docs: notice animation object is passed with the event

[ghost]

No description provided.

[ghost]

Example:

w = Widget()
a = Animation(x=1000)
def print_args(*args):
    print(args)
a.bind(
    on_start=print_args,
    on_progress=print_args,
    on_complete=print_args
)
a.start(w)

=============

(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.1465397709980607)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.1534331459988607)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.16588143699846114)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.17838505399777205)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.1908281949981756)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.20334659199943417)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.21581643099852954)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.22831405099714175)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.2407946749990515)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.2533919479974429)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.260219440999208)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.27268102299785824)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.285232095997344)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.2977462849994481)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.31030450699836365)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.3228108949988382)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.3354002539999783)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.3478754029965785)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.36031426199770067)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.3727887219974946)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.3852826529982849)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.3977674540001317)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.4102624629995262)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.42282263999732095)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.43532545099878917)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.44778382199729094)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.4602193049977359)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.47266693199708243)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.48525814399908995)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.49771529599820497)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.5102443709984072)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.5226822099975834)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.5352391739979794)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.547696638997877)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.5547685559977253)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.5673034020001069)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.5798044049988675)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.5922853819974989)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.6047944069978257)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.6172746199990797)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.6297325429986813)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.6422370739965118)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.6547629439992306)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.667284318999009)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.6797533949975332)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.6921899789995223)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.704873624999891)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.717449346997455)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.7299417569993238)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.7423888449993683)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.7552126749978925)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.7677383049995115)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.7801801809982862)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.7928287849972548)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.8052480899968941)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.817778623997583)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.8303008819966635)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.8428246079965902)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.8552797109987296)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.867735238000023)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.8802291799984232)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.8926899009966291)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.9051774269973976)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.9177359479981533)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.9303297949991247)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.9427630809987022)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.9552047599972866)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.9676593349977338)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.9801272409968078)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 0.9925353069993434)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>, 1.0)
(<kivy.animation.Animation object at 0x7f96257e37c0>, <kivy.uix.widget.Widget object at 0x7f9625aace50>)