Is there any way to limit the size of DropDown box? I would like to limit it to size of maybe 4-5 choices, instead of having it running all the way to the edge of screen.I started experimenting with DropDown as Spinner didn't have any interface for doing so.. Both elements in my use case should do the same, but it seemed like DropDown would provide more flexibility as I had to compose the picker myself. Unfortunately, changing hint or size for DropDown seems to do nothing, as the list still gets fully expanded.
Here is code for what I got now:
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.dropdown import DropDown
class DropDownPicker(Button):
def __init__(self, listOfChoices, **kwargs):
result = super(DropDownPicker, self).__init__(**kwargs)
self.text='Select'
pickerList = DropDown()
for item in listOfChoices:
choiceButton = Button(text=item, size_hint_y=None, height=25)
choiceButton.bind(on_release=lambda btn: pickerList.select(btn.text))
pickerList.add_widget(choiceButton)
self.bind(on_release=pickerList.open)
pickerList.bind(on_select=lambda instance, x: setattr(self, 'text', x))
pickerList.size_hint_y = None
pickerList.size = (0, 100)
return result
class TestApp(App):
def build(self):
choices = []
for x in range(50):
choices.append("Choice " + str(x))
return DropDownPicker(choices)
if __name__ == '__main__':
TestApp().run()
Those last 2 lines before return should be doing the trick, but they aren't. I also tried to specify this in DropDown constructor, however I changed this because at that time there might have been problem that final size is not yet known. This wasn't the case as it still doesn't work.
Try modyfing size_hint_y property, but not to None (it's default) but to the decimal value, for example:
from kivy.uix.dropdown import DropDown
from kivy.uix.button import Button
from kivy.base import runTouchApp
dropdown = DropDown()
dropdown.size_hint_y = 0.5
for index in range(100):
btn = Button(text='Value %d' % index, size_hint_y=None, height=44)
btn.bind(on_release=lambda btn: dropdown.select(btn.text))
dropdown.add_widget(btn)
mainbutton = Button(text='Hello', size_hint=(None, None))
mainbutton.bind(on_release=dropdown.open)
dropdown.bind(on_select=lambda instance, x: setattr(mainbutton, 'text', x))
runTouchApp(mainbutton)
Related
I have a screen with a StackLayout. The first row of the stack includes a textinput and a "+" button which is meant to add another identical row below the actual one in a loop (i.e. another textinput with another "add" button). Then there is a "Save" button, which is supposed to be always at the end of the stack.
The dictionary is supposed to later grab the input from the text field, when pressing the save button, but this should not be relevant to my problem.
There are two problems with my code:
First, when I press the "+" button in a row, the button that gets highlighted is not this button itself, but the one in the row below (e.g. if there are three rows and I press the button in the second row, the button in the third row is highlighted)
Second and most importantly, starting from the second row onwards, each press of the "+" button adds a new row above the actual one, rather than below it.
I am aware that kivy assigns reverse order to the widgets (i.e. the one added last will be drawn first) and that is why I am manually assigning indexes to the new rows. However, I cannot achieve the desired behavior.
