斯卡拉摆动重漆

Question

所以我对scala非常非常新。我用GUI实现Conways的生命游戏。当2D阵列发生变化时，我无法弄清楚如何让我的面板更新。有人可以指点我正确的方向吗？我的整个代码如下：

import swing._
import java.awt.{Color, Graphics2D, Dimension}


// initialize variables
// infinite plane variable
var infCurrent = scala.collection.mutable.ListBuffer[List[Int]]()
var infNext = scala.collection.mutable.ListBuffer[List[Int]]()
var infNext1 = scala.collection.mutable.ListBuffer[List[Int]]()
var infLifeTester = scala.collection.mutable.MutableList[List[Int]]()


// general variables
var lifeCount = 0
var yes = 1


// displayed variables
val xDim = 20
val yDim = 20
var currentState = Array.ofDim[Int](xDim, yDim)
var colorIndexList = scala.collection.mutable.ListBuffer[List[Int]]()
var colorData = Array.ofDim[Color](xDim, yDim)


// initial value
infCurrent = scala.collection.mutable.ListBuffer(List(6,6), List(6,7), List(6,8), List(5,8), List(4,7))


// this function tests if a CURRENTLY ALIVE CELL on the INF PLANE STAYS ALIVE
def infStayAlive(current: scala.collection.mutable.ListBuffer[List[Int]]): scala.collection.mutable.ListBuffer[List[Int]] = {
  for (i <- current) {
    var a = i(0)
    var b = i(1)
    if (current.contains(List(a - 1, b - 1))) lifeCount += 1
    if (current.contains(List(a - 1, b))) lifeCount += 1
    if (current.contains(List(a - 1, b + 1))) lifeCount += 1
    if (current.contains(List(a, b - 1))) lifeCount += 1
    if (current.contains(List(a, b + 1))) lifeCount += 1
    if (current.contains(List(a + 1, b - 1))) lifeCount += 1
    if (current.contains(List(a + 1, b))) lifeCount += 1
    if (current.contains(List(a + 1, b + 1))) lifeCount += 1
    if (lifeCount == 2) infNext = infNext :+ i
    lifeCount = 0
  }
  return infNext
}


// this function gets ALL NEIGHBORS for what's on the INF PLANE
def infGetNeighbors(current: scala.collection.mutable.ListBuffer[List[Int]]): scala.collection.mutable.MutableList[List[Int]] = {
  for (i <- current) {
    var a = i(0)
    var b = i(1)
    infLifeTester = infLifeTester :+ List(a - 1, b - 1)
    infLifeTester = infLifeTester :+ List(a - 1, b)
    infLifeTester = infLifeTester :+ List(a - 1, b + 1)
    infLifeTester = infLifeTester :+ List(a, b - 1)
    infLifeTester = infLifeTester :+ List(a, b + 1)
    infLifeTester = infLifeTester :+ List(a + 1, b - 1)
    infLifeTester = infLifeTester :+ List(a + 1,b)
    infLifeTester = infLifeTester :+ List(a + 1, b + 1)
  }
  infLifeTester = infLifeTester.distinct
  return infLifeTester
}


// this function determines whether cells on the INF PLANE DIE or COME ALIVE
def infComeAlive(infLifeTester: scala.collection.mutable.MutableList[List[Int]]): scala.collection.mutable.ListBuffer[List[Int]] = {
  for(i <- infLifeTester) {
    var a = i(0)
    var b = i(1)
    if (infCurrent.contains(List(a - 1, b - 1))) lifeCount += 1
    if (infCurrent.contains(List(a - 1, b))) lifeCount += 1
    if (infCurrent.contains(List(a - 1, b + 1))) lifeCount += 1
    if (infCurrent.contains(List(a, b - 1))) lifeCount += 1
    if (infCurrent.contains(List(a, b + 1))) lifeCount += 1
    if (infCurrent.contains(List(a + 1, b - 1))) lifeCount += 1
    if (infCurrent.contains(List(a + 1, b))) lifeCount += 1
    if (infCurrent.contains(List(a + 1, b + 1))) lifeCount += 1
    if (lifeCount == 3) infNext1 = infNext1 :+ i
    lifeCount = 0
  }
  infNext1 = infNext1.distinct
  return infNext1
}


def printGrid(infCurrent: scala.collection.mutable.ListBuffer[List[Int]]): Array[Array[Int]] = {
  for(i <- infCurrent) {
    if(i(0) >= 0) {
      if(i(0) < xDim) {
        if(i(1) >= 0) {
          if(i(1) < yDim) {
            currentState(i(0))(i(1)) = 1
            colorIndexList = colorIndexList :+ i
          }
        }
      }
    }
  }
  return currentState
}


def colorGrid(colorIndexList: scala.collection.mutable.ListBuffer[List[Int]]): Array[Array[Color]] = {
  for (i <- colorIndexList) {
    colorData(i(0))(i(1)) = Color.WHITE
  }
  return colorData
}


// define panel class
class DataPanel(data: Array[Array[Color]]) extends Panel {

  override def paintComponent(g: Graphics2D) {
    val dx = g.getClipBounds.width.toFloat  / data.length
    val dy = g.getClipBounds.height.toFloat / data.map(_.length).max
    for {
      x <- 0 until data.length
      y <- 0 until data(x).length
      x1 = (x * dx).toInt
      y1 = (y * dy).toInt
      x2 = ((x + 1) * dx).toInt
      y2 = ((y + 1) * dy).toInt
    } {
      data(x)(y) match {
        case c: Color => g.setColor(c)
        case _ => g.setColor(Color.BLACK)
        repaint
      }
      g.fillRect(x1, y1, x2 - x1, y2 - y1)
      println("hi")
    }
    println("hey")
  }
}


