Develop Reference

Kivy: How to move other buttons down/up when dropdown is down

Problem:
I have a dropdown button that produces a label. This label overlaps another button below it. Picture of what is going wrong.
What I Want:
I want the button that is being overlapped by the label from the dropdown to be moved downwards, preferably by same height as the label from the drop down. I then want the button to move back up when the drop down is "pulled up"
MRE
KV File:
#:import utils kivy.utils
#:import Factory kivy.factory.Factory
<CustomDropdown#DropDown>:
id: dropdown
on_select:
app.root.ids.btn.text = '{}'.format(args[1])
self.dismiss()
Label:
id: btn1
text: ' Information '
size_hint_y: None
height: 200
background_color: (1, 0, 0, .9)
canvas.before:
Color:
rgba: self.background_color
Rectangle:
size: self.size
pos: self.pos
<HomeScreen>:
FloatLayout:
canvas:
Color:
rgb: utils.get_color_from_hex("#FFFFFF")
Rectangle:
size: self.size
pos: self.pos
GridLayout:
rows: 8
cols: 1
spacing: 10
size_hint_y: None
height: 1200
width: self.minimum_width
Button:
text:"stuff1"
color: "black"
size_hint: 1,.18
on_press: Factory.CustomDropdown().open(self)
Button:
text:"stuff2"
color: "black"
size_hint: 1,.18
Main.py
from kivy.app import App
from kivy.core.window import Window
from kivy.lang import Builder
from kivy.uix.screenmanager import Screen
Window.size = (286.110236, 570.33070866)
class HomeScreen(Screen):
pass
GUI = Builder.load_file("main.kv")
class MainApp(App):
def build(self):
return GUI
MainApp().run()

Add widget dynamically from outside class (error)

