I was wondering if there has been any recent optimization of the scrolling behavior of the `LazyColu...

# compose

[Chachako]

I was wondering if there has been any recent optimization of the scrolling behavior of the LazyColumn. I compared it today to RecyclerView and it's really bad...

[Halil Ozercan]

There have been several patches that included optimizations to LazyColumn and those will sure continue. The best thing we developers can do is sharing our findings with the team. Would you be able to share your comparison code with the RecyclerView?

[romainguy]

We are working on various optimizations for this and other use cases. But please keep feedback coming

[Samir Basnet]

Yup it still needs a lot more optimization. The scrolling is not smooth even for a simple list layout

[Timo Drick]

In my experience the LazColumn do compete well with recyclerview. So it would be nice if you could provide samples where it does have problems. But i do not see really improvements from beta01 to beta05.
Here is a sample from my "Pixel 3a" (Without recording it is most of the time under the green line).

device-2021-04-25-022822.mp4

[Chachako]

@Halil Ozercan @romainguy They are the lists displayed by RecyclerView (1) and LazyColumn (2) respectively.

Just fill the LazyColumn with a randomly generated list:

val tests by lazy {
  (0..400).map {
    val length = (2..15).random()
    val allowedChars = ('A'..'Z') + ('a'..'z') + ('0'..'9')
    val prefix = if (length < 5) "." else ""
    val suffix = if (length > 7) ".${(1..5).map { allowedChars.random() }}" else ""
    val name = prefix + (1..length)
      .map { allowedChars.random() }
      .joinToString("") + suffix
    val isDirectory = (0..1).random() == 1

    FileItem(
      name = name,
      time = abs(System.currentTimeMillis() - Random().nextLong()).asMilliInstant().format("yyyy-MM-dd HH:mm"),
      size = (0L..1855425871872L).random().toReadableSize(),
      isDirectory = isDirectory
    )
  }
}

Android.mp4Compose.mp4