Develop Reference

(KivyMD) How to call a function when using 2 kv files/strings?

I have a kivymd app that has a screen with a button on it. When you click this button an MDCard will appear on the screen. When you click on this new MDCard it will call a function that will print a message on the terminal. However, I am having trouble getting this MDCard to call the function. I am getting the error:
AttributeError: 'MDCard' object has no attribute 'option'
The MDCard is in a separate kv string from the main kv string. Essentially I have two kv strings. When you press the button, the second kv string will be added as a widget to the first kv string.
I figured it is because the second kv string doesn't have a class as a root but I don't know how to do this. How can I get the MDCard to call the function??
MAIN.PY
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import ObjectProperty
from kivymd.app import MDApp
from button_screen import button_screen
MainNav = '''
<ContentNavigationDrawer>:
ScrollView:
MDList:
OneLineListItem:
text: 'Go to Button Screen'
on_press:
root.nav_drawer.set_state("close")
root.screen_manager.current = "go_to_button_screen"
Screen:
MDToolbar:
id: toolbar
pos_hint: {"top": 1}
elevation: 10
left_action_items: [["menu", lambda x: nav_drawer.set_state("open")]]
MDNavigationLayout:
x: toolbar.height
ScreenManager:
id: screen_manager
Screen:
name: "words_nav_item"
button_screen:
name: "go_to_button_screen"
MDNavigationDrawer:
id: nav_drawer
ContentNavigationDrawer:
screen_manager: screen_manager
nav_drawer: nav_drawer
'''
class ContentNavigationDrawer(BoxLayout):
screen_manager = ObjectProperty()
nav_drawer = ObjectProperty()
class main_test(MDApp):
def build(self):
self.theme_cls.primary_palette = "Red"
return Builder.load_string(MainNav)
main_test().run()
BUTTON SCREEN .PY FILE
from kivy.lang import Builder
from kivymd.uix.screen import MDScreen
button_screen_kv = '''
<button_screen>:
MDGridLayout:
cols: 1
size: root.width, root.height
spacing: 40
md_bg_color: [0,0,.1,.1]
MDGridLayout:
cols: 1
size_hint_y: None
height: 40
MDGridLayout:
cols: 1
Button:
text: "Click to add card"
on_release:
root.add_card("card 1")
MDGridLayout:
id: add_card_here_id
cols: 1
'''
md_card_kv = '''
MDCard:
orientation: 'vertical'
size_hint: None, None
size: "360dp", "120dp"
ripple_behavior: True
on_release:
root.option("MDCard was clicked")
MDLabel:
id: LabelTextID
text: "this is an MDCard"
halign: 'center'
'''
class button_screen(MDScreen):
def __init__(self, **kwargs):
super().__init__(**kwargs)
Builder.load_string(button_screen_kv)
self.md_card_widget = Builder.load_string(md_card_kv)
def option(self, string):
print(f"{string}")
def add_card(self, *args):
self.ids.add_card_here_id.add_widget(self.md_card_widget)

I came up with the following that works however, I am still new to programming so I don't know if this is a stable solution. Please advise me there
The Solution:
I added another class class user_card(MDGridLayout) in the buttonscreen.py and placed the kv string there.
I set that class as the root widget in the kv string
in the init method I placed a function that will return the kv string return self.user_card_string
then I added that class as a parameter in the add_widget and passed the col as an argument: self.ids.add_card_here_id.add_widget(user_card(cols=1))
Everything works but I have never used two classes before. So I am unsure if this will present a future problem.
button_screen.py:
from kivy.lang import Builder
from kivymd.uix.gridlayout import MDGridLayout
from kivymd.uix.screen import MDScreen
button_screen_kv = '''
<button_screen>:
MDGridLayout:
cols: 1
size: root.width, root.height
spacing: 40
md_bg_color: [0,0,.1,.1]
MDGridLayout:
cols: 1
size_hint_y: None
height: 40
MDGridLayout:
cols: 1
Button:
text: "Click to add card"
on_release:
root.add_card("card 1")
MDGridLayout:
id: add_card_here_id
cols: 1
'''
md_card_kv = '''
<user_card>:
MDGridLayout:
cols: 1
MDCard:
orientation: 'vertical'
size_hint: None, None
size: "360dp", "120dp"
ripple_behavior: True
on_release:
root.option()
MDLabel:
id: LabelTextID
text: "this is an MDCard"
halign: 'center'
'''
class user_card(MDGridLayout):
user_card_string = Builder.load_string(md_card_kv)
def __init__(self, *args, **kwargs):
super().__init__(**kwargs)
self.load_card()
def option(self, *args):
print("MDCard was clicked")
def load_card(self):
return self.user_card_string
class button_screen(MDScreen):
def __init__(self, **kwargs):
super().__init__(**kwargs)
Builder.load_string(button_screen_kv)
def add_card(self, *args):
self.ids.add_card_here_id.add_widget(user_card(cols=1))

