Summary of test application: I am writing a Kivy app with a scrollable view (named Scroller) with many fields (named Field) to look at. These separate fields are really difficult to distinguish on occasion, so I decided to use alternating background colors for each field to help distinguish each other. My testing application uses 20 individual fields each of which alternates between dark grey and darker grey.
Testing trials:
Starting the application, the program looks great. The alternating background appear just fine. Even when I scroll down the application looks fine. However, the application seems to get bizarre when I scroll up on the application. The text scrolls with the application, but the background does not. Even better (sarcastically), the text starts to fade away into their neighbors background. The problem just seems to vanish when I scroll down again (passed the point of the furthest scroll up point).
Brief problem description: The Field's "background color" messes up the application during scrolling up events.
Side note: I have also noticed that the application got a little sluggish after scrolling too much. I am not that familiar with the drawing cycle of Kivy, but blitting backgrounds should not yield an excessive slowdown.
Testing application:
import kivy
kivy.require('1.0.7')
from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.uix.scrollview import ScrollView
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.graphics import Color, Rectangle
class Main(App):
def build(self):
self.root = GridLayout(rows = 1)
self.root.add_widget(Scroller())
return self.root
class Scroller(ScrollView):
def __init__(self):
ScrollView.__init__(self)
self.view = GridLayout(cols = 1, size_hint = (1, None))
self.add_widget(self.view)
self.view.bind(minimum_height = self.view.setter('height'))
for i in range(20):
self.view.add_widget(Field('Test field {}'.format(i),i%2 is 0))
class Field(GridLayout):
def __init__(self, name, bg):
assert isinstance(name, str)
assert isinstance(bg, bool)
self.bg = bg
GridLayout.__init__(self,
rows = 1,
padding = 10,
size = (0, 60),
size_hint = (1, None))
self.add_widget(Label(text = name))
self.add_widget(Button(text = 'Test button',
size = (200, 0),
size_hint = (None, 1)))
self.bind(pos = self.change_background)
self.bind(size = self.change_background)
def change_background(self, *args):
with self.canvas.before:
if self.bg:
Color(0.2, 0.2, 0.2, mode = 'rgb')
else:
Color(0.1, 0.1, 0.1, mode = 'rgb')
Rectangle(pos = self.pos, size = self.size)
if __name__ in ('__main__', '__android__'):
app = Main()
app.run()
def change_background(self, *args):
self.canvas.before.clear()#<- clear previous instructions
with self.canvas.before:
if self.bg:
Color(0.2, 0.2, 0.2, mode = 'rgb')
else:
Color(0.1, 0.1, 0.1, mode = 'rgb')
Rectangle(pos = self.pos, size = self.size)
You are adding/piling instructions to the canvas every time the Field's position/size changes, without clearing the previous instructions.
You should also look into using kv as for anything more than a small snippet it ends up saving you a lot of time. You can convert you code using kv like so ::
import kivy
kivy.require('1.0.7')
from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.uix.scrollview import ScrollView
from kivy.properties import ObjectProperty, BooleanProperty
from kivy.lang import Builder
Builder.load_string('''
<Scroller>
# root is Scroller here
# create a new ObjectProperty in kv that holds the ref to Gridlayout
# so you can access the instance in python code
view: glayout
GridLayout:
id: glayout
cols: 1
size_hint: (1, None)
height: self.minimum_height
<Field>
canvas.before:
Color:
rgba: (0.2, 0.2, 0.2, 1) if self.bg else (0.1, 0.1, 0.1, 1)
Rectangle:
# binding properties is done implicitly and instructions aren't
# piled up while doing that.
pos: self.pos
# self here refers to Field as `self` is supposed to refer to the
# Widget not the drawing instruction
size: self.size
rows: 1
padding: 10
size: (0, 60)
size_hint: (1, None)
Label:
text: root.name
Button:
text: 'test button'
size: (200, 0)
size_hint: (None, 1)
''')
class Main(App):
def build(self):
self.root = GridLayout(rows = 1)
self.root.add_widget(Scroller())
return self.root
class Scroller(ScrollView):
def __init__(self, **kwargs):
super(Scroller, self).__init__(**kwargs)
for i in range(20):
# access self.view that was set in kv
self.view.add_widget(
Field(
name = 'Test field {}'.format(i),
bg = i%2 is 0))
class Field(GridLayout):
# use kivy's Properties so it becomes easier to observe and apply changes
# as a plus these can also be directly used in kv. As a advantage of using this now
# you can change name and bg dynamically and the changes should be reflected on
# screen
name = ObjectProperty('Test field uninitialized')
bg = BooleanProperty(False)
if __name__ in ('__main__', '__android__'):
app = Main()
app.run()
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 seems a lot of people have trouble with the on_press argument with Kivy, but I haven't found answers to my issue...
