Kivy adding and removing widgets from GridLayout gives weak reference issue - python

I am attempting to dynamically add and remove widgets from a GridLayout with Python-Kivy, and I am running into an issue with weak references. When the Screen containing the GridLayout is initialized, I am placing a Label inside of the GridLayout that contains text notifying the user that the container has no items (technically, it has the Label in there so it is not necessarily empty). Then I have a Button that allows the user to add individual GridLayout widgets to the GridLayout that contain a Label, a TextInput and a CheckBox, as well as a Button that allows the user to remove those individual GridLayout widgets that they created. If all of these widgets (dynamically added by the user) are removed, then the original Label is added back to the GridLayout.
When I attempt to construct this logic in Python to pair with Kivy, I run into an issue where the original Label never seems to be fully removed from the stack.
I was under the impression that self.ids.widget_list.remove_widget(self.ids.empty) would remove the Label widget with id empty, however this is not the case. It is clear that the widget still exists, when I call print(self.ids):
{'widget_list': <WeakProxy to <kivy.uix.gridlayout.GridLayout object at 0x0451F030>>, 'empty': <WeakProxy to <kivy.uix.gridlayout.GridLayout object at 0x0451F9D0>>}
Any help is much appreciated.
EDIT
When checking for i in self.layouts: print(i.children) every time the remove() method is called, shows that the references to the added widgets are never being completely removed. This may be where my issues resides, but unsure how to resolve it.
Python
import kivy
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.gridlayout import GridLayout
from kivy.uix.button import Button
from kivy.uix.textinput import TextInput
from kivy.uix.scrollview import ScrollView
from kivy.uix.label import Label
from kivy.uix.checkbox import CheckBox
from kivy.uix.popup import Popup
from kivy.uix.screenmanager import ScreenManager, Screen
#Load kv file
Builder.load_file('test.kv')
#First Screen
class Screen1(Screen):
layouts = []
def remove(self):
for i in self.layouts:
if i.children[0].active:
self.ids.widget_list.remove_widget(i)
if len(self.layouts)==0:
layout = GridLayout(rows=1, id=empty)
layout.add_widget(Label(text='Nothing Here'))
self.ids.widget_list.add_widget(layout)
else:
self.update_hints()
def add(self):
if len(self.ids.widget_list.children)<5:
print(self.ids)
self.ids.widget_list.remove_widget(self.ids.empty)
print(self.ids)
layout = GridLayout(cols=3)
layout.add_widget(Label(text='Test ' + str(len(self.ids.widget_list.children)+1)))
layout.add_widget(TextInput())
layout.add_widget(CheckBox())
self.ids.widget_list.add_widget(layout)
self.layouts.append(layout)
self.update_hints()
else:
layout = GridLayout(cols=1)
layout.add_widget(Label(text='Only five allowed at once.\nRemove at least one to add another.'))
button = Button(text='Acknowledge'); layout.add_widget(button)
popup = Popup(content=layout, title='Limit Reached', size_hint=(.5,.5), auto_dismiss=False)
button.bind(on_release=popup.dismiss)
popup.open()
def update_hints(self):
for i in self.layouts:
i.children[1].hint_text = 'Ex. ' + str(round(100/len(self.ids.widget_list.children),2)) + '%'
#Initialize Screens and Start App
class MyScreenManager(ScreenManager):
pass
#Main application
class SampleApp(App):
def build(self):
self.sm = MyScreenManager()
return self.sm
if __name__ == '__main__':
SampleApp().run()
kv
<MyScreenManager>:
Screen1:
name: 'screen1'
<Screen1>:
BoxLayout:
orientation: 'vertical'
GridLayout:
cols: 3
padding: 20
spacing: 20
size_hint: 1, .1
Label:
text: 'List of Widgets'
underline: True
Label:
text: 'Percentage'
underline: True
Label:
text: 'Remove (Y/N)'
underline: True
ScrollView:
size_hint: 1, .5
do_scroll_x: False
padding: 20
spacing: 20
GridLayout:
id: widget_list
cols: 1
spacing: 5
GridLayout:
id: empty
rows: 1
Label:
text: 'Nothing Here'
GridLayout:
cols: 3
padding: 20
spacing: 20
size_hint: 1, .2
Button:
text: 'Add Widget'
on_release: root.add()
Label:
text: ''
Button:
text: 'Remove Widget'
on_release: root.remove()

