These are the steps to use the adapter.
val filterAdapter = null // Your adapter instance here
filterAdapter.filter.filter(/*Pass your string here*/)| abstract class FilterableListAdapter<T, VH : RecyclerView.ViewHolder>( | |
| diffCallback: DiffUtil.ItemCallback<T> | |
| ) : ListAdapter<T, VH>(diffCallback), Filterable { | |
| private var originalList: List<T> = currentList.toList() | |
| override fun getFilter(): Filter { | |
| return object : Filter() { | |
| override fun performFiltering(constraint: CharSequence?): FilterResults { | |
| return FilterResults().apply { | |
| values = if (constraint.isNullOrEmpty()) | |
| originalList | |
| else | |
| onFilter(originalList, constraint.toString()) | |
| } | |
| } | |
| @Suppress("UNCHECKED_CAST") | |
| override fun publishResults(constraint: CharSequence?, results: FilterResults?) { | |
| submitList(results?.values as? List<T>, true) | |
| } | |
| } | |
| } | |
| override fun submitList(list: List<T>?) { | |
| submitList(list, false) | |
| } | |
| abstract fun onFilter(list: List<T>, constraint: String): List<T> | |
| /** | |
| * This function is responsible for maintaining the | |
| * actual contents for the list for filtering | |
| * The submitList for parent class delegates false | |
| * so that a new contents can be set | |
| * While a filter pass true which make sure original list | |
| * is maintained | |
| * | |
| * @param filtered True if the list was updated using filter interface | |
| * */ | |
| private fun submitList(list: List<T>?, filtered: Boolean) { | |
| if (!filtered) | |
| originalList = list ?: listOf() | |
| super.submitList(list) | |
| } | |
| } |