How can I access the root property of a class without getting ValueError

I am a kivy/kivymd novice learning how to make a Navigation Drawer following the kivymd website( https://kivymd.readthedocs.io/en/0.104.0/components/navigation-drawer/). I have my code towards the bottom.
Whenever, I run the code it gives this error:
kivy.lang.builder.BuilderException: Parser: File "<inline>", line 10:
...
8: icon: root.icon
9: theme_text_color: "Custom"
>> 10: text_color: root.text_color
11:
12:<ContentNavigationDrawer>:
...
ValueError: None is not allowed for IconLeftWidget.text_color
I know that root refers to the parent class that is in angle brackets, which in this case is the ItemDrawer. So I believe it should do ItemDrawer.text_color. I am a complete nube with kivy and kivymd, and I need help figuring out how to solve this issue!
Here is my code. First is the python file that contains my string, which the Builder loads:
proof_helper = """
<ItemDrawer>:
theme_text_color: "Custom"
on_release: self.parent.set_color_item(self)
#invokes DrawerList set_color_item method
IconLeftWidget:
id: icon
icon: root.icon
theme_text_color: "Custom"
text_color: root.text_color
<ContentNavigationDrawer>:
orientation: 'vertical'
padding: '8dp'
spacing: '8dp'
ScrollView:
DrawerList:
id: md_list
Screen:
MDNavigationLayout:
ScreenManager:
Screen:
BoxLayout:
orientation: 'vertical'
MDToolbar:
title: "Navigation Drawer"
elevation: 8
left_action_items : [["menu", lambda x: nav_drawer.set_state()]]
Widget:
Screen:
MDNavigationDrawer:
id: nav_drawer
ContentNavigationDrawer:
id: content_drawer
"""
Here is my main.py file:
from kivymd.app import MDApp
from kivymd.theming import ThemableBehavior
from kivy.lang import Builder
from kivymd.uix.list import MDList, OneLineListItem, OneLineIconListItem
from kivy.core.window import Window
from proof_nav import proof_helper
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import ObjectProperty, StringProperty
Window.size = (300, 500)
class ItemDrawer(OneLineIconListItem):
icon = StringProperty()
class ContentNavigationDrawer(BoxLayout):
pass
class DrawerList(ThemableBehavior, MDList):
def set_color_item(self, instance_item):
for item in self.children:
if item.text_color == self.theme_cls.primary_color:
item.text_color = self.theme_cls.text_color
break
instance_item.text_color = self.theme_cls.primary_color
class ProofApp(MDApp):
def build(self):
screen = Builder.load_string(proof_helper)
return screen
def on_start(self):
icons_item = {
"folder": "My files",
"account-multiple": "Shared with me",
"star": "Starred",
"history": "Recent",
"checkbox-marked": "Shared with me",
"upload": "Upload",
}
for item in icons_item:
self.root.ids.content_drawer.ids.md_list.add_widget(
ItemDrawer(icon=item, text=icons_item[item])
)
ProofApp().run()

The default text_color for a OneLineIconListItem is None. If you want to us that as you have, you must set its value to something other than None.
You could also do something like:
text_color: root.text_color if root.text_color else (0,0,0)

