Screen Manager in Kivy using. kv file in Python

Kivy is a platform-independent graphical user interface tool in Python. because it is compatible with Android, iOS, Linux, and Windows. It is generally utilized in the improvement of Android applications, however, that doesn't block its application to work area programs.

Widget for Screen Manager:

A widget called the screen manager is utilized to deal with a few screens in your program. The default ScreenManager just shows each screen in turn and switches between screens utilizing a TransitionBase. There are a few changes upheld.

Imported are the ScreenManager and Screen classes. The ScreenManager will be utilized in the following ways by the root:

Note: SlideTransition with parameters for direction and duration is the transition type used by default by ScreenManager.

Basic Method:

1) import kivy
2) import kivyApp
3) Import Screen Manager, Screen, "Transitions you want to use" 
4) Set minimum version(optional)
5) Create Different Screen classes and pass them
6) Create features of Screen classes in the .kv file 
       :: Add features on different screens
7) Create an App class
8) return screen manager
9) Run an instance of the class

The code's implementation using a .kv file in .py file is shown below.

# Program to Show how to create a switch
# import kivy module   
import kivy       
# Your app's basic class derives from the App class.   
# app: always refers to your application's instance.  
from kivy.app import App    
# This limits the kivy version, meaning that you cannot use the app or software below this kivy version. 
kivy.require('1.9.0') 
# When a .kv file is to be used in a .py file, a builder is used.
from kivy.lang import Builder 
# A widget devoted to handling numerous screens
# for your program is the screen manager.
from kivy. uix.screenmanager import ScreenManager, Screen  
# Your code can be created in the Python file.
Builder.load_string("""
<ScreenOne>:
    BoxLayout:
        Button:
            text: "Go to Screen 2"
            background_color : 0, 0, 1, 1
            on_press:
                # You can specify the slide's direction and the change's number and duration.
                root.manager.transition.direction = 'left'
                root.manager.transition.duration = 1
                root. manager.current = 'screen_two'  
<ScreenTwo>:
    BoxLayout:
        Button:
            text: "Go to Screen 3"
            background_color: 1, 1, 0, 1
            on_press:
                root.manager.transition.direction = 'left'
                root.manager.transition.duration = 1
                root. manager.current = 'screen_three'
<ScreenThree>:
    BoxLayout:
        Button:
            text: "Go to Screen 4"
            background_color: 1, 0, 1, 1
            on_press:
                root.manager.transition.direction = 'left'
                root.manager.transition.duration = 1
                root. manager.current = 'screen_four'
<ScreenFour>:
    BoxLayout:
        Button:
            text: "Go to Screen 5"
            background_color : 0, 1, 1, 1
            on_press:
                root.manager.transition.direction = 'left'
                root.manager.transition.duration = 1
                root. manager.current = 'screen_five'
<ScreenFive>:
    BoxLayout:
        Button:
            text: "Go to Screen 1"
            background_color: 1, 0, 0, 1
            on_press:
                root.manager.transition.direction = 'right'
                root. manager.current = 'screen_one' 
""")
# Make a class for every screen where you may add 
# helpful screen-specific functions.
class ScreenOne(Screen):
    pass  
class ScreenTwo(Screen):
    pass 
class ScreenThree(Screen):
    pass 
class ScreenFour(Screen):
    pass
class ScreenFive(Screen):
    pass
# Switching between screens is controlled by the ScreenManager.
screen_manager = ScreenManager()  
# Provide a name 
# to switch screens after adding the screens to the manager.
screen_manager.add_widget(ScreenOne(name ="screen_one"))
screen_manager.add_widget(ScreenTwo(name ="screen_two"))
screen_manager.add_widget(ScreenThree(name ="screen_three"))
screen_manager.add_widget(ScreenFour(name ="screen_four"))
screen_manager.add_widget(ScreenFive(name ="screen_five")) 
# Creating the App class
class ScreenApp(App):
    def build(self):
        return screen_manager 
# running the app
sample_app = ScreenApp()
sample_app.run()