Here is a minimal working version:
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.textinput import TextInput
from kivy.uix.stacklayout import StackLayout
from kivy.uix.screenmanager import ScreenManager, Screen
class AddWindow(Screen):
def __init__(self, **kwargs):
super(AddWindow, self).__init__(**kwargs)
self.grid = StackLayout()
self.grid.pos_hint = {"x":0.05,"top":0.8}
self.grid.size_hint = (0.9,None)
self.add_widget(self.grid)
self.i = 1
self.n = 1
self.inputs = {}
self.ing1 = TextInput(size_hint=(0.9,'0.3sp'))
self.grid.add_widget(self.ing1)
self.inputs['0'] = 'ing1'
self.addIng = Button(text="+", size_hint=(0.1,'0.3sp'))
self.addIng.bind(on_press=self.addIngredient)
self.grid.add_widget(self.addIng)
self.doneButton = Button(text="Save")
self.grid.add_widget(self.doneButton, index=0)
def addIngredient (self, instance):
self.ing = TextInput(size_hint=(0.9,'0.3sp'))
self.inputs[self.i] = 'ing{}'.format(self.i+1)
self.grid.add_widget(self.ing, index=self.n+1)
self.addNext = Button(text="+", size_hint=(0.1,'0.3sp'))
self.addNext.bind(on_press=self.addIngredient)
self.grid.add_widget(self.addNext, index=self.n+2)
self.i += 1
self.n += 2
print(self.inputs)
WMan = ScreenManager()
WMan.add_widget(AddWindow(name='add'))
class RecipApp(App):
def build(self):
return WMan
if __name__ == "__main__":
RecipApp().run()
What am I missing? Here is a screenshot for better clarity:
Screenshot
Here is a brute force method to do what you want by rebuilding the StackLayout each time a + `Button is pressed:
def addIngredient(self, instance):
tmp_children_list = self.grid.children[:]
self.grid.clear_widgets()
for index in range(len(tmp_children_list)-1, -1, -1):
child = tmp_children_list[index]
self.grid.add_widget(child)
if child == instance:
# this is the pressed Button, so add new row after it
self.n += 1
self.ing = TextInput(size_hint=(0.9,'0.3sp'))
self.ing.text = str(self.n) # add text just for identification
self.grid.add_widget(self.ing)
self.addNext = Button(text="+", size_hint=(0.1,'0.3sp'))
self.addNext.bind(on_press=self.addIngredient)
self.grid.add_widget(self.addNext)
Here is a quick and dirty approach , where your problems should be fixed due to a remove and add of the save button. Between those to actions you add a new row before you finally add the save button again. Hope it helps you to adjust your code. The key part is the custom on_press method of the AddButton.
from kivy.app import App
from kivy.uix.stacklayout import StackLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button
from kivy.core.window import Window
class AddButton(Button):
def __init__(self, **kwargs):
super(AddButton, self).__init__(**kwargs)
def on_press(self):
self.parent.remove_widget(self.parent.save_btn)
self.parent.add_widget(TextInput(size_hint=(None, None), size=(Window.width * 0.8 - self.parent.padding[1], Window.height * 0.1)))
self.parent.add_widget(AddButton(text="+", size_hint=(None, None), size=(Window.width * 0.2, Window.height * 0.1)))
self.parent.add_widget(self.parent.save_btn)
class MyApp(App):
def build(self):
Window.size = (400, 600)
layout = StackLayout(orientation="lr-tb", padding=(20, 40))
layout.save_btn = Button(text="Save", size_hint=(None, None),
size=(Window.width - layout.padding[1], Window.height * 0.1))
layout.add_widget(TextInput(size_hint=(None, None), size=(Window.width * 0.8 - layout.padding[1], Window.height * 0.1)))
layout.add_widget(AddButton(text="+", size_hint=(None, None), size=(Window.width * 0.2, Window.height * 0.1)))
layout.add_widget(layout.save_btn)
return layout
MyApp().run()
I have a question that i can't seem to find an anwser.
I have this label:
l = Label(text='Some Text', font_size=100)
I have also binded text input to 'l' that looks like this:
t = TextInput(font_size=80, size_hint_y=None, height=200, text='Time', halign='right')
t.bind(text=l.setter('text'))
So when i type something to my text input box, it instantly updates the label and shows result on screen.
But i want to update that text only when user presses 'Add' button.
I am new to kivy and i am still experiment with it.
Any help would be great.
Thanks!
