Sticky Headers doesn't shows in Expandable Sectionable Header, just view glitch

Hi there. I’m facing with trouble. Trying to add sticky header to a multi expand list and wanna show top level header item as sticky but sticky header doesn’t shows just small glitch\twitch on scrolling back to this item. RecyclerView wrapped with FrameLayout. Idk whats wrong or its just a bug. Please help. The code listed below

Adapter init

FlexibleAdapter(emptyList(), this, true)
                .setDisplayHeadersAtStartUp(true)
                .setUnlinkAllItemsOnRemoveHeaders(true)
                .setStickyHeaders(true)

Item

class ItemStructureUnit(val id: String,
                               @IntRange(from = 0, to = 9) val userExpandLevel: Int)
    : AbstractExpandableItem<ItemStructureUnit.ViewHolder, ItemStructureUnit>(),
        IHeader<ItemStructureUnit.ViewHolder>, ISectionable<ItemStructureUnit.ViewHolder, ItemStructureUnit> {
    class ViewHolder(view: View?, adapter: FlexibleAdapter<out IFlexible<*>>?, isSticky: Boolean) : ExpandableViewHolder(view, adapter, isSticky)

    private var header: ItemStructureUnit? = null

    override fun bindViewHolder(adapter: FlexibleAdapter<IFlexible<RecyclerView.ViewHolder>>?, holder: ViewHolder, position: Int, payloads: MutableList<Any>?) {
%binding%
    }

    override fun getHeader() = header

    override fun setHeader(header: ItemStructureUnit?) {
        this.header = header
    }

    override fun getExpansionLevel() = userExpandLevel

    override fun equals(other: Any?) = other is ItemStructureUnit && other.id == id

    override fun createViewHolder(view: View?, adapter: FlexibleAdapter<IFlexible<RecyclerView.ViewHolder>>?) = ViewHolder(view, adapter, userExpandLevel == 0)

    override fun getLayoutRes() = R.layout.item_structure_unit

    override fun hashCode(): Int {
        var result = id.hashCode()
        result = 31 * result + userExpandLevel
        return result
    }
}

Items creation:

   val header = ItemStructureUnit(UUID.randomUUID().toString(), 0)
   generateItemInDepth(header, depth = 9)

   private fun generateItemInDepth(item: ItemStructureUnit, height: Int = 1, depth: Int = 9) {
           if (depth == 1) {
               return
           }
           for (i in 0..height) {
               val subItem = ItemStructureUnit(UUID.randomUUID().toString(),
                       MAX_DEPTH - depth,/*expansion level*/
                       this).apply { header = item }
               generateItemInDepth(subItem, depth = depth - 1)
               item.addSubItem(subItem)
           }
     }

Logs:

D/StickyHeaderHelper: swapHeader newHeaderPosition=0
D/StickyHeaderHelper: clearHeader
D/StickyHeaderHelper: swapHeader newHeaderPosition=2
D/StickyHeaderHelper: clearHeader
V/FlexibleAdapter: onViewBound    viewSize=16 ViewHolder ViewHolder{fce59c8 position=0 id=612776204, oldPos=-1, pLpos:-1 no parent}
D/StickyHeaderHelper: swapHeader newHeaderPosition=0
D/StickyHeaderHelper: clearHeader
...
etc same

[Null45]

@davideas thanks. all works.

[davideas]

@Null45, the stickyHeader = true is mandatory in case of IHeader, you can’t set false, because it’s a fixed workaround caused by the fact we can’t extend some methods and some fields are private in the base object. I repeat, if you have all IHeaders you won’t have any sticky effect, the stitky routine will swap the header indefinitely, making the items normal.