Here is what's happening:
I'm getting started with my first app in python/kivy. I know python, but perhaps not enough concerning classes... I am able to create a button, with a on_press action that opens a popup.
Now the goal is the following: I have a function affiche_grille, which displays a grid with lines on the screen. Inside each square, I create a button, with a text (a number). This works. I would like to bind an on_press event on these buttons : but now, the syntax does not work any more... Maybe is it because the button is created in a "with self.canvas" instruction, and the self.function is not appropriate any more ?
Here is the (complete after edit) code :
from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.widget import Widget
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput
from kivy.uix.popup import Popup
from kivy.graphics import Color, Line
from kivy.core.window import Window
from kivy.core.text.text_layout import layout_text
from kivy.uix.floatlayout import FloatLayout
import numpy as np
from functools import partial # for on_press syntax
class Ecran_Principal(BoxLayout):
def build(self):
self.orientation='vertical'
self.liste_txt = np.zeros([9,9], dtype=object) # will contain Label
self.grille_affichee = np.zeros([9,9])
self.lGrille() # layout for the grid
self.lMenu() # layout for the menu
def lGrille(self):
LayGrille = GridLayout(cols=1,size_hint_y=0.8)
# window dimensions, in pixels
(L, H) = Window.size
H = int(0.8*H) # because of the 20% menu
if L > H: # landscape format - computer case
self.ymin = int(0.25*H) + int(0.05*H)
self.delta = int(0.1*H)
self.xmin = int((L-9*self.delta)/2.)
else: # portrait format - phone case
self.xmin = int(0.05*L)
self.delta = int(0.1*L)
self.ymin = int(0.25*H) + int((H-9*self.delta)/2.)
# end dimensions
self.deltaxrel = self.delta/H
self.deltayrel = self.delta/L
# grid definition (without numbers)
with self.canvas:
Color(1, 1, 1) # white
# automatic line traces
for i in range(4):
# big vertical lines
ymax = self.ymin+9*self.delta
xligne = self.xmin+i*3*self.delta
Line(points=[xligne, self.ymin, xligne, ymax], width=2)
# big horizontal lines
xmax = self.xmin+9*self.delta
yligne = self.ymin+i*3*self.delta
Line(points=[self.xmin, yligne, xmax, yligne], width=2)
# little intermediary lines
for ipetit in range(3):
if i ==3:
break
xpetit = xligne + ipetit*self.delta
Line(points=[xpetit, self.ymin, xpetit, ymax], width=1)
ypetit = yligne + ipetit*self.delta
Line(points=[self.xmin, ypetit, xmax, ypetit], width=1)
# end little lines
# end for
# grid display :
self.affiche_grille()
self.add_widget(LayGrille)
# end with
def affiche_grille(self):
# I tried to remove this 'with' instruction and does not change anything
with self.canvas:
for i in range(9): # line
for j in range(9): # colomn
valeur = self.grille_affichee[i,j]
val = "{0:.0f}".format(valeur)
layout = FloatLayout(size=(self.xmin + (j+0.5)*self.delta,
self.ymin + (8.5-i)*self.delta),
pos_hint=(None, None))
montexte = Button(text=val,
size_hint=(self.deltaxrel,
self.deltayrel),
pos=(self.xmin + (j+0.5)*self.delta,
self.ymin + (8.5-i)*self.delta),
background_color = (0,0.2,0,1),
background_normal = '',
on_press=partial(self.choisir_valeur, i, j)
)
self.liste_txt[i, j] = montexte
# THE BUTTONS AND THE TEXT ARE DISPLAYED,
# BUT NOTHING HAPPENS WHEN YOU PRESS THE BUTTONS
layout.add_widget(self.liste_txt[i, j])
# end j
# end i
# end with
def choisir_valeur(self, i, j):
print("Hello !") # NEVER DISPLAYED :(
#champ = TextInput(text=str(self.grille_affichee[i, j]),
# font_size=30,
# focus=True,
# multiline=False)
champ = Button(text=str(self.grille_affichee[i, j]))
popup = Popup(title='Value in line {} - colomn {}'.format(i, j),
content=champ,
size_hint=(0.5,0.5))
champ.bind(on_press=popup.dismiss)
popup.open()
def lMenu(self):
LayMenu = GridLayout(cols=2, rows=2, size_hint_y=0.2)
# Bouton Résoudre
self.BoutonResoudre=Button(text='Resoudre',size_hint=(0.5,0.1),pos_hint={'left': 0.},background_color=[0.9,0.9,0.9,1])
self.BoutonResoudre.bind(on_press=self.resoudre)
LayMenu.add_widget(self.BoutonResoudre)
