/* * Copyright (C) 2010 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.nfc; import java.util.HashMap; import android.annotation.SdkConstant; import android.annotation.SdkConstant.SdkConstantType; import android.app.Activity; import android.app.ActivityThread; import android.app.OnActivityPausedListener; import android.app.PendingIntent; import android.content.Context; import android.content.IntentFilter; import android.content.pm.IPackageManager; import android.content.pm.PackageManager; import android.net.Uri; import android.nfc.tech.MifareClassic; import android.nfc.tech.Ndef; import android.nfc.tech.NfcA; import android.nfc.tech.NfcF; import android.os.IBinder; import android.os.RemoteException; import android.os.ServiceManager; import android.util.Log; /** * Represents the local NFC adapter. *

* Use the helper {@link #getDefaultAdapter(Context)} to get the default NFC * adapter for this Android device. * *

*

Developer Guides

*

For more information about using NFC, read the * Near Field Communication developer guide.

*
*/ public final class NfcAdapter { static final String TAG = "NFC"; /** * Intent to start an activity when a tag with NDEF payload is discovered. * *

The system inspects the first {@link NdefRecord} in the first {@link NdefMessage} and * looks for a URI, SmartPoster, or MIME record. If a URI or SmartPoster record is found the * intent will contain the URI in its data field. If a MIME record is found the intent will * contain the MIME type in its type field. This allows activities to register * {@link IntentFilter}s targeting specific content on tags. Activities should register the * most specific intent filters possible to avoid the activity chooser dialog, which can * disrupt the interaction with the tag as the user interacts with the screen. * *

If the tag has an NDEF payload this intent is started before * {@link #ACTION_TECH_DISCOVERED}. If any activities respond to this intent neither * {@link #ACTION_TECH_DISCOVERED} or {@link #ACTION_TAG_DISCOVERED} will be started. * *

The MIME type or data URI of this intent are normalized before dispatch - * so that MIME, URI scheme and URI host are always lower-case. */ @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION) public static final String ACTION_NDEF_DISCOVERED = "android.nfc.action.NDEF_DISCOVERED"; /** * Intent to start an activity when a tag is discovered and activities are registered for the * specific technologies on the tag. * *

To receive this intent an activity must include an intent filter * for this action and specify the desired tech types in a * manifest meta-data entry. Here is an example manfiest entry: *

     * <activity android:name=".nfc.TechFilter" android:label="NFC/TechFilter">
     *     <!-- Add a technology filter -->
     *     <intent-filter>
     *         <action android:name="android.nfc.action.TECH_DISCOVERED" />
     *     </intent-filter>
     *
     *     <meta-data android:name="android.nfc.action.TECH_DISCOVERED"
     *         android:resource="@xml/filter_nfc"
     *     />
     * </activity>
* *

The meta-data XML file should contain one or more tech-list entries * each consisting or one or more tech entries. The tech entries refer * to the qualified class name implementing the technology, for example "android.nfc.tech.NfcA". * *

A tag matches if any of the * tech-list sets is a subset of {@link Tag#getTechList() Tag.getTechList()}. Each * of the tech-lists is considered independently and the * activity is considered a match is any single tech-list matches the tag that was * discovered. This provides AND and OR semantics for filtering desired techs. Here is an * example that will match any tag using {@link NfcF} or any tag using {@link NfcA}, * {@link MifareClassic}, and {@link Ndef}: * *

     * <resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
     *     <!-- capture anything using NfcF -->
     *     <tech-list>
     *         <tech>android.nfc.tech.NfcF</tech>
     *     </tech-list>
     *
     *     <!-- OR -->
     *
     *     <!-- capture all MIFARE Classics with NDEF payloads -->
     *     <tech-list>
     *         <tech>android.nfc.tech.NfcA</tech>
     *         <tech>android.nfc.tech.MifareClassic</tech>
     *         <tech>android.nfc.tech.Ndef</tech>
     *     </tech-list>
     * </resources>
* *

This intent is started after {@link #ACTION_NDEF_DISCOVERED} and before * {@link #ACTION_TAG_DISCOVERED}. If any activities respond to {@link #ACTION_NDEF_DISCOVERED} * this intent will not be started. If any activities respond to this intent * {@link #ACTION_TAG_DISCOVERED} will not be started. */ @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION) public static final String ACTION_TECH_DISCOVERED = "android.nfc.action.TECH_DISCOVERED"; /** * Intent to start an activity when a tag is discovered. * *

This intent will not be started when a tag is discovered if any activities respond to * {@link #ACTION_NDEF_DISCOVERED} or {@link #ACTION_TECH_DISCOVERED} for the current tag. */ @SdkConstant(SdkConstantType.ACTIVITY_INTENT_ACTION) public static final String ACTION_TAG_DISCOVERED = "android.nfc.action.TAG_DISCOVERED"; /** * Broadcast to only the activity that handles ACTION_TAG_DISCOVERED * @hide */ public static final String ACTION_TAG_LEFT_FIELD = "android.nfc.action.TAG_LOST"; /** * Mandatory extra containing the {@link Tag} that was discovered for the * {@link #ACTION_NDEF_DISCOVERED}, {@link #ACTION_TECH_DISCOVERED}, and * {@link #ACTION_TAG_DISCOVERED} intents. */ public static final String EXTRA_TAG = "android.nfc.extra.TAG"; /** * Extra containing an array of {@link NdefMessage} present on the discovered tag.

