
1874      * @return true if NDEF Push feature is enabled
1875      * @throws UnsupportedOperationException if FEATURE_NFC is unavailable.
1876      * @deprecated this feature is deprecated. File sharing can work using other technology like
1877      * Bluetooth.
1878      */
1879     @java.lang.Deprecated
1880 
isNdefPushEnabled()1881     public boolean isNdefPushEnabled() {
1882         synchronized (NfcAdapter.class) {
1883             if (!sHasNfcFeature) {
1884                 throw new UnsupportedOperationException();
1885             }
1886             if (!sHasBeamFeature) {
1887                 return false;
1888             }
1889         }
1890         try {
1891             return sService.isNdefPushEnabled();
1892         } catch (RemoteException e) {
1893             attemptDeadServiceRecovery(e);
1894             return false;
1895         }
1896     }
1897 
1898     /**
1899      * Signals that you are no longer interested in communicating with an NFC tag
1900      * for as long as it remains in range.
1901      *
1902      * All future attempted communication to this tag will fail with {@link IOException}.
1903      * The NFC controller will be put in a low-power polling mode, allowing the device
1904      * to save power in cases where it's "attached" to a tag all the time (e.g. a tag in
1905      * car dock).
1906      *
1907      * Additionally the debounceMs parameter allows you to specify for how long the tag needs
1908      * to have gone out of range, before it will be dispatched again.
1909      *
1910      * Note: the NFC controller typically polls at a pretty slow interval (100 - 500 ms).
1911      * This means that if the tag repeatedly goes in and out of range (for example, in
1912      * case of a flaky connection), and the controller happens to poll every time the
1913      * tag is out of range, it *will* re-dispatch the tag after debounceMs, despite the tag
1914      * having been "in range" during the interval.
1915      *
1916      * Note 2: if a tag with another UID is detected after this API is called, its effect
1917      * will be cancelled; if this tag shows up before the amount of time specified in
1918      * debounceMs, it will be dispatched again.
1919      *
1920      * Note 3: some tags have a random UID, in which case this API won't work reliably.
1921      *
1922      * @param tag        the {@link android.nfc.Tag Tag} to ignore.
1923      * @param debounceMs minimum amount of time the tag needs to be out of range before being
1924      *                   dispatched again.
1925      * @param tagRemovedListener listener to be called when the tag is removed from the field.
1926      *                           Note that this will only be called if the tag has been out of range
1927      *                           for at least debounceMs, or if another tag came into range before
1928      *                           debounceMs. May be null in case you don't want a callback.
1929      * @param handler the {@link android.os.Handler Handler} that will be used for delivering
1930      *                the callback. if the handler is null, then the thread used for delivering
1931      *                the callback is unspecified.
1932      * @return false if the tag couldn't be found (or has already gone out of range), true otherwise
1933      */
ignore(final Tag tag, int debounceMs, final OnTagRemovedListener tagRemovedListener, final Handler handler)1934     public boolean ignore(final Tag tag, int debounceMs,
1935                           final OnTagRemovedListener tagRemovedListener, final Handler handler) {
1936         ITagRemovedCallback.Stub iListener = null;
1937         if (tagRemovedListener != null) {
1938             iListener = new ITagRemovedCallback.Stub() {
1939                 @Override
1940                 public void onTagRemoved() throws RemoteException {
1941                     if (handler != null) {
1942                         handler.post(new Runnable() {
1943                             @Override
1944                             public void run() {
1945                                 tagRemovedListener.onTagRemoved();
1946                             }
1947                         });
1948                     } else {
1949                         tagRemovedListener.onTagRemoved();
1950                     }
1951                     synchronized (mLock) {
1952                         mTagRemovedListener = null;
1953                     }
1954                 }
1955             };
1956         }
1957         synchronized (mLock) {
1958             mTagRemovedListener = iListener;
1959         }
1960         try {
1961             return sService.ignore(tag.getServiceHandle(), debounceMs, iListener);
1962         } catch (RemoteException e) {
1963             return false;
1964         }
1965     }
1966 
1967     /**
1968      * Inject a mock NFC tag.<p>
1969      * Used for testing purposes.
1970      * <p class="note">Requires the
1971      * {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} permission.
1972      * @hide
1973      */
dispatch(Tag tag)1974     public void dispatch(Tag tag) {
1975         if (tag == null) {
1976             throw new NullPointerException("tag cannot be null");
1977         }
1978         try {
1979             sService.dispatch(tag);
1980         } catch (RemoteException e) {
1981             attemptDeadServiceRecovery(e);
1982         }
1983     }
1984 
1985     /**
1986      * @hide
1987      */
setP2pModes(int initiatorModes, int targetModes)1988     public void setP2pModes(int initiatorModes, int targetModes) {
1989         try {
1990             sService.setP2pModes(initiatorModes, targetModes);
1991         } catch (RemoteException e) {
1992             attemptDeadServiceRecovery(e);
1993         }
1994     }
1995 
1996     /**
1997      * Registers a new NFC unlock handler with the NFC service.