I´m learning kivy, and it has passed 3 weeks since i face this problem without encounter a solution, so i hope any of u guys could help me, i would appreciate it.
I have a main file:
from app import MyProgramApp
if __name__ == "__main__":
winapp = MyProgramApp()
winapp.run()
from where i start my app. Then i have a directory called "app", inside there is the following "init.py" file.
from kivy.app import App
from kivy.utils import QueryDict, rgba
from kivy.core.window import Window
from .view import MainWindow
Window.minimum_width = 500
Window.minimum_height = 650
Window.maximize()
class MyProgramApp(App):
colors = QueryDict()
colors.primary = rgba('#2D9CDB')
colors.secondary = rgba('#16213E')
colors.succes = rgba('#1FC98E')
colors.warning = rgba('#F2C94C')
colors.danger = rgba('#E85757')
colors.grey_dark = rgba('#C4C4C4')
colors.grey_light = rgba('#F5F5F5')
colors.black = rgba('#A1A1A1')
colors.white = rgba('#FFFFFF')
def build(self):
return MainWindow()
Same folder app, i have the following "view.py".
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.behaviors import ToggleButtonBehavior
from kivy.properties import StringProperty
from kivy.uix.screenmanager import ScreenManager
class MainWindow(BoxLayout):
username = StringProperty("Usuario")
def __init__(self, **kw):
super().__init__(**kw)
def on_press_home(self):
self.ids.scrn_mngr.current = "scrn_home"
class ViewManager(ScreenManager):
def __init__(self, **kw):
super().__init__(**kw)
class NavTab(ToggleButtonBehavior, BoxLayout):
text = StringProperty('')
icon = StringProperty('')
def __init__(self, **kw):
super().__init__(**kw)
and finally for that folder i have "myprogram.kv"
#:kivy 2.1.0
#:import Home views.home.Home
<MainWindow>:
spacing: dp(8)
canvas.before:
Color:
rgba: app.colors.white
Rectangle:
pos: self.pos
size: self.size
# NAVIGATION BAR
BoxLayout:
id: nav_menu
size_hint_x: .2
orientation: "vertical"
size_hint_min_x: dp(100)
# LOGO
BoxLayout:
id: logo_nbox
size_hint_y: .1
size_hint_min_y: dp(70)
padding: dp(16)
AnchorLayout:
anchor_x: "right"
size_hint_x: None
width: dp(52)
halign: "left"
Label:
text: "COMPANY"
halign: "center"
BoxLayout:
orientation: "vertical"
Label:
text: "COMPANY"
halign: "center"
Label:
text: "Phrase"
halign: "center"
# OPTIONS
GridLayout:
id: tabs_box
cols: 1
spacing: dp(4)
size_hint_y: .5
canvas.before:
Color:
rgba: app.colors.grey_dark
Rectangle:
pos: self.pos
size: [self.size[0], dp(1)]
NavTab:
text: "Home"
state: "down"
on_press: root.on_press_home()
# BODY
BoxLayout:
size_hint_x: .8
spacing: dp(8)
orientation: "vertical"
padding: [dp(16), dp(8), dp(12), dp(8)]
canvas.before:
Color:
rgba: app.colors.grey_light
Rectangle:
pos: self.pos
size: self.size
# SCREENS
BoxLayout:
ViewManager:
id: scrn_mngr
<ViewManager>:
Screen:
name: "scrn_home"
Home:
id: home
<NavTab>:
background_normal: ""
background_down: ""
background_color: [0,0,0,0]
group: "tabs"
size_hint_y: None
height: dp(45)
spacing: dp(4)
canvas.before:
Color:
rgba: [0,0,0,0] if self.state == "normal" else rgba("#E1F1FF")
Rectangle:
pos: self.pos
size: self.size
Color:
rgba: [0,0,0,0] if self.state == "normal" else app.colors.primary
Rectangle:
pos: [self.pos[0]+self.size[0]-dp(1), self.pos[1]]
size: [dp(8), self.size[1]]
Label:
halign: "left"
valign: "middle"
text: root.text
color: app.colors.grey_dark if root.state == "normal" else app.colors.primary
Then i got another folder called "views" inside i have another folder called "home", inside home we encounter 3 files "init.py", "home.kv", "home.py". the first one "init.py" is the following.
from .home import Home
then we got "home.kv".
#:kivy 2.1.0
<Home>:
orientation: "vertical"
Label:
size_hint_y: .1
text: "Other"
Button:
size_hint_y: .1
text: "popup"
on_press: root.open_popup()
BoxLayout:
size_hint_y: .8
id: home_box
<SomePopup>:
title: "SOME TITLE"
title_align: "center"
title_color: app.colors.primary
size_hint: .25, .8
size_hint_min_x: dp(200)
pos_hint: {"x": .1, "top": .9}
BoxLayout:
orientation: "vertical"
padding: [dp(0), dp(12), dp(0), dp(12)]
Label:
text: "Some text"
Button:
text: "create buttons on box"
on_press: root.modify_home_box()
and finally and the problem that i´m facing is whit the following file "home.py"
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
from kivy.factory import Factory
from kivy.uix.popup import Popup
from kivy.uix.button import Button
from kivy.app import App
Builder.load_file('views/home/home.kv')
class Home(BoxLayout):
def __init__(self, **kwargs):
super().__init__(**kwargs)
def open_popup(self):
Factory.SomePopup().open()
class SomePopup(Popup):
def __init__(self, **kw):
super().__init__(**kw)
def modify_home_box(self):
my_app = App.get_running_app().root
my_box = my_app.ids.home.ids.home_box
custom_button = Button(
text = "something"
)
my_box.add_widget(custom_button)
That i´m trying to do is actually modify "home_box" with is store on ids Home dictionary, i also try with ObjectProperty (but that gives and Attribute Error, since i only could read propertys but doesnt modify it), instance of a new Home class doesnt work... searching for current app in App appear doesnt work since Home is store i think on screenManager...
I need add a button or some widget to "home_box" from outside class "SomePopup". I also drop here a repository on github with the whole code. github_repo
I don't know how to solve my issue, and i try with the resources available here on stack as well other net places... any help would be appreciate.

Just a very complicated path to the widget of interest. In your modify_home_box() method, try replacing:
my_app = App.get_running_app().root
my_box = my_app.ids.home.ids.home_box
with:
my_app = App.get_running_app().root
my_box = my_app.ids.scrn_mngr.ids.home.ids.home_box