// make swing app
object Draw extends SimpleSwingApplication {

  val data = colorData

  def top = new MainFrame {
    background = Color.RED
    title = "Shombo's Game of Life"
    val button = new Button {
      text = "Stahhhp!!"
    }
    val life = new DataPanel(data) {
      preferredSize = new Dimension(500, 500)
    }
    contents = new BoxPanel(Orientation.Vertical) {
      contents += life
      contents += button
    }
  }
}



Draw.top.visible = true
while(yes == 1) {

  infLifeTester = infGetNeighbors(infCurrent)
  infNext = infStayAlive(infCurrent)
  infNext1 = infComeAlive(infLifeTester)
  infNext = scala.collection.mutable.ListBuffer.concat(infNext, infNext1)
  infCurrent = infNext

  infNext = scala.collection.mutable.ListBuffer[List[Int]]()
  infNext1 = scala.collection.mutable.ListBuffer[List[Int]]()
  infLifeTester = scala.collection.mutable.MutableList[List[Int]]()

  currentState = printGrid(infCurrent)

  println(currentState.deep.mkString("\n"))
  //println("\n")

  colorData = colorGrid(colorIndexList)
  Draw.top.contents.repaint()
  currentState = Array.ofDim[Int](xDim, yDim)
  colorIndexList = scala.collection.mutable.ListBuffer[List[Int]]()
  colorData = Array.ofDim[Color](xDim, yDim)
  yes = 1

}

Answer 1

你不清楚混合var个可变元素的情况。您应该将var与被替换的不可变状态组合，或者使用可变状态（例如数组），但是就地更新它并且不要创建新数组。

在您的应用程序中，您创建一个DataPanel实例，该实例将colorData中存储的数组作为参数。但是在你的迭代中，你不是更新colorData的内容，而是实际创建一个全新的数组并替换变量colorData的值：

colorData = Array.ofDim[Color](xDim, yDim)

因此，在第一次迭代之后，您的全局状态与DataPanel中存储的状态不同。

如果您在colorData中重新使用该阵列，则需要更改colorGrid以将黑色指定给不活动的单元格。您现在使用null颜色为黑色，Color.WHITE为白色。定义val colorData = Array.ofDim[Boolean](xDim, yDim)会更有意义。在colorGrid中，您首先要将所有元素设置为false，然后迭代colorIndexList。

您应该将迭代定义为在每个步骤中调用的函数。现在你有一个无限循环while(yes == 1)，因为永远不会改变yes。执行此操作将冻结您的计算机。

另请注意，调用Draw.top并不是这样，因为您将其定义为函数;这会在你每次打电话时创建一个新窗口。始终使用lazy val top =来防止此问题。

---

你的代码仍然很乱，但至少你会有一些东西可以继续下去。这是一个最小的工作示例，仅包含上述更改：

import scala.collection.mutable.ListBuffer

val colorData = Array.ofDim[Boolean](xDim, yDim)

def colorGrid(colorIndexList: ListBuffer[List[Int]]): Unit = {
  colorData.foreach { row => java.util.Arrays.fill(row, false) } // all 'black'
  for (i <- colorIndexList) {
    colorData(i(0))(i(1)) = true  // some 'white'
  }
}

class DataPanel(data: Array[Array[Boolean]]) extends Panel {

  override def paintComponent(g: Graphics2D): Unit = {
    val dx = g.getClipBounds.width.toFloat  / data.length
    val dy = g.getClipBounds.height.toFloat / data.map(_.length).max
    for {
      x <- 0 until data.length
      y <- 0 until data(x).length
      x1 = (x * dx).toInt
      y1 = (y * dy).toInt
      x2 = ((x + 1) * dx).toInt
      y2 = ((y + 1) * dy).toInt
    } {
      g.setColor(if (data(x)(y)) Color.black else Color.white) // !
      g.fillRect(x1, y1, x2 - x1, y2 - y1)
    }
  }
}

def step(): Unit = {
  infLifeTester = infGetNeighbors(infCurrent)
  infNext = infStayAlive(infCurrent)
  infNext1 = infComeAlive(infLifeTester)
  infNext = scala.collection.mutable.ListBuffer.concat(infNext, infNext1)
  infCurrent = infNext

  infNext = scala.collection.mutable.ListBuffer[List[Int]]()
  infNext1 = scala.collection.mutable.ListBuffer[List[Int]]()
  infLifeTester = scala.collection.mutable.MutableList[List[Int]]()

  currentState = printGrid(infCurrent)

  println(currentState.deep.mkString("\n"))
  //println("\n")

  colorGrid(colorIndexList)
  currentState = Array.ofDim[Int](xDim, yDim)
  colorIndexList = scala.collection.mutable.ListBuffer[List[Int]]()
}

object Draw extends SimpleSwingApplication {
    lazy val life = new DataPanel(colorData) {
      preferredSize = new Dimension(500, 500)
    }

    lazy val top = new MainFrame {
    background = Color.RED
    title = "Shombo's Game of Life"
    val button = Button("Step") {
      step()             // updates colorData
      life.repaint()     // refreshes view
    }
    contents = new BoxPanel(Orientation.Vertical) {
      contents += life
      contents += button
    }
  }
}

运行：Draw.main(Array())