migrate to Scala 3 new indent syntax

Author: bjornregnell

src/main/scala/introprog/BlockGame.scala

@@ -20,7 +20,7 @@ abstract class BlockGame(
   var framesPerSecond: Int = 50,
   val messageAreaHeight: Int = 2,
   val messageAreaBackground: Color = Color.gray.darker.darker
-) {
+):
   import introprog.PixelWindow
 
   /** Called when a key is pressed. Override if you want non-empty action.
@@ -85,78 +85,63 @@ abstract class BlockGame(
     * It draws only updated blocks aiming at the desired frame rate.
     * It calls each `onXXX` method if a corresponding event is detected.
     */
-  protected def gameLoop(stopWhen: => Boolean): Unit = while !stopWhen do {
+  protected def gameLoop(stopWhen: => Boolean): Unit = while !stopWhen do
     import PixelWindow.Event
     val t0 = System.currentTimeMillis
     pixelWindow.awaitEvent(MaxWaitForEventMillis.toLong)
-    while pixelWindow.lastEventType != PixelWindow.Event.Undefined do {
-      pixelWindow.lastEventType match {
+    while pixelWindow.lastEventType != PixelWindow.Event.Undefined do
+      pixelWindow.lastEventType match
         case Event.KeyPressed    => onKeyDown(pixelWindow.lastKey)
         case Event.KeyReleased   => onKeyUp(pixelWindow.lastKey)
         case Event.WindowClosed  => onClose()
         case Event.MousePressed  => onMouseDown(pixelWindow.lastMousePos)
         case Event.MouseReleased => onMouseUp(pixelWindow.lastMousePos)
         case _ =>
-      }
       pixelWindow.awaitEvent(1)
-    }
     gameLoopAction()
     drawUpdatedBlocks()
     val elapsed = System.currentTimeMillis - t0
-    if (gameLoopDelayMillis - elapsed) < MaxWaitForEventMillis then {
+    if (gameLoopDelayMillis - elapsed) < MaxWaitForEventMillis then
       onFrameTimeOverrun(elapsed)
-    }
     Thread.sleep((gameLoopDelayMillis - elapsed) max 0)
-  }
 
   /** Draw updated blocks and carry out post-update actions if any. */
-  private def drawUpdatedBlocks(): Unit = {
-    for x <- blockBuffer.indices do {
-      for y <- blockBuffer(x).indices do {
-        if isBufferUpdated(x)(y) then {
+  private def drawUpdatedBlocks(): Unit =
+    for x <- blockBuffer.indices do
+      for y <- blockBuffer(x).indices do
+        if isBufferUpdated(x)(y) then
           val pwx = x * blockSize
           val pwy = y * blockSize
           pixelWindow.fill(pwx, pwy, blockSize, blockSize, blockBuffer(x)(y))
           isBufferUpdated(x)(y) = false
-        }
-      }
-    }
     toDoAfterBlockUpdates.foreach(_.apply())
     toDoAfterBlockUpdates.clear()
-  }
 
   /** Erase all blocks to background color. */
-  def clearWindow(): Unit = {
+  def clearWindow(): Unit =
     pixelWindow.clear()
     clearMessageArea()
-    for x <- blockBuffer.indices do {
-      for y <- blockBuffer(x).indices do {
+    for x <- blockBuffer.indices do
+      for y <- blockBuffer(x).indices do
           blockBuffer(x)(y) = background
-      }
-    }
-  }
 
   /** Paint a block in color `c` at (`x`,`y`) in block coordinates. */
-  def drawBlock(x: Int, y: Int, c: Color): Unit = {
-    if blockBuffer(x)(y) != c then {
+  def drawBlock(x: Int, y: Int, c: Color): Unit =
+    if blockBuffer(x)(y) != c then
       blockBuffer(x)(y) = c
       isBufferUpdated(x)(y) = true
-    }
-  }
 
   /** Erase the block at (`x`,`y`) to `background` color. */
-  def eraseBlock(x: Int, y: Int): Unit = {
-    if blockBuffer(x)(y) != background then {
+  def eraseBlock(x: Int, y: Int): Unit =
+    if blockBuffer(x)(y) != background then
       blockBuffer(x)(y) = background
       isBufferUpdated(x)(y) = true
-    }
-  }
 
   /** Write `msg` in `color` in the middle of the window.
     * The drawing is postponed until the end of the current game loop
     * iteration and thus the text drawn on top of any updated blocks.
     */
-  def drawCenteredText(msg: String, color: Color = pixelWindow.foreground, size: Int = blockSize): Unit = {
+  def drawCenteredText(msg: String, color: Color = pixelWindow.foreground, size: Int = blockSize): Unit =
     toDoAfterBlockUpdates.append( () =>
       pixelWindow.drawText(
         msg,
@@ -165,23 +150,19 @@ abstract class BlockGame(
         size
       )
     )
-  }
 
  /** Write `msg` in `color` in the message area at ('x','y') in block coordinates. */
-  def drawTextInMessageArea(msg: String, x: Int, y: Int, color: Color = pixelWindow.foreground, size: Int = blockSize): Unit = {
+  def drawTextInMessageArea(msg: String, x: Int, y: Int, color: Color = pixelWindow.foreground, size: Int = blockSize): Unit =
     require(y < messageAreaHeight && y >= 0, s"not in message area: y = $y")
     require(x < dim._1 * blockSize && x >= 0, s"not in message area: x = $x")
     pixelWindow.drawText(msg, x * blockSize, (y + dim._2) * blockSize, color, size)
-  }
 