* This extra is mandatory for {@link #ACTION_NDEF_DISCOVERED} intents, * and optional for {@link #ACTION_TECH_DISCOVERED}, and * {@link #ACTION_TAG_DISCOVERED} intents.

* When this extra is present there will always be at least one * {@link NdefMessage} element. Most NDEF tags have only one NDEF message, * but we use an array for future compatibility. */ public static final String EXTRA_NDEF_MESSAGES = "android.nfc.extra.NDEF_MESSAGES"; /** * Optional extra containing a byte array containing the ID of the discovered tag for * the {@link #ACTION_NDEF_DISCOVERED}, {@link #ACTION_TECH_DISCOVERED}, and * {@link #ACTION_TAG_DISCOVERED} intents. */ public static final String EXTRA_ID = "android.nfc.extra.ID"; /** * Broadcast Action: The state of the local NFC adapter has been * changed. *

For example, NFC has been turned on or off. *

Always contains the extra field {@link #EXTRA_STATE} * @hide */ @SdkConstant(SdkConstantType.BROADCAST_INTENT_ACTION) public static final String ACTION_ADAPTER_STATE_CHANGED = "android.nfc.action.ADAPTER_STATE_CHANGED"; /** * Used as an int extra field in {@link #ACTION_STATE_CHANGED} * intents to request the current power state. Possible values are: * {@link #STATE_OFF}, * {@link #STATE_TURNING_ON}, * {@link #STATE_ON}, * {@link #STATE_TURNING_OFF}, * @hide */ public static final String EXTRA_ADAPTER_STATE = "android.nfc.extra.ADAPTER_STATE"; /** @hide */ public static final int STATE_OFF = 1; /** @hide */ public static final int STATE_TURNING_ON = 2; /** @hide */ public static final int STATE_ON = 3; /** @hide */ public static final int STATE_TURNING_OFF = 4; /** @hide */ public static final String ACTION_HANDOVER_TRANSFER_STARTED = "android.nfc.action.HANDOVER_TRANSFER_STARTED"; /** @hide */ public static final String ACTION_HANDOVER_TRANSFER_DONE = "android.nfc.action.HANDOVER_TRANSFER_DONE"; /** @hide */ public static final String EXTRA_HANDOVER_TRANSFER_STATUS = "android.nfc.extra.HANDOVER_TRANSFER_STATUS"; /** @hide */ public static final int HANDOVER_TRANSFER_STATUS_SUCCESS = 0; /** @hide */ public static final int HANDOVER_TRANSFER_STATUS_FAILURE = 1; /** @hide */ public static final String EXTRA_HANDOVER_TRANSFER_URI = "android.nfc.extra.HANDOVER_TRANSFER_URI"; // Guarded by NfcAdapter.class static boolean sIsInitialized = false; // Final after first constructor, except for // attemptDeadServiceRecovery() when NFC crashes - we accept a best effort // recovery static INfcAdapter sService; static INfcTag sTagService; /** * The NfcAdapter object for each application context. * There is a 1-1 relationship between application context and * NfcAdapter object. */ static HashMap sNfcAdapters = new HashMap(); //guard by NfcAdapter.class /** * NfcAdapter used with a null context. This ctor was deprecated but we have * to support it for backwards compatibility. New methods that require context * might throw when called on the null-context NfcAdapter. */ static NfcAdapter sNullContextNfcAdapter; // protected by NfcAdapter.class final NfcActivityManager mNfcActivityManager; final Context mContext; /** * A callback to be invoked when the system successfully delivers your {@link NdefMessage} * to another device. * @see #setOnNdefPushCompleteCallback */ public interface OnNdefPushCompleteCallback { /** * Called on successful NDEF push. * *

This callback is usually made on a binder thread (not the UI thread). * * @param event {@link NfcEvent} with the {@link NfcEvent#nfcAdapter} field set * @see #setNdefPushMessageCallback */ public void onNdefPushComplete(NfcEvent event); } /** * A callback to be invoked when another NFC device capable of NDEF push (Android Beam) * is within range. *

Implement this interface and pass it to {@link * NfcAdapter#setNdefPushMessageCallback setNdefPushMessageCallback()} in order to create an * {@link NdefMessage} at the moment that another device is within range for NFC. Using this * callback allows you to create a message with data that might vary based on the * content currently visible to the user. Alternatively, you can call {@link * #setNdefPushMessage setNdefPushMessage()} if the {@link NdefMessage} always contains the * same data. */ public interface CreateNdefMessageCallback { /** * Called to provide a {@link NdefMessage} to push. * *

This callback is usually made on a binder thread (not the UI thread). * *

Called when this device is in range of another device * that might support NDEF push. It allows the application to * create the NDEF message only when it is required. * *

NDEF push cannot occur until this method returns, so do not * block for too long. * *

