Add pause

Tetris Mac/TetrisHostingView.swift

@@ -42,6 +42,8 @@ class TetrisHostingView: NSHostingView<ContentView> {
             gameController.rotate(direction: .clockwise)
         case kVK_DownArrow:
             gameController.drop()
+        case kVK_Space:
+            gameController.togglePause()
         default:
             super.keyDown(with: event)
         }

TetrisKit/GameController.swift

@@ -14,6 +14,7 @@ public class GameController: ObservableObject {
     public let width = 10
     public let height = 20
     
+    var paused = false
     public var state: GameState = .waitingForStart
     
     @Published public var board: GameBoard
@@ -111,6 +112,7 @@ public class GameController: ObservableObject {
     
     public func step() {
         guard case .playing(_) = state,
+            !paused,
             let currentPiece = currentPiece else { return }
         
         let modifiedPiece = currentPiece.moved(by: (0, 1))
@@ -123,6 +125,7 @@ public class GameController: ObservableObject {
     
     public func rotate(direction: RotationDirection) {
         guard case let .playing(playState) = state,
+            !paused,
             playState != .dropped,
             let currentPiece = currentPiece else { return }
         
@@ -134,6 +137,7 @@ public class GameController: ObservableObject {
     
     public func left() {
         guard case let .playing(playState) = state,
+            !paused,
             playState != .dropped,
             let currentPiece = currentPiece else { return }
         let modifiedPiece = currentPiece.moved(by: (-1, 0))
@@ -145,6 +149,7 @@ public class GameController: ObservableObject {
     public func right() {
         guard case let .playing(playState) = state,
             playState != .dropped,
+            !paused,
             let currentPiece = currentPiece else { return }
         let modifiedPiece = currentPiece.moved(by: (1, 0))
         if !overlapsAny(modifiedPiece) {
@@ -153,13 +158,16 @@ public class GameController: ObservableObject {
     }
     
     public func drop() {
-        guard case let .playing(playState) = state, playState != .dropped else { return }
+        guard case let .playing(playState) = state,
+            !paused,
+            playState != .dropped else { return }
         currentPiece = currentPieceAtDropPoint
         state = .playing(.dropped)
     }
     
     public func hold() {
         guard case .playing(.normal) = state,
+//            !paused,
             let currentPiece = currentPiece else { return }
         if let heldTetromino = heldTetromino {
             self.heldTetromino = currentPiece.tetromino
@@ -171,6 +179,10 @@ public class GameController: ObservableObject {
         state = .playing(.switched)
     }
     
+    public func togglePause() {
+        paused = !paused
+    }
+    
     private func updateCurrentPieceAtDropPoint() {
         guard let currentPiece = currentPiece else { return }
         var prev = currentPiece