How to switch screens from a dynamically created button in kivy recycleview

Problem
I have a screen (OrderScreen) that populates with buttons if there is data to be processed. I would like the user to click one of the buttons to be brought to another screen (MenuScreen) to process the data. While my intention is to populate the next screen with data from the button, I am currently just trying to get the ScreenManager to change to the next screen after a button press. I added a pass_data() method to the OrderButton and tried to trigger the screen manager there but self.manager.current and root.manager.current were throwing exceptions. Any help would be greatly appreciated.
recycleview_test.py
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.label import Label
from kivy.uix.recycleview import RecycleView
from kivy.uix.screenmanager import ScreenManager, Screen
from random import randint
class MenuScreen(Screen):
def quit(self):
App.get_running_app.stop()
Window.close()
class OrderScreen(Screen):
pass
class OrderButton(Button):
def __init__(self, **kwargs):
super(OrderButton, self).__init__(**kwargs)
def pass_data(self):
print("button pushed")
class OrderScroll(RecycleView):
def __init__(self, **kwargs):
super(OrderScroll, self).__init__(**kwargs)
self.data = [{'text': str(f"Make {randint(10, 25)} items from package #{randint(1,4)}")} for x in range(12)]
class WindowManager(ScreenManager):
pass
class RecycleApp(App):
def build(self):
return WindowManager()
if __name__ == "__main__":
RecycleApp().run()
recycle.kv
#:import Factory kivy.factory.Factory
#: import ScreenManager kivy.uix.screenmanager.ScreenManager
#: import Screen kivy.uix.screenmanager.ScreenManager
#:import App kivy.app.App
<OrderScroll>:
viewclass: 'OrderButton'
manager: None
RecycleBoxLayout:
default_size: None, dp(56)
default_size_hint: 1, None
size_hint_y: None
height: self.minimum_height
orientation: 'vertical'
padding: 20
spacing: 10
<OrderButton>:
manager: None
font_size: 32
bold: True
on_release:
root.pass_data()
<WindowManager>:
id: screen_manager
OrderScreen:
id: order_screen
name: "OrderScreen"
manager: screen_manager
MenuScreen:
id: menu_screen
name: 'MenuScreen'
manager: screen_manager
<OrderScreen>:
BoxLayout:
orientation: "vertical"
Label:
text: "Data Buttons"
font_size: 64
size_hint_y: None
# pos_hint: {"x":0, "y":1}
height: 200
OrderScroll:
<MenuScreen>:
BoxLayout:
orientation: "vertical"
Label:
text: "Made it"
font_size: 64
FloatLayout:
Button:
text: 'Keep going'
font_size: 48
size_hint: .8,.5
pos_hint: {"center_x": .5, "center_y": .1}
FloatLayout:
Button:
text: 'Quit'
size_hint: .15,.3
pos_hint: {"center_x": .5, "center_y": .5}
on_release:
root.quit()

Try to create an object of screen manager:
class RecycleApp(App):
def build(self):
self.sm = WindowManager()
return self.sm
And then access it by:
App.get_running_app().sm.current = 'MenuScreen' # in Python
app.sm.current = 'MenuScreen' # in kv

