KVLang Series – 4

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Vertical BoxLayout

Content:
– .kv file
– .py file
– screenshot of output

0004_verticalBoxLayout.kv

Just add the BoxLayout orientation: ‘vertical’ property. This arranges its contents in a vertical manner instead of the default ‘horizontal’.

BoxLayout:
    orientation: 'vertical'
    Label:
        text: 'Input:'
    TextInput:
        text: 'Default Text'
    Button:
        text: 'Press Me'

0004_verticalBoxLayout.py

This is adapted from previous python file. Again we make minor changes to update the .kv filename and give a new window height.

1. EDIT

   CHANGE: The OLD self.root = Builder.load_file(”) TO the NEW

2. EDIT

   WAS: Config.set(‘graphics’, ‘height’, ’30’)

   NOW: Config.set(‘graphics’, ‘height’, ’90’)

''' 0004_verticalBoxLayout.py
Used to display 0004_verticalBoxLayout.kv - Again, no new concepts in here.
'''
import kivy
kivy.require('1.8.0') # replace with your current kivy version !

from kivy.app import App
from kivy.lang import Builder
from kivy.config import Config

Config.set('graphics', 'width',  '323')
Config.set('graphics', 'height', '90')

class MyApp(App):

    def build(self):
        self.root = Builder.load_file('0004_verticalBoxLayout.kv')
        return self.root

if __name__ == '__main__':
    MyApp().run()

0004_verticalBoxLayout ScreenShot

Here is what this looks like run on Windows XP. In Pixels, it has:
– width: 323
– height: 200

KVLang Series – 3

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More Widgets in a BoxLayout

Content:
– .kv file
– .py file
– screenshot of output

0003_moreWidgets.kv

In the .kv file we add some more widgets under a BoxLayout.
If we added the widgets directly to the file, not being underneath our layout, it would be and ERROR because they would be considered root rules and “you can have one root rule, and any number of class or template rules.”
The BoxLayout has a default orientation: ‘horizontal’.

### 0003_moreWidgets.kv

BoxLayout:
    Label:
        text: 'Input:'
    TextInput:
        text: 'Default Text'
    Button:
        text: 'Press Me'

0003_moreWidgets.py

This is adapted from previous python file. We make minor changes to update the .kv filename and give a new window height.

1. EDIT

   CHANGE: The OLD self.root = Builder.load_file(”) TO the NEW

2. EDIT

   WAS: Config.set(‘graphics’, ‘height’, ‘200’)

   NOW: Config.set(‘graphics’, ‘height’, ’30’)

''' 0003_moreWidgets.py
Used to display 0003_moreWidgets.kv - No new concepts in here.
'''
import kivy
kivy.require('1.8.0') # replace with your current kivy version !

from kivy.app import App
from kivy.lang import Builder
from kivy.config import Config

Config.set('graphics', 'width',  '323')
Config.set('graphics', 'height', '30')

class MyApp(App):

    def build(self):
        self.root = Builder.load_file('0003_moreWidgets.kv')
        return self.root

if __name__ == '__main__':
    MyApp().run()

0003_moreWidgets ScreenShot

Here is what this looks like run on Windows XP. In Pixels, it has:
– width: 323
– height: 200

KVLang Series – 2

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Window Size – Hello World Label Widget

Content:
– .kv file
– .py file
– screenshot of output

0002_windowSize.kv

This is PRETTY MUCH the same as before. Unfortunately (from my perspective), we must alter the .py file to change the window size. If anyone knows a way to do this in a .kv file please post it to the comments. Thanks.

Label:
    text: 'A smaller hello, world.'

0002_windowSize.py

As I said earlier, Unfortunately (from my perspective), we must alter the .py file to change the window size. If anyone knows a way to do this in a .kv file please post it to the comments. Thanks.

This is adapted from 0001_helloWorld.py. Here are the changes:

1. EDIT – Builder.load_file()

   WAS: self.root = Builder.load_file(‘0001_helloWorld.kv’)

   NOW: self.root = Builder.load_file(‘0002_windowSize.kv’)

2. ADD – Window Sizing Info

   AFTER: from kivy.lang import Builder

   BEFORE: class MyApp(App):

   INSERT:

   from kivy.config import Config

   Config.set(‘graphics’, ‘width’, ‘323’)

   Config.set(‘graphics’, ‘height’, ‘200’)

''' 0002_windowSize.py
Demonstrates Window Sizing - kivy.config - Config.set('graphics',
'''
import kivy
kivy.require('1.8.0') # replace with your current kivy version !

from kivy.app import App
from kivy.lang import Builder
from kivy.config import Config

Config.set('graphics', 'width',  '323')
Config.set('graphics', 'height', '200')

class MyApp(App):

    def build(self):
        self.root = Builder.load_file('0002_windowSize.kv')
        return self.root

if __name__ == '__main__':
    MyApp().run()

0002_windowSize ScreenShot

Here is what this looks like run on Windows XP. In Pixels, it has:
– width: 323
– height: 200

KVLang Series – 1

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Hello World Label Widget

Content:
– .kv file
– .py file
– screenshot of output

0001_helloWorld.kv

Here is the .kv == KVLang file for our hello world. It generates a GIGANTIC window containing a Kivy Builtin Label that says, “Hello, world.”

Label:
    text: 'Hello, world.'

0001_helloWorld.py

Here is a SIMPLE and what I believe is the MINIMAL, MOST GENERIC, python file to show our KVLang window. Hopefully this is a starting point template for KVLang projects.

This is adapted from:

• Kivy Guide Create an Application
• Gabriel Pettier’s mah_button.py

''' 0001_helloWorld.py 
A simple, general starting point Python template for KVLang projects.
'''
import kivy
kivy.require('1.8.0') # replace with your current kivy version !

from kivy.app import App
from kivy.lang import Builder

class MyApp(App):

    def build(self):
        self.root = Builder.load_file('0001_helloWorld.kv')
        return self.root

if __name__ == '__main__':
    MyApp().run()

0001_helloWorld ScreenShot

Here is what this looks like run on Windows XP. In Pixels, it has:
– width: 808
– height: 634

KVLang Series – 0

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KVLang Step by Step with Minimum Python

I am trying to see what the KVLang can do WITH MINIMUM PYTHON, to identify its features and understand its power.

I use Step by Step examples following the Version 1.8.0 documentation from

• Programming Guide – Kv language
• Kivy Language

Hopefully, the .py and .kv files are SIMPLE enough to be used as TEMPLATES for further investigation.

Click the Next → link at the top to get going.