NFC P2P mode tests

buildozer.spec

[app]

# (str) Title of your application
title = NFC P2P Chat

# (str) Package name
package.name = nfcp2pchat

# (str) Package domain (needed for android/ios packaging)
package.domain = com.meltingrocks

# (str) Source code where the main.py live
source.dir = .

# (list) Source files to include (let empty to include all the files)
source.include_exts = py,png,jpg,kv,atlas

# (list) Source files to exclude (let empty to not excluding anything)
#source.exclude_exts = spec

# (str) Application versionning (method 1)
version.regex = __version__ = '(.*)'
version.filename = %(source.dir)s/main.py

# (str) Application versionning (method 2)
# version = 1.2.0

# (list) Application requirements
requirements = kivy

# (str) Presplash of the application
#presplash.filename = %(source.dir)s/data/presplash.png

# (str) Icon of the application
#icon.filename = %(source.dir)s/data/icon.png

# (str) Supported orientation (one of landscape, portrait or all)
orientation = landscape

# (bool) Indicate if the application should be fullscreen or not
fullscreen = 1


#
# Android specific
#

# (list) Permissions
android.permissions = NFC

# (int) Android API to use
#android.api = 14

# (int) Minimum API required (8 = Android 2.2 devices)
#android.minapi = 8

# (int) Android SDK version to use
#android.sdk = 21

# (str) Android NDK version to use
#android.ndk = 8c

# (str) Android NDK directory (if empty, it will be automatically downloaded.)
#android.ndk_path =

# (str) Android SDK directory (if empty, it will be automatically downloaded.)
#android.sdk_path = 

# (str) Android entry point, default is ok for Kivy-based app
#android.entrypoint = org.renpy.android.PythonActivity

# (str) python-for-android branch to use, if not master, useful to try
# not yet merged features.
#android.branch = master

# (str) file to include as an intent filters in <activity> tag
android.manifest.intent_filters = nfc_filter.xml

#
# iOS specific
#

# (str) Name of the certificate to use for signing the debug version
#ios.codesign.debug = "iPhone Developer: <lastname> <firstname> (<hexstring>)"

# (str) Name of the certificate to use for signing the release version
#ios.codesign.release = %(ios.codesign.debug)s


[buildozer]

# (int) Log level (0 = error only, 1 = info, 2 = debug (with command output))
log_level = 1

main.py

__version__ = '1.0'

from jnius import autoclass, cast
from android.runnable import run_on_ui_thread
from android import activity
from kivy.app import App
from kivy.lang import Builder

NfcAdapter = autoclass('android.nfc.NfcAdapter')
PythonActivity = autoclass('org.renpy.android.PythonActivity')
Intent = autoclass('android.content.Intent')
IntentFilter = autoclass('android.content.IntentFilter')
PendingIntent = autoclass('android.app.PendingIntent')
NdefRecord = autoclass('android.nfc.NdefRecord')
NdefMessage = autoclass('android.nfc.NdefMessage')


class NfcApp(App):

    def nfc_init(self):
        print 'nfc_init()'

        print 'configure nfc'
        self.j_context = context = PythonActivity.mActivity
        self.nfc_adapter = NfcAdapter.getDefaultAdapter(context)
        self.nfc_pending_intent = PendingIntent.getActivity(context, 0,
            Intent(context, context.getClass()).addFlags(
                Intent.FLAG_ACTIVITY_SINGLE_TOP), 0)

        print 'p2p filter'
        self.ndef_detected = IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED)
        self.ndef_detected.addDataType('text/plain')
        self.ndef_exchange_filters = [self.ndef_detected]

    def on_new_intent(self, intent):
        print 'on_new_intent()', intent.getAction()
        if intent.getAction() != NfcAdapter.ACTION_NDEF_DISCOVERED:
            print 'unknow action, avoid.'
            return

        rawmsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES)
        print 'raw messages', rawmsgs
        if not rawmsgs:
            return

        for message in rawmsgs:
            message = cast(NdefMessage, message)
            print 'got message', message
            payload = message.getRecords()[0].getPayload()
            print 'payload: {}'.format(''.join(map(chr, payload)))

    def nfc_disable(self):
        print 'nfc_disable()'
        activity.unbind(on_new_intent=self.on_new_intent)

    def nfc_enable(self):
        print 'nfc_enable()'
        activity.bind(on_new_intent=self.on_new_intent)

    @run_on_ui_thread
    def nfc_enable_ndef_exchange(self):
        print 'create record'
        ndef_record = NdefRecord(
                NdefRecord.TNF_MIME_MEDIA,
                'text/plain', '', 'hello world')
        print 'create message'
        ndef_message = NdefMessage([ndef_record])

        print 'enable ndef push'
        self.nfc_adapter.enableForegroundNdefPush(self.j_context, ndef_message)

        print 'enable dispatch', self.j_context, self.nfc_pending_intent
        self.nfc_adapter.enableForegroundDispatch(self.j_context,
                self.nfc_pending_intent, self.ndef_exchange_filters, [])

    @run_on_ui_thread
    def nfc_disable_ndef_exchange(self):
        self.nfc_adapter.disableForegroundNdefPush(self.j_context)
        self.nfc_adapter.disableForegroundDispatch(self.j_context)

    def on_pause(self):
        self.nfc_disable()
        return True

    def on_resume(self):
        self.nfc_enable()

    def build(self):
        self.nfc_init()
        return Builder.load_string('''
BoxLayout:
    Button:
        text: 'Enable NDEF exchange'
        on_press: app.nfc_enable_ndef_exchange()
    Button:
        text: 'Disable NDEF exchange'
        on_press: app.nfc_disable_ndef_exchange()
''')

NfcApp().run()

nfc_filter.xml

<intent-filter>
	<action android:name="android.nfc.action.NDEF_DISCOVERED"/>
	<category android:name="android.intent.category.DEFAULT"/>
	<data android:mimeType="text/plain"/>
</intent-filter>

I do excatly (i hope) your sample (mainly the line 'android.permissions = NFC' in buildozer.spec), but on line : self.nfc_adapter.enableForegroundNdefPush(self.j_context, ndef_message), I have an exception : JVM exception occured: NFC permission required: Neither user 10087 nor current process has android.permission.NFC. Do you have an idea (Running on Samsung S4). Best regards.