|
| 1 | +Python API |
| 2 | +========== |
| 3 | + |
| 4 | +The Python for Android project includes a Python module called |
| 5 | +``android`` which consists of multiple parts that are mostly there to |
| 6 | +facilitate the use of the Java API. |
| 7 | + |
| 8 | +This module is not designed to be comprehensive. Most of the Java API |
| 9 | +is also accessible with PyJNIus, so if you can't find what you need |
| 10 | +here you can try using the Java API directly instead. |
| 11 | + |
| 12 | + |
| 13 | +Android (``android``) |
| 14 | +--------------------- |
| 15 | + |
| 16 | +.. module:: android |
| 17 | + |
| 18 | +.. function:: check_pause() |
| 19 | + |
| 20 | + This should be called on a regular basis to check to see if Android |
| 21 | + expects the application to pause. If it returns true, the app should call |
| 22 | + :func:`android.wait_for_resume()`, after storing its state as necessary. |
| 23 | + |
| 24 | +.. function:: wait_for_resume() |
| 25 | + |
| 26 | + This function should be called after :func:`android.check_pause()` and returns |
| 27 | + true. It does not return until Android has resumed from the pause. While in |
| 28 | + this function, Android may kill the app without further notice. |
| 29 | + |
| 30 | +.. function:: map_key(keycode, keysym) |
| 31 | + |
| 32 | + This maps an android keycode to a python keysym. The android |
| 33 | + keycodes are available as constants in the android module. |
| 34 | + |
| 35 | + |
| 36 | +Activity (``android.activity``) |
| 37 | +------------------------------- |
| 38 | + |
| 39 | +.. module:: android.activity |
| 40 | + |
| 41 | +The default PythonActivity has a observer pattern for `onActivityResult <http://developer.android.com/reference/android/app/Activity.html#onActivityResult(int, int, android.content.Intent)>`_ and `onNewIntent <http://developer.android.com/reference/android/app/Activity.html#onNewIntent(android.content.Intent)>`_. |
| 42 | + |
| 43 | +.. function:: bind(eventname=callback, ...) |
| 44 | + |
| 45 | + This allows you to bind a callback to an Android event: |
| 46 | + - ``on_new_intent`` is the event associated to the onNewIntent java call |
| 47 | + - ``on_activity_result`` is the event associated to the onActivityResult java call |
| 48 | + |
| 49 | + .. warning:: |
| 50 | + |
| 51 | + This method is not thread-safe. Call it in the mainthread of your app. (tips: use kivy.clock.mainthread decorator) |
| 52 | + |
| 53 | +.. function:: unbind(eventname=callback, ...) |
| 54 | + |
| 55 | + Unregister a previously registered callback with :func:`bind`. |
| 56 | + |
| 57 | +Example:: |
| 58 | + |
| 59 | + # This example is a snippet from an NFC p2p app implemented with Kivy. |
| 60 | + |
| 61 | + from android import activity |
| 62 | + |
| 63 | + def on_new_intent(self, intent): |
| 64 | + if intent.getAction() != NfcAdapter.ACTION_NDEF_DISCOVERED: |
| 65 | + return |
| 66 | + rawmsgs = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES) |
| 67 | + if not rawmsgs: |
| 68 | + return |
| 69 | + for message in rawmsgs: |
| 70 | + message = cast(NdefMessage, message) |
| 71 | + payload = message.getRecords()[0].getPayload() |
| 72 | + print 'payload: {}'.format(''.join(map(chr, payload))) |
| 73 | + |
| 74 | + def nfc_enable(self): |
| 75 | + activity.bind(on_new_intent=self.on_new_intent) |
| 76 | + # ... |
| 77 | + |
| 78 | + def nfc_disable(self): |
| 79 | + activity.unbind(on_new_intent=self.on_new_intent) |
| 80 | + # ... |
| 81 | + |
| 82 | + |
| 83 | +Billing (``android.billing``) |
| 84 | +----------------------------- |
| 85 | + |
| 86 | +.. module:: android.billing |
| 87 | + |
