Is ScreenManager compatible with DropDown in Kivy? - python

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

Related

Kivy Layout square Stacking

I was making a program similiar to exel.
And then I ran into a issue.
StackLayout stacks good, but because the size of inputs is static it leave a blank space in some cases.
I try to do like size=(self.width/5, self.height/5).
If someone saw how exel look now that there are more inputs of the screen this is why I use ScrollLayout and I want only 5 inputs in one row(user can change it in display settings(I will do it then creating rest of UI))
Here is what I had tried for now.
main.py:
from kivy.metrics import dp
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.gridlayout import GridLayout
from kivy.uix.stacklayout import StackLayout
from kivy.uix.textinput import TextInput
class EditorGrid(BoxLayout):
def __init__(self, **kwargs):
super().__init__(**kwargs)
size = dp(self.width / 5)
print(size)
for i in range(0, 100):
b = TextInput(text=str(i + 1), size_hint=(None, None), size=(dp(size), dp(size)))
self.add_widget(b)
def on_size(self, *args):
self.size = dp(self.width/5)
print(self.size)
pass
class pxApp(App):
pass
if __name__ == "__main__":
pxApp().run()
kivy file:
Scrolling:
<Scrolling#ScrollView>
do_scroll_x: True
do_scroll_y: True
EditorGrid:
size_hint: 1, None
height: self.minimum_height
<EditorGrid>:
There is next problem that in init window size is 100x100.
I recommend using setters in binding under kv script. If you want to apply it in python, you could use a binding function for each button.
b = TextInput(.......) #omit size_hint and size attributes
#the following function is called every time EditorGrid(self) size_hint changes when the function is bind
#The function could be defined in a outer scope.
#Look at kivy callback functions to better understand the syntax
binding_function = lambda ins, *a: setattr(ins, 'size_hint', tuple((dim/5 for dim in self.size_hint))
b.bind(size_hint=binding_function)

Kivy Python Scrollview event misfiring when in a class instantiated multiple times

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)

Getting TextInput value with ScreenManager in Kivy 1.10 and Python 2.7.9

Using Kivy 1.10.0 with Python 2.7.9 I am trying to get the TextInput value entered by user when Button (my_button2) is clicked .And although I have been able to get this working with GridLayout it seems like the method I am using is not working with ScreenManager with BoxLayout . Error received is : AttributeError: 'ScreenTwo' object has no attribute 'inpt' when my_button2
After clicking 'Next Screen ' button , it takes me to page where user enters text value , and 'print' button should print it
Please see below :
import kivy
from kivy.app import App
from kivy.uix.screenmanager import Screen, ScreenManager
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.textinput import TextInput
class ScreenOne(Screen):
def __init__ (self,**kwargs):
super (ScreenOne, self).__init__(**kwargs)
my_box1 = BoxLayout(orientation='vertical')
my_button1 = Button(text="Next Screen ",size_hint_y=None,size_y=100)
my_button1.bind(on_press=self.changer)
my_box1.add_widget(my_button1)
self.add_widget(my_box1)
def changer(self,*args):
self.manager.current = 'screen2'
class ScreenTwo(Screen):
def __init__(self,**kwargs):
super (ScreenTwo,self).__init__(**kwargs)
layout = BoxLayout(orientation='vertical')
self.add_widget(layout)
inpt = TextInput(text="Some text ",size_y=50)
layout.add_widget(inpt)
my_button2 = Button(text="Print ")
my_button2.bind(on_press=self.click)
layout.add_widget(my_button2)
Home_btn = Button(text="Back")
Home_btn.bind(on_press=self.home)
layout.add_widget(Home_btn)
def click(self,my_button2):
entered_value = self.inpt.text
print entered_value
def home(self,*args):
self.manager.current = 'screen1'
class TestApp(App):
def build(self):
my_screenmanager = ScreenManager()
screen1 = ScreenOne(name='screen1')
screen2 = ScreenTwo(name='screen2')
my_screenmanager.add_widget(screen1)
my_screenmanager.add_widget(screen2)
return my_screenmanager
if __name__ == '__main__':
TestApp().run()
second screen
When you use self you are trying to access members of the class, but in your case inpt it is not since it is a variable any, if you want to be a member of the class you must put forward self, in your case change:
inpt = TextInput(text="Some text ",size_y=50)
layout.add_widget(inpt)
to:
self.inpt = TextInput(text="Some text ",size_y=50)
layout.add_widget(self.inpt)
Note: I recommend you read OOP basics, if you are not going to have many of these problems.

Kivy. Changing Layouts

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.

Kivy select an item in ListView from code

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)

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