I wrote this code but now i don't know how to manipulate my images so I am stuck i need help on how to
add images if i have multiple screens
and how to also add other labels so basically screen manipulation with multiple screens
from kivymd.app import MDApp
from kivy.lang.builder import Builder
from kivy.uix.screenmanager import Screen, ScreenManager
screen_helper = """
ScreenManager:
MenuScreen:
ProfileScreen:
<MenuScreen>:
name: "menu"
MDRectangleFlatButton:
text: 'Profile'
pos_hint: {'center_x':0.5, 'center_y':0.5}
on_press: root.manager.current = 'profile'
<ProfileScreen>:
name: 'profile'
MDLabel:
text: 'Welcome Nate'
halign: 'center'
MDRectangleFlatButton:
text: 'Back'
pos_hint: {'center_x':0.5, 'center_y':0.2}
on_press: root.manager.current = 'menu'
"""
class MenuScreen(Screen):
pass
class ProfileScreen(Screen):
pass
sm = ScreenManager()
sm.add_widget(MenuScreen(name='menu'))
sm.add_widget(ProfileScreen(name='profile'))
class DemoApp(MDApp):
def build(self):
screen = Builder.load_string(screen_helper)
return screen
DemoApp().run()
You can use Image to put image
<ProfileScreen>:
name: 'profile'
Image:
source: '/home/furas/test/lenna.png'
MDLabel:
text: 'Welcome Nate'
halign: 'center'
MDRectangleFlatButton:
text: 'Back'
pos_hint: {'center_x':0.5, 'center_y':0.2}
on_press: root.manager.current = 'menu'
Result:
Original image from Wikipedia: Lenna
EDIT:
Full code
from kivymd.app import MDApp
from kivy.lang.builder import Builder
from kivy.uix.screenmanager import Screen, ScreenManager
screen_helper = """
ScreenManager:
MenuScreen:
ProfileScreen:
<MenuScreen>:
name: "menu"
Image:
source: '/home/furas/test/lenna.png'
MDRectangleFlatButton:
text: 'Profile'
pos_hint: {'center_x':0.5, 'center_y':0.5}
on_press: root.manager.current = 'profile'
<ProfileScreen>:
name: 'profile'
Image:
source: '/home/furas/test/lenna.png'
MDLabel:
text: 'Welcome Nate'
halign: 'center'
color: (0, 0, 0)
MDRectangleFlatButton:
text: 'Back'
pos_hint: {'center_x':0.5, 'center_y':0.2}
on_press: root.manager.current = 'menu'
"""
class MenuScreen(Screen):
pass
class ProfileScreen(Screen):
pass
sm = ScreenManager()
sm.add_widget(MenuScreen(name='menu'))
sm.add_widget(ProfileScreen(name='profile'))
class DemoApp(MDApp):
def build(self):
screen = Builder.load_string(screen_helper)
return screen
DemoApp().run()
Related
I have a problem with my Kivy Python Code. I have 2 screens: 1st is to navigate to the second screen and on the 2nd screen there is a button to add text to a scrollview...navigating is working but it does not add any text to the scrollview...I think I need some help here! AttributeError: 'super' object has no attribute 'getattr'
import kivy
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.clock import Clock, mainthread
from kivy.core.window import Window
from kivy.uix.scrollview import ScrollView
from kivy.effects.scroll import ScrollEffect
from kivy.lang import Builder
Builder.load_string("""
<MenuScreen>:
name: 'mainmenu'
BoxLayout:
spacing: 1
orientation: "vertical"
Label:
text: "MAIN MENU"
Button:
text: 'Go to Screen 2'
on_release:
root.manager.current = 'screen2'
root.manager.transition.direction = "left"
Button:
text: 'Quit'
on_release: root.manager.current = app.exit_software()
<Screen2>:
name: 'screen2'
BoxLayout:
spacing: 1
orientation: "vertical"
ScrollView:
id: scroll_view
always_overscroll: False
BoxLayout:
size_hint_y: None
height: self.minimum_height
orientation: 'vertical'
Label:
id: label
text: "You can add some Text here by pressing the button"
size_hint: None, None
size: self.texture_size
Button:
text: 'Add text!'