Ok, I seem to have found a simpler means of implementation that avoids specifying any id for the initial Label (the same one that shows if self.layouts==[]):
Python
import kivy
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.gridlayout import GridLayout
from kivy.uix.button import Button
from kivy.uix.textinput import TextInput
from kivy.uix.scrollview import ScrollView
from kivy.uix.label import Label
from kivy.uix.checkbox import CheckBox
from kivy.uix.popup import Popup
from kivy.uix.screenmanager import ScreenManager, Screen
#Load kv file
Builder.load_file('test.kv')
#First Screen
class Screen1(Screen):
count = 0
layouts = []
def remove(self):
for i in self.layouts:
if i.children[0].active:
self.ids.widget_list.remove_widget(i)
self.layouts = [i for i in self.layouts if not i.children[0].active]
if self.layouts!=[]:
self.update_hints()
else:
layout = GridLayout(rows=1)
layout.add_widget(Label(text='Nothing Here'))
self.ids.widget_list.add_widget(layout)
def add(self):
if self.layouts==[]:
self.ids.widget_list.clear_widgets()
if len(self.ids.widget_list.children)<5:
self.count+=1
layout = GridLayout(cols=3)
layout.add_widget(Label(text='Test ' + str(self.count)))
layout.add_widget(TextInput())
layout.add_widget(CheckBox())
self.ids.widget_list.add_widget(layout)
self.layouts.append(layout)
self.update_hints()
else:
layout = GridLayout(cols=1)
layout.add_widget(Label(text='Only five allowed at once.\nRemove at least one to add another.'))
button = Button(text='Acknowledge'); layout.add_widget(button)
popup = Popup(content=layout, title='Limit Reached', size_hint=(.5,.5), auto_dismiss=False)
button.bind(on_release=popup.dismiss)
popup.open()
def update_hints(self):
for i in self.layouts:
i.children[1].hint_text = 'Ex. ' + str(round(100/len(self.ids.widget_list.children),2)) + '%'
#Initialize Screens and Start App
class MyScreenManager(ScreenManager):
pass
#Main application
class SampleApp(App):
def build(self):
self.sm = MyScreenManager()
return self.sm
if __name__ == '__main__':
SampleApp().run()
kv
<MyScreenManager>:
Screen1:
name: 'screen1'
<Screen1>:
BoxLayout:
orientation: 'vertical'
GridLayout:
cols: 3
padding: 20
spacing: 20
size_hint: 1, .1
Label:
text: 'List of Widgets'
underline: True
Label:
text: 'Percentage'
underline: True
Label:
text: 'Remove (Y/N)'
underline: True
ScrollView:
size_hint: 1, .5
do_scroll_x: False
padding: 20
spacing: 20
GridLayout:
id: widget_list
cols: 1
spacing: 5
GridLayout:
rows: 1
Label:
text: 'Nothing Here'
GridLayout:
cols: 3
padding: 20
spacing: 20
size_hint: 1, .2
Button:
text: 'Add Widget'
on_release: root.add()
Label:
text: ''
Button:
text: 'Remove Widget'
on_release: root.remove()

