pythonkivykivy-language
Get access a variable inside a method from another class - Python and Kivy
I'm currently working with kivy to develop an application that will be printing numbers dinamically in several screens.
Right now is printing values from one screen but I also have to show values in other two screens, the problem is that I'm calling a method from one class to run continously in time and update the variable values and I would like to consult or get access to those variables from that method in other class to print them in the other screens, each class represents one screen so it's necessary their presence in code.
I would like to know if this is possible and how could I implement a solution to do it.
Let me share you my piece of code, it's very large so I would paste only relevant code:
gui.py
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition
from kivy.properties import ObjectProperty, StringProperty, NumericProperty
from kivy.uix.gridlayout import GridLayout
from kivy.clock import Clock
# Creating dynamic variables
class Show_Val(Screen):
timer_update = NumericProperty(0)
dist_travel = NumericProperty(0)
average_mph = NumericProperty(0)
temp = NumericProperty(0)
dist_travel_2 = NumericProperty(0)
# screen 1: this is working ok
class Main_Screen(Screen):
update_val = Show_Val()
def update(self, dt):
# these corresponds to the screen 1, their are currently working
self.update_val.timer_update += 1
self.update_val.dist_travel += 1
self.update_val.average_mph += 1
# temp variable would be printed in screen 2: Input_Screen
self.update_val.temp += 1
# and dist_travel_2 will be printed in screen 3: Route_Screen
self.update_val.dist_travel_2 += 1
# screen 2: here I need to get access to self.update_val.temp
class Input_Screen(Screen):
pass
# screen 3: here I need to get access to self.update_val.temp
class Route_Screen(Screen):
pass
# screen 0 or master screen management, it's just for reference
class Screen_Management(ScreenManager):
pass
presentation = Builder.load_file("gui.kv")
class guiApp(App):
def build(self):
main = Main_Screen()
# this call is my "loop" and is updating the variables at 50hz
# frequency, I tried to call differently functions like this one
# but with no success.
Clock.schedule_interval(main.update, 1.0/50.0)
return presentation
guiApp().run()
gui.kv
Screen_Management:
id: screen_management
transition: FadeTransition()
Main_Screen:
id: main_screen
name: "main_screen_name"
manager: screen_management
Input_Screen:
id: tire_setup_screen_id
name: "tire_setup_screen_name"
manager: screen_management
Route_Screen:
name: "route_input_screen_name"
##############################################################
##############################################################
# Screen 1: Main Screen
# working ok
<Main_Screen>:
canvas:
Color:
rgb: [.30, .30, .30]
Rectangle:
pos: self.pos
size: self.size
BoxLayout:
orientation: 'vertical'
Button:
id: timer_indicator
background_disabled_down: ('0.00.00,000')
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 100
text: str(root.update_val.timer_update)
#text: root.update_val.test
pos_hint: {'x': .2}
size_hint: [.8, 1]
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 100
text: str(root.update_val.dist_travel)
pos_hint: {'x': .2}
size_hint: [.8, 1]
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 100
text: str(root.update_val.average_mph)
pos_hint: {'x': .2}
size_hint: [.8, 1]
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
size_hint: .2, 1
pos_hint: {"x": 0, "center_y": .5}
on_release: app.root.current = "tire_setup_screen_name"
text: " INPUTS "
font_size: 30
##############################################################
##############################################################
# Screen 2: Input Screen
# I will need to print self.update_val.temp value in this creen
<Input_Screen>:
canvas:
Color:
rgb: [.30, .30, .30]
Rectangle:
pos: self.pos
size: self.size
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 30
size_hint: 0.2, .5
text: "MAIN"
pos_hint: {'x':0, 'y': 0}
on_release: app.root.current = "main_screen_name"
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 30
size_hint: .2, .5
text: "ROUTES"
pos_hint: {'x':0, 'y': .5}
on_release: app.root.current = "route_input_screen_name"
GridLayout:
cols: 2
pos: (205,150)
size_hint: (.8, .75)
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 30
text: " TIRE\nTEMP (°C)"
size_hint_x: None
width: 150
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 100
text: "000.000" # self.update_val.temp value it will be here
##############################################################
##############################################################
# Screen 3: Route Screen
# self.update_val.dist_travel_2 will be printed in this screen
<Route_Screen>:
canvas:
Color:
rgb: [.30, .30, .30]
Rectangle:
pos: self.pos
size: self.size
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 30
size_hint: 0.2, .5
text: "INPUTS"
pos_hint: {'x':0, 'y': 0}
on_release: app.root.current = "tire_setup_screen_name"
BoxLayout:
orientation: 'vertical'
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 50
text: "000.000 MPH" # self.update_val.dist_travel_2 value
pos_hint: {'x': .2}
size_hint: [.8, 1]
Thanks for your time and I hope that you could help me to solve this issue.
How can I access to variables from one method in other class?
Solution
Use Kivy ObjectProperty to hook up to the screen ids. Please refer to the example below for details.
