In my Kivy-App, i generate Buttons via a python-class based on a dictionary (in the following example i use a list but that's just an example for the underlying problem).
Within the App, the dictionary gets changed and i want to display that change (obviously) in my App (by adding/ removing/ rearranging the Buttons).
To achieve this, my approach is to either restart the entire App or only reload that particular BoxLayout. Unfortunately, non of my attempts worked out so far and i could not find any (working) solution on the internet.
This is my code example:
Python Code:
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
buttonlist = []
counter = 0
class MainWindow(BoxLayout):
def addbutton(self):
global buttonlist
global counter
buttonlist.append(counter)
counter += 1
class ButtonBox(BoxLayout):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.orientation = "vertical"
global buttonlist
for button in buttonlist:
b = Button(text=str(button))
self.add_widget(b)
class KivyApp(App):
def build(self):
return MainWindow()
KivyApp().run()
KV Code:
<MainWindow>:
BoxLayout:
ButtonBox:
Button:
text: "add Button"
on_press: root.addbutton()
My closest attempt was something containing a restart-Method like:
def restart(self):
self.stop()
return KivyApp().run()
and calling:
App.get_running_app().restart()
But for some reason, this does not stop the App but opens a second instance of the App within the first one (resulting in App in App in App in App if pressed often)
You can rebuild the ButtonBox by first calling clear_widgets() on the ButtonBox instance. Here is a modified version of your code that does that:
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
kv = '''
<MainWindow>:
BoxLayout:
ButtonBox:
id: box
Button:
text: "add Button"
on_press: root.addbutton()
'''
buttonlist = ['Abba', 'Dabba', 'Doo']
counter = 3
class MainWindow(BoxLayout):
def addbutton(self):
global buttonlist
global counter
buttonlist.append(str(counter))
counter += 1
self.ids.box.reload()
class ButtonBox(BoxLayout):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.orientation = "vertical"
self.reload()
def reload(self):
# method to rebuild the ButtonBox contents
global buttonlist
self.clear_widgets()
for button in buttonlist:
b = Button(text=str(button))
self.add_widget(b)
class KivyApp(App):
def build(self):
Builder.load_string(kv)
return MainWindow()
KivyApp().run()
I used your kv as a string, just for my own convenience.
Related
What I want to do is take input from kivy.uix.textinput.TextInput() and show it on the screen.
I am new to gui Programming and I think it is an easy task.
import kivy
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.textinput import TextInput
class MyWindowApp(App):
def __init__(self):
super(MyWindowApp, self).__init__()
self.lbl = Label(text='Read Me!')
self.inp = TextInput(multiline=False,
size_hint =(1, 0.05),
pos_hint = {"x":0, "y":0.05})
def build(self):
self.inp.bind(on_text_validate=self.on_enter)
#self.bt1.bind(on_press=self.clk)
layout = FloatLayout()
layout.orientation = 'vertical'
layout.add_widget(self.lbl)
layout.add_widget(self.inp)
return layout
def on_enter(self,value):
print(value)
def clk(self, obj):
print ('input')
x = input()
self.lbl.text = x
window = MyWindowApp()
window.run()
when i run the code, I get the regular output output.
when I type say "hello world" in the textbox, this is the output:
<kivy.uix.textinput.TextInput object at 0x03F5AE30>
I do not get what I typed.
please suggest what should I do
Modify the following ...
def on_enter(self, value):
print(value.text)
I need to know how to reference dynamically created objects. Like in the example, how can I change text of the buttons after creation? Normaly I would do it using their ids, but as far as I know, you can't give ids to objects created in python.
.py code
from kivy.app import App
from kivy.uix.screenmanager import Screen
from kivy.uix.button import Button
from kivy.clock import mainthread
NUMBER_OF_BUTTONS = 5
class MapScreen(Screen):
#mainthread
def on_enter(self):
for i in range(NUMBER_OF_BUTTONS):
button = Button(text="B_" + str(i))
self.ids.grid.add_widget(button)
class Test(App):
pass
Test().run()
.kv code
ScreenManager:
MapScreen:
<MapScreen>:
name: 'map'
GridLayout:
id: grid
cols: 1
You could just keep a list of the Buttons:
def on_enter(self):
self.buttons = []
for i in range(NUMBER_OF_BUTTONS):
button = Button(text="B_" + str(i))
self.buttons.append(button)
self.ids.grid.add_widget(button)
or you could create your own dictionary:
def on_enter(self):
self.buttons = {}
for i in range(NUMBER_OF_BUTTONS):
text = "B_" + str(i)
button = Button(text=text)
self.buttons[text] = button
self.ids.grid.add_widget(button)
I'm making an MP3 Player for a project using Kivy. I am having issues on updating the text of a Button.
