I am trying to center text in kivy. I tried using halign="center" like so:
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.label import CoreLabel
from kivy.graphics import Rectangle, Color
from kivy.core.window import Window
class MyWidget(Widget):
def __init__(self, **kwargs):
super().__init__(**kwargs)
Window.clearcolor = (1, 1, 1, 1)
self.canvas.clear()
with self.canvas:
Color(0, 0, 0, 1)
label = CoreLabel(text="Text", font_size=50, halign="center")
label.refresh()
text = label.texture
Rectangle(size=text.size, pos=(865, 30), texture=text)
class MyApp(App):
def build(self):
return MyWidget()
if __name__ == "__main__":
MyApp().run()
But that doesn't center the text around the given position (it is still left aligned). If I change the length of the text (and therefore its size), its position doesn't change, even though I want it to.
Try adding
label = CoreLabel(halign='center',valign='center')
Related
I want to create a list of coloured labels. The thing is that I could do it with the kv file, but I need to do it through the build() method. So I tried replicate what I have done, but it does not work. And I can't understand why.
This is what I've coded
from kivy.app import App
from kivy.uix.relativelayout import RelativeLayout
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.boxlayout import BoxLayout
from kivy.graphics import *
class RL(RelativeLayout): # Creates the background colour for each label
def __init__(self, **kwargs):
super().__init__(**kwargs)
with self.canvas:
Color(.7, 0, .5, 1)
Rectangle(size_hint=self.size)
class MainMenu(BoxLayout):
N_LBLS = 8
labels_text = []
RL_list = []
def __init__(self, **kwargs):
super().__init__(**kwargs)
button = Button(text='do something')
button.bind(on_release=self.change_text)
box = BoxLayout(orientation='vertical', padding= 10, spacing = 15)
for i in range(0, self.N_LBLS):
self.RL_list.append(RL())
self.labels_text.append(Label(text=f'{i}º label', size_hint=self.size))
self.RL_list[i].add_widget(self.labels_text[i])
box.add_widget(self.RL_list[i])
self.add_widget(button)
self.add_widget(box)
def change_text(self, instance):
for lbl in self.labels_text:
if lbl.text[0] == '5':
lbl.text = 'Text changed'
class MainApp(App):
def build(self):
return MainMenu()
if __name__ == '__main__':
MainApp().run()
It's supposed to make a button to the left, and a list of 8 coloured labels to the right.
The problem is that you are setting size_hint=self.size in each Label. The self.size is the size of the MainMenu, which is [100,100] when that code is executed. Note that size_hint is a multiplier that is applied to the parents size to calculate the widgets size. So a size_hint of [100,100] makes each Label 100 times bigger than the MainMenu. So your code is working, but the Labels are so large that the text is off the screen. Start by just removing size_hint=self.size.
And, to set a background color on a Label, you can just use the canvas of that Label, rather than some container. Here is a version of your code that does that:
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.boxlayout import BoxLayout
class ColorLabel(Label):
pass
Builder.load_string('''
<ColorLabel>:
bg_color: [.7, 0, .5, 1]
canvas.before:
Color:
rgba: self.bg_color
Rectangle:
pos: self.pos
size: self.size
''')
class MainMenu(BoxLayout):
N_LBLS = 8
labels_text = []
def __init__(self, **kwargs):
super().__init__(**kwargs)
button = Button(text='do something')
button.bind(on_release=self.change_text)
box = BoxLayout(orientation='vertical', padding=10, spacing=15)
for i in range(0, self.N_LBLS):
self.labels_text.append(ColorLabel(text=f'{i}º label'))
box.add_widget(self.labels_text[i])
self.add_widget(button)
self.add_widget(box)
def change_text(self, instance):
for lbl in self.labels_text:
if lbl.text[0] == '5':
lbl.text = 'Text changed'
lbl.bg_color = [0, 1, 0, 1]
class MainApp(App):
def build(self):
return MainMenu()
if __name__ == '__main__':
MainApp().run()
It's me again, trying to understand Kivy concepts.
I have a widget with a base class of RelativeLayout containing a chessboard image displaying in a splitter. I want to display a label, and 2 buttons horizontally below the chessboard spaced a small distance away from the chessboard and still have everything resizable with splitter. I've tried numerous ways to no avail. What I currently have is this:
What I want is this: (How do I achieve it?)