The Android operating system will usually show a system UI * on top of your activity during this time, so do not try to request * input from the user to complete the callback, or provide custom NDEF * push UI. The user probably will not see it. * * @param event {@link NfcEvent} with the {@link NfcEvent#nfcAdapter} field set * @return NDEF message to push, or null to not provide a message */ public NdefMessage createNdefMessage(NfcEvent event); } // TODO javadoc public interface CreateBeamUrisCallback { public Uri[] createBeamUris(NfcEvent event); } /** * Helper to check if this device has FEATURE_NFC, but without using * a context. * Equivalent to * context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_NFC) */ private static boolean hasNfcFeature() { IPackageManager pm = ActivityThread.getPackageManager(); if (pm == null) { Log.e(TAG, "Cannot get package manager, assuming no NFC feature"); return false; } try { return pm.hasSystemFeature(PackageManager.FEATURE_NFC); } catch (RemoteException e) { Log.e(TAG, "Package manager query failed, assuming no NFC feature", e); return false; } } /** * Returns the NfcAdapter for application context, * or throws if NFC is not available. * @hide */ public static synchronized NfcAdapter getNfcAdapter(Context context) { if (!sIsInitialized) { /* is this device meant to have NFC */ if (!hasNfcFeature()) { Log.v(TAG, "this device does not have NFC support"); throw new UnsupportedOperationException(); } sService = getServiceInterface(); if (sService == null) { Log.e(TAG, "could not retrieve NFC service"); throw new UnsupportedOperationException(); } try { sTagService = sService.getNfcTagInterface(); } catch (RemoteException e) { Log.e(TAG, "could not retrieve NFC Tag service"); throw new UnsupportedOperationException(); } sIsInitialized = true; } if (context == null) { if (sNullContextNfcAdapter == null) { sNullContextNfcAdapter = new NfcAdapter(null); } return sNullContextNfcAdapter; } NfcAdapter adapter = sNfcAdapters.get(context); if (adapter == null) { adapter = new NfcAdapter(context); sNfcAdapters.put(context, adapter); } return adapter; } /** get handle to NFC service interface */ private static INfcAdapter getServiceInterface() { /* get a handle to NFC service */ IBinder b = ServiceManager.getService("nfc"); if (b == null) { return null; } return INfcAdapter.Stub.asInterface(b); } /** * Helper to get the default NFC Adapter. *

* Most Android devices will only have one NFC Adapter (NFC Controller). *

* This helper is the equivalent of: *

     * NfcManager manager = (NfcManager) context.getSystemService(Context.NFC_SERVICE);
     * NfcAdapter adapter = manager.getDefaultAdapter();
* @param context the calling application's context * * @return the default NFC adapter, or null if no NFC adapter exists */ public static NfcAdapter getDefaultAdapter(Context context) { if (context == null) { throw new IllegalArgumentException("context cannot be null"); } context = context.getApplicationContext(); if (context == null) { throw new IllegalArgumentException( "context not associated with any application (using a mock context?)"); } /* use getSystemService() for consistency */ NfcManager manager = (NfcManager) context.getSystemService(Context.NFC_SERVICE); if (manager == null) { // NFC not available return null; } return manager.getDefaultAdapter(); } /** * Legacy NfcAdapter getter, always use {@link #getDefaultAdapter(Context)} instead.

* This method was deprecated at API level 10 (Gingerbread MR1) because a context is required * for many NFC API methods. Those methods will fail when called on an NfcAdapter * object created from this method.

* @deprecated use {@link #getDefaultAdapter(Context)} * @hide */ @Deprecated public static NfcAdapter getDefaultAdapter() { // introduced in API version 9 (GB 2.3) // deprecated in API version 10 (GB 2.3.3) // removed from public API in version 16 (ICS MR2) // should maintain as a hidden API for binary compatibility for a little longer Log.w(TAG, "WARNING: NfcAdapter.getDefaultAdapter() is deprecated, use " + "NfcAdapter.getDefaultAdapter(Context) instead", new Exception()); return NfcAdapter.getNfcAdapter(null); } NfcAdapter(Context context) { mContext = context; mNfcActivityManager = new NfcActivityManager(this); } /** * @hide */ public Context getContext() { return mContext; } /** * Returns the binder interface to the service. * @hide */ public INfcAdapter getService() { isEnabled(); // NOP call to recover sService if it is stale return sService; } /** * Returns the binder interface to the tag service. * @hide */ public INfcTag getTagService() { isEnabled(); // NOP call to recover sTagService if it is stale return sTagService; } /** * NFC service dead - attempt best effort recovery * @hide */ public void attemptDeadServiceRecovery(Exception e) { Log.e(TAG, "NFC service dead - attempting to recover", e); INfcAdapter service = getServiceInterface(); if (service == null) { Log.e(TAG, "could not retrieve NFC service during service recovery"); // nothing more can be done now, sService is still stale, we'll hit // this recovery path again later return; } // assigning to sService is not thread-safe, but this is best-effort code // and on a well-behaved system should never happen sService = service; try { sTagService = service.getNfcTagInterface(); } catch (RemoteException ee) { Log.e(TAG, "could not retrieve NFC tag service during service recovery"); // nothing more can be done now, sService is still stale, we'll hit // this recovery path again later } return; } /** * Return true if this NFC Adapter has any features enabled. * *

