package nfc.sample.Ndef.Read;
/*
* Copyright (c) 2012 Research In Motion Limited.
*
* 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.
*/
import net.rim.device.api.io.nfc.NFCException;
import net.rim.device.api.io.nfc.ndef.NDEFRecord;
import net.rim.device.api.io.nfc.readerwriter.ReaderWriterManager;
import net.rim.device.api.system.RuntimeStore;
import nfc.sample.Ndef.Read.ui.ListenerControlScreen;
public class NdefListenerManager {
private static NdefListenerManager _mgr;
private RuntimeStore rts = RuntimeStore.getRuntimeStore();
private NdefListenerManager() {
}
public synchronized static NdefListenerManager getInstance() {
if(_mgr == null) {
_mgr = new NdefListenerManager();
}
return _mgr;
}
/*
* This registers with the NFC Reader Writer Manager indicating our interest in receiving notification when Smart Tags come
* within range of the NFC antenna
*/
public void registerListener(NfcReadNdefSmartTagListener listener) {
ReaderWriterManager nfcManager;
Utilities.log("XXXX NfcReadNdefSmartTag about to add NDEF Message Listener");
try {
nfcManager = ReaderWriterManager.getInstance();
/*
* An NDEF record always contains:
*
* * 3-bit TNF (Type Name Format) field: Indicates how to
* interpret the type field
* * Variable length type: Describes
* the record format
* * Variable length ID: A unique identifier
* for the record
* * Variable length payload: The actual data
* payload
*
* The underlying record representation may be chunked across
* several NDEF records when the payload is large.
*
* NDEFRecord.TNF_WELL_KNOWN - indicates that we are interested
* in NDEF records of Type Name Format (TNF): "WELL_KNOWN"
*
* TNF_WELL_KNOWN included NFC RTD (Record Type Definitions)
* types such as RTD_TEXT and RTD_URI meaning that they will
* contain URIs or TEXT suitably encoded according to the NFC
* RTD specification
*
* "Sp" identifies the record type as Smart Poster - so we're
* only interested in being notified of Smart Poster records
* that contain plain text or URIs
*
* The final parameter "true" identifies that the application
* will be auto-started if it is not currently running when a
* smart tag is brought within range of the NFC antenna.
*
* This setting is persistent across device power resets.
*
* When the application is restarted automatically on
* presentation of a suitable smart tag to the device the
* application will be re-started but it is necessary to
* re-establish the NDEFMessageListener.
*
* Upon registering the listener again the tag that caused the
* application to be re-started is immediately presented to the
* listener making what is really a two stage process seem
* seamless.
*
* It is important to re-start the listener within about 15 seconds
* of the application being autostarted. Failure to do so will
* result in the queued message being lost.
*
* There is also no way to determine if the application was
* autostarted should you wish to automatically restart the
* listener in this case. Of course you could always leave your
* own tracks in the sand using the Persistent Store.
*
* This behaviour suggests that using the autostart option whilst
* managing the setting up of the listener via the UI is a combination
* that can lead to unexpected behaviour.
*
*/
nfcManager.addNDEFMessageListener(listener,
NDEFRecord.TNF_WELL_KNOWN, "Sp", true);
Utilities.log("XXXX NfcReadNdefSmartTag add NDEF Message Listener success");
rts.replace(Constants.LISTENER_STATE_TOKEN, new Boolean(true));
ListenerControlScreen.getInstance().setLed();
} catch (NFCException e) {
e.printStackTrace();
Utilities.log("XXXX NfcReadNdefSmartTag NFCException on register");
}
}
/*
* This unregisters with the NFC Reader Writer Manager We no longer want to be notified of Smart Tag events
*/
public void unRegisterListener() {
ReaderWriterManager nfcManager;
Utilities.log("XXXX NfcReadNdefSmartTag about to remove NDEF Message Listener");
try {
nfcManager = ReaderWriterManager.getInstance();
/*
* This is the converse of the call to register our interest in tags of a certain type. It should identify the same
* TNF and record type as when it was registered.
*/
nfcManager.removeNDEFMessageListener(NDEFRecord.TNF_WELL_KNOWN, "Sp");
Utilities.log("XXXX NfcReadNdefSmartTag remove NDEF Message Listener success");
rts.replace(Constants.LISTENER_STATE_TOKEN, new Boolean(false));
ListenerControlScreen.getInstance().setLed();
} catch(NFCException e) {
e.printStackTrace();
Utilities.log("XXXX NfcReadNdefSmartTag NFCException on unregister");
}
}
public boolean is_listening() {
Boolean state = (Boolean) rts.get(Constants.LISTENER_STATE_TOKEN);
if (state != null) {
Utilities.log("XXXX isListening:"+state);
return state.booleanValue();
} else {
Utilities.log("XXXX isListening: token not found. defaulting to false");
rts.replace(Constants.LISTENER_STATE_TOKEN, new Boolean(false));
return false;
}
}
}