Related

How to add Widgets from outside class with Kivy

Hy! I have this app here, a kind of "To Do List". When I press "Add Item" Button, it opens a PopUp Window and I want when "Up" Button is pressed to add "ItemTemplate" in "ItemsList". I am new in Kivy and I tried do that in last few days. How can I do that?
Thanks a lot!
Python code:
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.gridlayout import GridLayout
from kivy.uix.popup import Popup
class FirstBox(BoxLayout):
def btn(self):
Pu().open()
class ItemsList(GridLayout):
pass
class ItemTemplate(BoxLayout):
pass
class Pu(Popup):
pass
class MyAppApp(App):
pass
MyAppApp().run()
Kv code:
FirstBox:
<FirstBox>:
orientation: "vertical"
BoxLayout:
ScrollView:
ItemsList:
size_hint: 1, None
height: self.minimum_height
Button:
size_hint: 1,0.2
text: "Add Item"
on_release: root.btn()
<ItemsList>:
cols: 1
size_hint_y: None
ItemTemplate:
ItemTemplate:
ItemTemplate:
<ItemTemplate>:
size_hint: 1, None
CheckBox:
size_hint: 0.15, 1
Button:
text: "Task Name"
Button:
text: "Some action"
size_hint: 0.15,1
<Pu>:
size_hint: 1, 0.3
BoxLayout:
orientation: "vertical"
TextInput:
Button:
text: "Up"
Give id to your ItemList for add widget and TextInput for get text from.
ItemsList:
id: viewlist
and
TextInput:
id: new_task_input_id
Use StringProperty for dinamicly change text of ItemTemplate:
from kivy.properties import StringProperty
class ItemTemplate(BoxLayout):
task_text = StringProperty()
Edit .kv side dinamic: ( ItemTemplate's Button )
Button:
text: root.task_text
Trigger Up Button in .kv side: on_release: root.add_item()
Create this function in Pu class and add this operations:
def add_item(self,*args):
firstbox = App.get_running_app().root #access correctly main layout
itemlist = firstbox.ids.viewlist #find viewlist by id
new_task_text = self.ids.new_task_input_id.text #get textinput text
item = ItemTemplate() #create custom item
item.task_text = new_task_text #set item text
itemlist.add_widget(item) #add item to layout
Short function:
App.get_running_app().root.ids.viewlist.add_widget(ItemTemplate(task_text=self.ids.new_task_input_id.text))
Lets close popup after add new item:
self.dismiss()
Also if you want to add this widget to top, need to give index in add_widget :
itemlist.add_widget(item,len(itemlist.children))

Add a widget that was created in kv from py

Is there a way to reference a custom widget from the py file?
I made a widget in kv, but I want to reference it from py, then add it again to another widget in kv.
I tried doing this using id but I got an error (KeyError: 'words_entry').
This is what I tried:
from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.lang import Builder
from kivy.properties import ObjectProperty
from kivy.uix.textinput import TextInput
import os
class GetCount(Screen):
count_input = ObjectProperty(None)
def next(self):
# Setup next screen
text_inputs = [self.ids.words_entry for i in range(int(self.count_input.text))]
for text_input in text_inputs:
self.manager.ids.get_input.ids.grid.add_widget(text_input)
# Switch to next screen
self.manager.current = "get_input"
class GetInput(Screen):
pass
kv_file = Builder.load_string("""
ScreenManager:
GetCount:
name: "get_count"
id: get_count
GetInput:
name: "get_input"
id: get_input
<WordEntry#TextInput>:
id: words_entry
multiline: False
size_hint: (self.width, None)
<GetCount>:
count_input: count_input
FloatLayout:
Label:
text: "count"
size_hint: 1, 0.05
pos_hint: {"top":0.9}
TextInput:
id: count_input
size_hint: 0.8, 0.05
pos_hint: {"top":0.7, "x":0.1}
multiline: False
Button:
text: "Next"
on_release: root.next()
size_hint: 0.8, 0.05
pos_hint: {"top":0.5, "x":0.1}
<GetInput>:
ScrollView:
GridLayout:
size_hint_y: None
height: self.minimum_height
id: grid
cols: 1
""")
class MainApp(App):
def build(self):
return kv_file
if __name__ == "__main__":
app = MainApp()
app.run()
In this code, I want to add WordEntry to the GridLayout in GetInput from py (the reason is that I need to add multiple depending on the user's input).
You can use Factory to create an instance of a class that has been defined in kv. So your GetCount class can be:
from kivy.factory import Factory
class GetCount(Screen):
count_input = ObjectProperty(None)
def next(self):
# Setup next screen
for _ in range(int(self.count_input.text)):
new_word_entry = Factory.WordEntry()
self.manager.ids.get_input.ids.grid.add_widget(new_word_entry)
# Switch to next screen
self.manager.current = "get_input"

