EDIT: so this is a very simple version of what it is like in my app but i think you get the point. Basically i want to destroy the Buttons created in the for loop with the Button on the destroywidgets screen.
.kv:
MainWindow:
<MainWindow>
FloatLayout:
size_hint: 1, .1
Button:
text:"next screen"
size_hint:.1,1
pos_hint:{"x": 0, "y": 0}
on_release: app.root.current = "destroywidgets"
Button:
text:"laodwidgets"
on_release: root.create_widgets()
size_hint:.1, 1
pos_hint:{"x": .5, "y": 0}
.py:
from kivy.app import App
from kivy.clock import Clock
from kivy.lang import Builder
from kivy.uix.button import Button
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.gridlayout import GridLayout
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.scrollview import ScrollView
class MainWindow(Screen):
name = "mainwindow"
def __init__(self, **kwargs):
super(MainWindow, self).__init__()
self.scrl_view_1 = ScrollView(
size_hint_y=.85,
pos_hint={"x": 0, "y": .15},
do_scroll_x=False,
do_scroll_y=True,
size_hint_x=1
)
self.scrl_child_1 = GridLayout(
size_hint_x=1,
size_hint_y=None,
cols=2,
height=1000,
row_default_height=150,
row_force_default=True
)
self.add_widget(self.scrl_view_1)
self.scrl_view_1.add_widget(self.scrl_child_1)
def create_widgets(self):
print("creating widgets")
for i in range(0, 6):
btn = Button(
text=str(i)
)
self.scrl_child_1.add_widget(btn)
print("added")
class DestroyWidgets(Screen):
name = "destroywidgets"
def __init__(self, **kwargs):
super(DestroyWidgets, self).__init__()
btn_destroy_widgets = Button(
text="Destroy children of Mainwindow",
#some on release function to clear all children from scrl_child_1 in Mainwindow
)
self.add_widget(btn_destroy_widgets)
class ShoppingList(App):
def build(self):
self.sm = ScreenManager()
self.sm.add_widget(MainWindow(name="mainwindow"))
self.sm.add_widget(DestroyWidgets(name="destroywidgets"))
return self.sm
if __name__ == "__main__":
main_app = ShoppingList()
main_app.run()
So I have to reference a GridLayout which is inside of a ScrollView created in class A in class B. Since you cannot give Layouts an ID in python code and reference it with self.ids i can't figure out how to do it. I tried suggestions from another post with the weakref.ref method as example but i couldn't get it to work. The whole point is that i have to destroy all children of Layouts from other classes in a function somehow.
Heres just a little snippet of my code which i think will be enough. If you need more just write me. Thanks for all the help in advance!
class SelfMadePlans(Screen):
name = "selfmadeplans"
def __init__(self, **kwargs):
super(SelfMadePlans, self).__init__()
self.scrl_view_2 = ScrollView(
size_hint_y=.85,
pos_hint={"x": 0, "y": 0},
do_scroll_x=False,
do_scroll_y=True,
size_hint_x=1
)
self.scrl_child_2 = GridLayout(
size_hint_x=1,
size_hint_y=None,
cols=3,
height=20000,
row_default_height=150,
row_force_default=True,
)
self.add_widget(self.scrl_view_2)
self.scrl_view_2.add_widget(self.scrl_child_2)
and then something in another class like:
class B:
def destroy_children(self):
MDApp.get_running_app().sm.get_screen("selfmadeplans").ids.scrl_child_2.children.clear()
First of all you must pass var. no. of kwargs in __init__ in order to use and get all the default functionalities.
...
def __init__(self, **kwargs):
super(MainWindow, self).__init__(**kwargs)
...
etc.
Next to access certain screen from ScreenManager you can use method get_screen as follows,
...
btn_destroy_widgets = Button(
text="Destroy children of Mainwindow",
#some on release function to clear all children from scrl_child_1 in Mainwindow
)
btn_destroy_widgets.bind(on_release = self.destroy_widgets_on_main)
self.add_widget(btn_destroy_widgets)
def destroy_widgets_on_main(self, *args):
main_window = self.manager.get_screen("mainwindow")
main_window.scrl_child_1.clear_widgets()
Related
I have creating multiple buttons via for loop in Python/Kivy. I can't figureout how to implement for each button on_press and on_release function, so each button (having it's defined color) will come back to its original color after releasing.
Below You will find part of code in python and kivy.
