Thursday, January 19, 2017

JavaFX - Colors

To apply colors to an application, JavaFX provides various classes in the package javafx.scene.paint package. This package contains an abstract class named Paint and it is the base class of all the classes that are used to apply colors.

Using these classes, you can apply colors in the following patterns −
  • Uniform − In this pattern, color is applied uniformly throughout node.
  • Image Pattern − This lets you to fill the region of the node with an image pattern.
  • Gradient − In this pattern, the color applied to the node varies from one point to the other. It has two kinds of gradients namely Linear Gradient and Radial Gradient.
All those node classes to which you can apply color such as Shape, Text (including Scene), have methods named setFill() and setStroke(). These will help to set the color values of the nodes and their strokes respectively.
These methods accept an object of type Paint. Therefore, to create either of these type of images, you need to instantiate these classes and pass the object as a parameter to these methods.

Applying Color to the Nodes

To set uniform color pattern to the nodes, you need to pass an object of the class color to the setFill(), setStroke() methods as follows −
//Setting color to the text 
Color color = new Color.BEIGE 
text.setFill(color); 

//Setting color to the stroke 
Color color = new Color.DARKSLATEBLUE 
circle.setStroke(color);
In the above code block, we are using the static variables of the color class to create a color object.
In the same way, you can also use the RGB values or HSB standard of coloring or web hash codes of colors as shown below −
//creating color object by passing RGB values 
Color c = Color.rgb(0,0,255);   

//creating color object by passing HSB values
Color c = Color.hsb(270,1.0,1.0);  

//creating color object by passing the hash code for web 
Color c = Color.web("0x0000FF",1.0);

Example

Following is an example which demonstrates, how to apply color to the nodes in JavaFX. Here, we are creating a circle and text nodes and applying colors to them.
Save this code in a file with the name ColorExample.java.
import javafx.application.Application; 
import javafx.scene.Group; 
import javafx.scene.Scene; 
import javafx.scene.paint.Color; 
import javafx.stage.Stage; 
import javafx.scene.shape.Circle; 
import javafx.scene.text.Font; 
import javafx.scene.text.Text; 
         
public class ColorExample extends Application { 
   @Override 
   public void start(Stage stage) { 
      //Drawing a Circle 
      Circle circle = new Circle();    
      
      //Setting the properties of the circle 
      circle.setCenterX(300.0f); 
      circle.setCenterY(180.0f); 
      circle.setRadius(90.0f); 
       
      //Setting color to the circle 
      circle.setFill(Color.DARKRED);    
      
      //Setting the stroke width 
      circle.setStrokeWidth(3); 
      
      //Setting color to the stroke  
      circle.setStroke(Color.DARKSLATEBLUE);
      
      //Drawing a text 
      Text text = new Text("This is a colored circle"); 
      
      //Setting the font of the text 
      text.setFont(Font.font("Edwardian Script ITC", 50)); 
      
      //Setting the position of the text 
      text.setX(155); 
      text.setY(50); 
       
      //Setting color to the text 
      text.setFill(Color.BEIGE); 
      text.setStrokeWidth(2); 
      text.setStroke(Color.DARKSLATEBLUE); 
         
      //Creating a Group object  
      Group root = new Group(circle, text); 
         
      //Creating a scene object 
      Scene scene = new Scene(root, 600, 300);  
      
      //Setting title to the Stage 
      stage.setTitle("Color 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 ColorExample.java 
java ColorExample
On executing, the above program generates a JavaFX window as follows −
Color Example

Applying Image Pattern to the Nodes

To apply an image pattern to the nodes, instantiate the ImagePattern class and pass its object to the setFill(), setStroke() methods.
The constructor of this class accepts six parameters namely −
  • Image − The object of the image using which you want to create the pattern.
  • x and y − Double variables representing the (x, y) coordinates of origin of the anchor rectangle.
  • height and width − Double variables representing the height and width of the image that is used to create a pattern.
  • isProportional − This is a Boolean Variable; on setting this property to true, the start and end locations are set to be proportional.
ImagePattern radialGradient = new ImagePattern(dots, 20, 20, 40, 40, false);

