I’ve an `IconButton` in a list item of a `LazyColu...

# compose

[lilypuchi]

I’ve an IconButton in a list item of a LazyColumn to which I pass Icon in two ways:
1. using painterResource() with my in app Image drawables (vector)

Icon(
    modifier = Modifier.size(16.dp),
    painter = painterResource(
        id = if (isLiked) R.drawable.ic_like_filled else R.drawable.ic_like
    ),
    contentDescription = null,
    tint = if (isLiked) AppTheme.colors.selected else AppTheme.colors.unselected
)

This leads to Recomposition of Icon.

2. using imageVector with MaterialIcons

Icon(
    modifier = Modifier.size(16.dp),
    imageVector = if (isLiked) Icons.Rounded.Favorite else Icons.Rounded.FavoriteBorder,
    contentDescription = null,
    tint = if (isLiked) AppTheme.colors.selected else AppTheme.colors.unselected
)

This skips Recomposition of Icon.

Internally both seem to using rememberVectorPainter() and I’m failing to see why painterResource internal implementation can cause a Recomposition. Am I missing something here? 🤔

(Attaching the recomposition counter screenshots for reference. Attached in order of the above cases)

[lilypuchi]

Here’s TalkLikeCount just in case

@Composable
fun TalkLikeCount(
    modifier: Modifier = Modifier,
    likesCount: Int,
    isLiked: Boolean = false,
    onLikeClicked: () -> Unit
) {
    IconButton(
        modifier = modifier,
        onClick = onLikeClicked
    ) {
        Row {
            Icon(..)

            Text(text = "$likesCount")
        }
    }
}

[Pedro Alberto]

@lilypuchi can you try this

val ResId =  if (isLiked) R.drawable.ic_like_filled else R.drawable.ic_like
Icon(ImageVector.vectorResource(id = ResId), contentDescription = "")

and let me know ?

[MR3Y]

This line https://cs.android.com/androidx/platform/frameworks/support/+/androidx-main:compose/ui/ui/src/androidMain/kotlin/androidx/compose/ui/res/PainterResources.android.kt;l=58?q=painterresource bubbles up the recomposition to the caller. if you still can't understand why? see: https://kotlinlang.slack.com/archives/CJLTWPH7S/p1649702961980989?thread_ts=1649700912.623109&cid=CJLTWPH7S

[lilypuchi]

Thanks a lot!