If this method returns false, the NFC hardware is guaranteed not to * generate or respond to any NFC communication over its NFC radio. *

Applications can use this to check if NFC is enabled. Applications * can request Settings UI allowing the user to toggle NFC using: *

startActivity(new Intent(Settings.ACTION_NFC_SETTINGS))
* * @see android.provider.Settings#ACTION_NFC_SETTINGS * @return true if this NFC Adapter has any features enabled */ public boolean isEnabled() { try { return sService.getState() == STATE_ON; } catch (RemoteException e) { attemptDeadServiceRecovery(e); return false; } } /** * Return the state of this NFC Adapter. * *

Returns one of {@link #STATE_ON}, {@link #STATE_TURNING_ON}, * {@link #STATE_OFF}, {@link #STATE_TURNING_OFF}. * *

{@link #isEnabled()} is equivalent to * {@link #getAdapterState()} == {@link #STATE_ON} * * @return the current state of this NFC adapter * * @hide */ public int getAdapterState() { try { return sService.getState(); } catch (RemoteException e) { attemptDeadServiceRecovery(e); return NfcAdapter.STATE_OFF; } } /** * Enable NFC hardware. * *

This call is asynchronous. Listen for * {@link #ACTION_ADAPTER_STATE_CHANGED} broadcasts to find out when the * operation is complete. * *

If this returns true, then either NFC is already on, or * a {@link #ACTION_ADAPTER_STATE_CHANGED} broadcast will be sent * to indicate a state transition. If this returns false, then * there is some problem that prevents an attempt to turn * NFC on (for example we are in airplane mode and NFC is not * toggleable in airplane mode on this platform). * * @hide */ public boolean enable() { try { return sService.enable(); } catch (RemoteException e) { attemptDeadServiceRecovery(e); return false; } } /** * Disable NFC hardware. * *

No NFC features will work after this call, and the hardware * will not perform or respond to any NFC communication. * *

This call is asynchronous. Listen for * {@link #ACTION_ADAPTER_STATE_CHANGED} broadcasts to find out when the * operation is complete. * *

If this returns true, then either NFC is already off, or * a {@link #ACTION_ADAPTER_STATE_CHANGED} broadcast will be sent * to indicate a state transition. If this returns false, then * there is some problem that prevents an attempt to turn * NFC off. * * @hide */ public boolean disable() { try { return sService.disable(true); } catch (RemoteException e) { attemptDeadServiceRecovery(e); return false; } } /** * Set one or more {@link Uri}s to send using Android Beam (TM). Every * Uri you provide must have either scheme 'file' or scheme 'content'. * *

For the data provided through this method, Android Beam tries to * switch to alternate transports such as Bluetooth to achieve a fast * transfer speed. Hence this method is very suitable * for transferring large files such as pictures or songs. * *

The receiving side will store the content of each Uri in * a file and present a notification to the user to open the file * with a {@link android.content.Intent} with action * {@link android.content.Intent#ACTION_VIEW}. * If multiple URIs are sent, the {@link android.content.Intent} will refer * to the first of the stored files. * *

This method may be called at any time before {@link Activity#onDestroy}, * but the URI(s) are only made available for Android Beam when the * specified activity(s) are in resumed (foreground) state. The recommended * approach is to call this method during your Activity's * {@link Activity#onCreate} - see sample * code below. This method does not immediately perform any I/O or blocking work, * so is safe to call on your main thread. * *

{@link #setBeamPushUris} and {@link #setBeamPushUrisCallback} * have priority over both {@link #setNdefPushMessage} and * {@link #setNdefPushMessageCallback}. * *

If {@link #setBeamPushUris} is called with a null Uri array, * and/or {@link #setBeamPushUrisCallback} is called with a null callback, * then the Uri push will be completely disabled for the specified activity(s). * *

Code example: *

     * protected void onCreate(Bundle savedInstanceState) {
     *     super.onCreate(savedInstanceState);
     *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
     *     if (nfcAdapter == null) return;  // NFC not available on this device
     *     nfcAdapter.setBeamPushUris(new Uri[] {uri1, uri2}, this);
     * }
* And that is it. Only one call per activity is necessary. The Android * OS will automatically release its references to the Uri(s) and the * Activity object when it is destroyed if you follow this pattern. * *

If your Activity wants to dynamically supply Uri(s), * then set a callback using {@link #setBeamPushUrisCallback} instead * of using this method. * *

Do not pass in an Activity that has already been through * {@link Activity#onDestroy}. This is guaranteed if you call this API * during {@link Activity#onCreate}. * *

If this device does not support alternate transports * such as Bluetooth or WiFI, calling this method does nothing. * *

Requires the {@link android.Manifest.permission#NFC} permission. * * @param uris an array of Uri(s) to push over Android Beam * @param activity activity for which the Uri(s) will be pushed */ public void setBeamPushUris(Uri[] uris, Activity activity) { if (activity == null) { throw new NullPointerException("activity cannot be null"); } if (uris != null) { for (Uri uri : uris) { if (uri == null) throw new NullPointerException("Uri not " + "allowed to be null"); String scheme = uri.getScheme(); if (scheme == null || (!scheme.equalsIgnoreCase("file") && !scheme.equalsIgnoreCase("content"))) { throw new IllegalArgumentException("URI needs to have " + "either scheme file or scheme content"); } } } mNfcActivityManager.setNdefPushContentUri(activity, uris); } /** * Set a callback that will dynamically generate one or more {@link Uri}s * to send using Android Beam (TM). Every Uri the callback provides * must have either scheme 'file' or scheme 'content'. * *