How to set the text of optional labels in .kv from .py

I have problem with setting the labels texts.
I need to set different text on the different labels that just have an id in .kv file, so that means that I don't want to create a class for each of the labels.
But I want to have the access to changing each labels text.
Please, help me with that problem on Python 3.6 and Kivy 1.11.1
There is my main.py code:
from kivy.app import App
from kivymd.theming import ThemeManager
from kivymd.label import MDLabel
from kivy.uix.screenmanager import Screen
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.anchorlayout import AnchorLayout
from kivy.metrics import dp, sp, pt
def toast(text):
from kivymd.toast.kivytoast import toast
toast(text)
class MyScreen(Screen):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.menu_items = [
{
"viewclass": "MDMenuItem",
"text": "text%d" % i,
"callback": self.callback,
}
for i in range(1, 3)
]
self.menu_button = None
def change_variable(self, value):
print("\nvalue=", value)
self.VARIABLE = value
print("\tself.VARIABLE=", self.VARIABLE)
def callback(self, *args):
toast(args[0])
class MainApp(App):
title = "KivyMD MDDropdownMenu Demo"
theme_cls = ThemeManager()
def build(self):
return MyScreen()
def results(self):
msc = MyScreen()
msc.ids.firstlabel.text = 'FIRST TEXT'
msc.ids.secondlabel.text = 'SECOND TEXT'
msc.ids.thirdlabel.text = 'THIRD TEXT'
if __name__ == "__main__":
MainApp().run()
There is my main.kv code:
#:import MDDropdownMenu kivymd.menus.MDDropdownMenu
#:import MDRaisedButton kivymd.button.MDRaisedButton
#:import MDLabel kivymd.label.MDLabel
<OptionalLabel#MDLabel>:
halign: 'center'
font_size: dp(12)
<MDRB#MDRaisedButton>:
size_hint: None, None
size: 3 * dp(48), dp(48)
pos_hint: {'center_x': 0.5, 'center_y': 0.5}
opposite_colors: True
<MDMenuItem>:
on_release:
app.root.change_variable(self.text)
app.root.menu_button.text = self.text
<MyScreen>:
name: 'myscrn'
AnchorLayout:
anchor_y: 'center'
BoxLayout:
orientation: 'vertical'
size_hint: 0.1, 0.5
pos_hint: {'center_x': 0.5, 'center_y': 0.5}
spacing: dp(10)
MDRB:
id: mainbutton
text: 'MDButton1'
on_release:
root.menu_button = mainbutton
MDDropdownMenu(items=root.menu_items, width_mult=4).open(self)
MDRB:
id: secondbutton
text: 'MDButton2'
on_release:
root.menu_button = secondbutton
MDDropdownMenu(items=root.menu_items, width_mult=4).open(self)
MDRB:
text: 'set the labels'
on_release:
app.results()
OptionalLabel:
id: firstlabel
text: 'label1'
OptionalLabel:
id: secondlabel
text: 'label2'
OptionalLabel:
id: thirdlabel
text: 'label3'
Thanks for attention!

You are pretty close. Accessing a text by ids is the way you want to go, you just have another issue here.
In short, you are actually creating two different MyScreen objects, you have one in your build() (which is actually what shows on the window) and then you are creating another screen in local scope of the "results" function.
class MainApp(App):
title = "KivyMD MDDropdownMenu Demo"
theme_cls = ThemeManager()
def build(self):
return MyScreen() ///THIS IS A OBJECT IN MEMORY
def results(self):
msc = MyScreen() /// THIS IS A DIFFERENT OBJECT IN MEMORY, BUT DOESN'T REFERENCE THE SCREEN IN Build
msc.ids.firstlabel.text = 'FIRST TEXT'
msc.ids.secondlabel.text = 'SECOND TEXT'
msc.ids.thirdlabel.text = 'THIRD TEXT'
In this situation, I'd suggest taking your results function and bringing down into your MyScreen class like the below example. Key point here, you can bind to the on_release function from either KV lang or in Python Class. In the example below, I'm doing so in Python class.
from kivy.app import App
from kivy.lang import Builder
from kivymd.theming import ThemeManager
from kivymd.label import MDLabel
from kivy.uix.screenmanager import Screen
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.anchorlayout import AnchorLayout
from kivy.metrics import dp, sp, pt
Builder.load_string("""
#:import MDDropdownMenu kivymd.menus.MDDropdownMenu
#:import MDRaisedButton kivymd.button.MDRaisedButton
#:import MDLabel kivymd.label.MDLabel
<OptionalLabel#MDLabel>:
halign: 'center'
font_size: dp(12)
<MDRB#MDRaisedButton>:
size_hint: None, None
size: 3 * dp(48), dp(48)
pos_hint: {'center_x': 0.5, 'center_y': 0.5}
opposite_colors: True
<MDMenuItem>:
on_release:
app.root.change_variable(self.text)
app.root.menu_button.text = self.text
<MyScreen>:
name: 'myscrn'
AnchorLayout:
anchor_y: 'center'
BoxLayout:
orientation: 'vertical'
size_hint: 0.1, 0.5
pos_hint: {'center_x': 0.5, 'center_y': 0.5}
spacing: dp(10)
MDRB:
id: mainbutton
text: 'MDButton1'
on_release:
root.menu_button = mainbutton
MDDropdownMenu(items=root.menu_items, width_mult=4).open(self)
MDRB:
id: secondbutton
text: 'MDButton2'
on_release:
root.menu_button = secondbutton
MDDropdownMenu(items=root.menu_items, width_mult=4).open(self)
MDRB:
id: changesresultsbutton
text: 'set the labels'
OptionalLabel:
id: firstlabel
text: 'label1'
OptionalLabel:
id: secondlabel
text: 'label2'
OptionalLabel:
id: thirdlabel
text: 'label3'
""")
def toast(text):
from kivymd.toast.kivytoast import toast
toast(text)
class MyScreen(Screen):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.menu_items = [
{
"viewclass": "MDMenuItem",
"text": "text%d" % i,
"callback": self.callback,
}
for i in range(1, 3)
]
self.menu_button = None
self.ids.changesresultsbutton.bind(on_release = self.results)
def change_variable(self, value):
print("\nvalue=", value)
self.VARIABLE = value
print("\tself.VARIABLE=", self.VARIABLE)
def callback(self, *args):
toast(args[0])
def results(self, value):
self.ids.firstlabel.text = 'FIRST TEXT'
self.ids.secondlabel.text = 'SECOND TEXT'
self.ids.thirdlabel.text = 'THIRD TEXT'
class MainApp(App):
title = "KivyMD MDDropdownMenu Demo"
theme_cls = ThemeManager()
def build(self):
return MyScreen()
if __name__ == "__main__":
MainApp().run()

