코틀린 안드로이드 - 계산기 /다이얼로그 만들어보기

• layout

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <View
        android:id="@+id/toplayout"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@+id/tablelayout"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_weight="1" />

    <TextView
        android:id="@+id/TextView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginTop="40dp"
        android:text=""
        android:textSize="40sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="1.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">


    </TextView>

    <TextView
        android:id="@+id/resultTextView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="15dp"
        android:layout_marginEnd="15dp"
        android:layout_marginBottom="15dp"
        android:text=""
        android:textSize="30sp"
        app:layout_constraintBottom_toTopOf="@id/tablelayout"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent">

    </TextView>

    <TableLayout
        android:id="@+id/tablelayout"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:paddingTop="21dp"
        android:paddingBottom="0dp"
        android:shrinkColumns="*"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/toplayout"
        app:layout_constraintVertical_weight="2.5">


        <TableRow
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_weight="5">

            <Button
                android:id="@+id/clearbutton"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="clearButtonClick"
                android:stateListAnimator="@null"
                android:text="AC"
                android:textSize="20sp">

            </Button>

            <Button
                android:id="@+id/deleteButton"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="deleteButtonClick"
                android:stateListAnimator="@null"
                android:text="C"
                android:textColor="@color/cardview_dark_background"
                android:textSize="20sp">

            </Button>

            <Button
                android:id="@+id/includbutton"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="/"
                android:textSize="30sp">

            </Button>

            <Button
                android:id="@+id/expandbutton"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="X"
                android:textSize="30sp">

            </Button>

            <Button
                android:id="@+id/invidebutton"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="%"
                android:textSize="30sp">

            </Button>
        </TableRow>

        <TableRow android:layout_weight="1" />

        <TableRow android:layout_weight="1">

            <Button
                android:id="@+id/button0"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:contentDescription="@string/app_name"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="0"
                android:textSize="30sp">

            </Button>

            <Button
                android:id="@+id/button9"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="9"
                android:textSize="30sp">

            </Button>

            <Button
                android:id="@+id/button8"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="8"
                android:textSize="30sp">

            </Button>

            <Button

                android:id="@+id/button7"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="7"
                android:textSize="30sp">

            </Button>

            <Button
                android:id="@+id/minusbutton"
                android:layout_width="wrap_content"
                android:layout_height="85dp"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="-"
                android:textSize="30sp">

            </Button>
        </TableRow>

        <TableRow android:layout_weight="1">

            <Button
                android:id="@+id/button6"
                android:layout_width="60dp"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="6"
                android:textSize="30sp">

            </Button>

            <Button
                android:id="@+id/button5"
                android:layout_width="62dp"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="5"
                android:textSize="30sp">

            </Button>

            <Button
                android:id="@+id/button4"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="4"
                android:textSize="30sp">

            </Button>

            <Button
                android:id="@+id/button3"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="3"
                android:textSize="30sp">

            </Button>

            <Button
                android:id="@+id/plusbutton"
                android:layout_width="wrap_content"
                android:layout_height="90dp"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="+"
                android:textSize="30sp">

            </Button>
        </TableRow>

        <TableRow
            android:id="@+id/text1"
            android:layout_width="20dp"
            android:layout_weight="1">


            <Button

                android:id="@+id/button1"
                android:layout_width="30dp"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="1"
                android:textSize="30sp">

            </Button>

            <Button
                android:id="@+id/button2"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:stateListAnimator="@null"
                android:text="2"
                android:textSize="30sp">

            </Button>

            <Button
                android:id="@+id/jumbutton"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="buttonClick"
                android:text="."
                android:textSize="30sp">

            </Button>

            <Button
                android:id="@+id/resultbutton"
                android:layout_width="86dp"
                android:layout_height="match_parent"
                android:layout_margin="10dp"
                android:background="@drawable/button_background"
                android:onClick="resultButtonClick"
                android:text="="
                android:textSize="50sp">

            </Button>
        </TableRow>


    </TableLayout>


</androidx.constraintlayout.widget.ConstraintLayout>

 

 

• Onclick View Bind

<Button
android:onClick="buttonclick."

 buttonclick로 함수를 연결해준다. 액티비에서 onClickListener를 사용하지 않아도된다. 

그럼 MainActivity에서

 fun buttonclick(v: View) { 원하는 기능}

현재 View를 참조해서 함수를 만들수잇다. 이와같이 Button이 많을경우에 사용하면좋다.

