How to load string from text file to kivy label, Python 3.5 - python-3.x

I've been searching around for answers on stackoverflow for a couple of days now to be honest but I could not find the thing for me, lets say I have a text file named bind.txt with a couple lines of text, how can i load that text file to a kivy label? be it directly or indirectly. I've been trying to teach myself python and this is kind of in the way of me building my first app. Thank you in advance, and heres the code.
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.scrollview import ScrollView
from kivy.uix.widget import Widget
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder
from kivy.properties import StringProperty
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition
class MainScreen(Screen):
pass
class MainLabel(ScrollView):
text = StringProperty("")
class ScreenManagement(ScreenManager):
pass
presentation = Builder.load_file("bind.kv")
class MainApp(App):
def build(self):
return presentation
if __name__ == "__main__":
MainApp().run()
And the kv file.
#: import FadeTransition kivy.uix.screenmanager.FadeTransition
ScreenManagement:
transition: FadeTransition()
MainScreen:
<MainLabel>:
text: #bind.txt here, somehow..
Label:
text: root.text
font_size: 15
text_size: self.width, None
size_hint_y: None
height: self.texture_size[1]
<MainScreen>:
name: "main"
canvas.before:
Rectangle:
pos: self.pos
size: self.size
source: 'img/Fundal.png'
MainLabel

You can open file in reading mode, store contents in a variable and assign it to the text property.
For an example
with open("bind.txt") as f:
contents = f.read()
main_label.text = contents # main_label is an instance of kivy's Label class.

Related

How to use Splitters in kivy with multiple screens?

This is a simple example but essentially I need to use Splitter to separate and resize two individual Text input boxes horizontally, however when I'm trying to use the Splitter widget in a Screen its creating a double behind the original content and the Splitter is not functioning properly. Any help will be appreciated. Thank You.
main file
import kivy
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager , Screen
from kivy.core.window import Window
from kivy.factory import Factory
class TestScreen1(Screen):
pass
class TestScreen2(Screen):
pass
class Manager(ScreenManager):
pass
class MyApp(App):
def build(self):
return Builder.load_file("D:\MainProject\TestFiles\my.kv")
if __name__ == "__main__":
MyApp().run()
KV file
Manager:
TestScreen1:
TestScreen2:
<TestScreen1>:
name:"abc1"
BoxLayout:
orientation: 'horizontal'
Label:
text:"Next"
Splitter:
sizable_from:"left"
Button:
text: "next"
on_press: root.manager.current="abc2"
<TestScreen2>:
name:"abc2"
BoxLayout:
orientation: 'horizontal'
Label:
text:"pre"
Splitter:
sizable_from:"left"
Button:
text: "pre"
on_press: root.manager.current="abc1"
Your kv file is being loaded twice. Once by you Builder.load_file() and once by the App (see documentation). Just remove that Builder.load_file() line.

Get window size in Kivy not from the main class using kv file

I'm trying to define in a .kv file the size of a custom button, referring to the size of the window of the App.
Since the custom button class (<CustomButton # Button>:) is different from the main class ( :) returned by the build method, I cannot use size: (root.width, root.height).
I then tried to define an id for the main class and use it in the CustomButton class as size: (main_class_id.width, main_class_id.height), to use size: (Factory.MyMainClass (). Width, Factory.MyMainClass (). Height) , to use size: app.width, app.height but nothing seems to work.
Do you have any suggestions for getting what I want without using BoxLayout or anything else?
Following, I paste the py and kv files.
Thanks in advance for your answers.
py file:
from kivy.config import Config
Config.set('graphics', 'resizable', '0')
from kivy.core.window import Window
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.lang import Builder
Window.size = (320, 365)
Window.minimum_width, Window.minimum_height = Window.size
Window.clearcolor = (.95, .95, .95, 1)
Builder.load_file('exercise_1.kv')
class MyMainClass(Widget):
pass
class MyApp(App):
def build(self):
return MyMainClass()
if __name__ == '__main__':
MyApp().run()
kv file:
#:import Factory kivy.factory.Factory
<MyMainClass>:
id: main_class_id
Label:
id: display_label
text: '0'
size: root.width*0.95, root.height*0.23
pos: (root.width*0.5 - self.width*0.5), (root.height - self.height)
font_name: 'fonts/Lcd.ttf'
font_size: '48dp'
color: 0, 0, 0, 1
text_size: self.size
halign: 'right'
valign: 'middle'
CustomButton:
text: '1'
#size: root.width*0.2, root.height*0.1
<CustomButton#Button>:
background_color: 'red'
size: main_class_id.width*0.2, main_class_id.height*0.1 #Not workings
size: app.width*0.2, app.height*0.1 #Not workings
size: Factory.MyMainClass().width*0.2, Factory.MyMainClass().height*0.1 #Not workings
I found the solution:
The solution was to add the following attributes in the build method of the MyApp class:
class MyApp(App):
def build(self):
self.width = Window.width
self.height = Window.height
return MyMainClass()
Then use these two attributes in the kv file as follows:
<CustomButton#Button>:
size: app.width*0.2, app.height*0.1
I hope this information will be useful.
*This solution works only if you disable the resize

