In a Kivy/Python program, I have a class which contains a scrollview. I instantiate this class multiple times. The scrollview is bound to the on_scroll_stop event. My desired outcome is that the on_scroll_stop event will only fire within the instantiated class to which it belongs, but it seems that the event fires across all of the instantiated classes. Am I doing something wrong or is this expected behavior? Working sample below. In this example the "Left" section shows the issue most often, however the error is seen in the right section once you scroll up at the top or scroll down once reaching the bottom. To recreate scroll only one side, preferably the "Left" side. In my actual code which is far more complex the issue is much more prevalent.
import kivy
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.scrollview import ScrollView
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.label import Label
class DisplaySection(Widget):
def CreateSection(self):
self.display_panel_main_layout = BoxLayout(orientation='vertical')
self.elements_layout = FloatLayout(size_hint_y=None)
self.sv = ScrollView()
self.sv.bind(on_scroll_stop=self.on_scrolling_stop)
self.sv.add_widget(self.elements_layout)
self.display_panel_main_layout.add_widget(self.sv)
return self.display_panel_main_layout
def LoadElements(self,section_name):
self.section_name = section_name
number_of_elemements = 100
element_hieght = 40
layout_height = number_of_elemements * element_hieght
self.elements_layout.height = layout_height
xcord = 0
for x in range(number_of_elemements):
ycord = self.elements_layout.height - element_hieght*x
name = Label(text='Name' + str(x),size_hint_y=None, height=40,pos=(xcord,ycord))
self.elements_layout.add_widget(name)
def on_scrolling_stop(self, sv, value):
#print(sv,value)
print('I am',self.section_name)
class testscrollapp(App):
def build(self):
main_layout = BoxLayout()
section_names = ['Left','Right']
for x, section_name in enumerate(section_names):
section_layout = BoxLayout(orientation='vertical')
btn = Button(text=section_name,size_hint=(1,None))
section_layout.add_widget(btn)
# instantiate the class containing the scroll view
scroll_layout = DisplaySection()
scr = scroll_layout.CreateSection()
section_layout.add_widget(scr)
scroll_layout.LoadElements(section_name)
main_layout.add_widget(section_layout)
return main_layout
testscrollapp().run()
The on_scroll_stop event is dispatched just like touch events, so any ScrollView instance that subscribes to on_scroll_stop will get all the on_scroll_stop events. And just like a touch event, the subscribing ScrollView instance must determine which of the events it is interested in, and ignore the rest. Since the value argument to your on_scrolling_stop is the MouseMotionEvent, you can do a collide_point() test to determine if the scroll event is within the ScrollView:
def on_scrolling_stop(self, sv, value):
if sv.collide_point(*value.pos):
print('\tI am',self.section_name)
Related
I am using kivy and I am using Windows 10, Python 3.7.
I want to print out the name of each button when I press each button.
However, only the name of the last button is printed.
Below is the Python code
import kivy
kivy.require('2.0.0')
from kivy.app import App
from kivy.core.window import Window
from kivy.uix.gridlayout import GridLayout
from kivy.uix.button import Button
from kivy.uix.scrollview import ScrollView
import os
Window.clearcolor = (.6, 1, .8, 1)
Window.size = (563, 1001)
Window.top, Window.left = 30, 800
path_list = ["music1","music2","music3"]
music = ""
class TestApp(App):
def build(self):
global music
gl = GridLayout(cols=1, size_hint_y=None)
for music in path_list:
bt = Button(text=music, size_hint_y=None, height=50)
gl.add_widget(bt)
bt.bind(on_press=self.music_f)
sv = ScrollView(size_hint=(1, 1))
sv.add_widget(gl)
return sv
def music_f(self,name):
global music
name = music
print("pray "+str(name))
TestApp().run()
Bad design:
You use a music variable which will take the last value from the path_list due to the for loop, then you use that value to assign it to the name, this has no logic... Once the button is created with the text=music, you already have the value assign to the that button. As you bind on_press with music_f, the name should be the button, I would change that to button.
