Python API¶
The Python for Android project includes a Python module called
android
which consists of multiple parts that are mostly there to
facilitate the use of the Java API.
This module is not designed to be comprehensive. Most of the Java API is also accessible with PyJNIus, so if you can’t find what you need here you can try using the Java API directly instead.
Android (android
)¶
-
android.
check_pause
()¶ This should be called on a regular basis to check to see if Android expects the application to pause. If it returns true, the app should call
android.wait_for_resume()
, after storing its state as necessary.
-
android.
wait_for_resume
()¶ This function should be called after
android.check_pause()
and returns true. It does not return until Android has resumed from the pause. While in this function, Android may kill the app without further notice.
-
android.
map_key
(keycode, keysym)¶ This maps an android keycode to a python keysym. The android keycodes are available as constants in the android module.
Activity (android.activity
)¶
The default PythonActivity has a observer pattern for onActivityResult and onNewIntent.
-
android.activity.
bind
(eventname=callback, ...)¶ This allows you to bind a callback to an Android event: -
on_new_intent
is the event associated to the onNewIntent java call -on_activity_result
is the event associated to the onActivityResult java call警告
This method is not thread-safe. Call it in the mainthread of your app. (tips: use kivy.clock.mainthread decorator)
-
android.activity.
unbind
(eventname=callback, ...)¶ Unregister a previously registered callback with
bind()
.
Example:
# This example is a snippet from an NFC p2p app implemented with Kivy.
from android import activity
def on_new_intent(self, intent):
if intent.getAction() != NfcAdapter.ACTION_NDEF_DISCOVERED:
return
rawmsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES)
if not rawmsgs:
return
for message in rawmsgs:
message = cast(NdefMessage, message)
payload = message.getRecords()[0].getPayload()
print 'payload: {}'.format(''.join(map(chr, payload)))
def nfc_enable(self):
activity.bind(on_new_intent=self.on_new_intent)
# ...
def nfc_disable(self):
activity.unbind(on_new_intent=self.on_new_intent)
# ...
Billing (android.billing
)¶
This billing module gives an access to the In-App Billing:
Setup a test account, and get your Public Key
Export your public key:
export BILLING_PUBKEY="Your public key here"
Setup some In-App product to buy. Let’s say you’ve created a product with the id “org.kivy.gopremium”
In your application, you can use the
billing
module like this:from android.billing import BillingService from kivy.clock import Clock class MyBillingService(object): def __init__(self): super(MyBillingService, self).__init__() # Start the billing service, and attach our callback self.service = BillingService(billing_callback) # Start a clock to check billing service message every second Clock.schedule_interval(self.service.check, 1) def billing_callback(self, action, *largs): '''Callback that will receive all the events from the Billing service ''' if action == BillingService.BILLING_ACTION_ITEMSCHANGED: items = largs[0] if 'org.kivy.gopremium' in items: print "Congratulations, you have a premium acess" else: print "Unfortunately, you don't have premium access" def buy(self, sku): # Method to buy something. self.service.buy(sku) def get_purchased_items(self): # Return all the items purchased return self.service.get_purchased_items()
To initiate an in-app purchase, just call the
buy()
method:# Note: start the service at the start, and never twice! bs = MyBillingService() bs.buy('org.kivy.gopremium') # Later, when you get the notification that items have been changed, you # can still check all the items you bought: print bs.get_purchased_items() {'org.kivy.gopremium': {'qt: 1}}
You’ll receive all the notifications about the billing process in the callback.
Last step, create your application with
--with-billing $BILLING_PUBKEY
:./build.py ... --with-billing $BILLING_PUBKEY
Broadcast (android.broadcast
)¶
Implementation of the android BroadcastReceiver. You can specify the callback that will receive the broadcast event, and actions or categories filters.
-
class
android.broadcast.
BroadcastReceiver
¶ 警告
The callback will be called in another thread than the main thread. In that thread, be careful not to access OpenGL or something like that.