How can I add an amount of widgets in the kv file based on user input?

I'm trying to make a program that puts x amount of TextInputs based on the user's input. I can do that in the py file, but how do I do this in the kv file? I also need to be able to reference these TextInputs later on.
This is what I have so far:
from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.lang import Builder
from kivy.properties import ObjectProperty
from kivy.uix.textinput import TextInput
class GetCount(Screen):
count_input = ObjectProperty(None)
def next(self):
# Setup next screen
text_inputs = [TextInput(multiline=False) for i in range(int(self.count_input.text))]
for text_input in text_inputs:
self.manager.ids.get_input.ids.grid.add_widget(text_input)
# Switch to next screen
self.manager.current = "get_input"
class GetInput(Screen):
pass
kv_file = Builder.load_string("""
ScreenManager:
GetCount:
name: "get_count"
id: get_count
GetInput:
name: "get_input"
id: get_input
<GetCount>:
count_input: count_input
FloatLayout:
Label:
text: "count"
size_hint: 1, 0.05
pos_hint: {"top":0.9}
TextInput:
id: count_input
size_hint: 0.8, 0.05
pos_hint: {"top":0.7, "x":0.1}
multiline: False
Button:
text: "Next"
on_release: root.next()
size_hint: 0.8, 0.05
pos_hint: {"top":0.5, "x":0.1}
<GetInput>:
FloatLayout:
GridLayout:
id: grid
cols: 1
""")
class MainApp(App):
def build(self):
return kv_file
if __name__ == "__main__":
app = MainApp()
app.run()
The problem is, the TextInputs are being added and created by the py code, how can I create the widget in kv and then add it in py?

