[정현수_Android] 8주차 과제 제출

app/build.gradle.kts

@@ -3,6 +3,9 @@ plugins {
 }
 
 android {
+    viewBinding {
+        enable = true
+    }
     namespace = "com.example.android_2026_1"
     compileSdk = 36
 
@@ -37,6 +40,7 @@ dependencies {
     implementation(libs.material)
     implementation(libs.androidx.activity)
     implementation(libs.androidx.constraintlayout)
+    implementation(libs.androidx.recyclerview)
     testImplementation(libs.junit)
     androidTestImplementation(libs.androidx.junit)
     androidTestImplementation(libs.androidx.espresso.core)

app/src/main/java/com/example/android_2026_1/LapAdapter.kt

@@ -0,0 +1,26 @@
+package com.example.android_2026_1
+
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.TextView
+import androidx.recyclerview.widget.RecyclerView
+
+class LapAdapter(private val lapList: List<String>) : RecyclerView.Adapter<LapAdapter.LapViewHolder>() {
+
+    class LapViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
+        val textViewLap: TextView = itemView as TextView
+    }
+
+    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): LapViewHolder {
+        val view = LayoutInflater.from(parent.context)
+            .inflate(android.R.layout.simple_list_item_1, parent, false)
+        return LapViewHolder(view)
+    }
+
+    override fun onBindViewHolder(holder: LapViewHolder, position: Int) {
+        holder.textViewLap.text = lapList[position]
+    }
+
+    override fun getItemCount(): Int = lapList.size
+}

app/src/main/java/com/example/android_2026_1/MainActivity.kt

@@ -1,20 +1,121 @@
 package com.example.android_2026_1
 
+import android.annotation.SuppressLint
 import android.os.Bundle
+import android.os.SystemClock
 import androidx.activity.enableEdgeToEdge
 import androidx.appcompat.app.AppCompatActivity
 import androidx.core.view.ViewCompat
 import androidx.core.view.WindowInsetsCompat
+import androidx.lifecycle.lifecycleScope
+import androidx.recyclerview.widget.LinearLayoutManager
+import com.example.android_2026_1.databinding.ActivityMainBinding
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
 
 class MainActivity : AppCompatActivity() {
+
+    private lateinit var binding: ActivityMainBinding
+
+    private var timeCentiseconds = 0
+    private var timeJob: Job? = null
+
+    private var startTime = 0L
+    private var pausedTime = 0L
+
+    private lateinit var lapAdapter: LapAdapter
+    private val lapList = mutableListOf<String>()
+
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         enableEdgeToEdge()
-        setContentView(R.layout.activity_main)
-        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
+
+        binding = ActivityMainBinding.inflate(layoutInflater)
+        setContentView(binding.root)
+
+        ViewCompat.setOnApplyWindowInsetsListener(binding.main) { v, insets ->
             val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
             v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
             insets
         }
+
+        lapAdapter = LapAdapter(lapList)
+        binding.recyclerViewLaps.apply {
+            adapter = lapAdapter
+            layoutManager = LinearLayoutManager(this@MainActivity)
+        }
+
+        binding.buttonStartPause.setOnClickListener {
+            if (timeJob?.isActive == true) pauseTimer() else startTimer()
+        }
+
+        binding.buttonLap.setOnClickListener {
+            val currentText = getFormattedTime()
+            val secondsElapsed = timeCentiseconds / 100
+            val lapRecord = getString(R.string.lap_record_format, secondsElapsed, currentText)
+
+            lapList.add(0, lapRecord)
+            lapAdapter.notifyItemInserted(0)
+            binding.recyclerViewLaps.scrollToPosition(0)
+        }
+
+        binding.buttonStop.setOnClickListener {
+            resetTimer()
+            clearLapRecords()
+        }
+    }
+
+    private fun startTimer() {
+        startTime = SystemClock.elapsedRealtime() - pausedTime
+
+        timeJob = lifecycleScope.launch {
+            binding.buttonStartPause.text = getString(R.string.btn_pause)
+
+            while (isActive) {
+                val elapsedMillis = SystemClock.elapsedRealtime() - startTime
+                timeCentiseconds = (elapsedMillis / 10).toInt()
+
+                updateTimerText()
+                delay(10L)
+            }
+        }
+    }
+
+    private fun pauseTimer() {
+        timeJob?.cancel()
+        pausedTime = SystemClock.elapsedRealtime() - startTime
+        binding.buttonStartPause.text = getString(R.string.btn_start)
+    }
+
+    private fun resetTimer() {
+        timeJob?.cancel()
+        timeCentiseconds = 0
+        pausedTime = 0L
+        updateTimerText()
+        binding.buttonStartPause.text = getString(R.string.btn_start)
+    }
+
+    private fun getFormattedTime(): String {
+        val m = (timeCentiseconds / 6000).toString().padStart(2, '0')
+        val s = ((timeCentiseconds % 6000) / 100).toString().padStart(2, '0')
+        val ms = (timeCentiseconds % 100).toString().padStart(2, '0')
+
+        return "$m:$s:$ms"
+    }
+
+    private fun updateTimerText() {
+        val m = (timeCentiseconds / 6000).toString().padStart(2, '0')
+        val s = ((timeCentiseconds % 6000) / 100).toString().padStart(2, '0')
+        val ms = (timeCentiseconds % 100).toString().padStart(2, '0')
+
+        binding.textViewTime.text = "$m : $s : $ms"
+    }
+
+    @SuppressLint("NotifyDataSetChanged")
+    private fun clearLapRecords() {
+        lapList.clear()
+        lapAdapter.notifyDataSetChanged()
     }
 }