| 88 | +This billing module gives an access to the `In-App Billing <http://developer.android.com/guide/google/play/billing/billing_overview.html>`_: |
| 89 | + |
| 90 | +#. `Setup a test account <http://developer.android.com/guide/google/play/billing/billing_admin.html#billing-testing-setup>`_, and get your Public Key |
| 91 | +#. Export your public key:: |
| 92 | + |
| 93 | + export BILLING_PUBKEY="Your public key here" |
| 94 | + |
| 95 | +#. `Setup some In-App product <http://developer.android.com/guide/google/play/billing/billing_admin.html>`_ to buy. Let's say you've created a product with the id "org.kivy.gopremium" |
| 96 | + |
| 97 | +#. In your application, you can use the ``billing`` module like this:: |
| 98 | + |
| 99 | + |
| 100 | + from android.billing import BillingService |
| 101 | + from kivy.clock import Clock |
| 102 | + |
| 103 | + class MyBillingService(object): |
| 104 | + |
| 105 | + def __init__(self): |
| 106 | + super(MyBillingService, self).__init__() |
| 107 | + |
| 108 | + # Start the billing service, and attach our callback |
| 109 | + self.service = BillingService(billing_callback) |
| 110 | + |
| 111 | + # Start a clock to check billing service message every second |
| 112 | + Clock.schedule_interval(self.service.check, 1) |
| 113 | + |
| 114 | + def billing_callback(self, action, *largs): |
| 115 | + '''Callback that will receive all the events from the Billing service |
| 116 | + ''' |
| 117 | + if action == BillingService.BILLING_ACTION_ITEMSCHANGED: |
| 118 | + items = largs[0] |
| 119 | + if 'org.kivy.gopremium' in items: |
| 120 | + print "Congratulations, you have a premium acess" |
| 121 | + else: |
| 122 | + print "Unfortunately, you don't have premium access" |
| 123 | + |
| 124 | + def buy(self, sku): |
| 125 | + # Method to buy something. |
| 126 | + self.service.buy(sku) |
| 127 | + |
| 128 | + def get_purchased_items(self): |
| 129 | + # Return all the items purchased |
| 130 | + return self.service.get_purchased_items() |
| 131 | + |
| 132 | +#. To initiate an in-app purchase, just call the ``buy()`` method:: |
| 133 | + |
| 134 | + # Note: start the service at the start, and never twice! |
| 135 | + bs = MyBillingService() |
| 136 | + bs.buy('org.kivy.gopremium') |
| 137 | + |
| 138 | + # Later, when you get the notification that items have been changed, you |
| 139 | + # can still check all the items you bought: |
| 140 | + print bs.get_purchased_items() |
| 141 | + {'org.kivy.gopremium': {'qt: 1}} |
| 142 | + |
| 143 | +#. You'll receive all the notifications about the billing process in the callback. |
| 144 | + |
| 145 | +#. Last step, create your application with ``--with-billing $BILLING_PUBKEY``:: |
| 146 | + |
| 147 | + ./build.py ... --with-billing $BILLING_PUBKEY |
| 148 | + |
| 149 | + |
| 150 | +Broadcast (``android.broadcast``) |
| 151 | +--------------------------------- |
| 152 | + |
| 153 | +.. module:: android.broadcast |
| 154 | + |
| 155 | +Implementation of the android `BroadcastReceiver |
| 156 | +<http://developer.android.com/reference/android/content/BroadcastReceiver.html>`_. |
| 157 | +You can specify the callback that will receive the broadcast event, and actions |
| 158 | +or categories filters. |
| 159 | + |
| 160 | +.. class:: BroadcastReceiver |
| 161 | + |
| 162 | + .. warning:: |
| 163 | + |
| 164 | + The callback will be called in another thread than the main thread. In |
| 165 | + that thread, be careful not to access OpenGL or something like that. |
| 166 | + |
| 167 | + .. method:: __init__(callback, actions=None, categories=None) |
| 168 | + |
| 169 | + :param callback: function or method that will receive the event. Will |
