'가게 재고 관리 앱' 만들기

요구사항

• 가게가 보유한 물건의 이름과 제고를 조회, 추가, 삭제, 수정이 가능하다

DTO

class ProductDto (
    var name : String,
    var amount : Int
) : java.io.Serializable

MainActivity.kt

class MainActivity : AppCompatActivity() {
    private lateinit var binding: ActivityMainBinding
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        initialize()
    }

    private fun initialize(){
        binding.layoutInfo.setOnClickListener{
            var intent = Intent(this@MainActivity,StuffActivity::class.java)
            startActivity(intent)
        }
    }
}

activity_main.xml

ProductAdapter.kt

class ProductAdapter(private var productList : MutableList<ProductDto>) : BaseAdapter() {
    fun setList(list : MutableList<ProductDto>){
        productList = list
    }

    interface ItemClickListener{
        fun onClick(view: View, position: Int)
    }
    lateinit var itemClickListener: ItemClickListener

    override fun getCount(): Int = productList.size

    override fun getItem(position: Int): Any {
        return productList[position]
    }

    override fun getItemId(position: Int): Long {
        return position.toLong()
    }

    @SuppressLint("ViewHolder", "SetTextI18n")
    override fun getView(position: Int, view: View?, parent: ViewGroup): View {
        val view : View = LayoutInflater.from(parent.context).inflate(android.R.layout.simple_list_item_1,null)
        val dto = productList[position]
        view.findViewById<TextView>(android.R.id.text1).text = "물품 : ${dto.name} -> 수량 : ${dto.amount}"

        view.setOnClickListener{
            itemClickListener.onClick(view,position)
        }

        return view
    }
}

stuffActivity

class StuffActivity : AppCompatActivity() {
    private lateinit var binding: ActivityStuffBinding
    private var list = mutableListOf<ProductDto>()
    private lateinit var adapter: ProductAdapter
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityStuffBinding.inflate(layoutInflater)
        setContentView(binding.root)

        initialize()
    }

    fun initialize(){
        binding.btnAdd.setOnClickListener{
            var intent = Intent(this@StuffActivity,StuffEditActivity::class.java)
            addLauncher.launch(intent)
        }

        addData()
        adapter = ProductAdapter(list)
        adapter.itemClickListener = object : ProductAdapter.ItemClickListener{
            override fun onClick(view: View, position: Int) {
                var intent = Intent(this@StuffActivity,StuffEditActivity::class.java).apply {
                    putExtra("position",position)
                    putExtra("dto",list[position])
                }
                editLauncher.launch(intent)
            }
        }
        binding.list.adapter = adapter
    }

    fun addData(){
        list.add(ProductDto("사과",10))
        list.add(ProductDto("참외",11))
    }

    val addLauncher = registerForActivityResult(ActivityResultContracts.StartActivityForResult()){
        if(it.resultCode == RESULT_OK){
            Log.d(TAG,"return add")
            val dto = it.data?.getSerializableExtra("dto") as ProductDto
            list.add(dto)
            adapter.setList(list)
            adapter.notifyDataSetChanged()
        }
    }

    val editLauncher = registerForActivityResult(ActivityResultContracts.StartActivityForResult()){
        if(it.resultCode == RESULT_OK){
            Log.d(TAG,"return edit")
            val dto = it.data?.getSerializableExtra("dto") as ProductDto
            val position = it.data?.getIntExtra("position",-1) ?: -1
            if(position >= 0){
                list[position] = dto
            }
        }else if(it.resultCode == 10){
            Log.d(TAG,"return remove")
            val position = it.data?.getIntExtra("position",-1) ?: -1
            if(position >= 0){
                list.removeAt(position)
            }
        }
        adapter.setList(list)
        adapter.notifyDataSetChanged()
    }

activity_stuff

StuffEditActivity

class StuffEditActivity : AppCompatActivity() {
    private lateinit var binding: ActivityStuffEditBinding
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityStuffEditBinding.inflate(layoutInflater)
        setContentView(binding.root)

        initialize()
    }

    private fun initialize(){
        var position = intent.getIntExtra("position",-1)

        binding.apply {
            btnSave.setOnClickListener{
                var name = etProductName.text.toString()
                var amount = etProductAmount.text.toString().toInt()
                var dto = ProductDto(name,amount)
                var intent = Intent().apply {
                    putExtra("dto",dto)
                    putExtra("position",position)
                }
                setResult(RESULT_OK,intent)
                finish()
            }
            btnCancel.setOnClickListener{
                finish()
            }
        }

        if(position >= 0){ //수정
            Log.d(TAG,"edit")
            binding.apply {
                var dto = intent.getSerializableExtra("dto") as ProductDto
//                Log.d(TAG,"${dto.name}, ${dto.amount}")
                binding.etProductName.setText(dto.name)
                binding.etProductAmount.setText(dto.amount.toString())

                btnDelete.setOnClickListener{
                    var intent = Intent().apply {
                        putExtra("position",position)
                    }
                    setResult(10,intent)
                    finish()
                }
            }
        }else { //cancel
            Log.d(TAG,"add")
            binding.apply {
                btnDelete.setOnClickListener{
                    finish()
                }
            }
        }
    }
}

activity_stuff_edit.xml