haxe-react / react-native

React Native externs for Haxe
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How to handle animation style properties correctly #26

Open kiroukou opened 5 years ago

kiroukou commented 5 years ago

I needed to use an animatedValue for some fading animation.

The thing is that the animated component like AnimatedView etc have soem kind of magic to detect the animated properties and optimize it (more that a simple forceUpdate say the documentation).

The need is to use these like so :

<AnimatedView style=${[styles.main, {opacity: anim}]}>

So far, I got it working by 2 ways : change the externs from (eg ViewStyleProps) :

?opacity:Float

to

?opacity:haxe.extern.EitherType<Float, react.native.api.Animated.AnimatedValue>,

Or by forcing the update myself :

this.state.anim.addListener(onValueChange);

    function onValueChange(v:{value:Float}) {
        this.forceUpdate();
    }

That would be quite inelegant to change all the props so that they can be defined as animatable, so maybe we can do something else ? (abstract somewhere ?) What's your ideas? @kevinresol @back2dos @zabojad

kevinresol commented 5 years ago

I think AnimatedView should have its own Props instead of using View's one.

serjek commented 5 years ago

here is one way to get it, a bit dirty but it works: here you have both styles inlined <AnimatedView style=${cast ([styles.main, {opacity: anim}]:Array<Dynamic>)}>