Pattern: Builder

Author: harlem88

src/linuxMain/kotlin/org/dronix/kotlin/designpatterns/Main.kt

@@ -1,15 +1,43 @@
 package org.dronix.kotlin.designpatterns
 
+import org.dronix.kotlin.designpatterns.base.Maze
 import org.dronix.kotlin.designpatterns.creational.abstractFactory.BombedMazeFactory
+import org.dronix.kotlin.designpatterns.creational.builder.CountingMazeBuilder
+import org.dronix.kotlin.designpatterns.creational.builder.StandardMazeBuilder
 
 fun hello(): String = "Hello, Kotlin/Native Design Patterns!"
 
 fun main(args: Array<String>) {
 
+    val mazeBombed   = createBombedMaze()
+    val mazeStandard = createStandardMaze()
+    val countingMaze = createCountingMaze()
+
+    println(hello())
+}
+
+fun createBombedMaze(): Maze{
+
     val bombedMazeFactory = BombedMazeFactory()
     val mazeGame = MazeGame()
 
-    mazeGame.createMaze(bombedMazeFactory)
+    return mazeGame.createMaze(bombedMazeFactory)
+}
+
+fun createStandardMaze(): Maze{
+    val standardMazeBuilder = StandardMazeBuilder()
+    val mazeGame = MazeGame()
+
+    return mazeGame.createMaze(standardMazeBuilder)
+}
+
+fun createCountingMaze(): Maze{
+    val countingMazeBuilder = CountingMazeBuilder()
+    val mazeGame = MazeGame()
+
+    val maze = mazeGame.createMaze(countingMazeBuilder)
+    val (rooms, doors)= countingMazeBuilder.getCounts()
+    println("Maze rooms: $rooms doors: $doors")
+    return maze
+}
 
-    println(hello())
-}

src/linuxMain/kotlin/org/dronix/kotlin/designpatterns/MazeGame.kt

@@ -5,8 +5,30 @@ import org.dronix.kotlin.designpatterns.base.door.Door
 import org.dronix.kotlin.designpatterns.base.room.Room
 import org.dronix.kotlin.designpatterns.base.wall.Wall
 import org.dronix.kotlin.designpatterns.creational.abstractFactory.MazeFactory
+import org.dronix.kotlin.designpatterns.creational.builder.MazeBuilder
 
 class MazeGame {
+    fun createMaze(): Maze {
+        val aMaze = Maze()
+        val room1 = Room(1)
+        val room2 = Room(2)
+        val theDoor = Door(room1, room2)
+
+        aMaze.addRoom(room1)
+        aMaze.addRoom(room2)
+
+        room1.setSide(Direction.North, Wall())
+        room1.setSide(Direction.East, theDoor)
+        room1.setSide(Direction.South, Wall())
+        room1.setSide(Direction.West, Wall())
+
+        room2.setSide(Direction.North, Wall())
+        room2.setSide(Direction.East, Wall())
+        room2.setSide(Direction.South, Wall())
+        room2.setSide(Direction.West, theDoor)
+        return aMaze
+
+    }
 
     fun createMaze(mazeFactory: MazeFactory): Maze{
 
@@ -30,25 +52,20 @@ class MazeGame {
         return aMaze
     }
 
-    fun createMaze(): Maze {
-        val aMaze = Maze()
-        val room1 = Room(1)
-        val room2 = Room(2)
-        val theDoor = Door(room1, room2)
-
-        aMaze.addRoom(room1)
-        aMaze.addRoom(room2)
-
-        room1.setSide(Direction.North, Wall())
-        room1.setSide(Direction.East, theDoor)
-        room1.setSide(Direction.South, Wall())
-        room1.setSide(Direction.West, Wall())
-
-        room2.setSide(Direction.North, Wall())
-        room2.setSide(Direction.East, Wall())
-        room2.setSide(Direction.South, Wall())
-        room2.setSide(Direction.West, theDoor)
-        return aMaze
+    fun createMaze(mazeBuilder: MazeBuilder): Maze {
+        return mazeBuilder
+            .buildMaze()
+            .buildRoom(1)
+            .buildRoom(2)
+            .buildDoor(1, 2)
+            .build()
+    }
 
