scroll

scroll.py

from kivy.app import runTouchApp
from kivy.lang import Builder
from kivy.uix.textinput import TextInput


class TabTextInput(TextInput):

    def __init__(self, *args, **kwargs):
        super(TabTextInput, self).__init__(*args, **kwargs)

    def keyboard_on_key_down(self, window, keycode, text, modifiers):
        key, key_str = keycode
        if key is not 8:
            if key is 13 or self.cursor_col == 20:
                self.insert_text('\n')
                self.add_line()
                return False
        else:
            if self.cursor_col==0 and self.cursor_row>0:
                self.remove_line()
        return super(TabTextInput, self).keyboard_on_key_down(window, keycode, text, modifiers)

    def add_line(self):
        self.height += self.line_height

    def remove_line(self):
        self.height -= self.line_height

    def do_scroll(self, sv):
        parent = self.parent
        if not parent.height:
            return
        offset = self.height - (self.cursor[1] + 1) * self.line_height - self.padding_y[0]
        for sib in parent.children:
            if sib == self:
                break
            offset += sib.height
        scroll = offset / float(parent.height - sv.height)
        if sv.scroll_y > scroll:
            sv.scroll_y = offset / float(parent.height - sv.height)


runTouchApp(Builder.load_string("""
BoxLayout:
    orientation: 'vertical'
    ScrollView:
        id: sv
        on_scroll_y: print(self.scroll_y)
        GridLayout:
            cols: 1
            size_hint_y: None
            height: self.minimum_height
            on_height: tx1.do_scroll(sv) if tx1.focus else tx2.do_scroll(sv)
            TabTextInput:
                id: tx1
                font_size: 25
                size_hint_y: None
                height: self.line_height * 3 / 2.
            TabTextInput:
                id: tx2
                font_size: 25
                size_hint_y: None
                height: self.line_height * 3 / 2.
    Button:
        id: button_id
        size_hint_y: .5
        text: 'Keyboard'
        font_size: 120
        color: 0,0,0,1
"""))