Liu Xuan, a Chinese programmer, had written a Frozen Bubble game in JavaFX. He is kind to allow me to share his code here. The game was originally developed in Perl/SDL. A java port is available too. Liu’s program implemented a simplified version of the Frozen Bubble game in JavaFX.

Click on the below button to start the game, use left/right arrow key to aim and space button to fire.

The key handling code is accomplished in the class Container:

public class Container extends CustomNode{
    public var bubbles = new HashMap();
    public var fadeBubbles: Bubble[];
    public var fallBubbles: Bubble[];
    public var gun: Gun = Gun{};
    public var shootAngle: Number;
    public var group: Group = Group {
        content: [
            // backgroud
            Rectangle {
                width: 320
                height: 480
                strokeWidth: 1
                stroke: Color.BLACK
                fill: LinearGradient {
                    startX: 0.0,
                    startY: 0.0,
                    endX: 0.0,
                    endY: 1.0
                    proportional: true
                    stops: [ Stop {
                            offset: 0.0
                            color: Color.YELLOWGREEN },
                        Stop {
                            offset: 1.0
                        color: Color.LIGHTBLUE } ]
                }
                onKeyPressed: function(e: KeyEvent):Void {
                      .......   // keyboard event handling
             }
            }
            gun
            //warning line
            Line {
                startX: 0,
                startY: Config.RED_LINE
                endX: 320
                endY: Config.RED_LINE
                strokeWidth: 1
                stroke: Color.RED
            }
            ImageView {
                  .......
            }
        ]
    };   

    public var inverseX = 1;   

    //semi-transparent layer for game over screen
    var layer = Rectangle {
        width: 320
        height: 480
        fill: Color.BLACK
        opacity: .4
    }
    var text = Text {
        content: "Press Enter To Start"
        font: Font {
            size: 20
        }
        x: 60
        y: 250
    }   

    // status of the game
    // 0 - game start and wait for shooting
    // 1 - bubble is moving
    // 2 - game over, the animation timeLine instanc
   // will stop at this value
    public var state = 2 on replace {
        if(state == 2) {
            timeline.stop();
            insert layer into group.content;
            insert text into group.content;
        }
    }   

    override public function create(): Node {
        group
    }   

   public function getLocation(row: Integer, col: Integer) : Point{
        var locationY = Config.ROW_SPACE * row;
        var locationX;
        if(row mod 2 == 0) {
            locationX = Config.BUBBLE_DIAMETER * col
        } else {
            locationX =
            Config.BUBBLE_DIAMETER * (col + .5) as Integer
        }
        return new Point(locationX, locationY)
    }   

   public function getAround(row: Integer, col: Integer): Bubble[] {
        var bArray: Bubble[] = [];
        var flag: Integer = 0;
        if(row mod 2 == 0) {
            flag = -1;
        }
        var bubble0 = getBubble(row, col - 1);
        var bubble1 = getBubble(row - 1, col + flag);
        var bubble2 = getBubble(row - 1, col + 1 + flag);
        var bubble3 = getBubble(row, col + 1);
        var bubble4 = getBubble(row + 1, col + flag);
        var bubble5 = getBubble(row + 1, col + 1 + flag);
        insert bubble0 into bArray;
        insert bubble1 into bArray;
        insert bubble2 into bArray;
        insert bubble3 into bArray;
        insert bubble4 into bArray;
        insert bubble5 into bArray;
        return bArray;
    }   

    public function getAround(bubble: Bubble): Bubble[] {
        var row: Integer = bubble.index.x;
        var col: Integer = bubble.index.y;
        return getAround(row, col);
    }

   public function getSameBubble(bubble: Bubble): Vector {
     var vector: Vector = new Vector();
     vector.add(bubble);
     var cursor = 0;
     while(
      cursor < vector.size()) {
        var bubbleInVector: Bubble =
        vector.get(cursor++) as Bubble;
        var aroundBubbles:Bubble[]=getAround(bubbleInVector);
        for(aroundBubble in aroundBubbles) {
          if ( aroundBubble != null
               and aroundBubble.color == bubble.color
               and vector.indexOf(aroundBubble) == - 1) {
               vector.add(aroundBubble);
                }
            }
        }
        return vector;
    }   

    public function getConnected(bubble: Bubble): Vector {
      var vector: Vector = new Vector();
      vector.add(bubble);
      var cursor = 0;
      while(cursor < vector.size()) {
        var bubbleInVector: Bubble =
        vector.get(cursor++) as Bubble;
        var aroundBubbles:Bubble[]=getAround(bubbleInVector);
        for(aroundBubble in aroundBubbles) {
            if ( aroundBubble != null
              and vector.indexOf(aroundBubble) == - 1) {
              vector.add(aroundBubble);
              }
            }
        }
        return vector;
    }   

  public function getIsolatedBubble(vector: Vector): Vector {
    var islatedBubble: Vector = new Vector();
      for(object in vector) {
        var sameBubble: Bubble = object as Bubble;
        var aroundBubbles:Bubble[] = getAround(sameBubble);
        for(aroundBubble in aroundBubbles) {
          if(aroundBubble != null) {
            var connectedBubble:Vector=getConnected(aroundBubble);
            var islate = true;
            for(col in [0..= 3) {
              for(object in vector) {
                var sameBubble: Bubble = object as Bubble;
                bubbles.remove(sameBubble.index);
                insert sameBubble into fadeBubbles;
              }
              for(object in getIsolatedBubble(vector)) {
                var islatedBubble: Bubble = object as Bubble;
                bubbles.remove(islatedBubble.index);
                insert islatedBubble into fallBubbles;
              }
            }
            state = 0;
            checkGameOver();
        }
    }   

    var timeCount = 0;   

    //moving, erasing, dropping the bubbles
    def timeline = Timeline {
        repeatCount: Timeline.INDEFINITE
        keyFrames:[
            KeyFrame {
                time: 0.005s
                action: function() {
                    ......
                    checkGameOver();
                    .......
            //reduce the transparency to erase the bubbles
            for(fadeBubble in fadeBubbles) {
                fadeBubble.opacity -= .02;
                if(fadeBubble.opacity <= 0) {
                   fadeBubble.visible = false;
                   delete fadeBubble from fadeBubbles;
                   delete fadeBubble from group.content;
                   }
              }
              //drop those isolated bubbles
              for(fallBubble in fallBubbles) {
                fallBubble.locationY += 5;
                if(fallBubble.locationY >= 428) {
                   fallBubble.visible = false;
                   delete fallBubble from fallBubbles;
                   delete fallBubble from group.content;
                   }
                 }   

                if(state == 1) {
                        ......
                //rebounce and collision handling
                checkCollision(bubble);
                }
              }
            }
        ]
    }   

    // initialization
    public function gameStart():Void {
          .....
          timeline.play();
    }
}

Source code can be downloaded here. Please note that Liu Xuan has the copyright of the code.