Changing a label nested in a different screen in Kivy with screenmanager

I'm trying but failing on a simple task of changing a label nested in a different screen in Kivy with screenmanager.
I want to show "f_path" variable on "lbl_file_path" label. "lbl_file_path" label is on "W_MainMenu" screen. "f_path" is created on "W_FileSelector" screen.
How can I do this ? Any help is greatly appreciated. You may find the code below;
from logging import root
from charset_normalizer import from_path
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.core.window import Window
from kivy.properties import ObjectProperty
f_path = ""
class MyWinMan(ScreenManager):
pass
class W_MainMenu(Screen):
def transform_to_filechooser(self):
Window.size = (700, 950)
Window.top = 50
Window.left = 100
self.lbl_file_path.text = f_path
class W_FileSelector(Screen):
def transform_to_main(self):
Window.size = (700, 280)
Window.top = 50
Window.left = 100
def selected(self, filename):
try:
print(filename[0])
global f_path
f_path = filename[0]
except:
pass
kv = Builder.load_string("""
MyWinMan:
W_MainMenu:
W_FileSelector:
<W_MainMenu>:
lbl_file_path: lbl_file_path_k
name: "win_Main"
BoxLayout:
orientation: "vertical"
size: root.width, root.height
padding: 40
spacing: 10
BoxLayout:
orientation: "horizontal"
size: root.width, root.height
padding: 0
spacing: 10
Button:
text:'Browse for Source Excel File'
font_size: 20
on_release:
app.root.current = "win_FS"
root.manager.transition.direction = "up"
root.transform_to_filechooser()
Image:
source:""
size_hint: ( 0.2, 1)
Label:
text:'Selected Excel File Path'
size_hint: ( 1, 0.4)
font_size: 18
color: ( 180/255, 180/255, 180/255, 1)
background_color: ( 50/255,50/255,50/255,1)
canvas.before:
Color:
rgba: self.background_color
Rectangle:
pos: self.pos
size: self.size
Label:
text: "Initial Text"
# text: f_path
id: lbl_file_path_k
size_hint: ( 1, 0.4)
font_size: 18
color: ( 50/255, 50/255, 50/255,1)
background_color: ( 180/255, 180/255, 180/255, 1)
canvas.before:
Color:
rgba: self.background_color
Rectangle:
pos: self.pos
size: self.size
<W_FileSelector>:
name: "win_FS"
id: my_widget
BoxLayout:
orientation: "vertical"
size: root.width, root.height
padding: 50
spacing: 20
Label:
text:'Please select the file...'
size_hint: ( 1, 0.1)
font_size: 20
FileChooserListView:
id: filechooser
path: "."
on_selection:
my_widget.selected(filechooser.selection)
Button:
text:'OK'
font_size: 20
size_hint: ( 1, 0.1)
on_release:
app.root.current = "win_Main"
root.manager.transition.direction = "down"
root.transform_to_main()
""")
Window.size = (700, 280)
Window.top = 50
Window.left = 100
class MyApp(App):
def build(self):
self.title = "Data Importer"
return kv
if __name__ == '__main__':
MyApp().run()

You just need to access the right screen and its contents. One of the many ways would be using the method get_screen as follows,
def selected(self, filename):
try:
# Access the target screen.
main_screen = self.manager.get_screen("win_Main")
# Access its target label.
file_path_label = main_screen.ids.lbl_file_path_k
# Set the text.
file_path_label.text = filename[0]
print(filename[0])
# global f_path
f_path = filename[0]
except:
pass
Other ways include binding directly from FileChooserListView, defining custom variable in that class or in the App's class etc.

ids is empty in a python kivy boxlayout with children

I've created a Screen with a boxlayout and its children.
I wanna print size of the label "Hello" in the boxlayout, which has id:shadow_label
This size must be relative. But it's [100, 100]
Why?
What could I give more details for this post? Could this behavior be due to AnchorLayout?
Here is my code
kv file:
<WellcomeScreen>:
box_layout: wellcome_box
BoxLayout:
id: wellcome_box
orientation: 'vertical'
pos: self.parent.pos
size: self.parent.size
padding: [30, 30]
spacing: 10
canvas.before:
Rectangle:
source: 'Data\game background.png'
pos: self.pos
size: self.size
Label:
id:shadow_label
size_hint: (1, .6)
font_size: self.height/12
text_size: self.width-10, None
color: 'purple'
halign: "center"
text: "Hello"
AnchorLayout:
size_hint: (1,.3)
Button:
canvas.before:
Rectangle:
source: "Data\Button_start.png"
pos: self.pos
size: self.size
pos_hint: {"center_x":0.5,"center_y":0.5}
size_hint: (None, None)
size: (self.parent.height/4*3, self.parent.height/4*3)
background_color: (1,1,1,0)
font_size: self.height/4
text_size: self.width, None
text: "START"
color: "yellow"
bold: True
halign: 'center'
on_press:
root.manager.transition.direction = 'left'
root.manager.current = 'login'
python
from kivymd.app import MDApp
from kivy.uix.screenmanager import ScreenManager, Screen
from kivymd.uix.label import MDLabel
from kivy.uix.behaviors import ButtonBehavior
from kivy.properties import ObjectProperty
from kivy.config import Config
Config.set('graphics', 'resizable', '0')
Config.set('graphics', 'width', '420')
Config.set('graphics', 'height', '860')
class WellcomeScreen(Screen):
user_name = ObjectProperty()
box_layout = ObjectProperty()
wellcome_label = ObjectProperty()
def __init__(self, **kwargs):
super(WellcomeScreen, self).__init__(**kwargs)
class StartButton(ButtonBehavior, MDLabel):
def __init__(self, **kwargs):
super(StartButton, self).__init__(**kwargs)
self.background_normal = "Data\Button_start.png"
self.text = "START"
self.text_color = "yellow"
self.color = "white"
self.halign = "center"
class FastReadApp(MDApp):
def build(self):
sm = ScreenManager()
screen_wellcome = WellcomeScreen(name='wellcome')
sm.add_widget(screen_wellcome)
print(screen_wellcome.ids.shadow_label.size)
return sm
if __name__ == '__main__':
app = FastReadApp()
app.run()
There is the screen of my app:

