example

CropActivity.kt

// scroll initialization
cropFormPicker = binding.cropFormPicker
cropFormAdapter = CropFormAdapter(viewModel)
cropFormPicker.adapter = cropFormAdapter
cropFormPicker.setItemTransformer(ScaleTransformer.Builder()
                                                  .setMaxScale(1f)
                                                  .setMinScale(0.5f)
                                                  .setPivotX(Pivot.X.CENTER)
                                                  .setPivotY(Pivot.Y.CENTER)
                                                  .build())
cropFormPicker.addScrollStateChangeListener(cropFormAdapter)

CropFormAdapter.kt

class CropFormAdapter(private val vm: CropViewModel) : RecyclerView.Adapter<FormViewHolder>(), DiscreteScrollView.ScrollStateChangeListener<FormViewHolder> {

...

    override fun onScrollEnd(holder: FormViewHolder, position: Int) {
        holder.activateForm()
    }

    override fun onScrollStart(holder: FormViewHolder, position: Int) {
        Log.logger.d("CropFormAdapter", "onScrollStart() $position")
    }

    override fun onScroll(scrollPosition: Float, currentHolder: FormViewHolder, newCurrentHolder: FormViewHolder) {
        Log.logger.d("CropFormAdapter", "onScroll() currentHolder = ${currentHolder.adapterPosition} newCurrentHolder = ${newCurrentHolder.adapterPosition} scrollPosition = $scrollPosition")
    }
...

}