Python for Android

Python for android is a project to create your own Python distribution including the modules you want, and create an apk including python, libs, and your application.

• Website: http://python-for-android.rtfd.org/
• Forum: https://groups.google.com/forum/?hl=fr#!forum/python-android
• Mailing list: python-android@googlegroups.com

Global overview

1. Download Android NDK, SDK

• NDK: http://dl.google.com/android/ndk/android-ndk-r8c-linux-x86.tar.bz2
• More details at: http://developer.android.com/tools/sdk/ndk/index.html
• SDK: http://dl.google.com/android/android-sdk_r21.0.1-linux.tgz
• More details at:http://developer.android.com/sdk/index.html

1. Launch "android", and download latest Android platform, here API 14, which would be Android 4.0

2. Export some environment variables:

   export ANDROIDSDK="/path/to/android/android-sdk-linux_86"
   export ANDROIDNDK="/path/to/android/android-ndk-r8c"
   export ANDROIDNDKVER=r8c
   export ANDROIDAPI=14
   

(Of course correct the paths mentioned in ANDROIDSDK and ANDROIDNDK)

1. Clone python-for-android:

   git clone git://github.com/kivy/python-for-android
   

2. Build a distribution with OpenSSL module, PIL and Kivy:

   cd python-for-android
   ./distribute.sh -m "openssl pil kivy"
   

3. Go to your fresh distribution, build the APK of your application:

   cd dist/default
   ./build.py --package org.test.touchtracer --name touchtracer \
   --version 1.0 --dir ~/code/kivy/examples/demo/touchtracer debug
   

4. Install the debug apk to your device:

   adb install bin/touchtracer-1.0-debug.apk
   

5. Enjoy.

Troubleshooting

if you get the following message:

Android NDK: Host 'awk' tool is outdated. Please define HOST_AWK to point to Gawk or Nawk !

a solution is to remove the "awk" binary in the android ndk distribution

rm $ANDROIDNDK/prebuilt/linux-x86/bin/awk

Widgets

If you want to provide widgets, you need a 'WidgetProvider.py' file in your program directory which should be structured as follows:

class MyWidget1(Widget):
    '''This class is the central interface between the python code
    and the widgets. All events occurring for the widget will get
    passed down to the corresponding functions in this class.'''

    def __init__(self, widget = None):
        '''This function will initialize the given widget 'widget'
        and will set it's visual appearance. If this function
        throws an error, the initialisation is considered as failed
        and the widget will not be created.
        '''
        pass

    def updateWidget(self, updateType = None):
        '''This function gets called every time the widget receives
        an update. 'updateType' describes the type of the update.
        If it's self.OneTime_UpdateType, then it is an update
        scheduled with schedule_once.
        If it's self.Interval_UpdateType, then it is an interval
        update.
        If it's self.Hard_UpdateType, the update was a periodic
        update triggered trough the defined intervall at
        self.hard_update. This update might have woke up the device.
        '''
        pass

    def destroyWidget(self):
        '''This function is called if the user deletes a widget from
        the home screen.
        '''
        pass

An example 'WidgetProvider.py' is provided here.

For each widget you want to provide, you need a class which is a subclass of the Widget class at AndroidWidgets.py. You can also set certain properties of your widget by overwriting the corresponding attribute in your class:

class MyWidget2(Widget):
    widget_name = 'HelloWorldWidget'

Finally you need to set the '--widget' flag when building your app with build.py in dist/default.

Each widget has an id and a canvas. The canvas is used to define the widgets look. Just add a CanvasObject (aka. view) to the canvas and push the change to the screen:

self.canvas.add(view)
self.update_graphics() # Don't forget this!

Due to android limitations, only a few view types are allowed on the canvas:

• Layouts

• LinearLayout
• FrameLayout
• RelativeLayout
• GridLayout

• Views

• TextView
• AnalogClock
• Button
• Chronometer
• ImageButton
• ImageView
• ProgressBar
• ViewFlipper
• ListView
• GridView
• StackView
• AdapterViewFlipper
• ViewStub

You can get a new CanvasObject from every other CanvasObject or a canvas itself:

textview1 = self.canvas.TextView(text = 'Hello world!')
textview2 = textview1.TextView(text = 'How are you?')

For more information about the canvas system look at AndroidWidgets.py.