In music_f you can access the name by calling button.text
def music_f(self,button):
print("pray "+str(button.text))
I want to create an Accordion containing content consisting of an RstDocument and a button. The Accordion shall be scrollable as well as the content of the RstDocument when this content is larger than the given space. So I came up with the following code but after some clicks on AccordionItems all further interaction is blocking. What am I doing wrong here?
from kivy.app import App
from kivy.uix.scrollview import ScrollView
from kivy.uix.rst import RstDocument
from kivy.core.window import Window
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.accordion import Accordion, AccordionItem
from kivy.uix.button import Button
class ShowrstApp (App):
def update_size(self, instance, *args):
instance.size = 60 * len(instance.children)
def build (self):
numitems = 10
root = BoxLayout()
accheight = numitems * 60
accitems = Accordion(id='acc_panel', orientation='vertical', pos_hint={'top': 1}, size_hint_y=None,
height=accheight, md_bg_color=(1, 1, 1, 1))
for i in xrange(numitems):
item = AccordionItem(title='This is item: %d' % i)
somecontent = BoxLayout(orientation='vertical')
somecontent.add_widget(RstDocument(text='Some nicely formatted text here'))
somecontent.add_widget(Button(text='click here', height=(42), size_hint=(1,None)))
item.add_widget(somecontent)
item.bind(children=self.update_size)
accitems.add_widget(item)
sv = ScrollView(do_scroll_x = False)
sv.add_widget(accitems)
root.add_widget(sv)
return root
Window.size = (350,650)
showrst = ShowrstApp()
showrst.run()
Below the scrolling effect works when the RstDocument Boxlayout is either horizontal of vertical, but an issue I saw was that when the BoxLayout was set to vertical, the toggle of each item was mute, you had to go one by one from the bottom-up. This was weird. You can click on each AccordionItem, where the RstDocument is not. This should be a great starting point. Noticed this effect doesn't occur when using a Label, so that could be a another option.
from kivy.app import App
from kivy.uix.scrollview import ScrollView
from kivy.uix.rst import RstDocument
from kivy.core.window import Window
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.accordion import Accordion, AccordionItem
from kivy.uix.button import Button
class ShowrstApp (App):
def update_size(self, instance, *args):
instance.height = 100 * len(instance.children) # set Accordion height to the number of accordionItem times the height accordionItem height
def build (self):
numitems = 10
root = BoxLayout()
accheight = numitems * 60
accitems = Accordion(id='acc_panel', orientation='vertical', size_hint_y=None, pos_hint={'top':1}
height=accheight, md_bg_color=(1, 1, 1, 1))
for i in xrange(numitems * 2): # *2 to show it works
item = AccordionItem(title='This is item: %d' % i)
somecontent = BoxLayout(orientation = 'horizontal') # couldn't solve an issue I notice so I used horizontal
somecontent.add_widget(RstDocument(text='Some nicely formatted text here' * 10))
somecontent.add_widget(Button(text='click here', height=(42), size_hint=(1,None)))
item.add_widget(somecontent)
accitems.bind(size=self.update_size)
accitems.add_widget(item)
sv = ScrollView(do_scroll_x = False)
sv.add_widget(accitems)
root.add_widget(sv)
return root
Window.size = (350,650)
showrst = ShowrstApp()
showrst.run()
I was having the same issue with RstDocuments in a ScrollView. The problem arises because RstDocuments have their own scrolling and 'intercept' the scroll command because it thinks you're trying to scroll inside the RstDocument. If you're fine with non-scrolling RstDocuments, you can set do_scroll_y: False for RstDocument, and scrolling will then work fine in the ScrollView regardless of mousing over an RstDocument.
I'm something of a newbie to Python and Kivy. After making some progress, I've hit a brick wall and no amount of internet searching can find an answer.