For the data provided through this callback, Android Beam tries to * switch to alternate transports such as Bluetooth to achieve a fast * transfer speed. Hence this method is very suitable * for transferring large files such as pictures or songs. * *

The receiving side will store the content of each Uri in * a file and present a notification to the user to open the file * with a {@link android.content.Intent} with action * {@link android.content.Intent#ACTION_VIEW}. * If multiple URIs are sent, the {@link android.content.Intent} will refer * to the first of the stored files. * *

This method may be called at any time before {@link Activity#onDestroy}, * but the URI(s) are only made available for Android Beam when the * specified activity(s) are in resumed (foreground) state. The recommended * approach is to call this method during your Activity's * {@link Activity#onCreate} - see sample * code below. This method does not immediately perform any I/O or blocking work, * so is safe to call on your main thread. * *

{@link #setBeamPushUris} and {@link #setBeamPushUrisCallback} * have priority over both {@link #setNdefPushMessage} and * {@link #setNdefPushMessageCallback}. * *

If {@link #setBeamPushUris} is called with a null Uri array, * and/or {@link #setBeamPushUrisCallback} is called with a null callback, * then the Uri push will be completely disabled for the specified activity(s). * *

Code example: *

     * protected void onCreate(Bundle savedInstanceState) {
     *     super.onCreate(savedInstanceState);
     *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
     *     if (nfcAdapter == null) return;  // NFC not available on this device
     *     nfcAdapter.setBeamPushUrisCallback(callback, this);
     * }
* And that is it. Only one call per activity is necessary. The Android * OS will automatically release its references to the Uri(s) and the * Activity object when it is destroyed if you follow this pattern. * *

Do not pass in an Activity that has already been through * {@link Activity#onDestroy}. This is guaranteed if you call this API * during {@link Activity#onCreate}. * *

If this device does not support alternate transports * such as Bluetooth or WiFI, calling this method does nothing. * *

Requires the {@link android.Manifest.permission#NFC} permission. * * @param callback callback, or null to disable * @param activity activity for which the Uri(s) will be pushed */ public void setBeamPushUrisCallback(CreateBeamUrisCallback callback, Activity activity) { if (activity == null) { throw new NullPointerException("activity cannot be null"); } mNfcActivityManager.setNdefPushContentUriCallback(activity, callback); } /** * Set a static {@link NdefMessage} to send using Android Beam (TM). * *

This method may be called at any time before {@link Activity#onDestroy}, * but the NDEF message is only made available for NDEF push when the * specified activity(s) are in resumed (foreground) state. The recommended * approach is to call this method during your Activity's * {@link Activity#onCreate} - see sample * code below. This method does not immediately perform any I/O or blocking work, * so is safe to call on your main thread. * *

Only one NDEF message can be pushed by the currently resumed activity. * If both {@link #setNdefPushMessage} and * {@link #setNdefPushMessageCallback} are set, then * the callback will take priority. * *

If neither {@link #setNdefPushMessage} or * {@link #setNdefPushMessageCallback} have been called for your activity, then * the Android OS may choose to send a default NDEF message on your behalf, * such as a URI for your application. * *

If {@link #setNdefPushMessage} is called with a null NDEF message, * and/or {@link #setNdefPushMessageCallback} is called with a null callback, * then NDEF push will be completely disabled for the specified activity(s). * This also disables any default NDEF message the Android OS would have * otherwise sent on your behalf for those activity(s). * *

If you want to prevent the Android OS from sending default NDEF * messages completely (for all activities), you can include a * {@code <meta-data>} element inside the {@code <application>} * element of your AndroidManifest.xml file, like this: *

     * <application ...>
     *     <meta-data android:name="android.nfc.disable_beam_default"
     *         android:value="true" />
     * </application>
* *

The API allows for multiple activities to be specified at a time, * but it is strongly recommended to just register one at a time, * and to do so during the activity's {@link Activity#onCreate}. For example: *

     * protected void onCreate(Bundle savedInstanceState) {
     *     super.onCreate(savedInstanceState);
     *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
     *     if (nfcAdapter == null) return;  // NFC not available on this device
     *     nfcAdapter.setNdefPushMessage(ndefMessage, this);
     * }
* And that is it. Only one call per activity is necessary. The Android * OS will automatically release its references to the NDEF message and the * Activity object when it is destroyed if you follow this pattern. * *

If your Activity wants to dynamically generate an NDEF message, * then set a callback using {@link #setNdefPushMessageCallback} instead * of a static message. * *

Do not pass in an Activity that has already been through * {@link Activity#onDestroy}. This is guaranteed if you call this API * during {@link Activity#onCreate}. * *

For sending large content such as pictures and songs, * consider using {@link #setBeamPushUris}, which switches to alternate transports * such as Bluetooth to achieve a fast transfer rate. * *

