Simple Groupie sample

groupie_simple_sample.kt

class MainActivity : AppCompatActivity() {

    private val groupAdapter = GroupAdapter<ViewHolder>()

    // Hold a reference to the updating group, so we can, well, update it
    private var updatingGroup = Section()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        groupAdapter.apply {
            setOnItemClickListener(...)
            setOnItemLongClickListener(...)
        }

        populateAdapter()

        recyclerView.apply {
            layoutManager = LinearLayoutManager(this)
            adapter = groupAdapter
        }
    }

    private fun populateAdapter() {

        // Full bleed item
        groupAdapter += Section(HeaderItem(R.string.full_bleed_item)).apply {
            add(FullBleedCardItem(R.color.purple_200))
        }

        // Update in place group
        groupAdapter += Section().apply {
            val updatingHeader = HeaderItem(
                    R.string.updating_group,
                    R.string.updating_group_subtitle,
                    R.drawable.shuffle,
                    onShuffleClicked)
            setHeader(updatingHeader)

            updatingGroup.update(updatableItems)
            add(updatingGroup)
        }
    }
}