1998      *
1999      * <p />NFC unlock handlers are intended to unlock the keyguard in the presence of a trusted
2000      * NFC device. The handler should return true if it successfully authenticates the user and
2001      * unlocks the keyguard.
2002      *
2003      * <p /> The parameter {@code tagTechnologies} determines which Tag technologies will be polled for
2004      * at the lockscreen. Polling for less tag technologies reduces latency, and so it is
2005      * strongly recommended to only provide the Tag technologies that the handler is expected to
2006      * receive. There must be at least one tag technology provided, otherwise the unlock handler
2007      * is ignored.
2008      *
2009      * @hide
2010      */
2011     @SystemApi
2012     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
addNfcUnlockHandler(final NfcUnlockHandler unlockHandler, String[] tagTechnologies)2013     public boolean addNfcUnlockHandler(final NfcUnlockHandler unlockHandler,
2014                                        String[] tagTechnologies) {
2015         synchronized (NfcAdapter.class) {
2016             if (!sHasNfcFeature) {
2017                 throw new UnsupportedOperationException();
2018             }
2019         }
2020         // If there are no tag technologies, don't bother adding unlock handler
2021         if (tagTechnologies.length == 0) {
2022             return false;
2023         }
2024 
2025         try {
2026             synchronized (mLock) {
2027                 if (mNfcUnlockHandlers.containsKey(unlockHandler)) {
2028                     // update the tag technologies
2029                     sService.removeNfcUnlockHandler(mNfcUnlockHandlers.get(unlockHandler));
2030                     mNfcUnlockHandlers.remove(unlockHandler);
2031                 }
2032 
2033                 INfcUnlockHandler.Stub iHandler = new INfcUnlockHandler.Stub() {
2034                     @Override
2035                     public boolean onUnlockAttempted(Tag tag) throws RemoteException {
2036                         return unlockHandler.onUnlockAttempted(tag);
2037                     }
2038                 };
2039 
2040                 sService.addNfcUnlockHandler(iHandler,
2041                         Tag.getTechCodesFromStrings(tagTechnologies));
2042                 mNfcUnlockHandlers.put(unlockHandler, iHandler);
2043             }
2044         } catch (RemoteException e) {
2045             attemptDeadServiceRecovery(e);
2046             return false;
2047         } catch (IllegalArgumentException e) {
2048             Log.e(TAG, "Unable to register LockscreenDispatch", e);
2049             return false;
2050         }
2051 
2052         return true;
2053     }
2054 
2055     /**
2056      * Removes a previously registered unlock handler. Also removes the tag technologies
2057      * associated with the removed unlock handler.
2058      *
2059      * @hide
2060      */
2061     @SystemApi
2062     @RequiresPermission(android.Manifest.permission.WRITE_SECURE_SETTINGS)
removeNfcUnlockHandler(NfcUnlockHandler unlockHandler)2063     public boolean removeNfcUnlockHandler(NfcUnlockHandler unlockHandler) {
2064         synchronized (NfcAdapter.class) {
2065             if (!sHasNfcFeature) {
2066                 throw new UnsupportedOperationException();
2067             }
2068         }
2069         try {
2070             synchronized (mLock) {
2071                 if (mNfcUnlockHandlers.containsKey(unlockHandler)) {
2072                     sService.removeNfcUnlockHandler(mNfcUnlockHandlers.remove(unlockHandler));
2073                 }
2074 
2075                 return true;
2076             }
2077         } catch (RemoteException e) {
2078             attemptDeadServiceRecovery(e);
2079             return false;
2080         }
2081     }
2082 
2083     /**
2084      * @hide
2085      */
2086     @UnsupportedAppUsage
getNfcAdapterExtrasInterface()2087     public INfcAdapterExtras getNfcAdapterExtrasInterface() {
2088         if (mContext == null) {
2089             throw new UnsupportedOperationException("You need a context on NfcAdapter to use the "
2090                     + " NFC extras APIs");
2091         }
2092         try {
2093             return sService.getNfcAdapterExtrasInterface(mContext.getPackageName());
2094         } catch (RemoteException e) {
2095             attemptDeadServiceRecovery(e);
2096             return null;
2097         }
2098     }
2099 
enforceResumed(Activity activity)2100     void enforceResumed(Activity activity) {
2101         if (!activity.isResumed()) {
2102             throw new IllegalStateException("API cannot be called while activity is paused");
2103         }
2104     }
2105 
getSdkVersion()2106     int getSdkVersion() {
2107         if (mContext == null) {
2108             return android.os.Build.VERSION_CODES.GINGERBREAD; // best guess
2109         } else {
2110             return mContext.getApplicationInfo().targetSdkVersion;
2111         }
2112     }
2113 }
2114