The only method that I've used and successfully worked was to update the button text directly, but I want to update a variable that is what the button's text is.
Here's the minimum reproducible example:
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.boxlayout import BoxLayout
class FirstKivy(App):
def __init__(self, **kwargs):
super(FirstKivy, self).__init__(**kwargs)
self.pausePlay = "Play"
def build(self):
layout = BoxLayout(orientation = "vertical")
btn = Button(text = self.pausePlay)
btn.bind(on_press = self.changePausePlay)
layout.add_widget(btn)
return layout
def changePausePlay(self, button):
if self.pausePlay == "Play":
self.pausePlay = "Pause"
elif self.pausePlay == "Pause":
self.pausePlay = "Play"
FirstKivy().run()
I expect the button's text to change from "Play" to "Pause" on click and then from "Pause" to "Play on click again. No error messages are sent.
Any help is appreciated, I'm new to Kivy as well as OOP in Python.
The easiest way to do it is to use kv to build the gui with a StringProperty to hold the Button text:
from kivy.app import App
from kivy.lang import Builder
from kivy.properties import StringProperty
kv = '''
BoxLayout:
orientation: 'vertical'
Button:
text: app.pausePlay
on_press: app.changePausePlay(self)
'''
class FirstKivy(App):
pausePlay = StringProperty('Play')
def __init__(self, **kwargs):
super(FirstKivy, self).__init__(**kwargs)
def build(self):
layout = Builder.load_string(kv)
return layout
def changePausePlay(self, button):
if self.pausePlay == "Play":
self.pausePlay = "Pause"
elif self.pausePlay == "Pause":
self.pausePlay = "Play"
FirstKivy().run()
Some key points. The kv language automatically sets up bindings when it can (creating the same gui in Python does not). The StringProperty allows kv to set up the binding so that any change in pausePlay will be reflected in the Button text.
Struggling to pass a variable to kivy window. I have read similar threads all over the place but none of the fixes seem to work for me. Im sure this is simple to someone who knows their way around tiny, unfortunately I don't.
main.py
import kivy
from kivy.uix.togglebutton import ToggleButton
from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.clock import Clock
from kivy.lang import Builder
from kivy.app import App
kivy.require('1.10.0')
from phue import Bridge
import nest
b = Bridge('xxx.xxx.x.xxx')
b.connect()
b.get_api()
lights = b.lights
class Controller(GridLayout):
print("launching")
def __init__(self):
super(Controller, self).__init__()
def KitchenSpot1(self,state):
lights[0].name
lights[0].on = state
def update(dt):
if b.get_light(1, 'on')== True:
#print("down") # When this line is commented out I get an continuous accurate update on the status of the light, showing that its working.
return 'down' # This is the part I want passed to the state criteria in the ivy window
else:
#print("up")# When this line is commented out I get an continuous accurate update on the status of the light, showing that its working.
return 'down' # This is the part I want passed to the state criteria in the ivy window
class ActionApp(App):
def build(self):
Clock.schedule_interval(Controller.update, 1.0 / 60.0)
return Controller()
myApp = ActionApp()
myApp.run()
action.kv
<Controller>:
cols: 4
rows: 3
spacing: 10
ToggleButton:
id: KitchenSpot1Toggle
text: "Kitchen Spot 1"
on_press: root.KitchenSpot1(True)
#on_release: root.KitchenSpot1(False)
#state1 = app.update.h
state: Controller.update # This is the part that is throwing up the error.
The error:
11: #on_release: root.KitchenSpot1(False)
12: #state1 = app.update.h
>> 13: state: Controller.update
14:
15:
...
NameError: name 'Controller' is not defined
Thanks in advance to anyone that can help me.
