Kivy on_textinput fix window patch

window_patch_example.py

from kivy.core.window.window_sdl2 import WindowSDL
from kivy.uix.floatlayout import FloatLayout
from kivy.properties import StringProperty
from kivy.core.window import Window
from kivy.app import runTouchApp
from kivy.logger import Logger
from kivy.lang import Builder
from kivy.clock import Clock
from time import time

K_TAB = 9
def patch_window():
    def new_release_keyboard(self, *largs):
        super(WindowSDL, self).release_keyboard(*largs)
        # We comment this out make the event work again
        #
        # self._win.hide_keyboard()
        
        self._sdl_keyboard = None
        return True
    WindowSDL.release_keyboard = new_release_keyboard
    Logger.warning('window_patch: patched kivy Window.release_keyboard')

class RootWidget(FloatLayout):
    scheduled_testing = False
    lbltext = StringProperty('Text from Window.on_textinput event:\n')
    last_text = StringProperty()
    last_key = StringProperty()
    instructions = StringProperty(
        'What is this supposed to do?: \n'
        '0: last_textinput label should be displaying your last input text\n'
        '1: text from window widget should display all input text\n'
        '\n\n'
        'Instructions:\n\n0: Press a few letters, '
        'notice that everything works\n'
        '1: Press TAB twice to toggle '
        'focus on TextInput widget\n'
        '2: Press a few more letters, '
        'notice that sdl2 on_textinput event is no longer received\n'
        '3: Press ctrl to apply window patch and toggle TextInput focus again\n'
        '4: Press a few letters, notice that everything is fixed'
    )

    def __init__(self, **kwargs):
        super(RootWidget, self).__init__(**kwargs)
        Window.bind(on_textinput=self.on_textinput)
        Window.bind(on_key_down=self.on_key_down)

    def on_textinput(self, _, text):
        Logger.info('RootWidget: on_textinput(%s)' % (text))
        self.lbltext += text
        self.last_text = text

    def on_key_down(self, _, k, *args):
        Logger.info('RootWidget: on_key_down(%s)' % (k))
        self.last_key = str(k)
        if k in (305, 306):
            patch_window()
        if k == K_TAB:
            tw = self.ids.textinput
            tw.focus = not tw.focus


runTouchApp(Builder.load_string('''
<AppLabel@Label>:
    markup: True
    text_size: self.width, None
    halign: 'left'
    valign: 'top'
    background_color: 0.2, 0.2, 0.2, 1
    canvas.before:
        Color:
            rgba: self.background_color
        Rectangle:
            pos: self.pos
            size: self.size

RootWidget:
    AppLabel:
        size_hint: 1, 0.5
        pos: 0, root.top - self.height
        text_size: self.size
        text: root.instructions

    AppLabel:
        text: 'Last textinput: %s' % (root.last_text)
        size_hint: 0.5, 0.1
        pos_hint: {'center_x': 0.25, 'center_y': 0.45}
        background_color: 0.4, 0.2, 0.2, 1

    AppLabel:
        text: 'Last key_down: %s' % (root.last_key)
        size_hint: 0.5, 0.1
        pos_hint: {'center_x': 0.75, 'center_y': 0.45}
        background_color: 0.2, 0.4, 0.2, 1

    AppLabel:
        text: root.lbltext
        size_hint: 1, 0.1
        pos_hint: {'center_x': 0.5, 'center_y': 0.35}
        text_size: self.size

    TextInput:
        id: textinput
        size_hint: 1, 0.3
        background_active: ''
        background_normal: ''
        background_disabled_normal: ''
        background_color: (0.7, 0.3, 0.3, 1) if self.focus else (0.9, 0.9, 0.9, 1)
        pos_hint: {'center_x': 0.5, 'center_y': 0.15}
        hint_text: 'TextInput widget'
'''))