Example

Following is an example which demonstrates how to apply image pattern to the nodes in JavaFX. Here, we are creating a circle and a text node and applying an image pattern to them.
Save this code in a file with name ImagePatternExample.java.
import javafx.application.Application; 
import javafx.scene.Group; 
import javafx.scene.Scene; 
import javafx.scene.image.Image; 

import javafx.scene.paint.Color; 
import javafx.scene.paint.ImagePattern; 
import javafx.scene.paint.Stop; 

import javafx.stage.Stage; 
import javafx.scene.shape.Circle; 
import javafx.scene.text.Font; 
import javafx.scene.text.Text; 
         
public class ImagePatternExample extends Application { 
   @Override 
   public void start(Stage stage) {           
      //Drawing a Circle 
      Circle circle = new Circle();    
      
      //Setting the properties of the circle 
      circle.setCenterX(300.0f); 
      circle.setCenterY(180.0f); 
      circle.setRadius(90.0f); 
       
      //Drawing a text 
      Text text = new Text("This is a colored circle"); 
      
      //Setting the font of the text 
      text.setFont(Font.font("Edwardian Script ITC", 50)); 
      
      //Setting the position of the text
      text.setX(155); 
      text.setY(50); 
       
      //Setting the image pattern 
      String link = "https://encrypted-tbn1.gstatic.com" 
         + "/images?q=tbn:ANd9GcRQub4GvEezKMsiIf67U" 
         + "rOxSzQuQ9zl5ysnjRn87VOC8tAdgmAJjcwZ2qM";       
      
      Image image = new Image(link); 
      ImagePattern radialGradient = new ImagePattern(image, 20, 20, 40, 40, false); 
       
      //Setting the linear gradient to the circle and text 
      circle.setFill(radialGradient); 
      text.setFill(radialGradient); 
         
      //Creating a Group object  
      Group root = new Group(circle, text); 
         
      //Creating a scene object 
      Scene scene = new Scene(root, 600, 300);  
      
      //Setting title to the Stage 
      stage.setTitle("Image pattern 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 ImagePatternExample.java 
java ImagePatternExample
On executing, the above program generates a JavaFX window as follows −
Image Pattern Example

Applying Linear Gradient Pattern

To apply a Linear Gradient Pattern to the nodes, instantiate the LinearGradient class and pass its object to the setFill(), setStroke() methods.
The constructor of this class accepts five parameters namely −
  • startX, startY − These double properties represent the x and y coordinates of the starting point of the gradient.
  • endX, endY − These double properties represent the x and y coordinates of the ending point of the gradient.
  • cycleMethod − This argument defines how the regions outside the color gradient bounds, defined by the starting and ending points, should be filled.
  • proportional − This is a Boolean Variable; on setting this property to true, the start and end locations are set to a proportion.
  • Stops − This argument defines the color-stop points along the gradient line.
//Setting the linear gradient 
Stop[] stops = new Stop[] { 
   new Stop(0, Color.DARKSLATEBLUE),  
   new Stop(1, Color.DARKRED)
};  
LinearGradient linearGradient = 
   new LinearGradient(0, 0, 1, 0, true, CycleMethod.NO_CYCLE, stops);

Example

Following is an example which demonstrates how to apply a gradient pattern to the nodes in JavaFX. Here, we are creating a circle and a text nodes and applying linear gradient pattern to them.
Save this code in a file with name LinearGradientExample.java.
import javafx.application.Application; 
import javafx.scene.Group; 
import javafx.scene.Scene; 

import javafx.scene.paint.Color; 
import javafx.scene.paint.CycleMethod; 
import javafx.scene.paint.LinearGradient; 
import javafx.scene.paint.Stop; 

import javafx.stage.Stage; 
import javafx.scene.shape.Circle; 
import javafx.scene.text.Font; 
import javafx.scene.text.Text; 
         
public class LinearGradientExample extends Application { 
   @Override 
   public void start(Stage stage) {           
      //Drawing a Circle 
      Circle circle = new Circle();    
      
      //Setting the properties of the circle 
      circle.setCenterX(300.0f);  
      circle.setCenterY(180.0f); 
      circle.setRadius(90.0f); 
      
      //Drawing a text 
      Text text = new Text("This is a colored circle"); 
      
      //Setting the font of the text 
      text.setFont(Font.font("Edwardian Script ITC", 55)); 
      