#edit here is my code:
https://gist.githubusercontent.com/Gacut/d765231c2696831af8c8a3315fdabbfd/raw/e1bdcdd8aca588b1c9268e76f7a47fa7576d54cb/gistfile1.txt
and what i am trying to do, is this kind of app, but for android:
https://wumpa.app/
The
t.bind(text=l.setter('text'))
will do exactly what you describe, so that is not what you want. Instead, use the Button on_release property to call a method that does what you want. The simplest way to do that is to save references to the Widgets involved (t and lista), and use those references in the new method. Like this:
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button
class WumpaTime(App):
def build(self):
layout = BoxLayout(orientation='vertical')
title = Label(text='Wumpa Time Countdown', size_hint_y=None, height=100, )
self.t = TextInput(font_size=80, size_hint_y=None, height=200, halign='right')
self.lista = Label(font_size=100)
box = BoxLayout()
box2 = BoxLayout()
bremove = Button(text="Remove", size_hint=(None, None), size=(100, 100))
badd = Button(text="Add", size_hint=(None, None), size=(100, 200), on_release=self.update_label)
#t.bind(text=lista.setter('text'))
box.add_widget(self.t)
box.add_widget(badd)
layout.add_widget(title)
layout.add_widget(self.lista)
layout.add_widget(box)
return layout
def update_label(self, button_instance):
self.lista.text = self.t.text
WumpaTime().run()
The Goal
I want to create a small script that adds buttons dynamically, but still lets me perform functions on specific ones via root.
My Methods
I made this script.
It is capable of dynamically adding large buttons along the top. Each of these buttons slightly changes its own color when pressed.
It has two smalls buttons at the bottom. The first button dynamically adds new large buttons along the top.
The second button resets the color of the first large button on the top.
My Code
#!/usr/bin/env python3
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.widget import Widget
from kivy.uix.button import Button
from kivy.uix.floatlayout import FloatLayout
Builder.load_string('''
<RootWidget>:
Button:
text: 'Add'
size_hint: (None, None)
size: (40, 40)
pos: (40, 40)
group: 'action'
on_press: root.createNextTarget()
Button:
text: 'res'
size_hint: (None, None)
size: (40, 40)
pos: (100, 40)
group: 'action'
on_press: root.resetTarget()
''')
class RootWidget(FloatLayout):
def __init__(self, **kwargs):
super(RootWidget, self).__init__(**kwargs)
#note: self.ids isn't populated yet. I guess we can't use it yet.
self.createNextTarget()
def resetTarget(self):
f_target = self.ids['targetbutton0']
f_target.background_color = (1.0, 1.0, 1.0, 1.0)
return True
def countTargets(self):
return [str(x.__class__.__name__) for x in self.children if x != None].count('TargetButton')
def createNextTarget(self):
f_nextButton = TargetButton(id="targetbutton"+str(self.countTargets()),
size_hint=(None, None),
pos=(80 + (10 + 60) * self.countTargets(), 100),
size=(60, 60),
background_normal = '',
background_color = (1, 1, 1, 1),
group = 'target')
self.add_widget(f_nextButton)
f_nextButton.bind(on_press=TargetButton.lowerAllRGB)
class TargetButton(Button):
def __init__(self, **kwargs):
super(TargetButton, self).__init__(**kwargs)
def lowerAllRGB(self):
f_r, f_g, f_b, f_a = self.background_color
if f_r >= 0.1: f_r = f_r - 0.1
if f_g >= 0.1: f_g = f_g - 0.1
if f_b >= 0.1: f_b = f_b - 0.1
self.background_color = (f_r, f_g, f_b, f_a)
return True
class TestApp(App):
def build(self):
return RootWidget()
def on_stop(self):
print("TestApp.on_stop: finishing", self.root.ids)
if __name__ == '__main__':
TestApp().run()
The Problem
If I try to hit the reset button (that accesses the widget via root.ids), I get the error: KeyError: 'targetbutton0'
After finding a post about a similar problem, I thought root.ids just wouldn't work during RootWidget.__init__.
But when I use the button to add buttons after RootWidget.__init__ is finished, TestApp.on_stop() still prints:
TestApp.on_stop: finishing {}
So root.ids is still empty, and doesn't seem to include any dynamically added widgets despite me assigning an id attribute to each of them.
My questions to you
Given the way I am dynamically adding widgets, is using root.ids just worthless for my purposes?
Is there a decent way for me to access my widgets via id? I saw another question here asking something similar. But it didn't answer my question about dynamically added widgets.
Question 1 - root.ids / self.ids
Given the way I am dynamically adding widgets, is using root.ids just
worthless for my purposes?
Answer
id assigned to dynamically added widgets are not store in self.ids or root.ids. Therefore, you cannot access dynamically added widgets using self.ids['targetbutton0'] or self.ids.targetbutton0. If you do that, you will get a KeyError because it is not found in self.ids which is a dictionary type property.