Kivy ScreenManager: App stopped running after trying to add 2nd Window

I was building an app for my thesis and it worked so far quite well while using only one window. Now I was trying to add other windows for e.g. instructions. I was following the documentation for screen Manager and some examples for apps and tried to add my 2nd window alike. But somehow it fails to identifiy the ScreenManager class in my kv.file. Maybeyou can help out, I'm not sure what I'm missing.
main py: Peenomat.py
import kivy
# -*- coding: iso-8859-1 -*-
from kivy.app import App
from kivy.uix.button import Label
from kivy.uix.widget import Widget
from kivy.uix.textinput import TextInput
from kivy.lang import Builder
from kivy.uix.anchorlayout import AnchorLayout
from kivy.core.text import LabelBase
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import BooleanProperty
from kivy.properties import ObjectProperty
#additional .kv files used to speciffy layout and functions of peenomat.kv
Builder.load_file('Header.kv')
Builder.load_file('Statusbar.kv')
Builder.load_file('Inputparameters.kv')
Builder.load_file('Outputparameters.kv')
pm = Builder.load_file('peenomat.kv')
#Layout
"""
class Peenomat(AnchorLayout):
pass
"""
class Peenomat(Screen):
pass
class Instruction(Screen):
pass
class WindowManager(ScreenManager):
pass
#App
class PeenomatApp(App):
def build(self):
return pm
if __name__=="__main__":
PeenomatApp().run()
and the minimalized .kv file
peenomat.kv:
WindowManager:
Peenomat:
Instruction:
<Peenomat>
name: "peenomat"
AnchorLayout:
anchor_x: 'left'
anchor_y: 'bottom'
GridLayout:
cols: 1
Header:
id:
size_hint:
InputParameters:
id:
size_hint:
StatusBar:
id:
size_hint:
OutputParameters:
id:_
size_hint:
<Instruction>:
name: "instruction"
Button:
text: "Verstanden!"
on_release:
app.root.current = "main"
root.manager.transition.direction = "right"
So like I said the App worked before adding the Screen and ScreenManager classes and I'm getting the error:
Traceback (most recent call last):
File "C:/Users/schum/Dokumente/TUD/Masterthesis/Peenomat.py", line 21, in <module>
pm = Builder.load_file('peenomat.kv')
File "C:\Users\schum\Dokumente\TUD\Masterthesis\venv\lib\site-packages\kivy\lang\builder.py", line 301, in load_file
return self.load_string(data, **kwargs)
File "C:\Users\schum\Dokumente\TUD\Masterthesis\venv\lib\site-packages\kivy\lang\builder.py", line 399, in load_string
widget = Factory.get(parser.root.name)(__no_builder=True)
File "C:\Users\schum\Dokumente\TUD\Masterthesis\venv\lib\site-packages\kivy\factory.py", line 131, in __getattr__
raise FactoryException('Unknown class <%s>' % name)
kivy.factory.FactoryException: Unknown class <WindowManager>
eventhough they got the same name. Hope you can help me out!
So I found a solution by using an implementation of the ScreenManager in the py file. I switched this with the class WindowManager(ScreenManager) class:
sm = ScreenManager()
sm.add_widget(Peenomat(name='peenomat'))
sm.add_widget(Instruction(name='instruction'))
and therefore added to my builder:
class PeenomatApp(App):
def build(self):
return sm
I fully deleted the 3 lines with the WindowManager class out of my kv.file. Now it works perfectly fine

return a BoxLayout inside another one in Kivy?