size_hint_y: 0.1
on_release: app.add_text()
Button:
text: 'Back to main menu'
size_hint_y: 0.1
on_release:
root.manager.current = 'mainmenu'
root.manager.transition.direction = "right"
""")
# Declare both screens
class MenuScreen(Screen):
pass
class Screen2(Screen):
pass
class AddTextApp(App):
def __init__(self,**kwargs):
super().__init__(**kwargs)
def build(self):
# Create the screen manager
sm = ScreenManager()
sm.add_widget(MenuScreen(name='mainmenu'))
sm.add_widget(Screen2(name='screen2'))
return sm
def add_text(self):
self.root.ids.label.text += f"Some new Text\n"
self.root.ids.scroll_view.scroll_y = 0
def exit_software(self):
App.get_running_app().stop()
if __name__ == '__main__':
AddTextApp().run()
Thank you very much in advance!
The error occurred because self.root.ids gets access to widgets located in the root widget of the main class. To access the secondary screen elements, you need to add it to the main class (in your case, in ScreenManager) and set its id. Also, you have a lot of imported excess, so that it is clearly visible, I advise you to use Pycharm or something like that.
from kivy.app import App
from kivy.uix.screenmanager import Screen
from kivy.lang import Builder
kv = """
<MenuScreen>:
name: 'mainmenu'
BoxLayout:
spacing: 1
orientation: "vertical"
Label:
text: "MAIN MENU"
Button:
text: 'Go to Screen 2'
on_release:
root.manager.current = 'screen2'
root.manager.transition.direction = "left"
Button:
text: 'Quit'
on_release: root.manager.current = app.exit_software()
<Screen2>:
name: 'screen2'
BoxLayout:
spacing: 1
orientation: "vertical"
ScrollView:
id: scroll_view
always_overscroll: False
BoxLayout:
size_hint_y: None
height: self.minimum_height
orientation: 'vertical'
Label:
id: label
text: "You can add some Text here by pressing the button"
size_hint: None, None
size: self.texture_size
Button:
text: 'Add text!'
size_hint_y: 0.1
on_release: app.add_text()
Button:
text: 'Back to main menu'
size_hint_y: 0.1
on_release:
root.manager.current = 'mainmenu'
root.manager.transition.direction = "right"
ScreenManager:
MenuScreen:
id: menu_scr
Screen2:
id: scr_2
"""
class MenuScreen(Screen):
pass
class Screen2(Screen):
pass
class AddTextApp(App):
def __init__(self, **kwargs):
super().__init__(**kwargs)
def build(self):
return Builder.load_string(kv)
def add_text(self):
self.root.ids.scr_2.ids.label.text += f"Some new Text\n"
self.root.ids.scr_2.ids.scroll_view.scroll_y = 0
#staticmethod
def exit_software():
App.get_running_app().stop()
if __name__ == '__main__':
AddTextApp().run()
I am using the FileChooserListView from kivy and have run into a overlapping text on scroll with screens that another user came across as well. I looked through their post on GitHub and read that some people are using the plyer FileChooser. I also saw that someone mentioned that it has to do with the Building function of the .kv file. I created a new kivy app and the problem did not occur, but when I return to my older app (no changes of any kind) the problem still occurs.