Requires the {@link android.Manifest.permission#NFC} permission. * * @param message NDEF message to push over NFC, or null to disable * @param activity activity for which the NDEF message will be pushed * @param activities optional additional activities, however we strongly recommend * to only register one at a time, and to do so in that activity's * {@link Activity#onCreate} */ public void setNdefPushMessage(NdefMessage message, Activity activity, Activity ... activities) { int targetSdkVersion = getSdkVersion(); try { if (activity == null) { throw new NullPointerException("activity cannot be null"); } mNfcActivityManager.setNdefPushMessage(activity, message); for (Activity a : activities) { if (a == null) { throw new NullPointerException("activities cannot contain null"); } mNfcActivityManager.setNdefPushMessage(a, message); } } catch (IllegalStateException e) { if (targetSdkVersion < android.os.Build.VERSION_CODES.JELLY_BEAN) { // Less strict on old applications - just log the error Log.e(TAG, "Cannot call API with Activity that has already " + "been destroyed", e); } else { // Prevent new applications from making this mistake, re-throw throw(e); } } } /** * Set a callback that dynamically generates NDEF messages to send using Android Beam (TM). * *

This method may be called at any time before {@link Activity#onDestroy}, * but the NDEF message callback can only occur when the * specified activity(s) are in resumed (foreground) state. The recommended * approach is to call this method during your Activity's * {@link Activity#onCreate} - see sample * code below. This method does not immediately perform any I/O or blocking work, * so is safe to call on your main thread. * *

Only one NDEF message can be pushed by the currently resumed activity. * If both {@link #setNdefPushMessage} and * {@link #setNdefPushMessageCallback} are set, then * the callback will take priority. * *

If neither {@link #setNdefPushMessage} or * {@link #setNdefPushMessageCallback} have been called for your activity, then * the Android OS may choose to send a default NDEF message on your behalf, * such as a URI for your application. * *

If {@link #setNdefPushMessage} is called with a null NDEF message, * and/or {@link #setNdefPushMessageCallback} is called with a null callback, * then NDEF push will be completely disabled for the specified activity(s). * This also disables any default NDEF message the Android OS would have * otherwise sent on your behalf for those activity(s). * *

If you want to prevent the Android OS from sending default NDEF * messages completely (for all activities), you can include a * {@code <meta-data>} element inside the {@code <application>} * element of your AndroidManifest.xml file, like this: *

     * <application ...>
     *     <meta-data android:name="android.nfc.disable_beam_default"
     *         android:value="true" />
     * </application>
* *

The API allows for multiple activities to be specified at a time, * but it is strongly recommended to just register one at a time, * and to do so during the activity's {@link Activity#onCreate}. For example: *

     * protected void onCreate(Bundle savedInstanceState) {
     *     super.onCreate(savedInstanceState);
     *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
     *     if (nfcAdapter == null) return;  // NFC not available on this device
     *     nfcAdapter.setNdefPushMessageCallback(callback, this);
     * }
* And that is it. Only one call per activity is necessary. The Android * OS will automatically release its references to the callback and the * Activity object when it is destroyed if you follow this pattern. * *

Do not pass in an Activity that has already been through * {@link Activity#onDestroy}. This is guaranteed if you call this API * during {@link Activity#onCreate}. *

For sending large content such as pictures and songs, * consider using {@link #setBeamPushUris}, which switches to alternate transports * such as Bluetooth to achieve a fast transfer rate. *

Requires the {@link android.Manifest.permission#NFC} permission. * * @param callback callback, or null to disable * @param activity activity for which the NDEF message will be pushed * @param activities optional additional activities, however we strongly recommend * to only register one at a time, and to do so in that activity's * {@link Activity#onCreate} */ public void setNdefPushMessageCallback(CreateNdefMessageCallback callback, Activity activity, Activity ... activities) { int targetSdkVersion = getSdkVersion(); try { if (activity == null) { throw new NullPointerException("activity cannot be null"); } mNfcActivityManager.setNdefPushMessageCallback(activity, callback); for (Activity a : activities) { if (a == null) { throw new NullPointerException("activities cannot contain null"); } mNfcActivityManager.setNdefPushMessageCallback(a, callback); } } catch (IllegalStateException e) { if (targetSdkVersion < android.os.Build.VERSION_CODES.JELLY_BEAN) { // Less strict on old applications - just log the error Log.e(TAG, "Cannot call API with Activity that has already " + "been destroyed", e); } else { // Prevent new applications from making this mistake, re-throw throw(e); } } } /** * Set a callback on successful Android Beam (TM). * *

This method may be called at any time before {@link Activity#onDestroy}, * but the callback can only occur when the * specified activity(s) are in resumed (foreground) state. The recommended * approach is to call this method during your Activity's * {@link Activity#onCreate} - see sample * code below. This method does not immediately perform any I/O or blocking work, * so is safe to call on your main thread. * *

The API allows for multiple activities to be specified at a time, * but it is strongly recommended to just register one at a time, * and to do so during the activity's {@link Activity#onCreate}. For example: *

