nfc.py

from random import randint, choice
from time import sleep

from kivy.clock import Clock
from kivy.utils import platform

from toast import toast

nfc_instance = None


class NFC:
    def __init__(self):
        self._action = None

        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
        )
        self.on_new_intenting = False
        self.resuming = False
        self.dispatched = False
        self.nfc_enable_ndef_exchange()
        activity.bind(on_new_intent=self.on_new_intent)

    def register_action(self, action):
        self._action = action

    def remove_action(self, action):
        if self._action == action:
            self._action = None
            self.nfc_disable_ndef_exchange()
        else:
            # raise ValueError('Action isn\' defined')
            toast('Action isn\' defined')

    def on_new_intent(self, intent):
        self.on_new_intenting = True
        sleep(0.25)
        while self.resuming:
            sleep(0.1)

        if intent.getAction() != NfcAdapter.ACTION_TAG_DISCOVERED:
            toast('unknow action, avoid.')
            return

        tag_id = ''
        for i in intent.getByteArrayExtra(NfcAdapter.EXTRA_ID).tolist():
            tag_id += hex(i & 0xff)[2:]

        if self._action:
            self._action(tag_id)

        self.on_new_intenting = False

    # @run_on_ui_thread
    def nfc_enable_ndef_exchange(self):
        if self.on_new_intenting: # let it run, don't bother about initialising to saved
            return
        self.resuming = True
        print 'Resume'

        inten = Intent(self.j_context, self.j_context.getClass())
        inten.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP)

        pending_intent = PendingIntent.getActivity(self.j_context, 0, inten, 0)

        intent_filter = IntentFilter()
        intent_filter.addAction(NfcAdapter.ACTION_TAG_DISCOVERED)
        intent_filter.addCategory(Intent.CATEGORY_DEFAULT)
        intent_filter.addDataType("text/plain")

        try:
            if not self.dispatched:
                self.nfc_adapter.enableForegroundDispatch(
                    self.j_context,
                    pending_intent,
                    [intent_filter],
                    [[]]
                )
        except JavaException as e:
            print 'Java Error', e

        self.dispatched = True
        self.resuming = False

    # @run_on_ui_thread
    def nfc_disable_ndef_exchange(self):
        self.nfc_adapter.disableForegroundDispatch(self.j_context)
        self.dispatched = False


class FakeNFC:
    def __init__(self):
        self._action = None

    def register_action(self, action):
        self._action = action
        Clock.schedule_once(self.on_new_intent, 0)

    def remove_action(self, action):
        if self._action == action:
            self._action = None
            Clock.unschedule(self.on_new_intent)
        else:
            # raise ValueError('Action isn\' defined')
            toast('Action isn\' defined')

    def on_new_intent(self, *args):
        tag_id = ''.join([chr(randint(65, 90)) for i in range(6)])
        tag_id = choice(['xllpoj', 'aymoqf'])

        if self._action:
            self._action(tag_id.lower())
            Clock.schedule_interval(self.on_new_intent, 10)


if not nfc_instance:
    if platform == 'android':
        from jnius import autoclass
        from jnius.jnius import JavaException
        from android import activity

        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')

        nfc_instance = NFC()
    else:
        nfc_instance = FakeNFC()