Sorry for the long post, but I am unsure how these two kivy app codes are different. Am I calling something twice that is causing the FileChooser to "hold" it's position? I am not oppose to using plyer's FileChooser, but could someone give me an example on how to implement it?
testing_kivy.py
from kivy.app import App
from kivy.lang.builder import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.popup import Popup
from kivy.properties import ObjectProperty
from kivy.uix.floatlayout import FloatLayout
import os
def train_load(path, filename):
download_path = os.path.join(path, filename[0])
print(download_path)
class LoadDialog(FloatLayout):
load = ObjectProperty(None)
cancel = ObjectProperty(None)
class TrainingWindow(Screen):
def show_load_list(self):
content = LoadDialog(load=train_load, cancel=self.dismiss_popup)
self._popup = Popup(title="Load a file list", content=content, size_hint=(1, 1))
self._popup.open()
def dismiss_popup(self):
self._popup.dismiss()
class WindowManager(ScreenManager):
pass
kv_training = Builder.load_file('testing_kivy.kv')
class MyApp(App):
def build(self):
return kv_training
if __name__ == '__main__':
MyApp().run()
testing_kivy.kv
WindowManager:
TrainingWindow:
<TrainingWindow>
name: "training"
BoxLayout:
orientation: "vertical"
Button:
text: "Select Training Images"
font_size: 32
on_release: root.show_load_list()
Button:
text: "Select Training Annots"
font_size: 32
on_release: root.show_load_list()
Button:
text: "Set Parameters"
font_size: 32
on_release:
app.root.current = "parameters_train"
root.manager.transition.direction = "up"
Button:
text: "Back"
font_size: 16
on_release:
app.root.current = "select"
root.manager.transition.direction = "right"
<LoadDialog>:
BoxLayout:
size: root.size
pos: root.pos
orientation: "vertical"
FileChooserListView:
id: filechooser
BoxLayout:
size_hint_y: None
height: 30
Button:
text: "Cancel"
on_release: root.cancel()
Button:
text: "Load"
on_release: root.load(filechooser.path, filechooser.selection)
Older_app.py
from kivy.app import App
from kivy.lang.builder import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.popup import Popup
from kivy.uix.button import Button
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import ObjectProperty
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.spinner import SpinnerOption
import os
import pandas as pd
def invalid_login():
app = App.get_running_app()
app.root.current = "main"
# Create a BoxLayout to add multiple lines or buttons to a PopUp
box = BoxLayout()
# Create PopUp
pop = Popup(
title="Invalid Password",
size_hint=(None, None), size=(200, 100),
content=box,
auto_dismiss=False
)
# Dismiss PopUp
box.add_widget(Button(text="Close", on_release=pop.dismiss))
pop.open()
def model_load(path, filename):
download_path = os.path.join(path, filename[0])
print(download_path)
def train_load(path, filename):
download_path = os.path.join(path, filename[0])
print(download_path)
def train_model_load(path, filename):
download_path = os.path.join(path, filename[0])
print(download_path)
class MainWindow(Screen):
def login(self):
if self.ids.password.text == "password":
self.ids.password.text = ""
app = App.get_running_app()
app.root.current = "select"
else:
self.ids.password.text = ""
invalid_login()
class SelectWindow(Screen):
pass
class LoadDialog(FloatLayout):
load = ObjectProperty(None)
cancel = ObjectProperty(None)
class TrainingWindow(Screen):
def show_load_list(self):
content = LoadDialog(load=train_load, cancel=self.dismiss_popup)
self._popup = Popup(title="Load a file list", content=content, size_hint=(1, 1))
self._popup.open()
def dismiss_popup(self):
self._popup.dismiss()
class ModelWindow(Screen):
def show_load_list(self):
content = LoadDialog(load=model_load, cancel=self.dismiss_popup)
self._popup = Popup(title="Load a file list", content=content, size_hint=(1, 1))
self._popup.open()
def dismiss_popup(self):