You are printing the size of the label before its size is set, so you see the default size of (100,100). Just delay the print until the size is set. Use Clock.schedule_once() or use a Button to trigger the print.

kivy scrollview inside gridlayout on label

I trying to create a one screen app with one root rule set. by pressing a button i should see a scrollable text in the grid next to the button. In all the example solutions I see that scrollview is working in similar KV files that I have seen in other questions. Could someone please identify what I have missed in KV file.
my .py file:
import kivy
import string
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.gridlayout import GridLayout
from kivy.properties import ObjectProperty
from kivy.properties import StringProperty
from kivy.uix.scrollview import ScrollView
from kivy.core.window import Window
class RootContainer(BoxLayout):
instance = ObjectProperty(None)
def __init__(self, **kwargs):
super(RootContainer, self).__init__(**kwargs)
def clickAction1(self, instance):
#identify the button pressed
buttonText = instance.text
self.lbl1.text = instance.text + " some text goes here ... "
myresult = " this is scrolling text.\n " * 30
self.lbl5.text = myresult
class MBApp(App):
def build(self):
return RootContainer()
if __name__ == '__main__':
MBApp().run()
my KV file:
#:kivy 1.0.9
<RootContainer>:
id: theRoot
lbl1: my_labelC
lbl5: my_labelCS
BoxLayout:
orientation: 'vertical'
spacing: 20
padding: 20
canvas:
Color:
rgb: 0, .33, 0
Rectangle:
pos: self.pos
size: self.size
Button:
text: "This is 1st button"
text_size: self.size
size_hint: (.5,1)
on_press: theRoot.clickAction1(self)
Button:
text: "This is 2nd button"
text_size: self.size
size_hint: (.5,1)
on_press: root.clickAction1(self)
GridLayout:
rows: 2
cols: 1
spacing: 10
padding: 10
canvas:
Color:
rgb: .7, .63, 0
Rectangle:
pos: self.pos
size: self.size
Label:
id: my_labelC
canvas.before:
Color:
rgb: 0,0,0
Rectangle:
pos: self.pos
size: self.size
text: "Header text for button clicked ......."
text_size: self.size
ScrollView:
GridLayout:
cols:1
rows:1
height: self.minimum_height
Label:
id: my_labelCS
text: "Scrolling text goes here ....."
I hope this is not a duplicate. Any other suggestions to code are also welcome. Thank you.

You don't set the size of your Label, so the default applies, as any widget, the defaults are
size: 100, 100
size_hint: 1, 1
since size_hintis 1, 1, and the parent is a layout, size itself is overriden by the parent's available space
since you set size: minimum_size in the parent layout, it'll give the minimum size its children require, but the Label doesn't ask for any space, it's size_hint of 1, 1 means that it's happy to take all the available space. Kivy solve this situation by not giving it any space, so the Label size ends up being 0, 0, and the GridLayout's size as well.
So you want to disable size_hint (at least for the height, of the Label, and instead set it to the texture heights
size_hint_y: None
height: self.texture_size[1]
Which is usually sided with setting the texture width to the available width, by setting text_size.
text_size: self.width, None
size_hint_x: 1 # this is the default, so this line is not required, but you want to be sure not to disable this default

Do you really need the GridLayout inside your scrollview? This works for me:
ScrollView:
Label:
id: my_labelCS
size_hint: 1, None
text_size: self.width, None
height: self.texture_size[1]
text: "Scrolling text goes here ....."