| 170 | + receive the context and intent as argument. |
| 171 | + :param actions: list of strings that represent an action. |
| 172 | + :param categories: list of strings that represent a category. |
| 173 | + |
| 174 | + For actions and categories, the string must be in lower case, without the prefix:: |
| 175 | + |
| 176 | + # In java: Intent.ACTION_HEADSET_PLUG |
| 177 | + # In python: 'headset_plug' |
| 178 | + |
| 179 | + .. method:: start() |
| 180 | + |
| 181 | + Register the receiver with all the actions and categories, and start |
| 182 | + handling events. |
| 183 | + |
| 184 | + .. method:: stop() |
| 185 | + |
| 186 | + Unregister the receiver with all the actions and categories, and stop |
| 187 | + handling events. |
| 188 | + |
| 189 | +Example:: |
| 190 | + |
| 191 | + class TestApp(App): |
| 192 | + |
| 193 | + def build(self): |
| 194 | + self.br = BroadcastReceiver( |
| 195 | + self.on_broadcast, actions=['headset_plug']) |
| 196 | + self.br.start() |
| 197 | + # ... |
| 198 | + |
| 199 | + def on_broadcast(self, context, intent): |
| 200 | + extras = intent.getExtras() |
| 201 | + headset_state = bool(extras.get('state')) |
| 202 | + if headset_state: |
| 203 | + print 'The headset is plugged' |
| 204 | + else: |
| 205 | + print 'The headset is unplugged' |
| 206 | + |
| 207 | + # Don't forget to stop and restart the receiver when the app is going |
| 208 | + # to pause / resume mode |
| 209 | + |
| 210 | + def on_pause(self): |
| 211 | + self.br.stop() |
| 212 | + return True |
| 213 | + |
| 214 | + def on_resume(self): |
| 215 | + self.br.start() |
| 216 | + |
| 217 | + |
| 218 | +Mixer (``android.mixer``) |
| 219 | +------------------------- |
| 220 | + |
| 221 | +.. module:: android.mixer |
| 222 | + |
| 223 | +The `android.mixer` module contains a subset of the functionality in found |
| 224 | +in the `pygame.mixer <http://www.pygame.org/docs/ref/mixer.html>`_ module. It's |
| 225 | +intended to be imported as an alternative to pygame.mixer, using code like: :: |
| 226 | + |
| 227 | + try: |
| 228 | + import pygame.mixer as mixer |
| 229 | + except ImportError: |
| 230 | + import android.mixer as mixer |
| 231 | + |
| 232 | +Note that if you're using the `kivy.core.audio |
| 233 | +<http://kivy.org/docs/api-kivy.core.audio.html>`_ module, you don't have to do |
| 234 | +anything, it is all automatic. |
| 235 | + |
| 236 | +The `android.mixer` module is a wrapper around the Android MediaPlayer |
| 237 | +class. This allows it to take advantage of any hardware acceleration |
| 238 | +present, and also eliminates the need to ship codecs as part of an |
| 239 | +application. |
| 240 | + |
| 241 | +It has several differences with the pygame mixer: |
| 242 | + |
| 243 | +* The init() and pre_init() methods work, but are ignored - Android chooses |
| 244 | + appropriate settings automatically. |
| 245 | + |
| 246 | +* Only filenames and true file objects can be used - file-like objects |
| 247 | + will probably not work. |
| 248 | + |
| 249 | +* Fadeout does not work - it causes a stop to occur. |
| 250 | + |
| 251 | +* Looping is all or nothing, there is no way to choose the number of |
| 252 | + loops that occur. For looping to work, the |
| 253 | + :func:`android.mixer.periodic` function should be called on a |
| 254 | + regular basis. |
| 255 | + |
| 256 | +* Volume control is ignored. |
| 257 | + |
| 258 | +* End events are not implemented. |
| 259 | + |
| 260 | +* The mixer.music object is a class (with static methods on it), |
| 261 | + rather than a module. Calling methods like :func:`mixer.music.play` |
