Kivy update label dynamically on canvas - python

I am trying update Label on canvas , but it changed only if I call update() method from MyApp(APP).
And what is interesting that method obj Slider (on touch) works perfectly
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.core.window import Window
from kivy.uix.label import Label
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.gridlayout import GridLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.graphics import (Color, Ellipse)
from kivy.uix.slider import Slider
import random
from functools import partial
class Canvas_w(Widget):
def __init__(self, **kwargs):
self.i = 0
super(Canvas_w, self).__init__(**kwargs)
self.label_text =Label(text= "0",color = (255,0,0))
def update_text(self, text):
self.label_text.text = text
def on_touch_down(self, touch):
with self.canvas:
d=30
self.i+=1
Color(1., 0, 0)
Ellipse(pos=(touch.x - d/2, touch.y - d/2), size=(20,20))
self.label_text=str(self.i)
class Label_l(GridLayout):
bones = 0
def __init__(self, **kwargs):
super(Label_l, self).__init__(**kwargs)
self.label_text =Label(text= "0")
self.add_widget(self.label_text)
#self.label_text.text=self.C.i
def update_text(self, text):
Label_l.bones=text
self.label_text.text = str(Label_l().bones)#
Label_l.text=str(Label_l().bones)
class WidgetContainer(GridLayout):
sld_value = 0.00001
def __init__(self, **kwargs):
super(WidgetContainer, self).__init__(**kwargs)
self.cols = 1
self.speedControl = Slider(min=0.00001, max=3, step=0.0001)
self.add_widget(Label(text="Speed Iteration"))
self.add_widget(self.speedControl)
self.add_widget(Label(text=''))
self.speedValue = Label(text="0.00001")
self.add_widget(self.speedValue)
self.speedControl.bind(value=self.on_value)
def on_value(self, instance, speed):
self.sld_value = speed
WidgetContainer.sld_value = self.sld_value
self.speedValue.text = str(round(speed,5))
class MyApp(App):
def build(self):
b3 = BoxLayout(orientation="horizontal")
b1 = FloatLayout()
self.painter = Canvas_w()
self.label_l= Label_l()
b1.add_widget(self.label_l)
b1.add_widget(self.painter)
b1.add_widget(WidgetContainer())
b3.add_widget(b1)
return(b3)
if __name__=="__main__":
MyApp().run()
I am trying update Label on canvas , but it changed only if I call update() method from MyApp(APP).
And what is interesting that method obj Slider (on touch) works perfectly

A few problems with your code:
The color attribute of a Label requires a list of four values with each value in the range 0 to 1. Change self.label_text =Label(text= "0",color = (255,0,0)) to self.label_text =Label(text= "0",color = (1,0,0,1)) in the Canvas_w class.
The above Label is never getting drawn. You need to add self.add_widget(self.label_text) to the __init__() method of Canvas_w.
You have another Label in the Label_l class that is being drawn on top of the Label in the Canvas_w.
After fixing the above problems, I believe your code will work as you expect.
If you call self.canvas.clear(), it appears as though the label_text child of Canvas_w is removed. Actually it is not removed, but is just not visible (perhaps overdrawn). One way to make it visible is to just make sure it is drawn last by removing it and then re-adding it (last added child is drawn last), like this:
self.canvas.clear()
self.remove_widget(self.label_text)
self.add_widget(self.label_text)
After a bit more research, I believe that the canvas.clear() is removing the drawing of the Label from the Canvas. You can, however, do your drawing on canvas.before by using:
with self.canvas.before:
in the on_touch_down() method. And rather than using:
self.canvas.clear()
use:
self.canvas.before.clear()
I believe that your Label will be displayed correctly after doing the above.

