StackLayout + ScrollView trouble

[Carlos Vieira]

I'm at a loss, I can't get the StackLayout in the code below to stack its children properly. You can see in the image below there is no scroll bar in sight and the stack doesn't even start from the bottom.

It seems to stack fine if I remove "stack.size_hint_y = None". But as I understand it, that is necessary if I want scrolling to work (indeed, removing it makes it so the stacked widgets simply "overflow" to the right). Can anyone offer any insight? Thanks in advance.

Using python 3.6.5, Kivy v1.11.0.dev0

import kivy

kivy.require('1.11.0')

from kivy.app import App

from kivy.uix.stacklayout import StackLayout

from kivy.uix.scrollview import ScrollView

from kivy.uix.textinput import TextInput

class Arbrawf(App):

def build(self):

stack = StackLayout(orientation='bt-lr', padding=10, spacing=5)

# scrolling

stack.size_hint_y = None

stack.bind(minimum_height=stack.setter('height'))

for i in range(25):

stack.add_widget(TextInput(text=str(i), size_hint_y=None, height=35))

scroll = ScrollView(do_scroll_x=False)

scroll.add_widget(stack)

return scroll

if __name__ == '__main__':

Arbrawf().run()

[ZenCODE]

The scrollbar does not appear until it's needed. And here it is not. It's also hidden by default as it's not required on touch devices.  Look for the word scroll and read up here:

https://kivy.org/docs/api-kivy.config.html

Good luck

[Daniel kolim]

ScrollView + StackLayout - orientation='bt-lr'

To create a scrollable TextInput widgets stacking from bottom to top, and then left to right, do the following:

1. Set StackLayout size_hint_x to None because it is growing from left to right along x-axis
2. Bind StackLayout's width to minimum width
3. For each widget added dynamically,  set size_hint to (None, None)
4. Set ScrollView's size_hint to (None, None) and size to window's size (Window.width, Window.height)

ScrollView + StackLayout - orientation='rl-tb'

Please refer to my post at Scrollable menu list stacking from right to left, and then top to bottom

Example

import kivy
kivy.require('1.11.0')

from kivy.app import App
from kivy.uix.stacklayout import StackLayout
from kivy.uix.scrollview import ScrollView
from kivy.uix.textinput import TextInput

from kivy.core.window import Window


class Demo(App):
    title = "Kivy Scrollable StackLayout Orientation='bt-lr' Demo"

    def build(self):
        stack = StackLayout(orientation='bt-lr', padding=10, spacing=5)

        # scrolling

        stack.size_hint_x = None
        stack.bind(minimum_width=stack.setter('width'))

        for i in range(200):
            stack.add_widget(TextInput(text=str(i), write_tab=False, size_hint=(None, None), height=35))

        scroll = ScrollView(size_hint=(None, None), size=(Window.width, Window.height),
                            bar_width=10, bar_color=[0, 1, 0, 1], bar_inactive_color=[1, 0, 0, 1],
                            effect_cls="ScrollEffect", scroll_type=['bars'])

        scroll.add_widget(stack)
        return scroll


if __name__ == '__main__':

    Demo().run()

Output

[Carlos Vieira]

Daniel, thank you for the detailed answer! But what I intended, and should have made clear, was to have a sort of vertical Box Layout, but that stacks widgets from the bottom, instead of from the top. As you can see in the image below, that is perfectly possible, but I still haven't been able to make it so it continues to stack widgets up when inside a working Scroll View. If you or anyone else can shed some light on this on suggest some other way to go about it, I would be much obliged.

Thanks again

P.S. The image is reproducible from my original code by removing the "stack.size_hint_y = None" line and decreasing widgets being added.