     * protected void onCreate(Bundle savedInstanceState) {
     *     super.onCreate(savedInstanceState);
     *     NfcAdapter nfcAdapter = NfcAdapter.getDefaultAdapter(this);
     *     if (nfcAdapter == null) return;  // NFC not available on this device
     *     nfcAdapter.setOnNdefPushCompleteCallback(callback, this);
     * }
* And that is it. Only one call per activity is necessary. The Android * OS will automatically release its references to the callback and the * Activity object when it is destroyed if you follow this pattern. * *

Do not pass in an Activity that has already been through * {@link Activity#onDestroy}. This is guaranteed if you call this API * during {@link Activity#onCreate}. * *

Requires the {@link android.Manifest.permission#NFC} permission. * * @param callback callback, or null to disable * @param activity activity for which the NDEF message will be pushed * @param activities optional additional activities, however we strongly recommend * to only register one at a time, and to do so in that activity's * {@link Activity#onCreate} */ public void setOnNdefPushCompleteCallback(OnNdefPushCompleteCallback callback, Activity activity, Activity ... activities) { int targetSdkVersion = getSdkVersion(); try { if (activity == null) { throw new NullPointerException("activity cannot be null"); } mNfcActivityManager.setOnNdefPushCompleteCallback(activity, callback); for (Activity a : activities) { if (a == null) { throw new NullPointerException("activities cannot contain null"); } mNfcActivityManager.setOnNdefPushCompleteCallback(a, callback); } } catch (IllegalStateException e) { if (targetSdkVersion < android.os.Build.VERSION_CODES.JELLY_BEAN) { // Less strict on old applications - just log the error Log.e(TAG, "Cannot call API with Activity that has already " + "been destroyed", e); } else { // Prevent new applications from making this mistake, re-throw throw(e); } } } /** * Enable foreground dispatch to the given Activity. * *

This will give give priority to the foreground activity when * dispatching a discovered {@link Tag} to an application. * *

If any IntentFilters are provided to this method they are used to match dispatch Intents * for both the {@link NfcAdapter#ACTION_NDEF_DISCOVERED} and * {@link NfcAdapter#ACTION_TAG_DISCOVERED}. Since {@link NfcAdapter#ACTION_TECH_DISCOVERED} * relies on meta data outside of the IntentFilter matching for that dispatch Intent is handled * by passing in the tech lists separately. Each first level entry in the tech list represents * an array of technologies that must all be present to match. If any of the first level sets * match then the dispatch is routed through the given PendingIntent. In other words, the second * level is ANDed together and the first level entries are ORed together. * *

If you pass {@code null} for both the {@code filters} and {@code techLists} parameters * that acts a wild card and will cause the foreground activity to receive all tags via the * {@link NfcAdapter#ACTION_TAG_DISCOVERED} intent. * *

This method must be called from the main thread, and only when the activity is in the * foreground (resumed). Also, activities must call {@link #disableForegroundDispatch} before * the completion of their {@link Activity#onPause} callback to disable foreground dispatch * after it has been enabled. * *

Requires the {@link android.Manifest.permission#NFC} permission. * * @param activity the Activity to dispatch to * @param intent the PendingIntent to start for the dispatch * @param filters the IntentFilters to override dispatching for, or null to always dispatch * @param techLists the tech lists used to perform matching for dispatching of the * {@link NfcAdapter#ACTION_TECH_DISCOVERED} intent * @throws IllegalStateException if the Activity is not currently in the foreground */ public void enableForegroundDispatch(Activity activity, PendingIntent intent, IntentFilter[] filters, String[][] techLists) { if (activity == null || intent == null) { throw new NullPointerException(); } if (!activity.isResumed()) { throw new IllegalStateException("Foreground dispatch can only be enabled " + "when your activity is resumed"); } try { TechListParcel parcel = null; if (techLists != null && techLists.length > 0) { parcel = new TechListParcel(techLists); } ActivityThread.currentActivityThread().registerOnActivityPausedListener(activity, mForegroundDispatchListener); sService.setForegroundDispatch(intent, filters, parcel); } catch (RemoteException e) { attemptDeadServiceRecovery(e); } } /** * Disable foreground dispatch to the given activity. * *

After calling {@link #enableForegroundDispatch}, an activity * must call this method before its {@link Activity#onPause} callback * completes. * *

This method must be called from the main thread. * *

Requires the {@link android.Manifest.permission#NFC} permission. * * @param activity the Activity to disable dispatch to * @throws IllegalStateException if the Activity has already been paused */ public void disableForegroundDispatch(Activity activity) { ActivityThread.currentActivityThread().unregisterOnActivityPausedListener(activity, mForegroundDispatchListener); disableForegroundDispatchInternal(activity, false); } OnActivityPausedListener mForegroundDispatchListener = new OnActivityPausedListener() { @Override public void onPaused(Activity activity) { disableForegroundDispatchInternal(activity, true); } }; void disableForegroundDispatchInternal(Activity activity, boolean force) { try { sService.setForegroundDispatch(null, null, null); if (!force && !activity.isResumed()) { throw new IllegalStateException("You must disable foreground dispatching " + "while your activity is still resumed"); } } catch (RemoteException e) { attemptDeadServiceRecovery(e); } } /** * Enable NDEF message push over NFC while this Activity is in the foreground. * *