Related

Lines are not drawn in Kivy python

This is the code:
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.graphics import Color
from kivy.graphics import Line
class MainWidget(Widget):
v_l_s=.1
v_l_n=7
Vertical_lines=[]
def __init__(self,**kwargs):
super().__init__(**kwargs)
self.init_vertical_lines()
def on_size(self,*args):
self.update_vertical_lines()
def init_vertical_lines(self):
for num in range(0,self.v_l_n):
self.Vertical_lines.append(Line())
def update_vertical_lines(self):
cener_x=int(self.width/2)
before_lines=-(int(self.width/2))
line_x=cener_x+before_lines*self.v_l_s
for numb in range(0,self.v_l_n):
with self.canvas:
self.Vertical_lines[numb].points=[line_x,0,line_x,self.height]
before_lines+=1
class GameApp(App):
def build(self):
return MainWidget()
GameApp().run()
This code should return 7 vertical lines but it is showing nothing. What should I do to solve it ?(Note-An error is coming in publishing the question so don't care about this Note)
When you initially create the Line() instance, you are not doing in a canvas context. Just add with self.canvas: to the init_vertical_lines() method:
def init_vertical_lines(self):
with self.canvas:
for num in range(0, self.v_l_n):
self.Vertical_lines.append(Line())
Your code will then draw the 7 lines, but they are all in the same place (that's a different issue).

How do I control initial Size and positioning of labels and buttons in a splitter in Kivy?

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)

Kivy v1.9.1 canvas.clear() not working as expected

I'm not really sure as to why the canvas isn't clearing.
The first build(self) implementation that has the parent variable is the one that works. The only thing I see different is that the second implementation is adding the Button widget to the MyPaintWidget instead of both of those widgets getting added to a default Widget class.
Very new to kivy i'm semi-familiar with python. I'd love an explanation.
from random import random
import kivy
kivy.require('1.9.1')
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.widget import Widget
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput
from kivy.uix.gridlayout import GridLayout
from kivy.graphics import Color, Ellipse, Line
'''
class LoginScreen(GridLayout):
def __init__(self, **kwargs):
super(LoginScreen, self).__init__(**kwargs)
self.cols=2
self.add_widget(Label(text='User Name'))
self.username=TextInput(multiline=False)a
self.add_widget(self.username)
self.add_widget(Label(text='password'))
self.password=TextInput(password=True, multiline=False)
self.add_widget(self.password)
class MainApp(App):
def build(self):
return LoginScreen()
'''
class MyPaintWidget(Widget):
def on_touch_down(self, touch):
color = (random(), 1, 1)
with self.canvas:
Color(*color)
d = 30.
Ellipse(pos=(touch.x - d / 2, touch.y - d / 2), size=(d, d))
touch.ud['line'] = Line(points=(touch.x, touch.y))
print(touch)
def on_touch_move(self, touch):
touch.ud['line'].points += [touch.x, touch.y]
class MyPaintApp(App):
#WHY ARE THESE TWO IMPLEMENTATIONS OF BUILD SO DIFFERENT?????
'''
def build(self):
parent = Widget()
self.painter = MyPaintWidget()
clearbtn = Button(text='Clear')
clearbtn.bind(on_release=self.clear_canvas)
parent.add_widget(self.painter)
parent.add_widget(clearbtn)
return parent
'''
def build(self):
self.painter = MyPaintWidget()
clearbtn = Button(text='Clear')
clearbtn.bind(on_release=self.clear_canvas)
self.painter.add_widget(clearbtn)
return self.painter
def clear_canvas(self, obj):
self.painter.canvas.clear()
if __name__ == '__main__':
MyPaintApp().run()
Touches are dispatched down the widget tree, they enter at the root widget which must pass the touch down to its children (or fail to do so, if it wants).
Your MyPaintWidget class overrides on_touch_down but fails to pass the touch to its children, so the Button never receives the touch and never gets a chance to become pressed.
Add return super(MyPaintWidget, self).on_touch_down(touch) to the MyPaintWidget.on_touch_down to call the parent class method that automatically handles this for you.

