Python : Close popup using enter key

Question

How to dismiss popup.dismiss() using enter key. when i run test.py after click on ok button then open a popup.
Can someone tell me how to close popup using enter key and after close popup set focus=True into name TextInput.

test.py

import kivy

kivy.require('1.9.0')  # replace with your current kivy version !
from kivy.uix.screenmanager import Screen
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput
from kivy.lang import Builder
from kivy.uix.widget import Widget
from kivy.uix.popup import Popup
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.core.window import Window
from kivy.uix.boxlayout import BoxLayout

Window.size = (500, 150)


class TestScreen(Screen):

    def insert_data(self):
        Alert(title='yeah!', text='inputs are invalid')

class Alert(Popup):

    def __init__(self, title, text):
        super(Alert, self).__init__()

        box = BoxLayout(orientation='vertical', padding=(5))
        box.add_widget(Label(text=text))
        btn1 = Button(text="Close")
        box.add_widget(btn1)

        popup = Popup(title=title, title_size=(30),
                      title_align='center', content=box,
                      size_hint=(None, None), size=(300, 200),
                      auto_dismiss=True)

        btn1.bind(on_press=popup.dismiss)
        popup.open()


class Test(App):
    def build(self):
        self.root = Builder.load_file('test.kv')
        return self.root



if __name__ == '__main__':
    Test().run()

test.kv

TestScreen:

    GridLayout:
        cols: 2
        padding: 30, 30
        spacing: 10, 10
        row_default_height: '30dp'

        Label:
            text: 'Name'
            text_size: self.size
            valign: 'middle'
            #padding_x: 50

        TextInput:
            id: name

        Button:
            text: 'Ok'
            on_press: root.insert_data()

        Button:
            text: 'Cancel'
            on_press: app.stop()

Answer 1

In the example below, the following steps were done:

1. Use Keyboard interface that is returned by WindowBase.request_keyboard() to detect ENTER or NUMPENTERPAD key pressed.
2. Use an ObjectProperty to hook up to the TextInput.
3. Set auto_dismiss to False so that we invoke dismiss_callback method to give focus to TextInput (id: name) when the popup dismiss.
4. Class Alert is already a Popup widget, and you don't want to create another popup.

it is generally regarded as ‘best practice’ to use the ObjectProperty. This creates a direct reference, provides faster access and is more explicit.

Example

main.py

from kivy.uix.screenmanager import Screen
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.popup import Popup
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.core.window import Window
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import ObjectProperty

Window.size = (500, 150)


class TestScreen(Screen):
    name = ObjectProperty(None)

    def insert_data(self):
        Alert(title='yeah!', text='inputs are invalid')


class Alert(Popup):

    def __init__(self, title, text):
        super(Alert, self).__init__()
        self._keyboard = Window.request_keyboard(
            self._keyboard_closed, self, 'text')
        if self._keyboard.widget:
            # If it exists, this widget is a VKeyboard object which you can use
            # to change the keyboard layout.
            pass
        self._keyboard.bind(on_key_down=self._on_keyboard_down)

        box = BoxLayout(orientation='vertical', padding=(5))
        box.add_widget(Label(text=text))
        btn1 = Button(text="Close")
        box.add_widget(btn1)

        self.title = title
        self.title_size = 30
        self.title_align = 'center'
        self.content = box
        self.size_hint = (None, None)
        self.size = (300, 200)
        self.auto_dismiss = False

        btn1.bind(on_press=self.dismiss_callback)
        self.open()

    def _keyboard_closed(self):
        self._keyboard.unbind(on_key_down=self._on_keyboard_down)
        self._keyboard = None

    def _on_keyboard_down(self, keyboard, keycode, text, modifiers):
        if keycode[1] in ('enter', 'numpadenter'):
            print("keycode=", keycode)
            self.dismiss_callback()

        # Keycode is composed of an integer + a string
        # If we hit escape, release the keyboard
        if keycode[1] == 'escape':
            keyboard.release()

        # Return True to accept the key. Otherwise, it will be used by
        # the system.
        return True

    def dismiss_callback(self, instance=None):
        self.dismiss()
        App.get_running_app().root.name.focus = True


class Test(App):
    def build(self):
        self.root = Builder.load_file('test.kv')
        return self.root


if __name__ == '__main__':
    Test().run()

Output