   /** Clear a rectangle in the message area in block coordinates. */
-  def clearMessageArea(x: Int = 0, y: Int = 0, width: Int = dim._1, height: Int = messageAreaHeight): Unit = {
+  def clearMessageArea(x: Int = 0, y: Int = 0, width: Int = dim._1, height: Int = messageAreaHeight): Unit =
     require(y < messageAreaHeight && y >= 0, s"not in message area: y = $y")
     require(x < dim._1 * blockSize && x >= 0, s"not in message area: x = $x")
     pixelWindow.fill(
       x * blockSize,     (y + dim._2) * blockSize,
       width * blockSize, messageAreaHeight * blockSize + blockSize / 2,
       messageAreaBackground
     )
-  }
-}

src/main/scala/introprog/Dialog.scala

@@ -1,19 +1,17 @@
 package introprog
 
 /** A module with utilities for creating standard GUI dialogs. */
-object Dialog {
+object Dialog:
   import javax.swing.{JFileChooser, JOptionPane, JColorChooser}
 
   Swing.init() // get platform-specific look and feel
 
   /** Show a file choice dialog starting in `startDir` with confirm `button` text. */
-  def file(button: String = "Open", startDir: String = "~"): String = {
+  def file(button: String = "Open", startDir: String = "~"): String =
     val fs = new JFileChooser(new java.io.File(startDir))
-    fs.showDialog(null, button) match {
+    fs.showDialog(null, button) match
       case JFileChooser.APPROVE_OPTION => Option(fs.getSelectedFile.toString).getOrElse("")
       case _ => ""
-    }
-  }
 
   /** Show a dialog with a `message` text. */
   def show(message: String): Unit = JOptionPane.showMessageDialog(null, message)
@@ -45,4 +43,3 @@ object Dialog {
     default: java.awt.Color = java.awt.Color.red
   ): java.awt.Color =
     Option(JColorChooser.showDialog(null, message, default)).getOrElse(default)
-}

src/main/scala/introprog/IO.scala

@@ -1,33 +1,31 @@
 package introprog
 
 /** A module with input/output operations from/to the underlying file system. */
-object IO {
+object IO:
   /**
     * Load a string from a text file called `fileName` using encoding `enc`.
     *
     * @param fileName the path of the file.
     * @param enc the encoding of the file.
     * @return the content loaded from the file.
     * */
-  def loadString(fileName: String, enc: String = "UTF-8"): String = {
+  def loadString(fileName: String, enc: String = "UTF-8"): String =
     var result: String = ""
     val source = scala.io.Source.fromFile(fileName, enc)
     try result = source.mkString finally source.close()
     result
-  }
 
   /**
     * Load string lines from a text file called `fileName` using encoding `enc`.
     *
     * @param fileName the path of the file.
     * @param enc the encoding of the file.
     * */
-  def loadLines(fileName: String, enc: String = "UTF-8"): Vector[String] = {
+  def loadLines(fileName: String, enc: String = "UTF-8"): Vector[String] =
     var result = Vector.empty[String]
     val source = scala.io.Source.fromFile(fileName, enc)
     try result = source.getLines().toVector finally source.close()
     result
-  }
 
   /**
     * Save `text` to a text file called `fileName` using encoding `enc`.
@@ -36,11 +34,10 @@ object IO {
     * @param fileName the path of the file.
     * @param enc the encoding of the file.
     * */
-  def saveString(text: String, fileName: String, enc: String = "UTF-8"): Unit = {
+  def saveString(text: String, fileName: String, enc: String = "UTF-8"): Unit =
     val f = new java.io.File(fileName)
     val pw = new java.io.PrintWriter(f, enc)
     try pw.write(text) finally pw.close()
-  }
 
   /**
     * Save `lines` to a text file called `fileName` using encoding `enc`.
@@ -58,23 +55,21 @@ object IO {
     * @param fileName the path of the file.
     * @return the serialized object.
     * */
-  def loadObject[T](fileName: String): T = {
+  def loadObject[T](fileName: String): T =
     val f = new java.io.File(fileName)
     val ois = new java.io.ObjectInputStream(new java.io.FileInputStream(f))
     try ois.readObject.asInstanceOf[T] finally ois.close()
-  }
 
   /**
     * Serialize `obj` to a binary file called `fileName`.
     *
     * @param obj the object to be serialized.
     * @param fileName the path of the file.
     * */
-  def saveObject[T](obj: T, fileName: String): Unit = {
+  def saveObject[T](obj: T, fileName: String): Unit =
     val f = new java.io.File(fileName)
     val oos = new java.io.ObjectOutputStream(new java.io.FileOutputStream(f))
     try oos.writeObject(obj) finally oos.close()
-  }
 
   /**
     * Test if a file with name `fileName` exists.
@@ -123,20 +118,18 @@ object IO {
     * @param from the path of the file to be moved.
     * @param to the path the file will be moved to.
     * */
-  def move(from: String, to: String): Unit = {
+  def move(from: String, to: String): Unit =
     import java.nio.file.{Files, Paths, StandardCopyOption}
     Files.move(Paths.get(from), Paths.get(to), StandardCopyOption.REPLACE_EXISTING)
-  }
 
     /**
     * Deletes `fileName`.
     *
     * @param fileName the path the file that will be deleted.
     * */
-  def delete(fileName: String): Unit = {
+  def delete(fileName: String): Unit =
     import java.nio.file.{Files, Paths}
     Files.delete(Paths.get(fileName))
-  }
 
     /**
     * Load image from file.
@@ -214,4 +207,3 @@ object IO {
 
 
 
-}