 

when (v.id) {
            R.id.button0 -> buttonClick("0")
            R.id.button1 -> buttonClick("1")
            R.id.button2 -> buttonClick("2")
            R.id.button3 -> buttonClick("3")
            R.id.button4 -> buttonClick("4")
            R.id.button5 -> buttonClick("5")
            R.id.button6 -> buttonClick("6")
            R.id.button7 -> buttonClick("7")
            R.id.button8 -> buttonClick("8")
            R.id.button9 -> buttonClick("9")

            R.id.plusbutton -> operatorButtonClick("+")
            R.id.expandbutton -> operatorButtonClick("X")
            R.id.includbutton -> operatorButtonClick("/")
            R.id.minusbutton -> operatorButtonClick("-")
            R.id.invidebutton -> operatorButtonClick("%")
            R.id.jumbutton -> operatorButtonClick(".")

        }
    }

 

• MainActivity.kt

package com.example.part2chapter4

import android.content.Context
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.view.View.OnClickListener
import android.widget.TextView
import android.widget.Toast
import androidx.appcompat.app.AlertDialog
import com.example.part2chapter4.databinding.ActivityMainBinding


class MainActivity : AppCompatActivity() {

    //뷰 바인딩 변수 선언
    private var mainBinding: ActivityMainBinding? = null
    private val binding get() = mainBinding!!

    private val expreesionTextView: TextView by lazy {
        findViewById(R.id.TextView)
    }
    private val resultTextView: TextView by lazy {
        findViewById(R.id.resultTextView)
    }

    //계산식에 연산자가 있는지없는지 확인
    private var haveOperator = false

    //연산자를 사용하고있는지 확인
    private var isOperator = false


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        //oncreate생성
        mainBinding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)
    }

    fun buttonClick(v: View) {


        when (v.id) {
            R.id.button0 -> buttonClick("0")
            R.id.button1 -> buttonClick("1")
            R.id.button2 -> buttonClick("2")
            R.id.button3 -> buttonClick("3")
            R.id.button4 -> buttonClick("4")
            R.id.button5 -> buttonClick("5")
            R.id.button6 -> buttonClick("6")
            R.id.button7 -> buttonClick("7")
            R.id.button8 -> buttonClick("8")
            R.id.button9 -> buttonClick("9")

            R.id.plusbutton -> operatorButtonClick("+")
            R.id.expandbutton -> operatorButtonClick("X")
            R.id.includbutton -> operatorButtonClick("/")
            R.id.minusbutton -> operatorButtonClick("-")
            R.id.invidebutton -> operatorButtonClick("%")
            R.id.jumbutton -> operatorButtonClick(".")

        }
    }

    private fun buttonClick(number: String) {
        if (isOperator) {
            expreesionTextView.append("")
        }
        isOperator = false
        val expressionText = expreesionTextView.text.split(" ")
        if (expressionText.isNotEmpty() && expressionText.last().length > 15) {
            Toast.makeText(this, "15자리까지만사용할수있습니다", Toast.LENGTH_SHORT).show()
            return

        } else if (number == "0" && expressionText.last().isEmpty()) {
            Toast.makeText(this, "0은 제일 앞에 올수 없습니다", Toast.LENGTH_SHORT).show()
        }
        expreesionTextView.append(number)
        // TODO resulttextview실시간으로 계산결과를 넣음
        binding.resultTextView.text = calculateExpression()
    }

    private fun operatorButtonClick(operator: String) {
        if (expreesionTextView.text.isEmpty()) {
            return
        }
        when {

            haveOperator -> {
                Toast.makeText(this, "연산자는 한번만 사용할수잇습니다.", Toast.LENGTH_SHORT).show()
                return
            }
            else -> {
                haveOperator = true
                expreesionTextView.append(" $operator ")
            }

        }

    }

    fun resultButtonClick(v: View) {
        val expressionTexts = expreesionTextView.text.split("")
        if (expreesionTextView.text.isEmpty() || expressionTexts.size == 1) {
            return
        }
        if (expressionTexts.size != 3 && haveOperator) {
            Toast.makeText(this, "수식을 완성해주세요", Toast.LENGTH_SHORT).show()
            return
        }
        if (expressionTexts[0].isNumber().not() || expressionTexts[2].isNumber().not()) {
            Toast.makeText(this, "오류가 발생햇습니다", Toast.LENGTH_SHORT).show()

            return
        }

    }

    private fun calculateExpression(): String {
        val expressionTexts = expreesionTextView.text.split(" ")