app/src/main/res/layout/activity_main.xml

@@ -7,4 +7,63 @@
     android:layout_height="match_parent"
     tools:context=".MainActivity">
 
+    <TextView
+        android:id="@+id/textViewTime"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="@string/default_time"
+        android:textSize="32sp"
+        android:textStyle="bold"
+        app:layout_constraintBottom_toTopOf="@+id/linearLayoutButtons"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintVertical_bias="0.25" />
+
+    <androidx.recyclerview.widget.RecyclerView
+        android:id="@+id/recyclerViewLaps"
+        android:layout_width="0dp"
+        android:layout_height="0dp"
+        app:layout_constraintBottom_toBottomOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/linearLayoutButtons" />
+
+    <LinearLayout
+        android:id="@+id/linearLayoutButtons"
+        style="?android:attr/buttonBarStyle"
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="horizontal"
+        android:gravity="center"
+        android:padding="16dp"
+        app:layout_constraintBottom_toTopOf="@+id/recyclerViewLaps"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/textViewTime">
+
+        <Button
+            android:id="@+id/buttonStartPause"
+            style="?android:attr/buttonBarButtonStyle"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginEnd="8dp"
+            android:text="@string/btn_start" />
+
+        <Button
+            android:id="@+id/buttonStop"
+            style="?android:attr/buttonBarButtonStyle"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_marginEnd="8dp"
+            android:text="@string/btn_stop" />
+
+        <Button
+            android:id="@+id/buttonLap"
+            style="?android:attr/buttonBarButtonStyle"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:text="@string/btn_lap" />
+
+    </LinearLayout>
 </androidx.constraintlayout.widget.ConstraintLayout>

app/src/main/res/values/strings.xml

@@ -1,3 +1,12 @@
 <resources>
-    <string name="app_name">android_2026_1</string>
+    <string name="app_name">스톱워치</string>
+    <string name="btn_start">Start</string>
+    <string name="btn_pause">Pause</string>
+    <string name="btn_stop">Stop</string>
+    <string name="btn_lap">Lap</string>
+    <string name="default_time">00 : 00 : 00</string>
+
+    <string name="lap_record_format">%1$d초 경과 (%2$s)</string>
+    <string name="time_format">%02d : %02d : %02d</string>
+    <string name="time_format_simple">%02d:%02d:%02d</string>
 </resources>

gradle/libs.versions.toml

@@ -9,6 +9,7 @@ junitVersion = "1.3.0"
 espressoCore = "3.7.0"
 appcompat = "1.7.1"
 material = "1.14.0"
+recyclerview = "1.4.0"
 
 [libraries]
 androidx-constraintlayout = { module = "androidx.constraintlayout:constraintlayout", version.ref = "constraintlayout" }
@@ -19,6 +20,7 @@ androidx-junit = { group = "androidx.test.ext", name = "junit", version.ref = "j
 androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
 androidx-appcompat = { group = "androidx.appcompat", name = "appcompat", version.ref = "appcompat" }
 material = { module = "com.google.android.material:material", version.ref = "material" }
+androidx-recyclerview = { group = "androidx.recyclerview", name = "recyclerview", version.ref = "recyclerview" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }