The document discusses how to set up and use Kivy, an open source Python framework for developing multi-touch applications. It covers installing Kivy, basic components like App and widgets, different layouts, making a simple "Hello World" app, using the kv language to separate design from code, and packaging the app into an Android application.

1. Introduction
to Kivy
A Cross-Platform Python UI Library

2. In this Session we shall
discuss:
 How to setup kivy
 Some key features of kivy
 Make a simple ‘Hello World’ application
 Introduce the ‘kv’ language
 Package the application for the android market

3. Setting up Kivy
3 very simple commands:
1. Add Source
 sudo add-apt-repository ppa:kivy-team/kivy
2. Update
 sudo apt-get update
3. Install Kivy
 sudo apt-get install python-kivy


4. Basic Components of Kivy
§ App
§ Widget
§ ScreenManger
§ Screen
§ Layouts
§ Button
§ Label
§ TextInput
§ Image
§ Clock
§ SoundLoader
§ Animation

5. Types of Layouts
§ Anchor Layout
§ Box Layout
§ Float Layout
§ Relative Layout
§ Grid Layout
§ Stack Layout

6. Hello World
f r o m k i v y . a p p i m p o r t A p p
f r o m k i v y . u i x . f l o a t l a y o u t i m p o r t F l o a t L a y o u t
f r o m k i v y . u i x . b u t t o n i m p o r t B u t t o n
f r o m k i v y . u i x . l a b e l i m p o r t L a b e l
c l a s s M y A p p ( A p p ) :
t i t l e = ' H e l l o W o r l d '
d e f b u i l d ( s e l f ) :
s e l f . a p p w i n d o w = F l o a t L a y o u t ( )
b u t t o n = B u t t o n ( t e x t = ' C l i c k H e r e ' )
b u t t o n . b i n d ( o n _ r e l e a s e = s e l f . b u t t o n p r e s s )
s e l f . a p p w i n d o w . a d d _ w i d g e t ( b u t t o n )
r e t u r n s e l f . a p p w i n d o w
d e f b u t t o n p r e s s ( s e l f , * a r g s ) :
s e l f . a p p w i n d o w . c l e a r _ w i d g e t s ( )
s e l f . a p p w i n d o w . a d d _ w i d g e t ( L a b e l ( t e x t = ' H e l l o W o r l d ! ' ) )
i f _ _ n a m e _ _ = = ' _ _ m a i n _ _ ' :
g l o b a l m y a p p
m y a p p = M y A p p ( )
m y a p p . r u n ( )

7. The ‘kv’ Language
class MyButton(Button):
def __init__(self,**kwargs):
super(MyButton,self).__init__(**kwargs)
<MyButton>:
size_hint_x: None
size_hint_y: None
In the kv file:
In the python file:

8. Packaging the app
There are two ways to package the
app:
1. Manually using python-for-android
2.
3. Automatically using buildozer

9. Prerequisites for manual
packaging:
§ Build-Essential and others:
§ sudo apt-get install build-essential patch git-core ccache ant python-pip python-dev
§ Latest Cython:
§ Pip install –upgrade cython
§ Android SDK
§ http://developer.android.com/sdk/index.html
§ Android NDK
§ http://developer.android.com/sdk/ndk/index.html
§ Environment variables
§ export ANDROIDSDK=/path/to/android-sdk
§ export ANDROIDNDK=/path/to/android-ndk
§ export ANDROIDNDKVER=rX
§ export ANDROIDAPI=X
§ export PATH=$ANDROIDNDK:$ANDROIDSDK/platform-tools:$ANDROIDSDK/tools:
$PATH
§

10. Manually
§ Get python-for-android:
§ git clone git://github.com/kivy/python-for-android
§ Create distribution:
§ ./distribute.sh -m "kivy"
§ Build apk:
§ cd dist/default
§ ./build.py --dir <path to your app>
--name "<title>"
--package <org.of.your.app>
--version <human version>
--icon <path to an icon to use>
--orientation <landscape|portrait>
--permission <android permission like VIBRATE> (multiple
allowed)
<debug|release>

11. Automatic Packaging
using buildozer:
§ Get buildozer:
§ git clone https://github.com/kivy/buildozer.git
§ cd buildozer
§ sudo python2.7 setup.py install
§ Create spec file:
§ cd path/to/app
§ buildozer init
§ Build:
§ buildozer android <debug|release>

12. Signing and Aligning
(Only for Release apk)
§ Generate keystore
§ keytool -genkey -v -keystore
path/to/keystore/name.keystore -alias myalias
-keyalg RSA -keysize 2048 -validity 10000
§ <New Password>
§ Sign using keystore
§ jarsigner -verbose -sigalg SHA1withRSA -digestalg
SHA1 -keystore ./keystores/com-mydomain-
myapp.keystore ./myapp/bin/MyApp-1.0.0-
release-unsigned.apk myalias
§ <keystore password>
§ Zipalign
§ ~/.buildozer/android/platform/android-sdk-
21/tools/zipalign -v 4 ./myapp/bin/MyApp-1.0.0-
release-unsigned.apk ./myapp/bin/MyApp-
1.0.0.apk

13. All Done!
Congratulations on your first apk!

14. Thank You!