      //Setting the position of the text 
      text.setX(140); 
      text.setY(50); 
       
      //Setting the linear gradient 
      Stop[] stops = new Stop[] { 
         new Stop(0, Color.DARKSLATEBLUE),  
         new Stop(1, Color.DARKRED)
      };  
      LinearGradient linearGradient = 
         new LinearGradient(0, 0, 1, 0, true, CycleMethod.NO_CYCLE, stops); 
       
      //Setting the linear gradient to the circle and text 
      circle.setFill(linearGradient); 
      text.setFill(linearGradient); 
         
      //Creating a Group object  
      Group root = new Group(circle, text); 
         
      //Creating a scene object 
      Scene scene = new Scene(root, 600, 300);  
      
      //Setting title to the Stage 
      stage.setTitle("Linear Gradient 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 LinearGradientExample.java 
java LinearGradientExample
On executing, the above program generates a JavaFX window as follows −
Linear Gradient

Applying Radial Gradient Pattern

To apply a Radial Gradient Pattern to the nodes, instantiate the GradientPattern class and pass its object to the setFill(), setStroke() methods.
The constructor of this class accepts a few parameters, some of which are −
  • startX, startY − These double properties represent the x and y coordinates of the starting point of the gradient.
  • endX, endY − These double properties represent the x and y coordinates of the ending point of the gradient.
  • cycleMethod − This argument defines how the regions outside the color gradient bounds are defined by the starting and ending points and how they should be filled.
  • proportional − This is a Boolean Variable; on setting this property to true the start and end locations are set to a proportion.
  • Stops − This argument defines the color-stop points along the gradient line.
//Setting the radial gradient 
Stop[] stops = new Stop[] { 
   new Stop(0.0, Color.WHITE),  
   new Stop(0.3, Color.RED), 
   new Stop(1.0, Color.DARKRED) 
};        

RadialGradient radialGradient = 
   new RadialGradient(0, 0, 300, 178, 60, false, CycleMethod.NO_CYCLE, stops);

Example

Following is an example which demonstrates how to apply a radial gradient pattern to the nodes in JavaFX. Here, we are creating a circle and a text nodes and applying gradient pattern to them.
Save this code in a file with the name RadialGradientExample.java.
import javafx.application.Application; 
import javafx.scene.Group; 
import javafx.scene.Scene; 

import javafx.scene.paint.Color; 
import javafx.scene.paint.CycleMethod; 
import javafx.scene.paint.RadialGradient;  
import javafx.scene.paint.Stop; 

import javafx.stage.Stage; 
import javafx.scene.shape.Circle; 
import javafx.scene.text.Font; 
import javafx.scene.text.Text;   

public class RadialGradientExample extends Application {  
   @Override 
   public void start(Stage stage) { 
      //Drawing a Circle 
      Circle circle = new Circle(); 
      
      //Setting the properties of the circle 
      circle.setCenterX(300.0f); 
      circle.setCenterY(180.0f); 
      circle.setRadius(90.0f);  
      
      //Drawing a text 
      Text text = new Text("This is a colored circle"); 
      
      //Setting the font of the text 
      text.setFont(Font.font("Edwardian Script ITC", 50)); 
      
      //Setting the position of the text 
      text.setX(155); 
      text.setY(50);  
      
      //Setting the radial gradient 
      Stop[] stops = new Stop[] { 
         new Stop(0.0, Color.WHITE),  
         new Stop(0.3, Color.RED), 
         new Stop(1.0, Color.DARKRED) 
      };        
      RadialGradient radialGradient = 
         new RadialGradient(0, 0, 300, 178, 60, false, CycleMethod.NO_CYCLE, stops);  
      
      //Setting the radial gradient to the circle and text 
      circle.setFill(radialGradient); 
      text.setFill(radialGradient);  
      
      //Creating a Group object  
      Group root = new Group(circle, text);  
      
      //Creating a scene object 
      Scene scene = new Scene(root, 600, 300); 
      
      //Setting title to the Stage 
      stage.setTitle("Radial Gradient 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 RadialGradientExample.java 
java RadialGradientExample
On executing, the above program generates a JavaFX window as follows −
Radial Gradient
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