Problem when trying to create a left-aligned text using kivy

Question

I'm fairly new to Kivy, I've made a few small apps and stuff like that, but now I'm having a problem trying to create left-aligned typing effect text.

My idea was to have the text appear on the corner of the screen, similar to a terminal (I'll leave an example image taken from Pydroid). I was able to achieve this with static text, but for my project, I also needed a typing effect, which I also managed to implement. However, when trying to combine the two, I couldn't get the text to align to the left. It always stays in the middle.

My code:

from kivy.app import App
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.label import Label
from kivy.clock import Clock

class MyLabel(Label):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.text_to_type= self.text

        self.text = ""
 
        Clock.schedule_interval(self.type_text, 0.05)

    def type_text(self, txt):
        if len(self.text) < len(self.text_to_type):
            self.text += self.text_to_type[len(self.text)]



class Example(App):
    def build(self):             
        self.root = FloatLayout()
        self.root.add_widget(MyLabel(text='''
That's a typing text!


And I'm trying to make it aligned!''',
        size_hint=(1.0, 1.0),
        halign="left",
        valign="bottom"))

        return self.root

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

How could I make it align to the left, looking like the example photo I posted? Thanks in advance!

Pydroid example What am I getting

Answer 1

You need to set the text_size property of the Label in order for the alignment to work (see the documentation). Here is a modified version of your code that does that:

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.label import Label
from kivy.clock import Clock


class MyLabel(Label):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.text_to_type = self.text

        self.text = ""

        Clock.schedule_interval(self.type_text, 0.05)

    def type_text(self, txt):
        if len(self.text) < len(self.text_to_type):
            self.text += self.text_to_type[len(self.text)]

kv = '''
<MyLabel>:
     size_hint: (1.0, 1.0)
     text_size: self.size
     halign: "left"
     valign: "bottom"
'''


class Example(App):
    def build(self):
        Builder.load_string(kv)
        self.root = FloatLayout()
        self.root.add_widget(MyLabel(text='''
That's a typing text!


And I'm trying to make it aligned!'''))

        return self.root


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