| 262 | + should work. |
| 263 | + |
| 264 | + |
| 265 | +Runnable (``android.runnable``) |
| 266 | +------------------------------- |
| 267 | + |
| 268 | +.. module:: android.runnable |
| 269 | + |
| 270 | +:class:`Runnable` is a wrapper around the Java `Runnable |
| 271 | +<http://developer.android.com/reference/java/lang/Runnable.html>`_ class. This |
| 272 | +class can be used to schedule a call of a Python function into the |
| 273 | +`PythonActivity` thread. |
| 274 | + |
| 275 | +Example:: |
| 276 | + |
| 277 | + from android.runnable import Runnable |
| 278 | + |
| 279 | + def helloworld(arg): |
| 280 | + print 'Called from PythonActivity with arg:', arg |
| 281 | + |
| 282 | + Runnable(helloworld)('hello') |
| 283 | + |
| 284 | +Or use our decorator:: |
| 285 | + |
| 286 | + from android.runnable import run_on_ui_thread |
| 287 | + |
| 288 | + @run_on_ui_thread |
| 289 | + def helloworld(arg): |
| 290 | + print 'Called from PythonActivity with arg:', arg |
| 291 | + |
| 292 | + helloworld('arg1') |
| 293 | + |
| 294 | + |
| 295 | +This can be used to prevent errors like: |
| 296 | + |
| 297 | + - W/System.err( 9514): java.lang.RuntimeException: Can't create handler |
| 298 | + inside thread that has not called Looper.prepare() |
| 299 | + - NullPointerException in ActivityThread.currentActivityThread() |
| 300 | + |
| 301 | +.. warning:: |
| 302 | + |
| 303 | + Because the python function is called from the PythonActivity thread, you |
| 304 | + need to be careful about your own calls. |
| 305 | + |
| 306 | + |
| 307 | + |
| 308 | +Service (``android.service``) |
| 309 | +----------------------------- |
| 310 | + |
| 311 | +Services of an application are controlled through the class :class:`AndroidService`. |
| 312 | + |
| 313 | +.. module:: android.service |
| 314 | + |
| 315 | +.. class:: AndroidService(title, description) |
| 316 | + |
| 317 | + Run ``service/main.py`` from the application directory as a service. |
| 318 | + |
| 319 | + :param title: Notification title, default to 'Python service' |
| 320 | + :param description: Notification text, default to 'Kivy Python service started' |
| 321 | + :type title: str |
| 322 | + :type description: str |
| 323 | + |
| 324 | + .. method:: start(arg) |
| 325 | + |
| 326 | + Start the service. |
| 327 | + |
| 328 | + :param arg: Argument to pass to a service, through the environment variable |
| 329 | + ``PYTHON_SERVICE_ARGUMENT``. Defaults to '' |
| 330 | + :type arg: str |
| 331 | + |
| 332 | + .. method:: stop() |
| 333 | + |
| 334 | + Stop the service. |
| 335 | + |
| 336 | +Application activity part example, ``main.py``: |
| 337 | + |
| 338 | +.. code-block:: python |
| 339 | +
|
| 340 | + from android import AndroidService |
| 341 | +
|
| 342 | + ... |
| 343 | +
|
| 344 | + class ServiceExample(App): |
| 345 | +
|
| 346 | + ... |
| 347 | +
|
| 348 | + def start_service(self): |
| 349 | + self.service = AndroidService('Sevice example', 'service is running') |
| 350 | + self.service.start('Hello From Service') |
| 351 | +
|
| 352 | + def stop_service(self): |
| 353 | + self.service.stop() |
| 354 | +
|
| 355 | +Application service part example, ``service/main.py``: |
| 356 | + |
| 357 | +.. code-block:: python |
| 358 | +
|
| 359 | + import os |
| 360 | + import time |
| 361 | +
|
| 362 | + # get the argument passed |
| 363 | + arg = os.getenv('PYTHON_SERVICE_ARGUMENT') |
| 364 | +
|
| 365 | + while True: |
| 366 | + # this will print 'Hello From Service' continually, even when the application is switched |
| 367 | + print arg |
| 368 | + time.sleep(1) |
| 369 | +
|
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