self._popup.dismiss()
class TrainModelWindow(Screen):
def show_load_list(self):
content = LoadDialog(load=train_model_load, cancel=self.dismiss_popup)
self._popup = Popup(title="Load a file list", content=content, size_hint=(1, 1))
self._popup.open()
def dismiss_popup(self):
self._popup.dismiss()
class ParametersTrainModelWindow(Screen):
pass
class ParametersTrainWindow(Screen):
pass
class WindowManager(ScreenManager):
pass
class OverViewTrainWindow(Screen):
pass
class OverViewTrainModelWindow(Screen):
pass
class OverViewModelWindow(Screen):
pass
class MyOption(SpinnerOption):
pass
kv_main= Builder.load_file('main.kv')
class MyApp(App):
def build(self):
return kv_main
if __name__ == '__main__':
MyApp().run()
main.kv
#:import utils kivy.utils
#:include select.kv
#:include training.kv
#:include model.kv
#:include train_model.kv
#:include parameters_train.kv
#:include parameters_train_model.kv
#:include overview_train_model.kv
#:include overview_train.kv
#:include overview_model.kv
WindowManager:
MainWindow:
SelectWindow:
TrainingWindow:
ModelWindow:
TrainModelWindow:
ParametersTrainWindow:
ParametersTrainModelWindow
OverViewTrainWindow:
OverViewTrainModelWindow:
OverViewModelWindow:
<MainWindow>
name: "main"
GridLayout:
cols: 1
BoxLayout:
orientation: "vertical"
canvas.before:
Color:
rgba: 0,0,0,1
Rectangle:
pos: self.pos
size: self.size
Label:
size_hint: 1, 1
text: "SPECPHASE"
font_size: 50
color:
utils.get_color_from_hex('#FF0000')
Label:
size_hint: 1, 1
text: "Object Detection App"
font_size: 40
BoxLayout:
size_hint: 1, 0.005
canvas.before:
Color:
rgba: (1,1,1,1)
Rectangle:
size: self.size
pos: self.pos
BoxLayout:
orientation: "horizontal"
size_hint: (0.35, 0.35)
padding: (0,0,25,0)
Label:
font_size: 20
text: "Password"
size_hint: (0.5, 0.35)
pos_hint: {'x': 1, 'y': 0.4}
background_color: (0,0,0,1)
canvas.before:
Color:
rgba: self.background_color
Rectangle:
size: self.size
pos: self.pos
TextInput:
id: password
multiline: False
size_hint: (0.5, 0.35)
pos_hint: {'x': 1, 'y': 0.4}
focus: True
background_color:
utils.get_color_from_hex('#18B8D9')
cursor_color: (0,0,0,1)
password: True
Button:
text: "Submit"
on_release: root.login()
select.kv
<SelectWindow#Screen>:
name: "select"
GridLayout:
cols: 1
GridLayout:
cols: 2
Button:
text: "Train"
font_size: 32
on_release:
app.root.current = "training"
root.manager.transition.direction = "right"
Button:
text: "Model"
font_size: 32
on_release:
app.root.current = "model"
root.manager.transition.direction = "left"
Button:
text: "Train & Model"
font_size: 32
on_release:
app.root.current = "train_model"
root.manager.transition.direction = "up"
training.kv
<TrainingWindow#Screen>:
name: "training"
BoxLayout:
orientation: "vertical"
Button:
text: "Select Training Images"
font_size: 32
on_release: root.show_load_list()
Button:
text: "Select Training Annots"
font_size: 32
on_release: root.show_load_list()
Button:
text: "Set Parameters"
font_size: 32
on_release:
app.root.current = "parameters_train"
root.manager.transition.direction = "up"
Button:
text: "Back"
font_size: 16
on_release:
app.root.current = "select"
root.manager.transition.direction = "right"
<LoadDialog>:
BoxLayout:
size: root.size
pos: root.pos
orientation: "vertical"
FileChooserListView:
id: filechooser
BoxLayout:
size_hint_y: None
height: 30
Button:
text: "Cancel"
on_release: root.cancel()
Button:
text: "Load"
on_release: root.load(filechooser.path, filechooser.selection)
After taking a break from this for while and restarting my brain, I was able to find the problem.
Not included in my question, I have a couple more .kv files that have a similar layout to the training.kv. They are used to access other screens. I found that I was calling FileChooserListView in each screen and I belive that is why I was seeing the stacking problem. I ended up removing all of them except for the one in my training.kv file and all is working.