Here is the code:
import kivy
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.relativelayout import RelativeLayout
from kivy.uix.splitter import Splitter
from kivy.uix.image import Image
kivy.require('2.0.0')
class ChessBoardWidget(RelativeLayout): # FloatLayout
def __init__(self, **kwargs):
super(ChessBoardWidget, self).__init__(**kwargs)
repertoire_boxlayout = BoxLayout(orientation='horizontal')
repertoire_boxlayout.add_widget(Label(text='Repertoire for:'))
repertoire_boxlayout.add_widget(Button(text='White'))
repertoire_boxlayout.add_widget(Button(text='Black'))
chessboard_gui_boxlayout = BoxLayout(orientation='vertical')
chessboard_gui_boxlayout.add_widget(
Image(source="./data/images/chess-pieces/DarkerGreenGreyChessBoard.png", pos=self.pos,
size_hint=(1, 1), keep_ratio=True, allow_stretch=True))
chessboard_gui_boxlayout.add_widget(repertoire_boxlayout)
self.add_widget(chessboard_gui_boxlayout)
class SplitterGui(BoxLayout):
def __init__(self, **kwargs):
super(SplitterGui, self).__init__(**kwargs)
self.orientation = 'horizontal'
# Splitter 1
split1_boxlayout = BoxLayout(orientation='vertical')
split1 = Splitter(sizable_from='bottom', min_size=74, max_size=1100)
chessboard_widget = ChessBoardWidget()
split1.add_widget(chessboard_widget)
split1_boxlayout.add_widget(split1)
s3_button = Button(text='s3', size_hint=(1, 1))
split1_boxlayout.add_widget(s3_button)
self.add_widget(split1_boxlayout)
# Splitter 2
split2 = Splitter(sizable_from='left', min_size=74, max_size=1800)
s2_button = Button(text='s2', size_hint=(.1, 1))
split2.add_widget(s2_button)
self.add_widget(split2)
class ChessBoxApp(App):
def build(self):
return SplitterGui() # root
if __name__ == '__main__':
ChessBoxApp().run()
In a BoxLayout (see the documentation), you can use size_hint and size (or height, width) to adjust sizes. So, you can set the height of your Buttons, and let the Image use the remaining height of the BoxLayout:
class ChessBoardWidget(RelativeLayout):
def __init__(self, **kwargs):
super(ChessBoardWidget, self).__init__(**kwargs)
repertoire_boxlayout = BoxLayout(orientation='horizontal', size_hint=(1, None), height=30) # set height of Buttons
repertoire_boxlayout.add_widget(Label(text='Repertoire for:'))
repertoire_boxlayout.add_widget(Button(text='White'))
repertoire_boxlayout.add_widget(Button(text='Black'))
chessboard_gui_boxlayout = BoxLayout(orientation='vertical')
chessboard_gui_boxlayout.add_widget(
Image(source="./data/images/chess-pieces/DarkerGreenGreyChessBoard.png", pos=self.pos, keep_ratio=True, allow_stretch=True)) # default size_hint of (1,1) claims all of remaining height
chessboard_gui_boxlayout.add_widget(repertoire_boxlayout)
self.add_widget(chessboard_gui_boxlayout)
I want to change text color by passing the time.
I use Python and kivy.
This is my code.In this code, only a label come on.
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.label import Label
from kivy.clock import Clock
import random
class MyLabel(Label):
def callback(self, *arg):
self.evt = Clock.schedule_interval(self.callback, 1)
def on_value(self, *arg):
self.parent.lbl.color = random.choice(['red','blue','black'])
class MyApp(App):
def build(self):
layout=BoxLayout()
layout.lbl = Label(text='NESIA')
layout.add_widget(layout.lbl)
return layout
MyApp().run()
`
You never call the on_value() method you define. What you can do is use Clock.schedule_interval() when you build the app, passing in the method that changes the label's colour and the interval in which you want it to be called like so:
from kivy.app import App
from kivy.uix.label import Label
from kivy.clock import Clock
from kivy.uix.boxlayout import BoxLayout
import random
class MyLabel(Label):
def change_color(self, *args):
r, g, b = random.choice([[1, 0, 0],[0,0,1],[ 1, 1, 1]])
self.color = [r, g, b, 1]
class MyApp(App):
def build(self):
layout = BoxLayout()
label = MyLabel(text='NESIA')
Clock.schedule_interval(label.change_color, 1)
layout.add_widget(label)
return layout
MyApp().run()
This is assuming what you want is to have a label with the text NESIA whose colour is randomly set to red, blue, or black every second. Note that it's possible that random.choice() returns the same colour twice in a row, meaning it will look like it's not changing for however many seconds that happens for.
