Snakes on a Droid

A brief introduction to building Android apps in Python with Kivy, given at ValleyDevFest 2016

Transcript

1. Snakes on a Droid A brief introduction to building Android apps in Python with Kivy
2. #ValleyDevFest A brief introduction to building Android apps in Python with Kivy
3. bit.ly/kivy-devfest github.com/dmpayton/snakes-on-a-droid
4. Hi, I'm Derek.
5. I ❤ Python
6. Wait, no...
7. I ❤ Python
9. Batteries Included
10. Extensive Ecosystem
11. Amazing Community Hello!
12. Dependable
13. ♫ I'VE GOT ANOTHER CONFESSION TO MAKE ♫
16. meh.
17. I want to build software that works on my phone… ...but in general, I prefer to code in Python
18. kivy
19. Python library for creating multi-touch applications Kivy is...
20. Open Source MIT License Kivy is...
21. Cross-platform Kivy is...
22. Fast. Kivy is...
23. ✨ Production ready ✨ Kivy is...
24. You said Kivy is fast, but...
26. The missing link between the simplicity of Python and the speed of C cython
28. $ pip install Cython $ pip install kivy Installing Kivy
29. from kivy.app import App from kivy.uix.label import Label class DemoApp(App): def build(self): return Label(text='hello, world', font_size=60) if __name__ == '__main__': TestApp().run() 01. hello, world main.py
30. from kivy.app import App from kivy.uix.label import Label class DemoApp(App): def build(self): return Label(text='hello, world', font_size=60) if __name__ == '__main__': TestApp().run() main.py 01. hello, world
31. from kivy.app import App from kivy.uix.label import Label class DemoApp(App): def build(self): return Label(text='hello, world', font_size=60) if __name__ == '__main__': TestApp().run() main.py 01. hello, world
32. from kivy.app import App from kivy.uix.label import Label class DemoApp(App): def build(self): return Label(text='hello, world', font_size=60) if __name__ == '__main__': TestApp().run() main.py 01. hello, world
33. from kivy.app import App from kivy.uix.label import Label from kivy.uix.scatterlayout import ScatterLayout class DemoApp(App): def build(self): scatter = ScatterLayout() label = Label(text='hello, world', font_size=60) scatter.add_widget(label) return scatter if __name__ == '__main__': TestApp().run() main.py 02. multi-touch
34. from kivy.app import App from kivy.uix.label import Label from kivy.uix.scatterlayout import ScatterLayout class DemoApp(App): def build(self): scatter = ScatterLayout() label = Label(text='hello, world', font_size=60) scatter.add_widget(label) return scatter if __name__ == '__main__': TestApp().run() main.py 02. multi-touch
35. from kivy.app import App from kivy.uix.label import Label from kivy.uix.scatterlayout import ScatterLayout class DemoApp(App): def build(self): scatter = ScatterLayout() label = Label(text='hello, world', font_size=60) scatter.add_widget(label) return scatter if __name__ == '__main__': TestApp().run() main.py 02. multi-touch
36. from kivy.app import App from kivy.uix.button import Button from kivy.uix.floatlayout import FloatLayout from kivy.uix.popup import Popup ... main.py 03. events
37. ... class DemoApp(App): def build(self): layout = FloatLayout() open_button = Button( text='click me!', size_hint=(.5, .5), pos_hint={'center_x': .5, 'center_y': .5} ) layout.add_widget(open_button) ... main.py 03. events
38. ... popup = Popup( title='hello, world', auto_dismiss=False, size_hint=(.3, .3) ) close_button = Button(text='close me!') popup.add_widget(close_button) ... main.py 03. events
39. ... open_button.bind(on_release=popup.open) close_button.bind(on_release=popup.dismiss) return layout ... main.py 03. events
40. Kv Design Language
41. from kivy.app import App class DemoApp(App): pass if __name__ == '__main__': DemoApp().run() main.py 04. Kv lang demo.kv
42. FloatLayout: id: layout Button: id: open_button Popup: id: popup Button: id: close_button main.py 04. Kv lang demo.kv
43. FloatLayout: id: layout Button: id: open_button text: 'click me!' size_hint: (.5, .5) pos_hint: {'center_x': .5, 'center_y': .5} on_release: root.ids['popup'].open() Popup: id: popup ... Button: id: close_button ... main.py 04. Kv lang demo.kv
44. FloatLayout: ... Button: ... Popup: id: popup title: 'hello, world' auto_dismiss: True size_hint: (.3, .3) on_parent: if self.parent == layout: layout.remove_widget(self) Button: id: close_button text: 'close me!' on_release: root.ids['popup'].dismiss() main.py 04. Kv lang demo.kv
46. We haven't built an Android app...
47. We've built a Kivy app, and we need to package it for Android.
48. → ? →
49. Packages Python apps for Android python-for-android
50. Don't use it (directly). python-for-android
51. Tool for creating application packages buildozer
52. Build for Android or iOS using a common spec file. buildozer
53. $ pip install buildozer buildozer
54. $ buildozer init buildozer
55. [app] # (str) Title of your application title = My Application # (str) Package name package.name = myapp # (str) Package domain (needed for android/ios packaging) package.domain = org.test # (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 ... buildozer.spec
56. ... # # Android specific # # (bool) Indicate if the application should be fullscreen or not fullscreen = 1 # (list) Permissions android.permissions = INTERNET # (int) Android API to use android.api = 19 # (int) Minimum API required android.minapi = 9 ... buildozer.spec
57. $ buildozer android_new debug buildozer
58. $ buildozer android_new debug / deploy run buildozer
59. How do you do actual Androidy things?
60. pyjnius Python module to access Java classes through the JNI
61. from time import sleep from jnius import autoclass Hardware = autoclass('org.test.android.Hardware') Hardware.accelerometerEnable(True) for x in xrange(20): print(Hardware.accelerometerReading()) sleep(.1) pyjnius
62. But, what about the dream, man?
63. Platform-independent API for common hardware features plyer
64. plyer pyjnius on Android pyobjus on iOS
65. from time import sleep from plyer import accelerometer accelerometer.enable() for x in xrange(20): print(accelerometer.acceleration) sleep(.1) plyer
66. I ❤ Guitar
71. kivy.org
72. Shameless Plug The Fresno Python User Group meets every 4th Tuesday of the month, right here at Bitwise. FresnoPython.com
73. Thanks! Hit me up derek.payton@gmail.com twitter.com/dmpayton github.com/dmpayton