Python:
class PrButton(GridLayout):
def __init__(self, **kwargs):
super(PrButton, self).__init__(**kwargs)
self.build_grid()
def build_grid(self):
for i in hi_cat():
btn = ButtonDD(text=i[0].upper())
btn.background_color = i[1]
self.ids[i[0]] = btn
self.add_widget(btn)
kivy file:
<ButtonDD>
bold: True
from kivymd.app import MDApp
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
KV = """
<MainWidget>:
size : root.size
"""
class MainWidget(BoxLayout):
def __init__(self,**kwargs):
super().__init__(**kwargs)
for i in range(5):
btn = Button(text = str(i))
btn.bind(on_release = lambda i=i:self.clicked(i))
self.add_widget(btn)
def clicked(self,text):
print(text)
class MainApp(MDApp):
def build(self):
Builder.load_string(KV)
return MainWidget()
MainApp().run()
It is achieved by changing lambda x: self.clicked() To lambda i=i:self.clicked()
I've been stuck with this kind of problem for some time now. But I got my answer recently. So I hope this helps you
I am am doing python kivy scroll view program there is no error but it gives me blank output
in main python file:
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.stacklayout import StackLayout
from kivy.metrics import dp
class stacklayoutexample(StackLayout):
def __init__(self, **kwargs):
super().__init__(**kwargs)
for i in range(0,101):
size = dp(100)
b=Button(text=str(i), size_hint=(None,None), size=(size,size))
# self.orientation = "rl-bt"
# self.spacing = ("20dp","20dp")
self.add_widget(b)
class main(App):
pass
main().run()
in main.kv file:
scrollviewexample:
<scrollviewexample#ScrollView>:
stacklayoutex:
size_hint:1,None
<stacklayoutexample>:
When you use kv, you must capitalize all your classes. Also, is stacklayoutex intended to be stacklayoutexample? If so, here is a modified version of your code that I think will work:
main.kv:
Scrollviewexample:
<Scrollviewexample#ScrollView>:
Stacklayoutexample:
size_hint:1,None
<Stacklayoutexample>:
And the python code:
class Stacklayoutexample(StackLayout): # just capitalized
def __init__(self, **kwargs):
super().__init__(**kwargs)
for i in range(0, 101):
size = dp(100)
b = Button(text=str(i), size_hint=(None, None), size=(size, size))
# self.orientation = "rl-bt"
# self.spacing = ("20dp","20dp")
self.add_widget(b)
I have made a simple app in kivymd. But I can not change screen on click on button inside kivymd. Everything works great. But when I click on button then it popup toast also but screen is not changing. What will be changes or better implementation for this?
app.py
from kivymd.app import MDApp
from kivy.uix.screenmanager import Screen, ScreenManager
from kivy.lang import Builder
from main_screen_str import helper_string
from kivy.core.window import Window
from kivymd.toast import toast
from kivymd.uix.bottomsheet import MDGridBottomSheet
Window.size = (300, 500)
class MainScreen(Screen):
pass
class SettingsScreen(Screen):
pass
class AboutScreen(Screen):
pass
class MainApp(MDApp):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.sm = ScreenManager()
self.sm.add_widget(MainScreen(name="main_screen"))
self.sm.add_widget(SettingsScreen(name="settings_screen"))
self.sm.add_widget(AboutScreen(name="about_screen"))
self.main_str = Builder.load_string(helper_string)
def build(self):
screen = Screen()
screen.add_widget(self.main_str)
return screen
def callback_for_menu_items(self, *args):
if args[0] == 'Home':
toast(args[0])
self.sm.current = "main_screen"
if args[0] == 'Settings':
toast(args[0])
self.sm.current = "settings_screen"
if args[0] == 'About':
toast(args[0])
self.sm.current = "about_screen"
def show_example_grid_bottom_sheet(self):
self.bottom_sheet_menu = MDGridBottomSheet()
data = {
"Home": "home",
"Settings": "settings",
"About": "information-outline",
}
for item in data.items():
self.bottom_sheet_menu.add_item(
item[0],
lambda x, y=item[0]: self.callback_for_menu_items(y),
icon_src=item[1],
)
self.bottom_sheet_menu.open()
if __name__ == '__main__':
MainApp().run()
This builder string to create screen.