When your kv file is parsed, Kivy collects all the widgets tagged with id’s and places them in this self.ids dictionary type property.
Note:
These type of id (i.e. id assigned to dynamically created widget) is deprecated and will be removed in a future Kivy version.
[WARNING] Deprecated property "<StringProperty name=id>" of object "<kivy.uix.button.Button object at 0x7feeec0968d0>" has been set, it will be removed in a future version
Question 2
Is there a decent way for me to access my widgets via id?
Solution
You could create your own list of ids of dictionary type property.
Snippets
from kivy.properties import DictProperty
class RootWidget(FloatLayout):
dynamic_ids = DictProperty({}) # declare class attribute, dynamic_ids
def __init__(self, **kwargs):
super(RootWidget, self).__init__(**kwargs)
self.createNextTarget()
def resetTarget(self):
f_target = self.dynamic_ids['targetbutton0']
f_target.background_color = (0.0, 1.0, 1.0, 1.0) # cyan colour
return True
...
def createNextTarget(self):
id = "targetbutton" + str(self.countTargets())
f_nextButton = TargetButton(id=id,
size_hint=(None, None),
pos=(80 + (10 + 60) * self.countTargets(), 100),
size=(60, 60),
background_normal = '',
background_color = (1, 1, 1, 1), # white colour
group = 'target')
self.add_widget(f_nextButton)
self.dynamic_ids[id] = f_nextButton
f_nextButton.bind(on_press=TargetButton.lowerAllRGB)
Output
Kivy 2.0 throws an error when you use id='value' when dynamically creating kivy widgets from python main file. But by using weak references you achieve the following success.
from kivy.uix.widget import Widget
from kivy.properties import ObjectProperty
from kivy.lang import Builder
from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.textinput import TextInput
import weakref
class MyLayout(Widget):
def use_weakref_id_to_replace_text(self, *args):
self.ids.AddUserTextBox.text = "shotta"
print("released and renamed the text to shotta")
def add_textinpt_with_weak_ref_dyn_id(self, *args):
print('Pressed and added text input box')
textinput = TextInput(pos=(380,380),text='123')
self.add_widget(textinput)
# We'll use a weak ref to add our dynamic id
self.ids['AddUserTextBox'] = weakref.ref(textinput)
class MdApp(App):
def build(self):
root = MyLayout()
Btn = Button(size=(250,250), pos=(100,100),text="Dynamic id assign n use id to rename")
Btn.bind(on_release=root.use_weakref_id_to_replace_text,on_press=root.add_textinpt_with_weak_ref_dyn_id)
root.add_widget(Btn)
return root
if __name__ == '__main__':
MdApp().run()
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 want to iterate through a list of button and bind each button with a different function. But the result is always the last Button's function, not all in the list.
Here's my code:
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.label import Label
from kivy.uix.stacklayout import StackLayout
from kivy.uix.button import Button
class MyApp(App):
def build(self):
parent = StackLayout()
button_list = []
for i in range(0,11):
button_list.append( Button(text = str(i), size_hint = (None,0.15)) )
print i
for a_button in button_list:
parent.add_widget(a_button)
a_button.bind( on_press = lambda x: parent.add_widget( Label(text = a_button.text) ) )
return parent
if __name__ == "__main__":
MyApp().run()
There is some problem with my lambda function, I guessed.
This is a classic python problem, not actually related to kivy. It is discussed e.g. here.
For those still running into this problem 6 years later, here is my solution:
def buttongenerator(layout):
hellodict = {}
for k in range(50):
hellodict[str(k)] = 'Hello' + str(k)
btn = Button(text=str(k),
size_hint_y=None,
height='40dp')
btn.bind(on_release=(lambda instance, var=hellodict[str(k)]: print(var)))
layout.add_widget(btn)
Layout simply refers to a grid/box layout.
The instance variable is necessary because otherwise the button object will be passed into the lambda function and (in this case) will be printed to the console as a string. The instance variable sort of "absorbs" the button object, if that makes any sense. (The variable does not have to be named instance, it just has to be present)