LazyList and LazyGrid hijacker

LazyColumn is a very useful component of the compose ecosystem. It's the somewhat equivalent of RecyclerView from the view / XML world. However, it has a huge problem when it comes to changing the order of the list items, which was reported a few years ago first and it's yet to be fixed. This library is supposed to provide a quickfix for this until the official implementation gets fixed.

The solution works with any LazyList implementation, such as LazyColumn and LazyRow, as well as LazyGrid.

Install

Add the following dependency to your module build.gradle.kts file:

implementation("me.gingerninja.lazylist:hijacker:1.1.0")

If you are using Gradle instead of Kotlin DSL, add it to your module build.gradle file:

implementation "me.gingerninja.lazylist:hijacker:1.1.0"

Usage

You can get the hijacker instance for the LazyListState by calling

val hijacker = rememberLazyListStateHijacker(listState = listState)

or if you don't want to auto-enable it just yet (for whatever reason):

val hijacker = rememberLazyListStateHijacker(listState = listState, enabled = false)

It also works with LazyGrid:

val hijacker = rememberLazyGridStateHijacker(gridState = gridState)
// or if you don't want to auto-enable it just yet (for whatever reason):
// val hijacker = rememberLazyGridStateHijacker(gridState = gridState, enabled = false)

The returned instance can be controlled by its enabled flag:

hijacker.enabled = true // enable the hijacked implementation

hijacker.enabled = false // disable the hijacked implementation

Example

// create the LazyListState the usual way
val listState = rememberLazyListState()

// the magic happens here
rememberLazyListStateHijacker(listState = listState, enabled = true)

// use the LazyColumn as usual
LazyColumn(
    state = listState
) {
    // ...
}

ProGuard / R8

The library contains the ProGuard rules necessary for it to work with reflection, but in case you need them separately, here they are:

Lists

-keepclassmembers class androidx.compose.foundation.lazy.LazyListState {
    private androidx.compose.foundation.lazy.LazyListScrollPosition scrollPosition;
}

-keepclassmembers class androidx.compose.foundation.lazy.LazyListScrollPosition {
    private androidx.compose.runtime.MutableIntState index$delegate;
    private java.lang.Object lastKnownFirstItemKey;
}

Grids

-keepclassmembers class androidx.compose.foundation.lazy.grid.LazyGridState {
    private androidx.compose.foundation.lazy.grid.LazyGridScrollPosition scrollPosition;
}

-keepclassmembers class androidx.compose.foundation.lazy.grid.LazyGridScrollPosition {
    private androidx.compose.runtime.MutableIntState index$delegate;
    private java.lang.Object lastKnownFirstItemKey;
}

Compatibility

This lib was tested against the latest versions of the compose-foundation artifact, namely 1.5.3 and 1.6.2, but should work with earlier versions as well.

This library works only on the JVM as it relies on Java Reflection.