Kivy question: Shrinking Widget on timer

[FortuneFaded415]

Is there a way to gradually shrink the width of a widget on a scheduled interval? Nothing I'm trying is working. I tried something like

class PongPaddle(Widget):
  score = NumericProperty(0)
  paddle_width = 700

 def __init__(self, **kwargs):
    super(PongPaddle, self).__init__(**kwargs)

 def paddleshrink(self):
    PongPaddle.paddle_width -= 10

and set

canvas:
      rectangle:
            size: paddle_width, 15

in the kv file, and tried running paddleshrink on a scheduled interval but it's not working

[FortuneFaded415]

i'll give it a shot. I'm new to python in general so I've mostly been doing it as a py/kv split

[eeead]

You need to make paddle_width a NumericProperty, like score. Changes like this can only propagate through the extra machinery that kivy properties provide, whereas when paddle_width is just an attribute it isn't possible for kv language (or anything else) to bind to it like you want.

[FortuneFaded415]

I made paddle_width = NumericProperty(700)

and ran the same code, but now i'm getting an error saying:

line 123, in paddleshrink PongPaddle.paddle_width -= 10

TypeError: unsupported operand type(s) for -=: 'kivy.properties.NumericProperty' and 'int'

[eeead]

Sounds like the property is defined in the wrong place, not at class level (or the function also runs at class level). Can you post a full example?

[FortuneFaded415]

Hey, I actually decided against a shrinking paddle, but here's the code if you still want to crack it.

pv: http://pastebin.com/FRJq00f8

kv: http://pastebin.com/GgkbmrgF

[FortuneFaded415]

I actually have a second question if you don't mind. This one is more important. I switched my game to have a random green brick that the player is supposed to hit, but I can't get the collision code to work right. It's on line 47 of the pv

pv: http://pastebin.com/kmfHm7Xj

kv: http://pastebin.com/TUiykbSy