# Bouton Remplir
self.BoutonScanner=Button(text='Scanner',size_hint=(0.5,0.1),pos_hint={'left': 0.5},background_color=[0.9,0.9,0.9,1])
self.BoutonScanner.bind(on_press=self.scanner)
LayMenu.add_widget(self.BoutonScanner)
# Bouton Indice
self.BoutonIndice=Button(text='Indice',size_hint=(0.5,0.1),pos_hint={'bottom': 0.},background_color=[0.9,0.9,0.9,1])
self.BoutonIndice.bind(on_press=self.indice)
LayMenu.add_widget(self.BoutonIndice)
# Bouton Quitter
self.BoutonQuitter=Button(text='Quitter',size_hint=(0.5,0.1),background_color=[0.9,0.9,0.9,1])
self.BoutonQuitter.bind(on_press=self.quitter)
LayMenu.add_widget(self.BoutonQuitter)
self.add_widget(LayMenu)
def resoudre(self, instance):
content = Button(text='Resolution du sudoku', font_size=20)
popup = Popup(title='RESOLUTION',content=content, size_hint=(0.5,0.5))
content.bind(on_press=popup.dismiss)
popup.open()
def scanner(self, instance):
content = Button(text='Remplissage auto par photo', font_size=20)
popup = Popup(title='SCAN PHOTO',content=content, size_hint=(0.5,0.5))
content.bind(on_press=popup.dismiss)
popup.open()
def indice(self, instance):
content = Button(text='Affichage d\'un indice', font_size=20)
popup = Popup(title='INDICE',content=content, size_hint=(0.5,0.5))
content.bind(on_press=popup.dismiss)
popup.open()
def quitter(self, instance):
content = Button(text='Au revoir !', font_size=20)
popup = Popup(title='QUITTER',content=content, size_hint=(0.5,0.5))
content.bind(on_press=exit())
popup.open()
class Sudoku(App):
def build(self):
ecran=Ecran_Principal()
ecran.build()
return ecran
if __name__ == '__main__':
Sudoku().run()
Everything is interpreted, but the buttons inside the grid are not working...
I've seen the functools.partial() tip, but it does not seem to be enough...
Does anyone have an idea of what is happening ? I am not very familiar with classes in python and I have certainly missed something.
Thank you in advance, and sorry if the question is too basic.
Well, you now know that you can't add a widget to canvas. Also, you shouldn't have a build method in your Ecran_Principal class. build() only belongs in the Sudoku() App class. Use __init__ instead.
I think if you try separating the visual stuff into kv language things will be easier. Below is an example utilizing spacing and padding with GridLayouts to 'draw' the game board. The buttons are hooked up with a simple callback.
btngrid.py
from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.button import Button
class SmallGrid(GridLayout):
pass
class BigGrid(GridLayout):
pass
class GameBoard(AnchorLayout):
# A nice layout to use to keep things centered. Only one widget can be added to this.
def __init__(self, *args, **kwargs):
super(GameBoard, self).__init__(*args, **kwargs)
big = BigGrid()
for i in range(9):
small = SmallGrid()
for j in range(9):
small.add_widget(Button(text="{}, {}".format(i, j), on_release=self.callback))
big.add_widget(small)
self.add_widget(big)
def callback(self, button):
print button.text
class RootWidget(BoxLayout):
def __init__(self, *args, **kwargs):
super(RootWidget, self).__init__(*args, **kwargs)
self.orientation = 'vertical'
self.add_widget(GameBoard())
bottom_btns_container = GridLayout(cols=2, size_hint=(1, .2))
for i in range(4):
# Just for show, they don't do anything
bottom_btns_container.add_widget(Button(text="Button {}".format(i)))
self.add_widget(bottom_btns_container)
class BtnGridApp(App):
def build(self):
return RootWidget()
btngird.kv
<BigGrid>:
cols: 3
size_hint: (None, .8) # scales
width: self.height # scales
spacing: 5 # Width of lines
padding: 5 # perimeter border
# This draws a background for the whole grid.
# When used with spacing and padding, part of the background will show.
# Same with SmallGrid below
canvas.before:
Color:
rgba: [.9, .9, .9, 1]
Rectangle:
pos: self.pos
size: self.size
<SmallGrid>:
cols: 3
size_hint: (None, .8) # scales
width: self.height # scales
spacing: .25
canvas.before:
Color:
rgba: [.6, .6, .6, 1] # White lines
Rectangle:
pos: self.pos
size: self.size
<GameBoard>:
anchor_x: "center"
anchor_y: "center"
I had found a similar topic at stackoverflow but unluckily it didn't help me.
