JavaFX Text create animation

import javafx.animation.KeyFrame;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.text.Font;
import javafx.scene.text.Text;
import javafx.stage.Stage;
import javafx.util.Duration;

public class Main extends Application {
  @Override//  w  ww .  ja v  a  2 s  .co  m
  public void start(Stage primaryStage) {    
    Time time = new Time();
    Text text = new Text("00:00:00");
  
    Timeline animation = new Timeline(
      new KeyFrame(Duration.millis(1000), e -> {
        time.increase();
        text.setText(time.toString());
      }));
    animation.setCycleCount(Timeline.INDEFINITE);

    HBox hBox = new HBox(5);
    Button btStart = new Button("Start");
    Button btClear = new Button("Clear");
    hBox.getChildren().addAll(btStart, btClear);
    hBox.setAlignment(Pos.CENTER);
    
    btStart.setOnAction(e -> {
      if (btStart.getText().equals("Start")) {
        btStart.setText("Pause");
        animation.play();
      } 
      else if (btStart.getText().equals("Pause")) {
        btStart.setText("Resume");
        animation.pause();
      } 
      else if (btStart.getText().equals("Resume")) {
        btStart.setText("Pause");
        animation.play();
      } 
    });
    
    btClear.setOnAction(e -> {
      text.setText("00:00:00");
      animation.pause();
      btStart.setText("Start");
    });
    
    text.setFont(Font.font("Times", 35));
    
    BorderPane pane = new BorderPane();
    pane.setBottom(hBox);
    pane.setCenter(text);
    

    Scene scene = new Scene(pane, 200, 100);
    primaryStage.setTitle("Exercise16_20");
    primaryStage.setScene(scene);
    primaryStage.show();
  }


  public static void main(String[] args) {
    launch(args);
  }

  static class Time {
    int value = 0;
    
    int getSecond() {
      return value % 60;
    }
    
    int getMinute() {
      return (value / 60) % 60;
    }
    
    int getHour() {
      return value / 3600;
    }  
    
    void reset() {
      value = 0;
    }
    
    void increase() {
      value++;
    }
    
    @Override
    public String toString() {
      return getTwoDigitString(getHour()) + ":" + getTwoDigitString(getMinute())
        + ":" + getTwoDigitString(getSecond());
    }
    
    static String getTwoDigitString(int v) {
      if (v < 10)
        return "0" + v;
      else
        return "" + v;
    }
  }
}