How to move an image with keyboard in Kivy?

Question

I am simply trying to move an image from left to right using the keyboard keys. I tried making a class called movableImage that inherits from Image. I think this is where I did something wrong, specifically the init function. When I run the code below I am getting AttributeError: 'function' object has no attribute 'widget' on line 16. What am I doing wrong here?

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.image import Image
from kivy.input.motionevent import MotionEvent
from kivy.core.window import Window


class character(Widget):
    pass

class moveableImage(Image):
    def __init__(self, **kwargs):
        super(moveableImage, self).__init__(**kwargs)
        self._keyboard = Window.request_keyboard
        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)

    def on_keyboard_down(self, keyboard, keycode, text, modifiers):
        if keycode[1] == 'left':
            print keycode #move littleguy to the left
        elif keycode[1] == 'right':
            print keycode #move littleguy to the right
        return True

littleguy = moveableImage(source='selectionscreen/littleguy.zip', anim_available=True, anim_delay=.15)

class gameApp(App):
    def build(self):
        m = character()
        m.add_widget(littleguy)
        return m


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

I should also add that I HAVE read the Kivy keyboardlistener example and I am still stuck.

Answer 1

Here's a working example of what you're trying to do, just run it and use the right / left arrow keys to move it right / left:

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.image import Image
from kivy.core.window import Window


class character(Widget):
    pass


class MoveableImage(Image):

    def __init__(self, **kwargs):
        super(MoveableImage, self).__init__(**kwargs)
        self._keyboard = Window.request_keyboard(None, self)
        if not self._keyboard:
            return
        self._keyboard.bind(on_key_down=self.on_keyboard_down)

    def on_keyboard_down(self, keyboard, keycode, text, modifiers):
        if keycode[1] == 'left':
            self.x -= 10
        elif keycode[1] == 'right':
            self.x += 10
        else:
            return False
        return True


class gameApp(App):
    def build(self):
        wimg = MoveableImage(source='tools/theming/defaulttheme/slider_cursor.png')
        m = character()
        m.add_widget(wimg)
        return m


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

The problem you ran into, is that request_keyboard is a function, and needs to be called that way. You can also remove the if self._keyboard.widget: part.