It's the first time I try to seriously program a GUI and I'm really getting mad.
I'm doing one step at a time, towards what I will finally need.
Now I'm trying to add a simple drop down menu in the top left corner of my widget, whose element should call a function whenever they are selected. I really looked for this in kivy documentation, and in this forum but I can't really solve this.
import multiprocessing
from mesh import MeshApp
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.dropdown import DropDown
from kivy.uix.button import Button
import os
MAINDIR = os.path.dirname(os.path.realpath(__file__))
categories = {}
def getCategories():
for dir in os.walk(MAINDIR):
if len(dir[1]) == 0:
filelist = set()
for mesh in dir[2]:
filelist.add(mesh.replace('_FRONT.png','').replace('_SIDE.png','').replace('_TOP.png',''))
categories.update({dir[0]: filelist})
#class CategoriesList(DropDown):
# pass
class MainWindow(Widget):
def __init__(self):
#self.categorieslist = CategoriesList()
categories_list = DropDown()
for i in categories.keys():
btn = Button(text=i.replace(MAINDIR, ''), size_hint_y=None, height=30)
btn.bind(on_release=lambda btn: categories_list.select(btn.text))
categories_list.add_widget(btn)
mainbutton = Button(text='Choose directory', size_hint=(1, 1))
mainbutton.bind(on_release=categories_list.open)
categories_list.bind(on_select=lambda instance, x: setattr(mainbutton, 'text', x))
#and now???
class RenderApp(App):
def build(self):
self.launchMeshApp()
return MainWindow()
def launchMeshApp(self):
app = MeshApp()
p = multiprocessing.Process(target=app.run)
p.start()
if __name__ == '__main__':
getCategories()
RenderApp().run()
And:
#:kivy 1.9.1
<MainWindow>:
canvas.before:
Color:
rgba: 0.6, 0.6, 1, 1
Rectangle:
pos: self.pos
size: self.size
canvas:
Color:
rgba: 0, 0, 0, 0.5
Rectangle:
pos: 0, self.height * 5 / 6 - 1
size: self.width, 2
I've created the dropdown as seen in the docs and in several other forum. But I need to place it in the top left corner, and I never found, or understood, the way to do this. Moreover I didn't get how to make them call a function with a parameter whenever they are clicked.
Thank you very much
EDIT: I don't know why but the first line with "Hi all" is automatically deleted
I don't know about the dropdown menu, but I can answer the data one.
When you bind a callback, the first argument you receive will be which widget that is bound to the callback. So the idea is to create a class that uses Button as its base class, then you can define whatever extra information you need.
Here is a rough, non tested example based on the button API example:
class MyAwesomeButton(Button):
def __init__(self, **kwargs):
super(MyAwesomeButton, self).__init__(**kwargs)
self.my_data = {} # enter your data here
def callback(instance):
print('The button <%s> is being pressed' % instance.text)
print instance.my_data
btn1 = MyAwesomeButton(text='Hello world 1')
btn1.bind(on_press=callback)
btn2 = MyAwesomeButton(text='Hello world 2')
btn2.bind(on_press=callback)
I'm trying to display an image as an intro to an app. Every time the user runs the program, it should display the image, then when press, it should open a few buttons which are popups.
from kivy.app import runTouchApp
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.popup import Popup
from kivy.uix.image import Image
from kivy.lang import Builder
kv = '''
BoxLayoutWithPopup:
orientation:'horizontal'
spacing:10
padding:5
Image:
source: 'appintro.png'
size:100,100
on_press:
root.pop1()
'''
#Helpme:
#title: 'Help Me'
#content: 'helpme.png'
# size_hint: None,None
# pos_hint: 700,320
# size: 250,100
#Games:
# title: 'Games'
# content: 'helpme.png'
# size_hint: None,None
# pos_hint: 100,20
# size: 250,100
class BoxLayoutWithPopup(BoxLayout):
def pop1(self):
# root.add_widget(HelpMe)
# root.add_widget(Games)
helpme = Popup(title='helpme', content=Image(source='helpme.png'),
size_hint=(.8, .8), pos=(1,30), size=(200, 200))
helpme.open()
#def pop2(self):
games = Popup(title='games', content=Image(source='games.png'),
size_hint=(.5, .5), pos=(20,80), size=(200,200))
games.open()
settings = Popup(title='settings', content=Image(source='settings.png'),
size_hint=(.3, .3), pos=(1,1), size=(400, 400))
settings.open()
if __name__ == '__main__':
runTouchApp(Builder.load_string(kv))
Can anyone help me identify what is wrong with this code? I'm trying to display an intro when the app is initialized, which opens the main page when pressed, but the image for the intro and images for the popups are not being displayed. I also tried moving the popup positions, it seem to not be working. please help me.