Kivy - First Widget of Class not getting color

I have some simple code below that is just creating some rectangles with a color assigned to them, and then storing them into a FloatLayout. For some reason, the very first rectangle 'Brick' that I create, doesnt get a color, but all subsequent ones do. I have issues with my game also where when another widget collides with a brick, it updates the attributes of the brick to its left, and not itself. I think the two issues are related.
What is going on with the first instance of Brick (brick1) that is being added to the FloatLayout that it doesnt get the color created?
import kivy
kivy.require('1.10.0')
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.core.window import Window
from kivy.properties import NumericProperty, ReferenceListProperty
from kivy.clock import Clock
from kivy.graphics import Rectangle, Ellipse, Color
from kivy.uix.floatlayout import FloatLayout
from kivy.vector import Vector
from kivy.utils import get_color_from_hex
import random
from kivy.config import Config
Window.size = (300,600)
class Brick(Widget):
def __init__(self, xloc, yloc, **kwargs):
super().__init__(**kwargs)
with self.canvas:
self.size = (25,25)
self.x = xloc
self.y = yloc
self.pos = (self.x,self.y)
self.body = Rectangle(pos=self.pos,size = self.size)
self.c = Color(1,0,1)
class Game(Widget):
def __init__(self,**kwargs):
super().__init__(**kwargs)
self.brick_container = FloatLayout(size = (25,25))
brick1 = Brick(50,100)
brick2 = Brick(100,100)
self.brick_container.add_widget(brick1)
self.brick_container.add_widget(brick2)
self.add_widget(self.brick_container)
def update(self,dt):
self.name = 'nothing'
class MyApp(App):
def build(self):
game = Game()
Clock.schedule_interval(game.update, 1.0/60.0)
return game
if __name__ == '__main__':
MyApp().run()
You have to set the color first and then the rectangle
class Brick(Widget):
def __init__(self, xloc, yloc, **kwargs):
super().__init__(**kwargs)
self.size = (25,25)
self.pos = (xloc , yloc)
with self.canvas:
self.c = Color(1,0,1)
self.body = Rectangle(pos=self.pos,size = self.size)
According to the docs when using a Drawing Instruction, use the color set above.
Drawing instructions
Drawing instructions range from very simple
ones, like drawing a line or a polygon, to more complex ones, like
meshes or bezier curves:
with self.canvas:
# draw a line using the default color
Line(points=(x1, y1, x2, y2, x3, y3))
# lets draw a semi-transparent red square
Color(1, 0, 0, .5, mode='rgba')
Rectangle(pos=self.pos, size=self.size)
For that reason in your original code the first Brick used the color by default(white), and the others if they had the correct color.

Kivy Dynamic selection image according to button

I want to place image on button. Button's size depends on size of screen. I want to select ideal image's size according to button's size. Buttons are defined in class ButtonTools. With my knowledges I cann obtain size only in fuction of class ButtonTools. How do I obtain size of screen?
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.image import Image
class Paint(Widget):
pass
class ButtonTools(BoxLayout):
def __init__(self, **kwargs):
super(ButtonTools, self).__init__(**kwargs)
self.size_hint = (1, None)
self.height = 50
but = Button(on_press = self.DrawAbscissa)
but.background_normal = 'abscissa.png'
self.add_widget(but)
but = Button( on_press = self.DrawCurve)
but.background_normal ='curve.png'
self.add_widget(but)
def DrawAbscissa(self, obj):
size = self.parent.size
p=1
pass
def DrawCurve(self, obj):
pass
class WorkShop(BoxLayout):
def __init__(self, **kwargs):
super(WorkShop, self).__init__(**kwargs)
self.orientation = "vertical"
self.paint = Paint()
self.tools = ButtonTools()
self.add_widget(self.paint)
self.add_widget(self.tools)
class MyPaintApp(App):
def build(self):
return WorkShop()
if __name__ == '__main__':
MyPaintApp().run()
You can obtain the screen size using the following:
from kivy.core.window import Window
...
print("Window.size={}".format(Window.size))
print("Window.height={}".format(Window.height))
print("Window.width={}".format(Window.width))

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