Make update an instance method and use a StringProperty to update state property in your kv:
main.py:
import kivy
kivy.require('1.10.0')
from kivy.app import App
from kivy.clock import Clock
from kivy.lang import Builder
from kivy.properties import StringProperty
from kivy.uix.gridlayout import GridLayout
from kivy.uix.togglebutton import ToggleButton
from phue import Bridge
import nest
b = Bridge('xxx.xxx.x.xxx')
b.connect()
b.get_api()
lights = b.lights
class Controller(GridLayout):
state = StringProperty('normal') # <<<<<<<<<<<<
def __init__(self, **kwargs):
super(Controller, self).__init__(**kwargs)
Clock.schedule_interval(self.update, 1.0 / 60.0)
def KitchenSpot1(self,state):
lights[0].name
lights[0].on = state
def update(self, dt):
if b.get_light(1, 'on'):
self.state = 'down' # <<<<<<<<<<<<
else:
self.state = 'normal' # <<<<<<<<<<<<
class ActionApp(App):
def build(self):
return Controller()
if __name__ == "__main__":
myApp = ActionApp()
myApp.run()
action.kv:
<Controller>:
cols: 4
rows: 3
spacing: 10
state: "normal" # <<<<<<<<<<<<
ToggleButton:
id: KitchenSpot1Toggle
text: "Kitchen Spot 1"
on_press: root.KitchenSpot1(True)
#on_release: root.KitchenSpot1(False)
#state1 = app.update.h
state: root.state # <<<<<<<<<<<<
Here is a more generic simplified answer from the kivy documentation, look for the section called "Keyword arguments and init()" because there are some other ways to do it as well.
The following code passes myvar to the build() method of MyApp. It does this by over-riding the init() of the Kivy App class by a new init() that calls App.init() and then continues with whatever extra initialisation you want. You can then store variables in the MyApp class instances and use them in build().
from kivy.app import App
from kivy.uix.label import Label
myvar = 'Hello Kivy'
class MyApp(App):
def __init__(self, myvar, **kwargs):
super(MyApp, self).__init__(**kwargs)
self.myvar = myvar
def build(self):
widget = Label(text=self.myvar)
return widget
if __name__ == '__main__':
MyApp(myvar).run()
New to kivy, and OOP.
I'm trying to update a label in kivy with data I pull from a temp sensor. The code that pulls in the sensor data is in labeltempmod. I created a function getTheTemp() that is called every second. In the function I try to assign the text of the label via Label(text=(format(thetemp)), font_size=80). The program ignores this. What am I doing wrong here?
#This is a test to see if I can write the temp to label
import labeltempmod
import kivy
from kivy.app import App
from kivy.clock import Clock
from kivy.uix.label import Label
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.textinput import TextInput
from kivy.uix.boxlayout import BoxLayout
def getTheTemp(dt):
thetemp = labeltempmod.readtemp()
Label(text=(format(thetemp)), font_size=80)
print thetemp
class LabelWidget(BoxLayout):
pass
class labeltestApp(App):
def build(self):
# call get_temp 0.5 seconds
Clock.schedule_interval(getTheTemp, 1)
return LabelWidget()
if __name__ == "__main__":
labeltestApp().run()
Here is the kivy language file:
<LabelWidget>:
orientation: 'vertical'
TextInput:
id: my_textinput
font_size: 80
size_hint_y: None
height: 100
text: 'default'
FloatLayout:
Label:
id: TempLabel
font_size: 150
text: 'Temp Test'
Thanks.
Sorry but you never update something You are just creating another label
Try this:
class LabelWidget(BoxLayout):
def __init__(self, **kwargs):
super(LabelWidget, self).__init__(**kwargs)
Clock.schedule_interval(self.getTheTemp, 1)
def getTheTemp(self, dt):
thetemp = labeltempmod.readtemp()
self.ids.TempLabel.text = thetemp
print thetemp
class labeltestApp(App):
def build(self):
return LabelWidget()
if __name__ == "__main__":
labeltestApp().run()
Update : for your last request, I think the best way to do that is:
...
class LabelWidget(BoxLayout):
def __init__(self, **kwargs):
super(LabelWidget, self).__init__(**kwargs)
self.Thetemp = None
Clock.schedule_interval(self.getTheTemp, 1)
def getTheTemp(self, dt):
if self.Thetemp is None:
self.thetemp = labeltempmod.readtemp()
else:
self.thetemp = labeltempmod.readtemp(self.theTemp)
self.ids.TempLabel.text = str(self.thetemp)