You are passing a tuple as the pos_hint when it expects a dict. If you want to specify the position, you should use pos instead - so instead of pos_hint=(1,1) you would use pos=(1,1). If you want to specify a position relative to the parent, you can use pos_hint={'x': 0, 'y': 0} for example.
import os,sys,random
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.button import Button
from kivy.graphics import Color, Rectangle
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.image import Image
from kivy.uix.screenmanager import ScreenManager, Screen , SlideTransition
from kivy.animation import Animation
from kivy.properties import StringProperty
class Page(Screen):
source = StringProperty()
class Imglayout(FloatLayout):
def __init__(self,**args):
super(Imglayout,self).__init__(**args)
with self.canvas.before:
Color(0,0,0,0)
self.rect=Rectangle(size=self.size,pos=self.pos)
self.rootpath = os.path.dirname(os.path.realpath(sys.argv[0]))
self.images=[]
for img in os.listdir(self.rootpath+'/images'):
self.images.append(self.rootpath+'/images/'+img)
self.index=random.randint(0,len(self.images)-1)
self.im=Image(source=self.images[self.index])
self.im.keep_ratio= False
self.im.allow_stretch = True
#self.add_widget(self.im)
self.sm = ScreenManager(transition=SlideTransition())
self.page1=Page(name='page1', source = self.images[self.index])
self.page2=Page(name='page2', source = self.images[self.index+1])
self.sm.add_widget(self.page1)
self.sm.add_widget(self.page2)
self.bind(size=self.updates,pos=self.updates)
def updates(self,instance,value):
self.rect.size=instance.size
self.rect.pos=instance.pos
def on_touch_down(self,touch):
if self.collide_point(*touch.pos):
if(self.sm.current == 'page1'):
next='page2'
page=self.page2
else:
next='page1'
page=self.page1
self.index=(self.index+1)%len(self.images)
page.source = self.images[self.index]
page.background.scale = 1.0
self.sm.transition=SlideTransition()
self.sm.current = next
anim = Animation(
scale=page.background.scale*1.3,
duration=15.0
)
anim.start(page.background)
return True
return False
class MainTApp(App):
def build(self):
root = BoxLayout(orientation='vertical',spacing=10)
c = Imglayout()
root.add_widget(c)
cat=Button(text="Categories",size_hint=(1,.05))
cat.bind(on_press=self.callback)
root.add_widget(cat);
return root
def callback(self,value):
print "CALLBACK CAT"
if __name__ == '__main__':
MainTApp().run()
Taking some hints from here i made the above program. It says that Page does not have a background attribute in both my and the referenced code. Its kind of obvious since there is no background attribute. I thought it inherited that from Screen. I am trying to make a slideshow kind of thing. But i cant find any information on how to set the background of a screen.
And if i comment out everything with .background and run the app. click on the black space, then i start getting this error continuously on the terminal
[ERROR ] [OSC ] Address 127.0.0.1:3333 already in use, retry
in 2 second
And i still dont get any background on the app.(its all black.)
and if i print self.sm.current on the touich function. Then i find that its always page1, it never changes.
The Kivy Guide explains how to add a background to a Widget. Briefly, you can do it in Python using the following code which binds to the position and size of the widget to make sure the background moves with the widget.
with widget_instance.canvas.before:
Color(0, 1, 0, 1) # green; colors range from 0-1 instead of 0-255
self.rect = Rectangle(size=layout_instance.size,
pos=layout_instance.pos)
widget_instance.bind(size=self._update_rect, pos=self._update_rect)
...
def _update_rect(self, instance, value):
self.rect.pos = instance.pos
self.rect.size = instance.size
Or you can do it more naturally with the kv language e.g.
MyWidget:
canvas.before:
Color:
rgba: 0, 1, 0, 1
Rectangle:
# self here refers to the widget i.e screen
pos: self.pos
size: self.size