        if (haveOperator.not() || expressionTexts.size != 3) {
            return ""
        } else if (expressionTexts[0].isNumber().not() || expressionTexts[2].isNumber().not()) {
            return ""
        }
        val exp1 = expressionTexts[0].toBigInteger()
        val exp2 = expressionTexts[2].toBigInteger()
        val op = expressionTexts[1]

        return when (op) {
            "+" -> (exp1 + exp2).toString()
            "X" -> (exp1 * exp2).toString()
            "/" -> (exp1 / exp2).toString()
            "-" -> (exp1 - exp2).toString()
            "%" -> (exp1 % exp2).toString()
            else -> " "
        }
    }

    fun clearButtonClick(v: View) {
        expreesionTextView.text = ""
        resultTextView.text = ""
        haveOperator = false
        isOperator = false
    }

    private fun String.isNumber(): Boolean {
        return try {
            this.toBigInteger()
            true
        } catch (e: NumberFormatException) {
            false
        }
    }
          //알림창 띄우기
    fun deleteButtonClick(view: View) {
        AlertDialog.Builder(this).run {
            setTitle("Test 계산기")
            setIcon(android.R.drawable.ic_dialog_info)
            setMessage("정말 종료하시겠습니까?")
            setPositiveButton("OK", null)
            setNegativeButton("Cancel", null)
            setNeutralButton("More", null)
            show()
        }
    }
}

 

• Text Drop

 expreesionTextView.text = text.dropLast(1)

위와 같이 TextView의 text의 글자를 원하는 만큼 drop 할수있다.

 

• Spannable

Spannable은 텍스트에 부분적으로 효과를 적용할때 사용된다.

setSpan( 적용할 효과, 효과의 시작, 효과의 끝, 문자열 추가시 span값 적용 유뮤) 의 인자를 가지고있다.
효과
ForegroundColorSpan- 색깔
UnderlineSpan - 밑줄
AbsoluteSizeSpan - 텍스크 크기

효과지정 시작과끝 - 배열과같이 시작값은 0

마지막 인자 - span이 적용된 좌우측에 문자열이 추가될때 이 span값을 적용할 것인지 아닌지 정한다.

SPAN_EXCLUSIVE_EXCLUSIE : 왼쪽제거, 오른쪽 제거
SPAN_EXCLUSIVE_INCLUSIVE : 왼쪽 제거 오른쪽 포함
위처럼 EXCLUSIVE는 제거 , INCLUSIVE는포함으로 표현횐다.

확장함수

fun String.isNumber(): Boolean {}

이처럼 String객체를 확장하는 함수를 만들어줄 수가있다.
isNumber처럼 없는 기능을 만들어 볼수도 있고 여러가지 쓸수있을거같다.

 

• 애뮬레이터

 

• deletbuttonClick을이용해 알림창띄우기!

fun deleteButtonClick(view: View) {
        AlertDialog.Builder(this).run {
            setTitle("Test 계산기")
            setIcon(android.R.drawable.ic_dialog_info)
            setMessage("정말 종료하시겠습니까?")
            setPositiveButton("OK", null)
            setNegativeButton("Cancel", null)
            setNeutralButton("More", null)
            show()
        }
    }

 

• 버튼의 이벤트 핸들러등록

            val eventHandler = object : DialogInterface.OnClickListener {
                override fun onClick(p0: DialogInterface?, p1: Int) {
                    if (p1 == DialogInterface.BUTTON_POSITIVE) {
                        Log.d("hello", "YES BUTTON")
                    } else if (p1 == DialogInterface.BUTTON_NEGATIVE) {
                        Log.d("hello", "NO BUTTON")
                    } else if (p1 == DialogInterface.BUTTON_NEUTRAL) {
                        Log.d("hello", "MORE BUTTON")
                    }
                }
            }
            setPositiveButton("YES", eventHandler)
            setNegativeButton("NO", eventHandler)
            setNeutralButton("MORE", eventHandler)
        }

• 목록을 출력하는 알림창 띄우기

  val items = arrayOf<String>("apple", "banana", "peach", "lemon", "orange")

        AlertDialog.Builder(this).run {
            setTitle("items test")
            setIcon(android.R.drawable.ic_dialog_info)
            setItems(items, object : DialogInterface.OnClickListener {
                override fun onClick(p0: DialogInterface?, p1: Int) {
                    Log.d("hello", "Selected fruit : ${items[p1]}")
                }
            })
            setPositiveButton("OK", null)
            show()
        }
    }