I'm trying to make a simple application in Python 3.5 and kivy that starts with a simple screen and when you click on it, goes to another one which shows 3 lists that let you chose the data:
The Python file:
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.listview import ListItemButton
from kivy.properties import ListProperty
from dataTopy import rlists
# Transition des ecrans:
class MainScreen(Screen):
pass
class AnotherScreen(Screen):
pass
class ScreenManagement(ScreenManager):
pass
presentation = Builder.load_file("ex44.kv")
#
class FirstListItemButton(ListItemButton):
pass
class SecondListItemButton(ListItemButton):
pass
class ThirdListItemButton(ListItemButton):
pass
class Ex44(BoxLayout):
d1 = ListProperty([str(i) for i in range(1990,2014)] )
d2 = ListProperty(['']*100)
d3 = ListProperty(['']*100)
def change(self,c):
try: self.d2,self.d3 = rlists(int(c.text))
except:
import os
CurDir = os.getcwd()
print('Can not find data in ' + CurDir)
def change1(self,c):
print('M => '+c.text)
def change2(self,c):
print('F => '+c.text)
class Ex44App(App):
def build(self):
return presentation
if __name__ == '__main__':
Ex44App().run()
The kivy file:
#: import FadeTransition kivy.uix.screenmanager.FadeTransition
#: import ListAdapter kivy.adapters.listadapter.ListAdapter
#: import ex44 ex44
ScreenManagement:
transition: FadeTransition()
MainScreen:
AnotherScreen:
<MainScreen>:
name: "main"
Button:
on_release: app.root.current = "other"
text: "Next Screen"
font_size: 50
<AnotherScreen>:
name: "other"
BoxLayout:
Ex44
Button:
color: 0,1,0,1
font_size: 25
size_hint: 0.3,0.2
text: "Back Home"
on_release: app.root.current = "main"
pos_hint: {"right":1, "top":1}
<FirstListItemButton>:
on_press: app.root.change(*args)
<SecondListItemButton>:
on_press: app.root.change1(*args)
<ThirdListItemButton>:
on_press: app.root.change2(*args)
<Ex44>:
ListView:
adapter:
ListAdapter(data=root.d1,
selection_mode='single',
cls=ex44.FirstListItemButton)
ListView:
adapter:
ListAdapter(data=root.d2,
selection_mode='single',
cls=ex44.SecondListItemButton)
ListView:
adapter:
ListAdapter(data=root.d3,
selection_mode='single',
cls=ex44.ThirdListItemButton)
When I try to run the app, it tells me: "Unknown class "
It is weird because the class Ex44 works alone but not when I'm trying to add it into the main application logic.
I've tried to return a widget instead of a BoxLayout for the class, to return Ex44 alone in the kivy file, etc. but I always get the same error in return.
Is it possible to return a BoxLayout inside another one in Kivy?
You are building the kv file too soon (before the class is defined). move the Builder.from_file call to the build method
...
def build(self):
return Builder.load_file("ex44.kv")

Updating a Label In Kivy

I am trying to update a label in python. It is a simple Guess the num game. Currently it prints the Computer responses in PC but I want it to print those to a label.
here is the main .py file
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
import random
secret=random.randint(1,100)
class Application(BoxLayout):
label1=""
def button_press(self):
global label1
if (int(self.user_guess.text)<secret):
print("Higher")
self.label1="Higher"
elif(int(self.user_guess.text)>secret):
print("Lower")
self.label1="Lower"
elif(int(self.user_guess.text)==secret):
print("You WOn")
self.label1="You WOn"
class WeatherApp(App):
pass
if __name__ == '__main__':
WeatherApp().run()
the .kv file
Application:
<Application>:
size:(480,30)
user_guess:guess
size_hint:(None,None)
text:""
orientation: "vertical"
BoxLayout:
Button:
text:'Play'
on_press:root.button_press()
TextInput:
id:guess
text:''
Label:
text:root.label1
I think you should use
self.label1.text="Higher"

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