-
__init__
(callback, actions=None, categories=None)¶ パラメータ: - callback – function or method that will receive the event. Will receive the context and intent as argument.
- actions – list of strings that represent an action.
- categories – list of strings that represent a category.
For actions and categories, the string must be in lower case, without the prefix:
# In java: Intent.ACTION_HEADSET_PLUG # In python: 'headset_plug'
-
start
()¶ Register the receiver with all the actions and categories, and start handling events.
-
stop
()¶ Unregister the receiver with all the actions and categories, and stop handling events.
-
Example:
class TestApp(App):
def build(self):
self.br = BroadcastReceiver(
self.on_broadcast, actions=['headset_plug'])
self.br.start()
# ...
def on_broadcast(self, context, intent):
extras = intent.getExtras()
headset_state = bool(extras.get('state'))
if headset_state:
print 'The headset is plugged'
else:
print 'The headset is unplugged'
# Don't forget to stop and restart the receiver when the app is going
# to pause / resume mode
def on_pause(self):
self.br.stop()
return True
def on_resume(self):
self.br.start()
Mixer (android.mixer
)¶
The android.mixer module contains a subset of the functionality in found in the pygame.mixer module. It’s intended to be imported as an alternative to pygame.mixer, using code like:
try:
import pygame.mixer as mixer
except ImportError:
import android.mixer as mixer
Note that if you’re using the kivy.core.audio module, you don’t have to do anything, it is all automatic.
The android.mixer module is a wrapper around the Android MediaPlayer class. This allows it to take advantage of any hardware acceleration present, and also eliminates the need to ship codecs as part of an application.
It has several differences with the pygame mixer:
- The init() and pre_init() methods work, but are ignored - Android chooses appropriate settings automatically.
- Only filenames and true file objects can be used - file-like objects will probably not work.
- Fadeout does not work - it causes a stop to occur.
- Looping is all or nothing, there is no way to choose the number of
loops that occur. For looping to work, the
android.mixer.periodic()
function should be called on a regular basis. - Volume control is ignored.
- End events are not implemented.
- The mixer.music object is a class (with static methods on it),
rather than a module. Calling methods like
mixer.music.play()
should work.
Runnable (android.runnable
)¶
Runnable
is a wrapper around the Java Runnable class. This
class can be used to schedule a call of a Python function into the
PythonActivity thread.
Example:
from android.runnable import Runnable
def helloworld(arg):
print 'Called from PythonActivity with arg:', arg
Runnable(helloworld)('hello')
Or use our decorator:
from android.runnable import run_on_ui_thread
@run_on_ui_thread
def helloworld(arg):
print 'Called from PythonActivity with arg:', arg
helloworld('arg1')
This can be used to prevent errors like:
- W/System.err( 9514): java.lang.RuntimeException: Can’t create handler inside thread that has not called Looper.prepare()
- NullPointerException in ActivityThread.currentActivityThread()
警告
Because the python function is called from the PythonActivity thread, you need to be careful about your own calls.
Service (android.service
)¶
Services of an application are controlled through the class AndroidService
.
-
class
android.service.
AndroidService
(title, description)¶ Run
service/main.py
from the application directory as a service.パラメータ: -
start
(arg)¶ Start the service.
パラメータ: arg (str) – Argument to pass to a service, through the environment variable PYTHON_SERVICE_ARGUMENT
. Defaults to ‘’
-
stop
()¶ Stop the service.
-
Application activity part example, main.py
:
from android import AndroidService
...
class ServiceExample(App):
...
def start_service(self):
self.service = AndroidService('Sevice example', 'service is running')
self.service.start('Hello From Service')
def stop_service(self):
self.service.stop()
Application service part example, service/main.py
:
import os
import time
# get the argument passed
arg = os.getenv('PYTHON_SERVICE_ARGUMENT')
while True:
# this will print 'Hello From Service' continually, even when the application is switched
print arg
time.sleep(1)