I have a python/kivy script which starts with a GridLayout selection menu. Then I would like to "Click Next" and replace the GridLayout with a BoxLayout to display the output. The Python script is:
import sys
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.checkbox import CheckBox
from kivy.uix.gridlayout import GridLayout
from kivy.uix.pagelayout import PageLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.properties import StringProperty, ListProperty, DictProperty
from kivy.uix.widget import Widget
from brp_stats import *
from dice_roller import *
#from display import *
race = ''
statblock = ''
class Test(GridLayout):
def printcharacter(self,my_sb,my_cr,my_scm,my_scb):
printable_stats = print_stats(my_sb)
printable_rolls = print_rolls(my_cr)
printable_scm = print_scm(my_scm)
printable_scb = print_scb(my_scb)
self.clear_widgets()
self.add_widget(Label(text_size=(300, None),
text='Stats\n' + str(printable_stats)))
self.add_widget(Label(text_size=(300, None),
text='Rolls\n' + str(printable_rolls)))
self.add_widget(Label(text_size=(300, None),
text='SCM\n' + str(printable_scm)))
self.add_widget(Label(text_size=(300, None),
text='SCB\n' + str(printable_scb)))
wayout = Button(text='Way Out')
self.add_widget(wayout)
wayout.bind(on_press=self.canvas.clear)
# def bar():
# print ("BAR")
def human(self,a,b):
if b==True:
self.Status="human"
race=self.Status
statblock = human()
characteristic_rolls = rolls(statblock)
skill_category_modifiers = scm(statblock)
skill_category_bonuses = scb(statblock)
# TestApp.foo()
# Test.bar()
Test.printcharacter( \ self,statblock,characteristic_rolls,skill_category_modifiers,skill_category_bonuses)
class TestApp(App):
# def foo():
# print ("FOO")
def build(self):
self.title="BRP Character Generator"
return Test()
#### MAIN CODE ####
if __name__ == '__main__':
TestApp().run()
And the KV script is
<Test>:
cols: 2
canvas:
Color:
rgb: .2,.2,.2
Rectangle:
pos: self.pos
size: self.size
Label:
text: 'Human'
CheckBox:
group: 'race_group'
on_active: root.human(*args)
Button:
text: 'Next'
on_press: printcharacter()
What's happening is I select an option (Human in this example). It should wait until I click Next before displaying the results. However, as soon as I select Human, it immediately prints the result, in a GridLayout. Two questions spring to mind, which I'm hoping the experts here can help with:
1) Why does the Select screen not wait until I have clicked Next before displaying the results?
2) How do I swap the layout from Grid to Box when I display the second screen?
Any pointers or suggestions would be gratefully received.
Regards,
Colin
Your Checkbox calls Test.human(*args) when it is active (pressed/selected), and the last line of Test.human() calls Test.printcharacter() which explains why it is printing before you hit the 'Next' button.
Since your Test class inherits from GridLayout the widgets you add to a root Test layout will be added as if to a GridLayout. There are several ways to handle switching the layout to a BoxLayout, one of which would be to not inherit directly from a particular Layout class and instead add/remove different Layout widgets to Test as needed.
For example, Test could start off with a GridLayout child widget that is the parent of the Label, CheckBox, and Button widgets. Then when you want to switch layouts for printing your results, you clear those widgets and start by adding a BoxLayout to Test.
I want to generate a dropdown-list in my second screen managed by Kivys ScreenManager. If I do so, I get this traceback:
...
File "C:/Users/ORANG/PycharmProjects/waldi/playground/cw.py", line 76, in on_text
instance.drop_down.open(instance)
File "C:\Kivy-1.9.0-py2.7-win32-x64\kivy27\kivy\uix\dropdown.py", line 215, in open
'Cannot open a dropdown list on a hidden widget')
kivy.uix.dropdown.DropDownException: Cannot open a dropdown list on a hidden widget
This is the code, which is basically the same as in this
example, just embedded in a screenmanager scenario simple as can be:
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.dropdown import DropDown
from kivy.uix.button import Button
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.textinput import TextInput
from kivy.properties import ListProperty, StringProperty
import re
from kivy.lang import Builder
Builder.load_string('''
<Lieferant>:
ComboLayout:
Label:
text: 'Label'
ComboEdit:
size_hint: .5, .3
pos_hint: {'center':(.5, .5)}
# `args` is the keyword for arguments passed to `on_text` in kv language
on_text: self.parent.on_text(self, args[1])
''')
class ComboEdit(TextInput):
"""
This class defines a Editable Combo-Box in the traditional sense
that shows it's options
"""
options = ListProperty(('',))
'''
:data:`options` defines the list of options that will be displayed when
touch is released from this widget.