+    fun createComplexMaze(mazeBuilder: MazeBuilder): Maze {
+        return mazeBuilder
+            .buildMaze()
+            .buildRoom(1)
+            .buildRoom(1001)
+            .build()
     }
 }

src/linuxMain/kotlin/org/dronix/kotlin/designpatterns/base/wall/BombedWall.kt

@@ -1,5 +1,3 @@
 package org.dronix.kotlin.designpatterns.base.wall
 
-class BombedWall: Wall() {
-
-}
+class BombedWall: Wall()

src/linuxMain/kotlin/org/dronix/kotlin/designpatterns/base/wall/CommonWall.kt

@@ -0,0 +1,10 @@
+package org.dronix.kotlin.designpatterns.base.wall
+
+import org.dronix.kotlin.designpatterns.base.Direction
+import org.dronix.kotlin.designpatterns.base.room.Room
+
+object CommonWall{
+    fun getDirection(room1: Room, room2: Room) : Direction{
+        return Direction.East
+    }
+}

src/linuxMain/kotlin/org/dronix/kotlin/designpatterns/creational/builder/CountingMazeBuilder.kt

@@ -0,0 +1,38 @@
+package org.dronix.kotlin.designpatterns.creational.builder
+
+import org.dronix.kotlin.designpatterns.base.Maze
+
+class CountingMazeBuilder: MazeBuilder {
+    private var doors: Int = 0
+    private var rooms: Int = 0
+    private var currentMaze: Maze? = null
+
+    override fun buildMaze(): MazeBuilder {
+        currentMaze = Maze()
+        doors = 0
+        rooms = 0
+        return this
+    }
+
+    override fun buildRoom(roomNumber: Int): MazeBuilder {
+        rooms++
+        return this
+    }
+
+    override fun buildDoor(roomFrom: Int, roomTo: Int): MazeBuilder {
+        doors++
+        return this
+    }
+
+    public fun getCounts(): Count {
+        return Count(this.rooms, this.doors)
+    }
+
+    override fun build(): Maze {
+        val maze = currentMaze
+        return maze ?: Maze()
+    }
+
+}
+
+data class Count(val rooms: Int, val doors: Int)

src/linuxMain/kotlin/org/dronix/kotlin/designpatterns/creational/builder/MazeBuilder.kt

@@ -0,0 +1,12 @@
+package org.dronix.kotlin.designpatterns.creational.builder
+
+import org.dronix.kotlin.designpatterns.base.Maze
+
+interface MazeBuilder {
+
+    fun buildMaze(): MazeBuilder
+    fun buildRoom(roomNumber: Int): MazeBuilder
+    fun buildDoor(roomFrom: Int, roomTo: Int): MazeBuilder
+
+    fun build(): Maze
+}

src/linuxMain/kotlin/org/dronix/kotlin/designpatterns/creational/builder/StandardMazeBuilder.kt

@@ -0,0 +1,53 @@
+package org.dronix.kotlin.designpatterns.creational.builder
+
+import org.dronix.kotlin.designpatterns.base.Direction
+import org.dronix.kotlin.designpatterns.base.Maze
+import org.dronix.kotlin.designpatterns.base.door.Door
+import org.dronix.kotlin.designpatterns.base.room.Room
+import org.dronix.kotlin.designpatterns.base.wall.CommonWall
+import org.dronix.kotlin.designpatterns.base.wall.Wall
+
+class StandardMazeBuilder : MazeBuilder {
+    private var currentMaze: Maze? = null
+
+    override fun buildMaze(): MazeBuilder {
+        currentMaze = Maze()
+        return this
+    }
+
+    override fun buildRoom(roomNumber: Int): MazeBuilder {
+        currentMaze = currentMaze ?: Maze()
+
+        if (currentMaze?.getRoomFromNumber(roomNumber) == null) {
+            val room = Room(roomNumber)
+
+            currentMaze?.addRoom(room)
+
+            room.setSide(Direction.North, Wall())
+            room.setSide(Direction.South, Wall())
+            room.setSide(Direction.East, Wall())
+            room.setSide(Direction.West, Wall())
+        }
+        return this
+    }
+
+    override fun buildDoor(roomFrom: Int, roomTo: Int): MazeBuilder {
+        currentMaze = currentMaze ?: Maze()
+
+        val room1 = currentMaze?.getRoomFromNumber(roomFrom)
+        val room2 = currentMaze?.getRoomFromNumber(roomTo)
+
+        if (room1 != null && room2 != null) {
+            val door = Door(room1, room2)
+
+            room1.setSide(CommonWall.getDirection(room1, room2), door)
+            room2.setSide(CommonWall.getDirection(room2, room1), door)
+        }
+
+        return this
+    }
+
+    override fun build(): Maze {
+        return currentMaze ?: Maze()
+    }
+}