I'm trying to use the id function to reference text_input from MDTextField, however I can't understand how does the id function works. Does anyone know what is wrong in my code?
The first code is the Main App and the second one is where all the widgets are. I've already searched for a solution in internet, but I can't understand why my code does not work.
from kivy.lang import Builder
from kivymd.app import MDApp
from kivy.uix.screenmanager import Screen, ScreenManager
from Screen_helper import Home
class MenuScreen(Screen):
pass
class ProfileScreen(Screen):
pass
sm = ScreenManager()
sm.add_widget(MenuScreen(name='Menu'))
sm.add_widget(MenuScreen(name='Profile'))
class Mainapp(MDApp):
def build(self):
screen = Screen()
helper = Builder.load_string(Home)
screen.add_widget(helper)
key = self.root.ids.username_input
return screen
Mainapp().run()
Home = '''
ScreenManager:
MenuScreen:
ProfileScreen:
<MenuScreen>:
name: 'Menu'
MDRectangleFlatButton:
id: my_button
text: 'Profile'
pos_hint: {'center_x': 0.5, 'center_y': 0.1}
on_press: root.manager.current = 'Profile'
MDTextField:
id: username_input
input_filter: "int"
hint_text: 'CHIAVE NUMERICA'
helper_text: 'compresa tra 0 e 95'
helper_text_mode: 'on_focus'
icon_right: 'key-variant'
icon_right_color: app.theme_cls.primary_color
pos_hint: {'center_x':0.5,'center_y':0.55}
size_hint_x:None
width:230
input_filter: 'int'
<ProfileScreen>:
name: 'Profile'
MDLabel:
text: 'Welcome'
halign: 'center'
MDRectangleFlatButton:
text: 'back'
pos_hint: {'center_x': 0.5, 'center_y': 0.3}
on_press: root.manager.current = 'Menu' '''
Give an id to the MenuScreen class and then access to the widget.
Add this to the kv file.
<MenuScreen>:
id: menu
To access the widget you can now do this in python:
key = self.root.menu.ids.username_input
I am currently building a mobile app with kivy. In one of my screens I am trying to include an MDExpansionPanel, although I have tried with a lot of different codes, and searched on the web for solutions, either I get an error, or simply the Expansion Panel is not rendered in my screen. I am using ScreenManager since I have 5 screens, with the possibility of increasing such number.
The relevant Python code is the following:
from kivy.app import App
from kivy.properties import ObjectProperty
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.screenmanager import ScreenManager, Screen
from kivymd.app import MDApp
from kivymd.theming import ThemeManager
from kivymd.toast import toast
from kivymd.uix.picker import MDDatePicker, MDTimePicker
from kivymd.uix.expansionpanel import MDExpansionPanel
from kivymd.uix.boxlayout import MDBoxLayout
class LoginWindow(Screen):
pass
class CreateAccountWindow(Screen):
pass
class MainWindow(Screen):
pass
class TravelManagerWindow(Screen):
pass
class IngActivWindow(Screen):
panel_container = ObjectProperty(None)
def on_pre_enter(self, *args):
self.add_panels()
def show_timepicker(self):
picker = MDTimePicker()
picker.bind(time=self.got_time)
picker.open()
def got_time(self, picker_widget, time):
self.text = str(time.hour) + ":" + str(time.minute)
self.focus = False
# selectedTime= self.text
print(self.text)
self.ids.tiempoActiv.text = self.text
def add_panels(self):
for i in range(5):
IngActivWindow.ids.panel_container.add_widget(
MDExpansionPanel(
icon="actividades.png",
content=MyContent(),
panel_cls=MDExpansionPanelOneLine(