Are there any better solution for this?
builder string
helper_string = """
ScreenManager:
MainScreen:
SettingsScreen:
AboutScreen:
<MainScreen>:
name: 'main_screen'
MDIconButton:
icon: "menu"
theme_text_color: "Custom"
text_color: 1,0,0,1
on_press: app.show_example_grid_bottom_sheet()
<SettingsScreen>:
name: 'settings_screen'
<AboutScreen>:
name: 'about_screen'
"""
In your __init__() method of the App, you are building self.sm with the lines:
self.sm = ScreenManager()
self.sm.add_widget(MainScreen(name="main_screen"))
self.sm.add_widget(SettingsScreen(name="settings_screen"))
self.sm.add_widget(AboutScreen(name="about_screen"))
But self.sm is not used as part of your GUI. So your changes to self.sm has no effect on your GUI. The line following that:
self.main_str = Builder.load_string(helper_string)
basically does exactly the same thing as the previous lines.
Then in your build() method, you are creating a new Screen and adding the self.main_str as a child of that Screen.
While you can have a ScreenManager as a child of a Screen, in your posted example that does not seem to serve any purpose.
Here is a modified version of part of the MainApp that I think will do what you want:
class MainApp(MDApp):
# def __init__(self, **kwargs):
# super().__init__(**kwargs)
# self.sm = ScreenManager()
# self.sm.add_widget(MainScreen(name="main_screen"))
# self.sm.add_widget(SettingsScreen(name="settings_screen"))
# self.sm.add_widget(AboutScreen(name="about_screen"))
#
# self.main_str = Builder.load_string(helper_string)
def build(self):
self.sm = Builder.load_string(helper_string)
return self.sm
# screen = Screen()
# screen.add_widget(self.main_str)
# return screen
The above code greatly simplifies the build() method, eliminates the __init__() method, and now self.sm is actually part of the GUI.
Note that when you load a kv string that has a root node with Builder.load_string(), that root node is created and returned. The lines in your kv string:
ScreenManager:
MainScreen:
SettingsScreen:
AboutScreen:
result in a ScreenManager instance being created along with the three children listed for it, so the code in your __init__() method was duplicating that.
i'm using kivy for building an app screen with 3 screens.
my main screen ( class Base) is showing data from a SQL request.
i would like the user to be able to update these data using a button.
first this class Base is called in the screen manager which is itself called in my root class.
So my question is , how do i clear the data in my class Base and update it with the new data?
i tried to clear the data in my class screen manager.
the refresh function is called from the root class.
i have the below error:
'ScreenManager uses remove_widget only for removing Screens'
from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.gridlayout import GridLayout
from kivy.uix.button import Button
from kivy.uix.label import Label
from sql import runsql2
from kivy.core.window import Window
class Manager(ScreenManager):
def __init__(self):
super(Manager, self).__init__()
for i in range(2):
txt = 'Screen {}'.format(i)
lbl = Label(text=txt)
screen = Screen(name=txt)
screen.add_widget(lbl)
self.add_widget(screen)
base=Base('main')
self.add_widget(base)
def refresh(self):
self.clear_widgets(screens='main')
base=Base('main')
self.add_widget(base)
class Nav(GridLayout):
def __init__(self,sm=None):
super(Nav, self).__init__()
self.sm = sm
self.cols =3
self.size_hint = (1,0.1)
self.add_widget(Button(text="Clearing Screen", on_release=self.change))
self.add_widget(Button(text="Go screen 2", on_release=self.goscreen))
self.add_widget(Button(text="Quit", on_release=self.quit))
def change(self, btn):
#self.sm.current = btn.text
self.sm.current='main'
def quit(self,ins):
exit()
def goscreen(self,ins):
self.sm.current='Screen 1'
class Base(Screen):
def __init__(self,name):
super(Base, self).__init__()
self.lay=GridLayout()
self.name=name
self.bout=['[color=33ff99]Refresh[/color]','',"","","","","","","","",""]
self.data=runsql2()
self.lay.cols = 11
self.titre=['[color=ff9900]Market[/color]', '[color=ff9900]B/S[/color]', '[color=ff9900]Volume[/color]', '[color=ff9900]Contract[/color]',
'[color=ff9900]C/P[/color]', '[color=ff9900]Expiry[/color]', '[color=ff9900]Strike[/color]', '[color=ff9900]Price[/color]',
'[color=ff9900]Account[/color]', '[color=ff9900]Give up Member[/color]', '[color=ff9900]Allocation Account[/color]']
#self.lay.add_widget(Button(text='[color=33ff99]Refresh[/color]', size_hint=(1, 0.15), markup=True,on_release=self.do))
for i in range(11):
self.lay.add_widget(Label(text='', size_hint=(1, 0.15)))
for j in range(11):
self.lay.add_widget(Label(text=str(self.titre[j]),size_hint=(0.2,0.2),markup=True))
long = len(self.data)
for i in range(long):
for j in range(11):
self.lay.add_widget(Label(text=str(self.data[i][j])))
self.add_widget(self.lay)
class Root(BoxLayout):
def __init__(self):
super(Root, self).__init__()
self.orientation = "vertical"
#Window.clearcolor = (0.6, 0.6, 0.6,1)
sm = Manager()
self.add_widget(Nav(sm=sm))
self.add_widget(sm)
self.add_widget(Button(text='refresh',size_hint=(0.2,0.2),on_release=self.refresh))
Window.size = (1500, 900)
def refresh(self,ins):
sm=Manager()
sm.refresh()
class TestApp(App):
def build(App):
return Root()
if __name__ == '__main__':
TestApp().run()
Two problems with your code. First, in your refresh() method, the self.clear_widgets(screens='main') is incorrect. The screens arg must be a list of screens. So it should be
def refresh(self):
self.clear_widgets(screens=[self.get_screen('main')])
base=Base('main')
self.add_widget(base)
Since you are only removing one screen, you could use self.remove_widget(self.get_screen('main')) instead.