Output:

Transitions That Change:

As a matter of transitions, you have various changes available to you, including:

NoTransition immediately and without any animation changes screens.
Using the slide transition, The screen can be moved in any direction.
CardTransition relies upon the mode, the new screen either slides onto the bygone one or the old screen slides off the upgraded one
The implementation of the iOS swap transition is called SwapTransition.
Screen-fading shader called FadeTransition
To clear the screens off of right to left, utilize the shader WipeTransition.
The old screen "falls" and turns straightforward in the FallOutTransition shader, uncovering the enhanced one taking cover behind it.
RiseInTransition is a shader that makes a screen ascend from the focal point of the screen as it changes from straightforward to misty.

By altering the ScreenManager.transition property, you can quickly change transitions:

# Program to Demonstrate the Creation of a Switch
# Importing the kivy module   
import kivy       
# Your app's basic class derives from the App class.   
# app: always refers to your application's instance.  
from kivy.app import App
# This limits the kivy version, that is
# Below this Kivy version, the app or program is not usable. 
kivy.require('1.9.0') 
# When a .kv file is to be used in a .py file, a builder is used.
from kivy.lang import Builder 
# A widget  devoted to handling
# numerous screens for your programme is the screen manager.
from kivy. uix. screen manager import (ScreenManager, Screen, NoTransition,
SlideTransition, CardTransition, SwapTransition,
FadeTransition, WipeTransition, FallOutTransition, RiseInTransition)  
# Your kv code can be created in the Python file.
Builder.load_string("""
<ScreenOne>:
    BoxLayout:
        Button:
            text: "Go to Screen 2"
            background_color : 0, 0, 1, 1
            on_press:
                # You can specify the slide's direction and the change's number and duration.
                root.manager.transition.direction = 'left'
                root.manager.transition.duration = 1
                root. manager.current = 'screen_two'  
<ScreenTwo>:
    BoxLayout:
        Button:
            text: "Go to Screen 3"
            background_color: 1, 1, 0, 1
            on_press:
                root.manager.transition.direction = 'left'
                root.manager.transition.duration = 1
                root. manager.current = 'screen_three' 
<ScreenThree>:
    BoxLayout:
        Button:
            text: "Go to Screen 4"
            background_color: 1, 0, 1, 1
            on_press:
                root.manager.transition.direction = 'left'
                root.manager.transition.duration = 1
                root. manager.current = 'screen_four'
<ScreenFour>:
    BoxLayout:
        Button:
            text: "Go to Screen 5"
            background_color : 0, 1, 1, 1
            on_press:
                root.manager.transition.direction = 'left'
                root.manager.transition.duration = 1
                root. manager.current = 'screen_five'
<ScreenFive>:
    BoxLayout:
        Button:
            text: "Go to Screen 1"
            background_color: 1, 0, 0, 1
            on_press:
                root.manager.transition.direction = 'right'
                root. manager.current = 'screen_one'
""") 
# For each screen you can include, create a class.
# practical techniques particular to that screen
class ScreenOne(Screen):
    pass  
class ScreenTwo(Screen):
    pass 
class ScreenThree(Screen):
    pass 
class ScreenFour(Screen):
    pass 
class ScreenFive(Screen):
    pass  
# Switching between screens is controlled by the ScreenManager.
# The transitions can be adjusted accordingly.
screen_manager = ScreenManager(transition = RiseInTransition())  
# Give the manager the screens, then give it a name.
# that switches between screens
screen_manager.add_widget(ScreenOne(name ="screen_one"))
screen_manager.add_widget(ScreenTwo(name ="screen_two"))
screen_manager.add_widget(ScreenThree(name ="screen_three"))
screen_manager.add_widget(ScreenFour(name ="screen_four"))
screen_manager.add_widget(ScreenFive(name ="screen_five"))
 
# Creating the App class
class ScreenApp(App):
    def build(self):
        return screen_manager
# running the app
sample_app = ScreenApp()
sample_app.run()