Kivy - base application has strange alignment

Question

I am trying to build a basic Kivy app. After adding the basic elements, and running the app, all of the elements are crammed into the bottom left corner. It shows up like th

Answer 1

I recently wrote a post of a little trick I use when I am programming interfaces. The trick will let you see a border around all the widgets (layouts included) you add to the screen. This would be the result for your code:

It takes advantage of inheritance and the Kivy rules to overwrite the base class of all widgets. You just have to add:

<Widget>:
    canvas.after:
        Line:
            rectangle: self.x+1,self.y+1,self.width-1,self.height-1

at the beginning of this file:

<SublimeLauncher>:
    FloatLayout:
        BoxLayout:
            orientation: 'vertical'
            spacing: 10
            Label:
                text: "Enter the path to the folder to open.\nPress OK if you would like to open without a directory"
            TextInput:
                id: folderpath
            Button:
                text: 'OK'

Answer 2

Your layout has a default size of 100x100 pixels. You can try to color it to see how much space does it take:

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.lang import Builder

kv = '''
<SublimeLauncher>:
    BoxLayout:
        canvas:
            Color:
                rgb: 1, 0, 0
            Rectangle:
                size: self.size
        orientation: 'vertical'
        spacing: 10
        Label:
            text: "Enter the path to the folder to open.\\nPress OK if you would like to open without a directory"
        TextInput:
            id: folderpath
        Button:
            text: 'OK'
'''
Builder.load_string(kv)

class SublimeLauncher(Widget):
    pass

class SublimeLauncherApp(App):
    def build(self):
        return SublimeLauncher()

if __name__ == "__main__":
    SublimeLauncherApp().run()

Setting non-default size:

kv = '''
<SublimeLauncher>:
    BoxLayout:
        size: 250, 250
        canvas:
            Color:
                rgb: 1, 0, 0
            Rectangle:
                size: self.size
        orientation: 'vertical'
        spacing: 10
        Label:
            text: "Enter the path to the folder to open.\\nPress OK if you would like to open without a directory"
        TextInput:
            id: folderpath
        Button:
            text: 'OK'
'''
Builder.load_string(kv)

Taking full space:

kv = '''
<SublimeLauncher>:
    BoxLayout:
        size: root.size
        canvas:
            Color:
                rgb: 1, 0, 0
            Rectangle:
                size: self.size
        orientation: 'vertical'
        spacing: 10
        Label:
            text: "Enter the path to the folder to open. \\nPress OK if you would like to open without a directory"
        TextInput:
            id: folderpath
        Button:
            text: 'OK'
'''
Builder.load_string(kv)

Answer 3

As your root widget is not a layout (you made SublimeLauncher inherit Widget), it doesn't set its children size/positions. So your FloatLayout have the defaults, since you don't override them manually either.

pos: 0, 0
size: 100, 100

And these defaults of course constraints the child, since FloatLayout by constraint their size based on their size_hint property.

You want to give them more space, as Nykakin pointed out.

Also, as your text is bigger than the Label (you didn't set halign and text_size either) its texture is centered on the center of the Label, and so some part of it is out of screen. You want to have a look at kivy/examples/widgets/textalign.py