text="Text",
)
)
)
class MyContent(MDBoxLayout):
pass
class WindowManager(ScreenManager):
ScreenManager().add_widget(LoginWindow(name='login'))
ScreenManager().add_widget(CreateAccountWindow(name='create'))
ScreenManager().add_widget(MainWindow(name='main'))
ScreenManager().add_widget(IngActivWindow(name='ingActiv'))
ScreenManager().add_widget(TravelManagerWindow(name='travelManager'))
class powerApp1(MDApp):
def build(self):
self.theme_cls.primary_palette = "Teal"
return WindowManager()
if __name__ == "__main__":
powerApp1().run()
The relevant kv code is the following:
(I have an image on the background and an Action Bar before the MDBoxLayout where I am trying to add the Expansion Panel)
<WindowManager>:
LoginWindow:
CreateAccountWindow:
MainWindow:
IngActivWindow:
TravelManagerWindow:
<IngActivWindow>:
name: 'ingActiv'
panel_container: panel_container
FloatLayout:
cols:1
canvas.before:
Rectangle:
pos: self.pos
size: self.size
source: 'ingActiv_background.png'
ActionBar:
pos_hint: {'top':1}
ActionView:
use_separator: True
ActionPrevious:
title: '---------'
with_previous: False
ActionButton:
icon: 'homeIcon.png'
on_press:
root.manager.current = 'main'
root.manager.transition.direction = 'right'
ActionGroup:
text: 'Gastos de Viaje'
mode: 'spinner'
size_hint:(None,None)
size: root.width/5,root.height/12
ActionButton:
text: 'Solicitar'
on_release:
root.manager.current = 'solicitud'
root.manager.transition.direction = 'left'
ActionButton:
text: 'Comprobar'
on_release:
root.manager.current = 'comprobar'
root.manager.transition.direction = 'left'
ActionGroup:
text: 'Opciones'
mode: 'spinner'
size_hint:(None,None)
size: root.width/5,root.height/12
ActionButton:
text: 'Ingresar Actividad'
on_release:
root.manager.current = 'ingActiv'
root.manager.transition.direction = 'left'
ActionButton:
text: 'Enviar Reporte'
ActionButton:
text: 'Cerrar Sesion'
on_release:
root.manager.current = 'login'
root.manager.transition.direction = 'down'
MDBoxLayout:
cols:1
size_hint: 1,0.6
pos_hint: {"center_x": 0.5, "center_y": 0.5}
ScrollView:
GridLayout:
id: panel_container
cols: 1
pos_hint: {"center_x": 0.5, "center_y": 0.5}
<MyContent>:
size_hint: 1, None
height: self.minimum_height
orientation: 'horizontal'
Button:
size_hint: None, None
Thanks a lot in advance for your support,
Have a great day.
After much headbanging, I've created an app that opens the FileChooser and picks an image. A function will then transform the image and change it on the screen.
< FirstScreen > is just something to start with, relatively unimportant.
< SecondScreen > is the file chooser. The path may need editing. < ThirdScreen > shoudl show the image along with buttons that will eventually lead elsewhere.
I suspect the problem is that the line
sm.current = "_third_screen_"
is creating a new instance separate to everything else I've passed items too. How do I show the image I selected?
from kivy.lang import Builder
from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.properties import ObjectProperty, StringProperty
Builder.load_string("""
<MyScreenManager>:
FirstScreen:
SecondScreen:
ThirdScreen:
<FirstScreen>:
name: '_first_screen_'
BoxLayout:
orientation: "horizontal"
Label:
id: first_screen_label
text: "Hi, I'm the home page"
BoxLayout:
orientation: "vertical"
Button:
text: "Okay!"
on_press: root.manager.current = '_second_screen_'
Button:
text: "Cancel!"