And, second, your refresh() method in the Root class is creating a new Manager class and calling the refresh() method of that new Manager rather than the one you have displayed. To correct this, you can save a reference to the original Manager, and use that reference in the refresh() method:
class Root(BoxLayout):
def __init__(self):
super(Root, self).__init__()
self.orientation = "vertical"
#Window.clearcolor = (0.6, 0.6, 0.6,1)
sm = Manager()
self.sm = sm # keep a reference for later use
self.add_widget(Nav(sm=sm))
self.add_widget(sm)
self.add_widget(Button(text='refresh',size_hint=(0.2,0.2),on_release=self.refresh))
Window.size = (1500, 900)
def refresh(self,ins):
self.sm.refresh()
I have the following Kivy app and I'm trying to change the text of a Label based on another widget's variable.
I mean, if the variable testing of the class TestApp changes, I want also the value of the variable text of the class TestLabel to change.
To do so, I've created a BooleanProperty in the TestLabel class that points to the testing variable of the TestApp class. The problem is that this callback is never executed despite being changing it each time I press the button.
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder
from kivy.properties import BooleanProperty
Builder.load_string('''
<MainApp>:
orientation: 'horizontal'
rows: 2
TestButton:
text: 'Change value'
on_release: self.change_value()
TestLabel:
''')
class TestLabel(Label):
testing = BooleanProperty()
def __init__(self, **kwargs):
super(TestLabel, self).__init__(**kwargs)
self.app = App.get_running_app()
self.testing = self.app.testing
self.bind(testing=self.changed_value)
def changed_value(self, _instance, newvalue):
self.text = str(newvalue)
class TestButton(Button):
def __init__(self, **kwargs):
super(TestButton, self).__init__(**kwargs)
self.app = App.get_running_app()
def change_value(self):
self.app.testing = not self.app.testing
class MainApp(BoxLayout):
pass
class TestApp(App):
testing = BooleanProperty(False)
def build(self):
return MainApp()
if __name__ == '__main__':
TestApp().run()
It is not necessary to create a testing property in TestLabel since when you do: self.bind(testing = self.changed_value) you are connecting the testing of TestLabel and not the testing of TestApp , so as it never changes testing after the bind then it never gets call the callback.
The bind has to be done using the object that has that property, and in your case the testing belongs to the App, so you must the App.
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder
from kivy.properties import BooleanProperty
Builder.load_string('''
<MainApp>:
orientation: 'horizontal'
rows: 2
TestButton:
text: 'Change value'
on_release: self.change_value()
TestLabel:
''')
class TestLabel(Label):
def __init__(self, **kwargs):
super(TestLabel, self).__init__(**kwargs)
self.app = App.get_running_app()
self.app.bind(testing=self.changed_value)
def changed_value(self, _instance, newvalue):
self.text = str(newvalue)
class TestButton(Button):
def __init__(self, **kwargs):
super(TestButton, self).__init__(**kwargs)
self.app = App.get_running_app()
def change_value(self):
self.app.testing = not self.app.testing
class MainApp(BoxLayout):
pass
class TestApp(App):
testing = BooleanProperty(False)
def build(self):
return MainApp()
if __name__ == '__main__':
TestApp().run()