Passing Kivy Widget to another class

I am building a dynamic user interface using Python and Kivy. Because I need to add and remove widgets dynamically I want to use a separate class to handle adding and removing widgets from a GridLayout. I called this class LayoutManager.
The GridLayout is defined in my kv-File (id: "config_box_layout"). Inside my root widget class in my python code I am referencing the GridLayout via id. This is working properly. This reference is passed to the LayoutManager in the constructor. I tried passing it via ObjectProperty or GridLayout.
The problem is that I always end up with this kind of error if I try to remove widgets from the Layout:
'kivy.properties.ObjectProperty' object has no attribute 'remove_widget'
If I try to remove a widget in the save-method inside my Tab class using config_box_layout.remove_widget(some newly created Label) it's working properly.
I think the problem is that Kivy and all the kv-widgets are weakly-referenced and handling those references over to other classes seem to be not the intended use case.
I try to seperate classes to avoid doing all the coding stuff in one big fat main Layout class.
Looking forward to any help! :)
main.py
import kivy
from util.layoutManager import LayoutManager
from kivy.app import App
kivy.require('1.11.1')
from kivy.uix.label import Label
from kivy.uix.tabbedpanel import TabbedPanel
from kivy.properties import ObjectProperty
from kivy.uix.popup import Popup
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.dropdown import DropDown
from kivy.uix.button import Button
from functools import partial
class ChooseDirectoryDialog(FloatLayout):
add = ObjectProperty(None)
cancel = ObjectProperty(None)
save = ObjectProperty(None)
class Tab(TabbedPanel):
config_add_src = ObjectProperty()
ingest_layout = ObjectProperty()
configManager = ConfigManager()
config_box_layout = ObjectProperty()
layoutManager = LayoutManager(config_box_layout)
def add_src(self):
content = ChooseDirectoryDialog(cancel=self.cancel, save=self.save)
self._popup = Popup(title="Add Source", content=content,
size_hint=(0.9, 0.9))
self._popup.open()
def cancel(self):
self._popup.dismiss()
def delete_source(self, description, widget):
self.configManager.delete_source(description)
self.remove_source_from_ui(description)
def remove_source_from_ui(self, description):
self.layoutManager.remove_configuration(description)
def save(self, srcpath, destpath, description):
desc_label = Label(text=description)
desc_label.size_hint_y = None
desc_label.height = 30
self.config_box_layout.add_widget(desc_label)
srcpath_label = Label(text=srcpath)
srcpath_label.size_hint_y = None
srcpath_label.height = 30
self.config_box_layout.add_widget(srcpath_label)
destpath_label = Label(text=destpath)
destpath_label.size_hint_y = None
destpath_label.height = 30
self.config_box_layout.add_widget(destpath_label)
deleteButton = Button(text="Quelle löschen")
deleteButton.size_hint_y = None
deleteButton.height = 30
deleteButton.bind(on_press=partial(self.delete_source, description))
self.config_box_layout.add_widget(deleteButton)
self.layoutManager.add_configuration(description,
desc_label, srcpath_label, destpath_label, deleteButton)
self.configManager.add_source(description, srcpath, destpath)
self._popup.dismiss()
def copyToDestination(self, srcpath, destpath):
pass
class AutoIngest(App):
def build(self):
return Tab()
if __name__ == '__main__':
#Builder.load_file('autoingest.kv')
AutoIngest().run()
autoingest.kv
#:kivy 1.11.1
<Tab>:
do_default_tab: False
config_add_button: add_button
config_box_layout: config_box
TabbedPanelItem:
text: 'Konfiguration'
TabbedPanel:
tab_width: 200
do_default_tab: False
TabbedPanelItem:
text: 'Quellen verwalten'
StackLayout:
orientation: "lr-tb"
padding: 10
Button:
size_hint: .2, .1
id: add_button
text: 'Quelle hinzufügen'
on_press: root.add_src()
GridLayout:
id: config_box
cols: 4
Label:
size_hint_y: None
height: 30
text: "Bezeichnung"
Label:
size_hint_y: None
height: 30
text: "Quell-Pfad"
Label:
size_hint_y: None
height: 30
text: "Ziel-Pfad"
Label:
size_hint_y: None
height: 30
text: "Aktionen"
<ChooseDirectoryDialog>:
text_input: text_input
BoxLayout:
size: root.size
pos: root.pos
orientation: "vertical"
Label:
size_hint_y: None
height: 30
text: "Bezeichnung"
TextInput:
id: text_input
size_hint_y: None
height: 30
multiline: False
Label:
size_hint_y: None
height: 30
text: "Quellverzeichnis auswählen"
FileChooserListView:
id: source_chooser
Label:
size_hint_y: None
height: 30
text: "Zielverzeichnis auswählen"
FileChooserListView:
id: destination_chooser
BoxLayout:
size_hint_y: None
height: 30
Button:
text: "Cancel"
on_release: root.cancel()
Button:
text: "Add"
on_release: root.save(source_chooser.path, destination_chooser.path, text_input.text)
layoutManager.py
from kivy.uix.gridlayout import GridLayout
from kivy.properties import ObjectProperty
class LayoutManager:
#I alrey tried to pass the GridLayout itself. This didn't work either.
def __init__(self, configlayout: ObjectProperty):
self.configurations = {}
self.configlayout = configlayout
def remove_configuration(self, description):
widgets = self.configurations.get(description)
for x in widgets:
self.configlayout.remove_widget(x)
def add_configuration(self, description, *widgets):
self.configurations[description] = {'widgets': widgets}
I believe the problem is that the Tab instance ids have not been setup when your lines:
config_box_layout = ObjectProperty()
layoutManager = LayoutManager(config_box_layout)
are executed, so config_box_layout is not yet set.
You can force the creation of the LayoutManager to delay until the ids are created using kivy.clock in the build() method of the App:
class AutoIngest(App):
def build(self):
Clock.schedule_once(self.setup_layoutManager)
return Tab()
def setup_layoutManager(self, dt):
self.root.layoutManager = LayoutManager(self.root.config_box_layout)
Also, the line:
layoutManager = LayoutManager(config_box_layout)
can be removed from the Tab class.
Once that is working you will discover issues in your remove_configuration() method of LayoutManager.