'''
def __init__(self, **kw):
ddn = self.drop_down = DropDown()
ddn.bind(on_select=self.on_select)
super(ComboEdit, self).__init__(**kw)
def on_options(self, instance, value):
ddn = self.drop_down
# clear old options
ddn.clear_widgets()
for option in value:
# create a button for each option
but = Button(text=option,
size_hint_y=None,
height='36sp',
# and make sure the press of the button calls select
# will results in calling `self.on_select`
on_release=lambda btn: ddn.select(btn.text))
ddn.add_widget(but)
def on_select(self, instance, value):
# on selection of Drop down Item... do what you want here
# update text of selection to the edit box
self.text = value
class ComboLayout(BoxLayout):
rtsstr = StringProperty("".join(("Substrate1,,,Substrate1,,,Substrate1,,,",
"Substrate1,,,Substrate1,,,Substrate_coating",
",,,silicon,,,silicon_Substrate,,,substrate_",
"silicon,,,")))
def on_text(self, instance, value):
if value == '':
instance.options = []
else:
match = re.findall("(?<=,{3})(?:(?!,{3}).)*?%s.*?(?=,{3})" % value, \
self.rtsstr, re.IGNORECASE)
# using a set to remove duplicates, if any.
instance.options = list(set(match))
instance.drop_down.open(instance)
class Intro(Screen):
pass
class Lieferant(Screen):
pass
class CWApp(App):
def build(self):
sm = ScreenManager()
sm.add_widget(Intro(name='Intro'))
sm.add_widget(Lieferant(name='Lieferant'))
return sm
if __name__ == '__main__':
CWApp().run()
Is it possible to combine them? How would you do this?
This code is running if I just comment this line out, which adds a screen before the screen with the dropdown:
sm.add_widget(Intro(name='Intro'))
Ok - for this question I got the "Tumbleweed Badget" - LOL
I admit it's a very special one and makes obvious, how much I am a beginner here. So I asked another question based on the same problem and spend some effort to make it easier to understand the code and to reproduce it. This paid off! Look here for the solution if you tumble once into that kind of problem: Is it a bug in Kivy? DropDown + ScreenManager not working as expected
I use a ListAdapter to dispaly data in a ListView.
How do I select an item in the ListView from code?
You can get your list items from ListAdapter using get_view() method. If list item is a ListItemButton then you can simulate pressing using trigger_action() method of ButtonBehavior mixin (ButtonBehavior is parent of Button and Button is parent of ListItemButton). This will also trigger on_selection_change event, so you might need a variable to distinguish this from normal selection. An example:
from kivy.uix.listview import ListView, ListItemButton
from kivy.uix.boxlayout import BoxLayout
from kivy.adapters.dictadapter import ListAdapter
from kivy.uix.button import Button
from random import randint
class MainView(BoxLayout):
def __init__(self, **kwargs):
kwargs['cols'] = 2
super(MainView, self).__init__(**kwargs)
self.orientation = 'vertical'
self.list_adapter = ListAdapter(data=["Item #{0}".format(i) for i in range(10)], cls=ListItemButton, sorted_keys=[])
self.list_adapter.bind(on_selection_change=self.selection_change)
list_view = ListView(adapter=self.list_adapter)
self.add_widget(list_view)
self.add_widget(Button(text="select random item", on_press=self.callback))
def callback(self, instance):
index = randint(0, 9)
self.change_from_code = True
if not self.list_adapter.get_view(index).is_selected:
self.list_adapter.get_view(index).trigger_action(duration=0)
self.change_from_code = False
def selection_change(self, adapter, *args):
if self.change_from_code:
print "selection change from code"
else:
print "selection changed by click"
if __name__ == '__main__':
from kivy.base import runTouchApp
runTouchApp(MainView(width=800))
The ListAdapter function handle_selection already handles this. It's not in the documentation, but it's in the code. All you need to know is the list item that you're looking for.
item = list_adapter.get_data_item(0)
list_adapter.handle_selection(item)
If you don't want to fire a on_selection_change event add True. This tells handle_selection not to fire the dispatch.
item = list_adapter.get_data_item(0)
list_adapter.handle_selection(item, True)