LazyColumnFor does not scroll smoothly as ScrollableColumn [168293643]

Fixed

Bug

Status Update

No update yet.

Description

gs...@gmail.com

created issue #1

Sep 12, 2020 01:39PM

Android Studio Build: Android Studio Canary 9
Version of Gradle Plugin: gradle:4.2.0-alpha09
OS: Android 9

Compose version : 1.0.0-alpha02
Kotlin compiler: 1.4.0

Problem

When I use LazyColumnFor and try to drag all the list to the end or do a fast drag between items it seems like its choppy and not smooth, if I drag till the end it will glitch on the last item

Example

@Composable
fun RecipeColumnListDemo(recipeList:List<Recipe>){
LazyColumnFor(items = recipeList) { item ->
RecipeCard(recipe = item)
}
}

where RecipeCard(recipe) loads images sincronously

@Composable
private fun RecipeCard(recipe: Recipe){
val image = imageResource(R.drawable.header)
Surface(shape = RoundedCornerShape(8.dp),elevation = 8.dp,modifier = Modifier.padding(8.dp)) {
Column(modifier = Modifier.padding(16.dp)) {
val imageModifier = Modifier.preferredHeight(150.dp).fillMaxWidth().clip(shape = RoundedCornerShape(8.dp))
Image(asset = image,modifier = imageModifier,contentScale = ContentScale.Crop)
Spacer(modifier = Modifier.preferredHeight(16.dp))
Text(text = recipe.title,style = typography.h6)
for(ingredient in recipe.ingredients){
Text(text = "* $ingredient",style = typography.body2)
}
}
}
}

I have also changed the way I load images with loadImageResource, but its also not a smooth scroll when I fast drag to the end of the list

Is this issue on my side ?

I have tried JetChat and it uses a ScrollableColumn which the scrolling is smoother than the the LazyColumnFor

Video:

https://drive.google.com/file/d/1RniEokUmaVlehvMBRNjMPZS9AgIXkVZI/view?usp=sharing

Comments

gs...@gmail.com <gs...@gmail.com> #2Sep 12, 2020 03:59PM

Hi,

I also see my text cut off when I set maxLines = 2. Is it the same issue?

  Box(
    modifier =
      Modifier.size(
        width = 108dp,
        height = 34dp,
      ),
    contentAlignment = Alignment.Center,
  ) {
    BasicText(
      text = "text text text",
      maxLines = 2,
      autoSize = AutoSize.StepBased(minFontSize = 1.sp, maxFontSize = 13.sp, stepSize = 0.2.sp),
    )
  }

cl...@google.com <cl...@google.com> Sep 14, 2020 09:25AM

Assigned to an...@google.com.

an...@google.com <an...@google.com> #3Sep 14, 2020 01:19PM

Project: platform/frameworks/support
Branch: androidx-main
Author: Jossi Wolf <jossiwolf@google.com>
Link: https://android-review.googlesource.com/3450389

Fix TextAutoSize bug with maxLines = 1

Expand for full commit details

Fix TextAutoSize bug with maxLines = 1 
 
We were overcaching the paragraphIntrinsics in MultiParagraphLayoutCache when mutating the style. For `AutoSizeStepBased` instances with biased windows (more values smaller/bigger than the optimal), this could result in performing layout with outdated intrinsics, and thus an outdated style and font size, without surfacing this in the TextLayoutResult. 
 
Test: New MultiParagraphLayoutCacheTests and manual testing 
Relnote: Fixed a bug in BasicText with TextAutoSize and maxLines set to 1. 
Fixes: 376834366 
 
Change-Id: Ic0450c763c5d764492995b44ee1fe570246a9689

Files:

M compose/foundation/foundation/src/androidInstrumentedTest/kotlin/androidx/compose/foundation/text/modifiers/MultiParagraphLayoutCacheTest.kt
M compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/text/modifiers/MultiParagraphLayoutCache.kt

Hash: e1b712d78cc60384ed67a56c006148291ba146a6
Date: Tue Jan 07 18:52:26 2025

gs...@gmail.com <gs...@gmail.com> #4Sep 14, 2020 01:30PM

#2, yeah, that's the same issue.

ap...@google.com <ap...@google.com> #5Sep 23, 2020 11:17AM

Thanks @jo...@google.com for fixing this! Do you know when the fix would be available for g3 apps?

ap...@google.com <ap...@google.com> #6Oct 6, 2020 12:21PM

Moving the internal discussion offline. The bug is fixed and the fix available in snapshot builds. We will comment on this issue when the bug fix is included in a release.

an...@google.com <an...@google.com> #7Oct 7, 2020 02:06PM

Marked as fixed.

The following release(s) address this bug.It is possible this bug has only been partially addressed:

androidx.compose.foundation:foundation:1.8.0-beta01
androidx.compose.foundation:foundation-android:1.8.0-beta01
androidx.compose.foundation:foundation-jvmstubs:1.8.0-beta01
androidx.compose.foundation:foundation-linuxx64stubs:1.8.0-beta01

al...@mercari.com <al...@mercari.com> #8Oct 20, 2020 01:12PM

Thanks for your efforts improving the performance of the lazy lists! I was able to observe some improvements.

However it's still slow from my testing on alpha05. I tried removing the image loading (which I was loading with Glide) and just replaced them with Box(Modifier.background(DsToken.colors.backgroundSecondary) and the )(slow) performance is around the same for the initial scroll.

It seems, when all items have been rendered, it starts to scroll smoothly. So I supposed there's something slow with the initial composition for each of the lazy item. Before, the scrolling was just slow throughout the whole app session.

Message last modified on Oct 20, 2020 01:14PM

an...@google.com <an...@google.com> #9Oct 20, 2020 01:21PM

yes, the composition itself is still quite slow. so we do pretty much a lot of work every time we need to compose a new item.
maybe if you can create a working repro sample app which I can check out and debug more?