on_press: app.stop()
<SecondScreen>:
name: '_second_screen_'
id: file_chooser
BoxLayout:
id: file_chooser_box_layout
orientation: "horizontal"
Button
text: "Open"
on_press:
root.callback_image_and_other_stuff(file_chooser_list_view.selection)
FileChooserListView:
id: file_chooser_list_view
<ThirdScreen>:
name: '_third_screen_'
BoxLayout:
orientation: "vertical"
id: third_screen
Label:
id: main_title
text: "Upload"
size_hint: (1, 0.1)
Image:
id: main_image
source: root.img
size_hint: (1, 0.75)
BoxLayout:
orientation: "horizontal"
padding: 10
size_hint: (1, 0.15)
Button:
text: "Okay"
size_hint: (0.5, 1)
on_press: image_viewer.image_accepted_by_user(filechooser.selection)
Button:
text: "Cancel"
size_hint: (0.5, 1)
on_press: root.manager.current = '_first_screen_'
""")
class FirstScreen(Screen):
pass
class SecondScreen(Screen):
def callback_image_and_other_stuff(self, new_image_address):
# do other stuff here also, then pass new_image_address along
new_image_address = new_image_address[0].replace("\\", "/")
third_screen = ThirdScreen()
third_screen.callback_image(new_image_address)
class ThirdScreen(Screen):
img = ObjectProperty(None)
def __init__(self, **kwargs):
super(Screen, self).__init__(**kwargs)
def callback_image(self, new_image_address):
sm.current = "_third_screen_"
self.img = new_image_address
self.ids.main_image.source = self.img
print(self.img)
# Create the screen manager
sm = ScreenManager() # Problem?
sm.add_widget(FirstScreen(name='_first_screen_'))
sm.add_widget(SecondScreen(name='_second_screen_'))
sm.add_widget(ThirdScreen(name='_third_screen_'))
class MyApp(App):
def build(self):
return sm
if __name__ == '__main__':
MyApp().run()
Every time you use some_obj = SomClass() you are creating a new object, in your case that is what you are doing, you are creating a new ThirdScreen different from the one shown by that you do not observe the image, the solution is that you have to access to the initial object using the ScreenManager and name screen.
from kivy.lang import Builder
from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.properties import ObjectProperty, StringProperty
Builder.load_string("""
<FirstScreen>:
BoxLayout:
orientation: "horizontal"
Label:
id: first_screen_label
text: "Hi, I'm the home page"
BoxLayout:
orientation: "vertical"
Button:
text: "Okay!"
on_press: root.manager.current = '_second_screen_'
Button:
text: "Cancel!"
on_press: app.stop()
<SecondScreen>:
id: file_chooser
BoxLayout:
id: file_chooser_box_layout
orientation: "horizontal"
Button
text: "Open"
on_press:
root.callback_image_and_other_stuff(file_chooser_list_view.selection)
FileChooserListView:
id: file_chooser_list_view
<ThirdScreen>:
BoxLayout:
orientation: "vertical"
id: third_screen
Label:
id: main_title
text: "Upload"
size_hint: (1, 0.1)
Image:
id: main_image
source: root.img
size_hint: (1, 0.75)
BoxLayout:
orientation: "horizontal"
padding: 10
size_hint: (1, 0.15)
Button:
text: "Okay"
size_hint: (0.5, 1)
on_press: image_viewer.image_accepted_by_user(filechooser.selection)
Button:
text: "Cancel"
size_hint: (0.5, 1)
on_press: root.manager.current = '_first_screen_'
""")
class FirstScreen(Screen):
pass
class SecondScreen(Screen):
def callback_image_and_other_stuff(self, new_image_address):
if new_image_address:
third_screen = self.manager.get_screen("_third_screen_")
# do other stuff here also, then pass new_image_address along
new_image_address = new_image_address[0].replace("\\", "/")
third_screen.callback_image(new_image_address)
class ThirdScreen(Screen):
img = ObjectProperty(None)
def __init__(self, **kwargs):
super(Screen, self).__init__(**kwargs)
def callback_image(self, new_image_address):
sm.current = "_third_screen_"
self.img = new_image_address
self.ids.main_image.source = self.img
print(self.img)
# Create the screen manager
sm = ScreenManager() # Problem?
sm.add_widget(FirstScreen(name='_first_screen_'))
sm.add_widget(SecondScreen(name='_second_screen_'))
sm.add_widget(ThirdScreen(name='_third_screen_'))
class MyApp(App):
def build(self):
return sm
if __name__ == '__main__':
MyApp().run()