Search Box with suggestions in kivy?

I am new to kivy wanted to know how we can bind textinput box to suggestion so that user and touch and select the suggestions.
I have long list of buttons out of which i want to select on the basis of name.

i am using kivymd i dont real know how to do it in kivy but here are the codes for kivymd
from kivy.lang import Builder
from kivy.properties import StringProperty
from kivy.uix.screenmanager import Screen
from kivymd.icon_definitions import md_icons
from kivymd.app import MDApp
from kivymd.uix.list import OneLineIconListItem
Builder.load_string(
'''
#:import images_path kivymd.images_path
<CustomOneLineIconListItem>:
IconLeftWidget:
icon: root.icon
<PreviousMDIcons>:
BoxLayout:
orientation: 'vertical'
spacing: dp(10)
padding: dp(20)
BoxLayout:
size_hint_y: None
height: self.minimum_height
MDIconButton:
icon: 'magnify'
MDTextField:
id: search_field
hint_text: 'Search icon'
on_text: root.set_list_md_icons(self.text, True)
RecycleView:
id: rv
key_viewclass: 'viewclass'
key_size: 'height'
RecycleBoxLayout:
padding: dp(10)
default_size: None, dp(48)
default_size_hint: 1, None
size_hint_y: None
height: self.minimum_height
orientation: 'vertical'
'''
)
class CustomOneLineIconListItem(OneLineIconListItem):
icon = StringProperty()
class PreviousMDIcons(Screen):
def set_list_md_icons(self, text="", search=False):
'''Builds a list of icons for the screen MDIcons.'''
def add_icon_item(name_icon):
self.ids.rv.data.append(
{
"viewclass": "CustomOneLineIconListItem",
"icon": name_icon,
"text": name_icon,
"callback": lambda x: x,
}
)
self.ids.rv.data = []
for name_icon in md_icons.keys():
if search:
if text in name_icon:
add_icon_item(name_icon)
else:
add_icon_item(name_icon)
class MainApp(MDApp):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.screen = PreviousMDIcons()
def build(self):
return self.screen
def on_start(self):
self.screen.set_list_md_icons()
MainApp().run()
some results
here is the screen shot result when your not searching for anything
here is a screen shot when i am trying to search
second
here is a result when the word am searching does not exist

