Kivy is a platform independent GUI tool in Python. As it can be run on Android, IOS, linux, and Windows, etc. It is basically used to develop the Android application, but it does not mean that it can not be used on Desktops applications.
Kivy Tutorial – Learn Kivy with Examples.
Image Widget:
The Image widget is used to display an image. To use the image widget you must have to import :
from kivy.uix.image import Image, AsyncImage (not necessary while working with .kv file)
because the module kivy.uix.image have all the functionality related to images.
Images can be loaded to the Application via two types:
1) Synchronous Loading: Loading image from the system (must be from the folder in which .py and .kv file is saved)
2) Asynchronous Loading: To load an image asynchronously (for example from an external webserver)
Note: By default, the image is centered and fits inside the widget bounding box. If you don’t want that, you can set allow_stretch to True and keep_ratio to False.
Basic Approach to create multiple layout in one file: 1) import kivy 2) import kivyApp 3) import image 4) import BoxLayout 5) set minimum version(optional) 6) Create the Layout class 7) Create App class 8) Create .kv file: 1) Add BoxLayout 2) Add Label 3) Add Image 4) Resizing, Positioning etc of Image 9) return instance of the layout class 10) Run an instance of the class
So in the below code, we will explain How to load Synchronous and Asynchronous images. Also How to resize, Positioning, Label, etc the image with some more stuff.
.py file –
## Sample Python application demonstrating the ## working with images in Kivy using .kv file ################################################## # import kivy module import kivy
# base Class of your App inherits from the App class. # app:always refers to the instance of your application from kivy.app import App
# this restrict the kivy version i.e # below this kivy version you cannot # use the app or software kivy.require( '1.9.0' )
# BoxLayout arranges children in a vertical or horizontal box. # or help to put the children at the desired location. from kivy.uix.boxlayout import BoxLayout
# to change the kivy default settings we use this module config from kivy.config import Config
# 0 being off 1 being on as in true / false # you can use 0 or 1 && True or False Config. set ( 'graphics' , 'resizable' , True )
# creating the root widget used in .kv file class Imagekv(BoxLayout):
'''
no need to do anything here as
we are building things in .kv file
'''
pass
# class in which name .kv file must be named My.kv. class MyApp(App):
# define build() function
def build( self ):
# returning the instance of Imagekv class
return Imagekv()
# run the App if __name__ = = '__main__' :
MyApp().run()
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.kv file implementation –
# How to use images in kivy using .kv # root widget of Imagekv Class <Imagekv>: # Giving orientation to Box Layout
orientation: 'vertical'
############################################### # Adding Box Layout
BoxLayout:
padding: 5
# Adding image from the system
Image:
source: 'download.jpg'
# Giving the size of image
size_hint_x: 0.4
# allow stretching of image
allow_stretch: True
# Giving Label to images
Label:
text: "Python"
font_size: 11
bold: True
Label:
text: "Programming Language"
font_size: 10
############################################### # Drawing the line between the multiples
Label:
canvas.before:
Color:
rgba: ( 1 , 1 , 1 , 1 )
Rectangle:
size: self .size
pos: self .pos
size_hint_y: None
height: 1
################################################ # Another Box Layout
BoxLayout:
padding: 5
Image:
source: "downloading.jpg"
size_hint_x: 0.4
allow_stretch: True
Label:
text: "Image"
font_size: 11
bold: True
Label:
text: "Python Image"
font_size: 10
############################################# # Drawing the line between the multiples
Label:
canvas.before:
Color:
rgba: ( 1 , 1 , 1 , 1 )
Rectangle:
size: self .size
pos: self .pos
size_hint_y: None
height: 1
############################################### # Adding next Box Layout
BoxLayout:
padding: 5
# To load an image asynchronously
# (for example from an external webserver)
AsyncImage:
width: 100
allow_stretch: True
Label:
text: " Asynchronous Image "
font_size: 11
bold: True
Label:
text: "Kivy Logo"
font_size: 10
#################################################### # Drawing the line between the multiples
Label:
canvas.before:
Color:
rgba: ( 1 , 1 , 1 , 1 )
Rectangle:
size: self .size
pos: self .pos
size_hint_y: None
height: 1
##################################################### # LAst Box Layout
BoxLayout:
padding: 5
AsyncImage:
size_hint_y: None
width: 100
allow_stretch: True
Label:
text: "Asynchronous Image "
font_size: 11
bold: True
Label:
text: " Webserver image "
font_size: 10
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Output: