Question

I’ve recently started learning Kivy and using it. Today I’ve come across a problem that I’m not sure if it’s a bug in Kivy or a misunderstanding from my behalf. This is a simplified version.

I was working on a GUI that has a text input on top for searching. My Kv file looks like this:

#:kivy 1.0
#:import kivy kivy

<SearchPanel>:
    searchquery: searchquery

    AnchorLayout:
        orientation: 'vertical'
        anchor_x: 'center'
        anchor_y: 'top'
        padding: 10

        TextInput:
            id: searchquery
            text: 'What to search for'
            size_hint_x: 0.98
            size_hint_y: None
            height: 30
            on_enter: root.search()

The application code looks like this:

# -*- coding: utf-8 -*-
import kivy
kivy.require('1.4.1')

from kivy.app import App
from kivy.uix.anchorlayout import AnchorLayout


class SearchPanel(AnchorLayout):
    def search(self):
        pass


class ExampleApp(App):
    def build(self):
        return SearchPanel()


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

The problem is that when I run the app I get this traceback:

Traceback (most recent call last):
  File "example.py", line 24, in <module>
    ExampleApp().run()
  File "/home/testing/.virtualenvs/kivy2/local/lib/python2.7/site-packages/Kivy-1.4.1-py2.7-linux-x86_64.egg/kivy/app.py", line 523, in run
    root = self.build()
  File "example.py", line 20, in build
    return SearchPanel()
  File "/home/testing/.virtualenvs/kivy2/local/lib/python2.7/site-packages/Kivy-1.4.1-py2.7-linux-x86_64.egg/kivy/uix/anchorlayout.py", line 62, in __init__
    super(AnchorLayout, self).__init__(**kwargs)
  File "/home/testing/.virtualenvs/kivy2/local/lib/python2.7/site-packages/Kivy-1.4.1-py2.7-linux-x86_64.egg/kivy/uix/layout.py", line 60, in __init__
    super(Layout, self).__init__(**kwargs)
  File "/home/testing/.virtualenvs/kivy2/local/lib/python2.7/site-packages/Kivy-1.4.1-py2.7-linux-x86_64.egg/kivy/uix/widget.py", line 113, in __init__
    Builder.apply(self)
  File "/home/testing/.virtualenvs/kivy2/local/lib/python2.7/site-packages/Kivy-1.4.1-py2.7-linux-x86_64.egg/kivy/lang.py", line 1217, in apply
    self._apply_rule(widget, rule, rule)
  File "/home/testing/.virtualenvs/kivy2/local/lib/python2.7/site-packages/Kivy-1.4.1-py2.7-linux-x86_64.egg/kivy/lang.py", line 1346, in _apply_rule
    crule, idmap)})
  File "_event.pyx", line 184, in kivy._event.EventDispatcher.bind (/tmp/easy_install-PMy51_/Kivy-1.4.1/kivy/_event.c:2038)
KeyError: 'enter'

Apparently I cannot plug in on_enter callback to the root layout, what am I doing wrong? If I change on_enter with on_text it works.

Answer 1

Ok, I figured out that on_enter is not a TextInput event.

Instead you need to use on_text_validate which only works with monoline text inputs. Or you can bind your widget’s on_text_validate to an on_enter function or method if you prefer it.