You must explicitly call this method every time the activity is * resumed, and you must call {@link #disableForegroundNdefPush} before * your activity completes {@link Activity#onPause}. * *

Strongly recommend to use the new {@link #setNdefPushMessage} * instead: it automatically hooks into your activity life-cycle, * so you do not need to call enable/disable in your onResume/onPause. * *

For NDEF push to function properly the other NFC device must * support either NFC Forum's SNEP (Simple Ndef Exchange Protocol), or * Android's "com.android.npp" (Ndef Push Protocol). This was optional * on Gingerbread level Android NFC devices, but SNEP is mandatory on * Ice-Cream-Sandwich and beyond. * *

This method must be called from the main thread. * *

Requires the {@link android.Manifest.permission#NFC} permission. * * @param activity foreground activity * @param message a NDEF Message to push over NFC * @throws IllegalStateException if the activity is not currently in the foreground * @deprecated use {@link #setNdefPushMessage} instead */ @Deprecated public void enableForegroundNdefPush(Activity activity, NdefMessage message) { if (activity == null || message == null) { throw new NullPointerException(); } enforceResumed(activity); mNfcActivityManager.setNdefPushMessage(activity, message); } /** * Disable NDEF message push over P2P. * *

After calling {@link #enableForegroundNdefPush}, an activity * must call this method before its {@link Activity#onPause} callback * completes. * *

Strongly recommend to use the new {@link #setNdefPushMessage} * instead: it automatically hooks into your activity life-cycle, * so you do not need to call enable/disable in your onResume/onPause. * *

This method must be called from the main thread. * *

Requires the {@link android.Manifest.permission#NFC} permission. * * @param activity the Foreground activity * @throws IllegalStateException if the Activity has already been paused * @deprecated use {@link #setNdefPushMessage} instead */ @Deprecated public void disableForegroundNdefPush(Activity activity) { if (activity == null) { throw new NullPointerException(); } enforceResumed(activity); mNfcActivityManager.setNdefPushMessage(activity, null); mNfcActivityManager.setNdefPushMessageCallback(activity, null); mNfcActivityManager.setOnNdefPushCompleteCallback(activity, null); } /** * Enable NDEF Push feature. *

This API is for the Settings application. * @hide */ public boolean enableNdefPush() { try { return sService.enableNdefPush(); } catch (RemoteException e) { attemptDeadServiceRecovery(e); return false; } } /** * Disable NDEF Push feature. *

This API is for the Settings application. * @hide */ public boolean disableNdefPush() { try { return sService.disableNdefPush(); } catch (RemoteException e) { attemptDeadServiceRecovery(e); return false; } } /** * Return true if the NDEF Push (Android Beam) feature is enabled. *

This function will return true only if both NFC is enabled, and the * NDEF Push feature is enabled. *

Note that if NFC is enabled but NDEF Push is disabled then this * device can still receive NDEF messages, it just cannot send them. *

Applications cannot directly toggle the NDEF Push feature, but they * can request Settings UI allowing the user to toggle NDEF Push using * startActivity(new Intent(Settings.ACTION_NFCSHARING_SETTINGS)) *

Example usage in an Activity that requires NDEF Push: *

     * protected void onResume() {
     *     super.onResume();
     *     if (!nfcAdapter.isEnabled()) {
     *         startActivity(new Intent(Settings.ACTION_NFC_SETTINGS));
     *     } else if (!nfcAdapter.isNdefPushEnabled()) {
     *         startActivity(new Intent(Settings.ACTION_NFCSHARING_SETTINGS));
     *     }
     * }
* * @see android.provider.Settings#ACTION_NFCSHARING_SETTINGS * @return true if NDEF Push feature is enabled */ public boolean isNdefPushEnabled() { try { return sService.isNdefPushEnabled(); } catch (RemoteException e) { attemptDeadServiceRecovery(e); return false; } } /** * Inject a mock NFC tag.

* Used for testing purposes. *

Requires the * {@link android.Manifest.permission#WRITE_SECURE_SETTINGS} permission. * @hide */ public void dispatch(Tag tag) { if (tag == null) { throw new NullPointerException("tag cannot be null"); } try { sService.dispatch(tag); } catch (RemoteException e) { attemptDeadServiceRecovery(e); } } /** * @hide */ public void setP2pModes(int initiatorModes, int targetModes) { try { sService.setP2pModes(initiatorModes, targetModes); } catch (RemoteException e) { attemptDeadServiceRecovery(e); } } /** * @hide */ public INfcAdapterExtras getNfcAdapterExtrasInterface() { if (mContext == null) { throw new UnsupportedOperationException("You need a context on NfcAdapter to use the " + " NFC extras APIs"); } try { return sService.getNfcAdapterExtrasInterface(mContext.getPackageName()); } catch (RemoteException e) { attemptDeadServiceRecovery(e); return null; } } void enforceResumed(Activity activity) { if (!activity.isResumed()) { throw new IllegalStateException("API cannot be called while activity is paused"); } } int getSdkVersion() { if (mContext == null) { return android.os.Build.VERSION_CODES.GINGERBREAD; // best guess } else { return mContext.getApplicationInfo().targetSdkVersion; } } }