Using Animated Values ​​in List Rendering

[pioner92]

How can I use the values useSharedValue or useDerivedValue inside list rendering if I need to consider the index in these values, and have the ability to refer to the actual size of the canvas from "const canvasSize = useSharedValue" during calculations? Previously, it was possible to use "Selector", but how can such a result be achieved now? Using usePathValue does not allow manipulating the shape color based on the index.

I'm making this progress component

Here is a rough code example.

   const ITEMS_COUNT = 5
   const OFFSET = 10

    const canvasSize = useSharedValue({
      width: CANVAS_WIDTH,
      height: HEIGHT,
    })

----
<Canvas onSize={canvasSize} style={s.container}>
       {steps.map((el, index) => (
       <Fragment key={index}>
           {percentStep > index ? (
                <Rect x={Selector(canvasSize,(c)=>(c.width / ITEMS_COUNT) * index + OFFSET )} 
                    y={10} 
                    width={Selector(canvasSize,(c)=>c.width + OFFSET )} 
                    height={HEIGHT / 2}
                >
                  <BlurMask blur={5} style={'normal'} />
                </Rect>
              ) : null}
              <RoundedRect
                  x={Selector(canvasSize,(c)=>(c.width / ITEMS_COUNT) * index + OFFSET )}
                  r={ITEM_RADIUS}
                  width={Selector(canvasSize,(c)=>c.width + OFFSET )}
                  y={0}
                  height={HEIGHT}
                  color={progress < el ? '#DDE4FA' : 'red'}
              />
         </Fragment>
          ))}
</Canvas>

[wcandillon]

here you would simply need to make a component for this and use a useDerivedValue where you would have your Selector

…

On Fri, Feb 9, 2024 at 8:59 AM Alex Shumihin ***@***.***> wrote: How can I use the values useSharedValue or useDerivedValue inside list rendering if I need to consider the index in these values, and have the ability to refer to the actual size of the canvas from "const canvasSize = useSharedValue" during calculations? Previously, it was possible to use "Selector", but how can such a result be achieved now? Using usePathValue does not allow manipulating the shape color based on the index. I'm making this progress component 2024-02-09.08.54.15.png (view on web) <https://github.com/Shopify/react-native-skia/assets/53976385/4258e02b-596d-4f9e-be18-143f9600b1c3> Here is a rough code example. const ITEMS_COUNT = 5 const OFFSET = 10 const canvasSize = useSharedValue({ width: CANVAS_WIDTH, height: HEIGHT, }) ----<Canvas onSize={canvasSize} style={s.container}> {steps.map((el, index) => ( <Fragment key={index}> {percentStep > index ? ( <Rect x={Selector(canvasSize,(c)=>(c.width / ITEMS_COUNT) * index + OFFSET )} y={10} width={Selector(canvasSize,(c)=>c.width + OFFSET )} height={HEIGHT / 2} > <BlurMask blur={5} style={'normal'} /> </Rect> ) : null} <RoundedRect x={Selector(canvasSize,(c)=>(c.width / ITEMS_COUNT) * index + OFFSET )} r={ITEM_RADIUS} width={Selector(canvasSize,(c)=>c.width + OFFSET )} y={0} height={HEIGHT} color={progress < el ? '#DDE4FA' : 'red'} /> </Fragment> ))}</Canvas> — Reply to this email directly, view it on GitHub <#2211>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AACKXVVAH7CXR3EHEYAK5GLYSXJNRAVCNFSM6AAAAABDBBHK3OVHI2DSMVQWIX3LMV43ERDJONRXK43TNFXW4OZWGE4TQNJTGE> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[pioner92]

@wcandillon

if I have 10 elements, and the offset depends on the size of the canvas and the index of this element, how do I calculate this using the index and useDerivedValue ?
if I count everything in useDerivedValue
then for the component I will have to use
derivedArray.value[index] means that when the canvas size is updated, these values ​​will not be updated for the component

const offsetsArray = useDerivedValue(()=>{
   const itemWidth = canvasSize.value.width / steps.length
   return  steps.map((s,index)=> (itemWidth + SOME_SPACE) * index))
},[canvasSize])
....
steps.map((el,index)=>
...
 <RoundedRect
  x={offsetsArray.value[index]}
....

[wcandillon]

that‘s a good point. you can use „notigyChange(value)“ to let reanimated now that something has changed

…

On Fri 9 Feb 2024 at 09:57, Alex Shumihin ***@***.***> wrote: @wcandillon <https://github.com/wcandillon> if I have 10 elements, and the offset depends on the size of the canvas and the index of this element, how do I calculate this using the index and useDerivedValue ? if I count everything in useDerivedValue then for the component I will have to use derivedArray.value[index] means that when the canvas size is updated, these values ​​will not be updated for the component const offsetsArray = useDerivedValue(()=>{ const itemWidth = canvasSize.value.width / steps.length return steps.map((s,index)=> (itemWidth + SOME_SPACE) * index))},[canvasSize])....steps.map((el,index)=> ... <RoundedRect x={offsetsArray.value[index]} .... — Reply to this email directly, view it on GitHub <#2211 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AACKXVSTQWAYXHOBMUGFZH3YSXQGDAVCNFSM6AAAAABDBBHK3OVHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM4DIMJWGQZDK> . You are receiving this because you were mentioned.Message ID: ***@***.*** com>

[pioner92]

in this way?

const offsetsArray = useDerivedValue(()=>{
   const itemWidth = canvasSize.value.width / steps.length

   notifyChange(canvasSize) // HERE

   return  steps.map((s,index)=> (itemWidth + SOME_SPACE) * index))
},[canvasSize])

[pioner92]

It seems that it won't be possible to update this here.

 <RoundedRect
  x={offsetsArray.value[index]}