Snippets
Python Script
class Screen_Management(ScreenManager):
main_screen = ObjectProperty(None)
input_screen = ObjectProperty(None)
route_screen = ObjectProperty(None)
...
class Main_Screen(Screen):
update_val = Show_Val()
def update(self, dt):
# these corresponds to the screen 1, their are currently working
self.update_val.timer_update += 1
self.update_val.dist_travel += 1
self.update_val.average_mph += 1
# temp variable would be printed in screen 2: Input_Screen
self.update_val.temp += 1
self.manager.input_screen.access_update_val(self.update_val)
self.manager.route_screen.access_update_val(self.update_val)
# and dist_travel_2 will be printed in screen 3: Route_Screen
self.update_val.dist_travel_2 += 1
kv file
<Screen_Management>:
id: screen_management
main_screen: main_screen
input_screen: tire_setup_screen_id
route_screen: route_screen
transition: FadeTransition()
Main_Screen:
id: main_screen
name: "main_screen_name"
manager: screen_management
Input_Screen:
id: tire_setup_screen_id
name: "tire_setup_screen_name"
manager: screen_management
Route_Screen:
id: route_screen
name: "route_input_screen_name"
Example
gui2.py
from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.properties import ObjectProperty, NumericProperty
from kivy.clock import Clock
# Creating dynamic variables
class Show_Val(Screen):
timer_update = NumericProperty(0)
dist_travel = NumericProperty(0)
average_mph = NumericProperty(0)
temp = NumericProperty(0)
dist_travel_2 = NumericProperty(0)
# screen 1: this is working ok
class Main_Screen(Screen):
update_val = Show_Val()
def update(self, dt):
# these corresponds to the screen 1, their are currently working
self.update_val.timer_update += 1
self.update_val.dist_travel += 1
self.update_val.average_mph += 1
# temp variable would be printed in screen 2: Input_Screen
self.update_val.temp += 1
self.manager.input_screen.access_update_val(self.update_val)
self.manager.route_screen.access_update_val(self.update_val)
# and dist_travel_2 will be printed in screen 3: Route_Screen
self.update_val.dist_travel_2 += 1
# screen 2: here I need to get access to self.update_val.temp
class Input_Screen(Screen):
def access_update_val(self, obj):
print("Input_Screen: update_val.temp={}".format(obj.temp))
# screen 3: here I need to get access to self.update_val.temp
class Route_Screen(Screen):
def access_update_val(self, obj):
print("Route_Screen: update_val.temp={}".format(obj.temp))
# screen 0 or master screen management, it's just for reference
class Screen_Management(ScreenManager):
main_screen = ObjectProperty(None)
input_screen = ObjectProperty(None)
route_screen = ObjectProperty(None)
class gui2App(App):
def build(self):
sm = Screen_Management()
# this call is my "loop" and is updating the variables at 50hz
# frequency, I tried to call differently functions like this one
# but with no success.
Clock.schedule_interval(sm.main_screen.update, 1.0/50.0)
return sm
if __name__ == "__main__":
gui2App().run()
gui2.kv
#:kivy 1.10.0
#:import FadeTransition kivy.uix.screenmanager.FadeTransition
<Screen_Management>:
id: screen_management
main_screen: main_screen
input_screen: tire_setup_screen_id
route_screen: route_screen
transition: FadeTransition()
Main_Screen:
id: main_screen
name: "main_screen_name"
manager: screen_management
Input_Screen:
id: tire_setup_screen_id
name: "tire_setup_screen_name"
manager: screen_management
Route_Screen:
id: route_screen
name: "route_input_screen_name"
##############################################################
##############################################################
# Screen 1: Main Screen
# working ok
<Main_Screen>:
canvas:
Color:
rgb: [.30, .30, .30]
Rectangle:
pos: self.pos
size: self.size
BoxLayout:
orientation: 'vertical'
Button:
id: timer_indicator
background_disabled_down: ('0.00.00,000')
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 100
text: str(root.update_val.timer_update)
#text: root.update_val.test
pos_hint: {'x': .2}
size_hint: [.8, 1]
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 100
text: str(root.update_val.dist_travel)
pos_hint: {'x': .2}
size_hint: [.8, 1]
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 100
text: str(root.update_val.average_mph)
pos_hint: {'x': .2}
size_hint: [.8, 1]
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
size_hint: .2, 1
pos_hint: {"x": 0, "center_y": .5}
on_release: app.root.current = "tire_setup_screen_name"
text: " INPUTS "
font_size: 30
##############################################################
##############################################################
# Screen 2: Input Screen
# I will need to print self.update_val.temp value in this creen
<Input_Screen>:
canvas:
Color:
rgb: [.30, .30, .30]
Rectangle:
pos: self.pos
size: self.size
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 30
size_hint: 0.2, .5
text: "MAIN"
pos_hint: {'x':0, 'y': 0}
on_release: app.root.current = "main_screen_name"
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 30
size_hint: .2, .5
text: "ROUTES"
pos_hint: {'x':0, 'y': .5}
on_release: app.root.current = "route_input_screen_name"
GridLayout:
cols: 2
pos: (205,150)
size_hint: (.8, .75)
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 30
text: " TIRE\nTEMP (°C)"
size_hint_x: None
width: 150
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 100
text: "000.000" # self.update_val.temp value it will be here
##############################################################
##############################################################
# Screen 3: Route Screen
# self.update_val.dist_travel_2 will be printed in this screen
<Route_Screen>:
canvas:
Color:
rgb: [.30, .30, .30]
Rectangle:
pos: self.pos
size: self.size
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 30
size_hint: 0.2, .5
text: "INPUTS"
pos_hint: {'x':0, 'y': 0}
on_release: app.root.current = "tire_setup_screen_name"
BoxLayout:
orientation: 'vertical'
Button:
background_color: .52, .52, .52, 1
bold: 1
color: .0078,.67,.69,1
font_size: 50
text: "000.000 MPH" # self.update_val.dist_travel_2 value
pos_hint: {'x': .2}
size_hint: [.8, 1]
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