In the colors section of this tutorial, we have learned that JavaFX nodes can be colored with various colors. However, we had only learned about coloring objects using setFill() method; we can also use animation to change the fill colors of a shape. This type of animation is known as Fill Transition.

Fill transition is a type of transition that changes the color of a JavaFX node during a specified period. This transition is commonly used in applications to conduct quizzes: where the option turns “green” if the answer is correct and “red” otherwise.

Fill Transition

Fill Transition is performed on a JavaFX node using the FillTransition class which belongs to the javafx.animation package. This class contains various properties which can be used to setup the animation on an object.

• duration − The duration of this FillTransition.

• shape − The target shape of this FillTransition.

• fromValue − Specifies the start color value for this FillTransition.

• toValue − Specifies the stop color value for this FillTransition.

Example

Following is the program which demonstrates Fill Transition in JavaFX. Save this code in a file with the name FillTransitionExample.java.

import javafx.animation.FillTransition; 
import javafx.application.Application; 
import javafx.scene.Group; 
import javafx.scene.Scene; 
import javafx.scene.paint.Color; 
import javafx.scene.shape.Circle; 
import javafx.stage.Stage; 
import javafx.util.Duration; 
         
public class FillTransitionExample extends Application { 
   @Override 
   public void start(Stage stage) {      
      //Drawing a Circle 
      Circle circle = new Circle(); 
      
      //Setting the position of the circle 
      circle.setCenterX(300.0f); 
      circle.setCenterY(135.0f); 
      
      //Setting the radius of the circle 
      circle.setRadius(100.0f); 
      
      //Setting the color of the circle 
      circle.setFill(Color.BROWN); 
      
      //Setting the stroke width of the circle 
      circle.setStrokeWidth(20); 
       
      //Creating the fill Transition 
      FillTransition fillTransition = new FillTransition(Duration.millis(1000)); 
      
      //Setting the shape for Transition 
      fillTransition.setShape(circle); 
      
      //Setting the from value of the transition (color) 
      fillTransition.setFromValue(Color.BLUEVIOLET);  
      
      //Setting the toValue of the transition (color) 
      fillTransition.setToValue(Color.CORAL); 
      
      //Setting the cycle count for the transition 
      fillTransition.setCycleCount(50); 
      
      //Setting auto reverse value to false 
      fillTransition.setAutoReverse(false);  
      
      //Playing the animation 
      fillTransition.play(); 
         
      //Creating a Group object  
      Group root = new Group(circle); 
         
      //Creating a scene object 
      Scene scene = new Scene(root, 600, 300);   
      
      //Setting title to the Stage
      stage.setTitle("Fill transition example"); 
         
      //Adding scene to the stage 
      stage.setScene(scene); 
         
      //Displaying the contents of the stage 
      stage.show(); 
   }      
   public static void main(String args[]){ 
      launch(args); 
   } 
}

Compile and execute the saved java file from the command prompt using the following commands.

javac --module-path %PATH_TO_FX% --add-modules javafx.controls FillTransitionExample.java 
java --module-path %PATH_TO_FX% --add-modules javafx.controls FillTransitionExample

Output

On executing, the above program generates a JavaFX window as shown below.