I am getting to know with kivy's manual slowly. I need to centered image in FloatLayout ans I set up size for FloatLayout according to advice: Kivy: Image sometimes is not centered in BoxLayout . Image is now in center FloatLayout sometimes. Position image in center dependes on value of parameter orientation. Influence of parameter' value is described here:
orientation = 'horizontal' - ---> image is centered
orientation = 'vertical' -----> image isn't centered
Thank You for your help!
from kivy.app import App
from kivy.core.window import Window
from kivy.lang import Builder
from kivy.uix.image import Image
from kivy.uix.button import Button
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.graphics import Ellipse
Window.size = (300, 300)
class Scene(FloatLayout):
def __init__(self, **kwargs):
super(Scene,self).__init__(**kwargs)
self.size = 300,300
def create(self):
img = Image(pos = (0, 0), source = 'grase40.png') # square 40x40pixels
self.add_widget(img)
with self.canvas:
Color=(1,0,0)
Ellipse(pos = (80,80), size = (40, 40))
class Title(BoxLayout):
def __init__(self,**kwargs):
super(Title, self).__init__(**kwargs)
self.orientation ='vertical'
self.scene = Scene()
self.add_widget(self.scene)
but = Button(text ='hallo', size_hint = (0.2, 1))
self.add_widget(but)
class SceneApp(App):
def build(self):
title = Title()
title.scene.create()
return title
if __name__ == '__main__':
SceneApp().run()
Problem in hand is that i have a screen where i have created 4 widgets under gridlayout . Widget one is a custom widget which have a boxlayout and have 2 images and a button .
and other 3 widgets are simple buttons
Now i want to have a background image or coloured rectangle to the 1st widget but image is getting drawn at position 0,0 . I am trying to use canvas instructions to create a rectangle or Border Image but seems gridlayout shows the widget position as 0,0 and hence it created the rectangle at 0,0 . please see the code below :
Any ideas how to fix this and create rectangle as at the border of widget 1?
from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen,FallOutTransition
from kivy.uix.image import Image
from kivy.uix.gridlayout import GridLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.core.window import Window
from kivy.graphics import BorderImage
from kivy.graphics import Color, Rectangle ,Line
################# Images ######################
S = Image(source='images/Sti.png')
L = 'images/spinnin.gif'
################# Images ######################
class CButtonW(BoxLayout):
def __init__(self, **kwargs):
print "init --> CButton self.pos is ",self.pos
super(CButtonW, self).__init__(**kwargs)
self.orientation = 'vertical'
with self.canvas.before:
Color(1, 1, 0, 1, mode='rgba')
Rectangle(pos=self.pos,size=self.size)
BorderImage(
border=(10, 10, 10, 10),
source='images/tex.png')
self.add_widget(S)
self.add_widget(Button(text="Button 1"))
self.add_widget(Image(source=L))
class LevelScreen(Screen,GridLayout):
def __init__(self, **kwargs):
super(LevelScreen, self).__init__(**kwargs)
with self.canvas:
Line(points=(10, 10, 20, 30, 40, 50))
Color(1, 0, 1, 1, mode='rgba')
Rectangle(pos=self.pos, size=Window.size)
self.layout = GridLayout(cols=3,spacing=1,padding=10)
self.Button1 = CButtonW(id='1',text='Level 1')
self.Button2 = Button(id='2',text='Level 2')
self.Button3 = Button(id='3',text='Level 3')
self.Button4 = Button(id='4',text='Level 4')
self.layout.add_widget(self.Button1)
self.layout.add_widget(self.Button2)
self.layout.add_widget(self.Button3)
self.layout.add_widget(self.Button4)
LevelScreen.cols=3
LevelScreen.add_widget(self,self.layout)
print "position of 1st button is ",self.Button1.pos
print "position of 2 button is ",self.Button2.pos
# App Class
class MyJBApp(App):
def build(self):
sm = ScreenManager(transition= FallOutTransition())
sm.add_widget(LevelScreen(name='level'))
return sm
if __name__ == '__main__':
MyJBApp().run()
Your canvas instructions are drawn before the CButtonW is positioned by its layout, so at that point it's still in its default position of 0, 0.
You can fix it by adding code to reposition the instructions when the widget's position or size changes. The easiest way is to just use kv language in the first place, which will automatically create the relevant bindings, but you can also bind to pos or size in python, or use the on_propertyname events associated with their changes.