Here is a simple example that will use the use text input to search in the option_list and will display the suggestion under the text input widget.
I used the kivymd widget to get a nice look design you replaced with the normal kivy widgets if you want
from kivy.properties import ListProperty
from kivymd.app import MDApp
from kivymd.uix.list import OneLineAvatarIconListItem
from kivymd.uix.textfield import MDTextField
kv = """
Screen:
BoxLayout:
orientation: 'vertical'
spacing: 1
BoxLayout:
size_hint_y: 1/5
canvas.before:
Color:
rgba: 0, 0, 0, 1
Rectangle:
pos: self.pos
size: self.size[0], 2
MDIconButton:
icon: 'magnify'
size_hint_y: 1
SearchTextInput:
id: Search_TextInput_id
size_hint_y: .97
pos_hint:{ 'left':0 , 'top': 1}
hint_text: 'search'
hint_text_color: 1,1,1,1
icon_left: 'magnify'
mode: "fill"
helper_text_mode: "persistent"
helper_text: "Search"
line_color: [1,1,1,1]
color_normal: [1,1,1,1]
font_size: .35 * self.height
active_line: False
multiline: False
MDIconButton:
icon: 'close'
size_hint_y:1
text_color: 0,0,0,1
BoxLayout:
orientation: 'vertical'
padding: 4
RecycleView:
viewclass: 'Search_Select_Option'
data:app.rv_data
RecycleBoxLayout:
spacing: 15
padding : 10
default_size: None, None
default_size_hint: 1, None
size_hint_y: None
height: self.minimum_height
orientation: 'vertical'
<Search_Select_Option>:
on_release: print(self.text)
IconRightWidget:
icon: "arrow-top-left"
"""
class Search_Select_Option(OneLineAvatarIconListItem):
pass
class SearchTextInput(MDTextField):
option_list = 'one1,two1,two2,three1,three2,three3,four1,four2,four3,four4,five1,five2,five3,five4,five5'.split(',')
def on_text(self, instance, value):
app = MDApp.get_running_app()
option_list = list(set(self.option_list + value[:value.rfind(' ')].split(' ')))
val = value[value.rfind(' ') + 1:]
if not val:
return
try:
app.option_data = []
for i in range(len(option_list)):
word = [word for word in option_list if word.startswith(val)][0][len(val):]
if not word:
return
if self.text + word in option_list:
if self.text + word not in app.option_data:
popped_suggest = option_list.pop(option_list.index(str(self.text + word)))
app.option_data.append(popped_suggest)
app.update_data(app.option_data)
except IndexError:
pass
class RVTestApp(MDApp):
rv_data = ListProperty()
def update_data(self, rv_data_list):
self.rv_data = [{'text': item} for item in rv_data_list]
print(self.rv_data, 'update')
def build(self):
return Builder.load_string(kv)
RVTestApp().run()

Incase anyone is wondering how can get the value of the selected item from the list, I have a little updated version here:
from kivymd.icon_definitions import md_icons
from kivy.lang import Builder
from kivymd.app import MDApp
from kivymd.uix.list import OneLineListItem
from kivy.uix.screenmanager import Screen
KV = '''
<ListSelect>
BoxLayout:
orientation: 'vertical'
spacing: dp(10)
padding: dp(20)
pos_hint:{'center_x': 0.5, 'y': 0.85}
BoxLayout:
size_hint_y: None
height: self.minimum_height
MDIconButton:
icon: 'magnify'
MDTextField:
id: search_field
hint_text: 'Search icon'
on_text:
root.set_list(self.text)
RecycleView:
pos_hint:{'center_x': 0.5, 'center_y': 0.4}
MDList:
id: container
'''
class ListSelect(Screen):
def pressed(self, value):
# value here is the OneLineListItem
self.ids.container.clear_widgets()
# set TextField text to selected list item
self.ids.search_field.text = value.text
print(value.text)
def set_list(self, text=" "):
# text defaults to blank space to not show any icons initally
# each OneLineListItem takes the pressed func on press
self.ids.container.clear_widgets() # refresh list
for icon in md_icons.keys():
# using casefold() to make the input case insensitve
if icon.startswith(text.casefold()):
self.ids.container.add_widget(
OneLineListItem(text=icon, on_press=self.pressed)
)
class Test(MDApp):
def build(self):
Builder.load_string(KV)
self.screen = ListSelect()
return self.screen
def on_start(self):
self.screen.set_list()
Test().run()
One catch: the search needs quite a long time to finish. If anyone has any hints on how to speed it up, you are very welcome!