Fragment에서 반복되는 부분을 제거하기 위해 Base Fragment를 많이 만들어서 사용한다.

RecyclerView에서도 마찬가지로 반복되는 부분이 많은데, Base RecyclerView를 만들어서 이를 제거해보자.

---

전체 예시 코드

BaseRecyclerViewAdapter.kt

abstract class BaseRecyclerViewAdapter<T : Any, VB : ViewBinding>(
	private val bindingInflater: (inflater: LayoutInflater, parent: ViewGroup, attachToParent: Boolean) -> VB) : RecyclerView.Adapter<BaseRecyclerViewAdapter.BaseViewHolder<VB>>() {

    var items = listOf<T>()
        set(value) {
            field = value
            notifyDataSetChanged()
        }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): BaseViewHolder<VB> {
        val inflater = LayoutInflater.from(parent.context)
        val binding = bindingInflater.invoke(inflater, parent, false)
        return BaseViewHolder(binding)
    }

    var listener: ((view: View, item: T, position: Int) -> Unit)? = null

    override fun getItemCount(): Int = items.size

    abstract fun onBind(binding: VB, item: T)

    class BaseViewHolder<VB : ViewBinding>(val binding: VB) : RecyclerView.ViewHolder(binding.root)
} // End of BaseRecyclerViewAdapter class

Adapter class

class MeetingSelectedCommitteeListAdapter() : BaseRecyclerViewAdapter<SimpleUser, ItemSimpleuserListBinding>(
        { inflater, parent, attachToParent ->
            ItemSimpleuserListBinding.inflate(
                inflater,
                parent,
                attachToParent
            )
        }
    ) {
    override fun onBindViewHolder(
        holder: BaseViewHolder<ItemSimpleuserListBinding>,
        position: Int
    ) {
        val item = items[position]
        onBind(holder.binding, item)
    } // End of onBindViewHolder()

    override fun onBind(binding: ItemSimpleuserListBinding, item: SimpleUser) {
        binding.tvSimpleuserListEmpId.text = item.empId.toString()
        binding.tvSimpleuserListName.text = item.name
        binding.ivSimpleUserCheck.visibility = View.GONE
    } // End of onBind()
} // End of MeetingSelectedCommitteeListAdapter class

Fragment

...

	// Committeee RecyclerView
    private lateinit var commitRecyclerView: RecyclerView
    private lateinit var commitAdapter: MeetingSelectedCommitteeListAdapter

...


중간 부분 생략

...

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        commitListAdapter()
        
    } // End of onViewCreated()

...


중간 부분 생략

...
    private fun commitListAdapter() {
        commitRecyclerView = binding.rvMeetingAddCommittee
        commitAdapter = MeetingSelectedCommitteeListAdapter()

        commitRecyclerView.layoutManager = LinearLayoutManager(mContext)
        commitRecyclerView.adapter = commitAdapter
    } // End of commitListAdapter()

...

---

검색 기능 구현

BaseRecyclerView를 응용해서 검색기능을 만들어 보자

검색 기능을 만들어서 이름으로 검색해서 나오는 사람의 명단 RecyclerView에 표시할 것이다.

검색은 버튼을 따로만들지 않고 addTextChangedListener를 EditText의 글자가 변경될 때 이벤트가 발생하도록 했다.

    private fun initAdapter() {
        recyclerView = binding.rvMeetingAddCommitteeList
        meetingCommitteeListAdapter = MeetingCommitteeListAdapter(mContext)

        recyclerView.layoutManager = LinearLayoutManager(mContext)
        recyclerView.adapter = meetingCommitteeListAdapter


        binding.edCommitteeAddCommitteeList.addTextChangedListener(object : TextWatcher {
            override fun beforeTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            }

            override fun onTextChanged(p0: CharSequence?, p1: Int, p2: Int, p3: Int) {
            }

            override fun afterTextChanged(p0: Editable?) {
                filterList(p0.toString())
            }
        })
    } // End of initAdapter
    
    
    private fun filterList(query: String?) {
        val filteredCourseAry: ArrayList<SimpleUser> = ArrayList()
        for (eachCourse in commiteeList) {
            if (eachCourse.name.toLowerCase(Locale.ROOT)
                    .contains(query!!.toLowerCase(Locale.ROOT))
            ) {
                filteredCourseAry.add(eachCourse)
            }
        }
        meetingCommitteeListAdapter.setFilteredList(filteredCourseAry)
    } // End of filterList()
   

class MeetingCommitteeListAdapter(private val context: Context) :
    BaseRecyclerViewAdapter<SimpleUser, ItemSimpleuserListBinding>({ inflater, parent, attachToParent ->
        ItemSimpleuserListBinding.inflate(
            inflater, parent, attachToParent
        )
    }) {
    override fun onBindViewHolder(
        holder: BaseViewHolder<ItemSimpleuserListBinding>, position: Int
    ) {
        val item = items[position]
        onBind(holder.binding, item)

        holder.binding.apply {
            clSimpleuserListContainer.setOnClickListener {
                item.isSelected = !item.isSelected
                notifyItemChanged(position) // 변경된 아이템을 업데이트
            }
        }
    } // End of onBindViewHolder()

    override fun onBind(binding: ItemSimpleuserListBinding, item: SimpleUser) {
        binding.apply {
            tvSimpleuserListEmpId.text = item.empId.toString()
            tvSimpleuserListName.text = item.name

            if (!item.isSelected) {
                ivSimpleUserCheck.background.setTint(
                    ContextCompat.getColor(
                        context, R.color.dark_gray
                    )
                )
            } else {
                ivSimpleUserCheck.background.setTint(
                    ContextCompat.getColor(context, R.color.check_blue)
                )
            }
        }
    } // End of onBind()

    fun setFilteredList(userList: List<SimpleUser>) {
        this.items = userList
        notifyDataSetChanged()
    } // End of setFilteredList()
} // End of MeetingCommitteeListAdapter class

filterList() 함수를 통해서 검색되는 값만 필터링하여 RecyclerView의 List를 갱신한다.

여기서 this.items = userList 에서 this.items가

이 부분이 된다.