How to ensure proper functionality when adding widgets to Kivy

I am attempting to create a Kivy/Python application which gets the user to push a button on one screen, and in turn adds several widgets to the next screen. However, when I run the script, the button appears and can be clicked on the first page, and the widgets are visible on the second page, but they can not be interacted with.
Here is an example of my code, any help is appreciated:
py:
import kivy
kivy.require('1.11.1')
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.gridlayout import GridLayout
from kivy.properties import ListProperty, StringProperty, ObjectProperty
from kivy.core.window import Window
from kivy.uix.label import Label
from kivy.uix.scrollview import ScrollView
from kivy.uix.button import Button
from kivy.uix.spinner import Spinner
sm = None
class RcGUITestApp(App):
def build(self):
global sm
Window.clearcolor = (0, 0, 0.35, 1)
sm = ScreenManager()
sm.add_widget(NewJobPage(name="new_job_page"))
sm.add_widget(IPMConfirmPage(name = "ipm_confirm_page"))
return sm
class NewJobPage(Screen):
def retrieve(self):
global rc
global sm
sm.get_screen("ipm_confirm_page").displayIPM()
class IPMConfirmPage(Screen):
grid = ObjectProperty(None)
def displayIPM(self):
for ipm in range(50):
self.grid.add_widget(Label(text="A"))
self.grid.add_widget(Spinner(text="B"))
self.grid.add_widget(Spinner(text="C"))
def main():
rc_gui = RcGUITestApp()
rc_gui.run()
if __name__ == "__main__":
main()
kv:
<NewJobPage>:
BoxLayout:
orientation: "horizontal"
size_hint: (1, .35)
Button:
text: "RETRIEVE"
pos_hint: {"center_x": .5, "center_y": .5}
size_hint: (.33, .33)
color: (1,1,1,1)
on_press:
root.retrieve()
root.manager.transition.direction = "left"
root.manager.transition.duration = .8
root.manager.current = "ipm_confirm_page"
<IPMConfirmPage>:
grid: Grid
GridLayout:
cols: 1
size_hint_x: 1
padding: 10
spacing: 10
BoxLayout:
size_hint: (1, 0.1)
Label:
text: "IPM"
Label:
text: "CD#"
Label:
text: "CONDUCTOR"
ScrollView:
GridLayout:
id: Grid
cols: 3
height: self.minimum_height
size_hint: 1, None
spacing: 50
padding: 30
First Page output
Second Page output
You need to provide the height of each widget added to grid. There are two solutions to the problem.
Method 1 - kv file
This method involves changing only the kv file by adding row_force_default: True and row_default_height: 40.
Snippets - kv file
ScrollView:
GridLayout:
row_force_default: True
row_default_height: 40
...
Method 2 - py file
This method involves changing only the py file by adding size_hint_y=None and height=40.
Snippets
def displayIPM(self):
for ipm in range(50):
self.grid.add_widget(Label(text="A", size_hint_y=None, height=40))
self.grid.add_widget(Spinner(text="B", size_hint_y=None, height=40))
self.grid.add_widget(Spinner(text="C", size_hint_y=None, height=40))

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