옵저버 패턴 자료 업로드

app/src/main/java/com/example/apptivedevstudy/debug/Matrix.kt

@@ -1,8 +1,13 @@
 package com.example.apptivedevstudy.debug
 
+import com.example.apptivedevstudy.debug.dataclass.Location
+import com.example.apptivedevstudy.debug.dataclass.Size
+import com.example.apptivedevstudy.debug.enums.Tile
+
 class Matrix(private val rows: MutableList<Row>) {
     val value: List<Row> get() = rows
-    val size: Size get() {
+    val size: Size
+        get() {
         return Size(
             width = value[0].size,
             height = value.size

app/src/main/java/com/example/apptivedevstudy/debug/Row.kt

@@ -1,5 +1,7 @@
 package com.example.apptivedevstudy.debug
 
+import com.example.apptivedevstudy.debug.enums.Tile
+
 class Row(var values: MutableList<Tile> = mutableListOf()) {
     val size: Int get() = values.size
 

app/src/main/java/com/example/apptivedevstudy/debug/boj14502.kt

@@ -1,6 +1,7 @@
 package com.example.apptivedevstudy.debug
 
 import com.example.apptivedevstudy.debug.dataclass.Location
+import com.example.apptivedevstudy.debug.enums.Tile
 import java.util.*
 
 fun getMatrix(): Matrix {

app/src/main/java/com/example/apptivedevstudy/observer/Listener.kt

@@ -0,0 +1,14 @@
+package com.example.apptivedevstudy.observer
+
+import androidx.lifecycle.LiveData
+
+interface LiveDataObserver<T> {
+    fun update(data: T)
+}
+
+class Observer<T>(var value: T, val name: String): LiveDataObserver<T> {
+    override fun update(data: T) {
+        value = data
+        println("${name}의 값이 수정되었습니다! ")
+    }
+}

app/src/main/java/com/example/apptivedevstudy/observer/SimbleObserver.kt

@@ -0,0 +1,60 @@
+package com.example.apptivedevstudy.observer
+
+interface Observable {
+    fun update()
+}
+
+class Armor: Observable {
+    override fun update() {
+        println("방어구가 데미지를 받았습니다!")
+    }
+}
+
+class Weapon: Observable {
+    override fun update() {
+        println("무기가 데미지를 받았습니다.")
+    }
+}
+class Subject(private var text: String) {
+    private val events = ArrayList<Observable>()
+
+    fun attach(event: Observable) {
+        events.add(event)
+    }
+
+    fun detach(event: Observable) {
+        events.remove(event)
+    }
+
+    fun setText(newText: String) {
+        text = newText
+        notifyObservers()
+    }
+
+    private fun notifyObservers() {
+        for (event in events) {
+            event.update()
+        }
+    }
+}
+
+fun myLambda() {
+    println("첫 번째 람다")
+    println("첫 번째 람다가 실행되었습니다.")
+}
+
+private fun main() {
+    val subject = Subject("초기값")
+    val armor = Armor()
+    val weapon = Weapon()
+
+    subject.attach(armor)
+    subject.attach(weapon)
+
+    subject.setText("데미지 1 받음")
+    subject.setText("데미지 2 받음")
+
+    subject.detach(armor)
+    println("-----------------방어구 깨짐")
+    subject.setText("데미지 3 받음")
+}

app/src/main/java/com/example/apptivedevstudy/observer/Subject.kt

@@ -0,0 +1,22 @@
+package com.example.apptivedevstudy.observer
+
+class MyLiveData<T>(
+    private var data: T
+) {
+    val events = ArrayList<LiveDataObserver<T>>()
+
+    fun observe(event: LiveDataObserver<T>) {
+        events.add(event)
+    }
+
+    fun setValue(newData: T) {
+        data = newData
+        notifyObservers()
+    }
+
+    private fun notifyObservers() {
+        for (event in events) {
+            event.update(data)
+        }
+    }
+}

app/src/main/java/com/example/apptivedevstudy/observer/main.kt

@@ -0,0 +1,16 @@
+package com.example.apptivedevstudy.observer
+
+private fun main() {
+    val liveData = MyLiveData("초기값")
+    val observer1 = Observer(value = "1", "1번 옵저버")
+    val observer2 = Observer(value = "2", "2번 옵저버")
+    val observer3 = Observer(value = "3", "3번 옵저버")
+    val observer4 = Observer(value = "4", "4번 옵저버")
+
+    liveData.observe(observer1)
+    liveData.observe(observer2)
+    liveData.observe(observer3)
+    liveData.observe(observer4)
+
+    liveData.setValue("변경한 값")
+}