Scalable Vector Graphics (SVG) has become a versatile and widely adopted format for rendering two-dimensional graphics on the web. It allows for rich, dynamic, and resolution-independent graphics, making it a favorite choice for web designers and developers. However, what if you want to bring SVG images to life outside of web browsers? This article explores the creation of an SVG viewer, and also demonstrates how to convert them into JavaFX-compatible BufferedImages.
What is SVG, and Why Does it Matter?
Before diving into the details of building an SVG viewer, it’s essential to understand what SVG is and why it’s a valuable asset for developers. SVG, or Scalable Vector Graphics, is a widely supported XML-based vector image format. Unlike raster images, SVGs are resolution-independent, ensuring they look crisp and clear at any size.
SVGs are particularly useful for displaying icons, maps, diagrams, and other graphical content that must adapt to various screen sizes and resolutions. By using JavaFX to create an SVG viewer, you can provide a responsive and visually appealing experience to your users.
Introducing the Batik Library
Batik is an open-source Java library developed by the Apache Software Foundation, which allows you to work with SVG content programmatically. This library is an invaluable resource when building an SVG viewer in JavaFX.
To get started, make sure to include the Batik library in your project’s dependencies. You can add it manually or use a build tool like Maven or Gradle to manage dependencies. The Batik library provides comprehensive support for SVG parsing, rendering, and manipulation, making it a perfect companion for our project. You can find the necessary JAR files and code for automation tools by visiting the official Batik download page at Download Apache(tm) Batik.
At the time of writing this article, the following dependency was the latest release available for Maven. To obtain the most up-to-date version, please visit their download page:
<dependency>
<groupId>org.apache.xmlgraphics</groupId>
<artifactId>batik-all</artifactId>
<version>1.17</version>
</dependency>Loading and Displaying SVG Files
Now, let’s start by loading and displaying an SVG file in your JavaFX application. The Batik library simplifies this process considerably. Below is a snippet demonstrating how to load and display an SVG file using JavaFX and Batik:
import javafx.application.Application;
import javafx.embed.swing.SwingNode;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.scene.Scene;
import org.apache.batik.swing.JSVGCanvas;
public class SVGViewerJSVGCanvasExample extends Application {
// The parent layout manager
private final StackPane parent = new StackPane();
@Override
public void init() throws Exception {
super.init();
buildUI();
}
private void buildUI() {
// Create an SVGViewer and add it to the parent StackPane
SVGViewer svgViewer = new SVGViewer("house.svg");
this.parent.getChildren().add(svgViewer);
}
@Override
public void start(Stage stage) throws Exception {
// Create a scene with the StackPane as the root
Scene scene = new Scene(parent, 640, 480);
// Set the stage title
stage.setTitle("Displaying SVG Images in JavaFX");
// Set the scene for the stage
stage.setScene(scene);
// Center the stage on the screen
stage.centerOnScreen();
// Display the stage
stage.show();
}
}
class SVGViewer extends SwingNode {
public SVGViewer(String svgFilePath) {
// Create a new JSVGCanvas
JSVGCanvas svgCanvas = new JSVGCanvas();
// Load an SVG document from the given file path
svgCanvas.setURI(svgFilePath);
// Wrap the JSVGCanvas in a SwingNode to integrate it into JavaFX
this.setContent(svgCanvas);
}
}In the code above, we create a JavaFX application with a JSVGCanvas component provided by the Batik library. We load the SVG file using the setURI method and then we wrap the JSVGCanvas in a SwingNode for integration with JavaFX.
Converting SVG to Image
While the previous section demonstrated how to load and display SVG files using the Batik library directly, there are situations where you might want to convert an SVG to an Image object, which can be more versatile for JavaFX applications. This can be particularly useful when you want to perform operations like scaling, compositing, or adding effects to the SVG image.
To convert an SVG to an Image, you can use the Apache Batik library in combination with JavaFX’s SwingFXUtils. The SwingFXUtils class provides methods for converting BufferedImage objects to JavaFX Image objects.
Here is an example of how you can convert an SVG to a JavaFX Image:
import javafx.application.Application;
import javafx.embed.swing.SwingFXUtils;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;
import javafx.scene.Scene;
import org.apache.batik.transcoder.TranscoderException;
import org.apache.batik.transcoder.TranscoderInput;
import org.apache.batik.transcoder.TranscoderOutput;
import org.apache.batik.transcoder.image.ImageTranscoder;
import java.awt.image.BufferedImage;
public class SVGViewerImageExample extends Application {
// The parent layout manager
private final StackPane parent = new StackPane();
@Override
public void init() throws Exception {
super.init();
buildUI();
}
private void buildUI() throws TranscoderException {
// Create an SVGConverter instance with the path to the SVG file
SVGConverter converter = new SVGConverter("house.svg");
// Convert the SVG to a JavaFX Image
Image image = converter.toImage();
// Display the SVG image using an ImageView
ImageView imageView = new ImageView(image);
// Add the ImageView to the parent layout
this.parent.getChildren().add(imageView);
}
@Override
public void start(Stage stage) throws Exception {
// Create a scene with the StackPane as the root
Scene scene = new Scene(parent, 640, 480);
// Set the stage title
stage.setTitle("Displaying SVG Images in JavaFX");
// Set the scene for the stage
stage.setScene(scene);
// Center the stage on the screen
stage.centerOnScreen();
// Display the stage
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
class SVGConverter extends ImageTranscoder {
private BufferedImage image;
public SVGConverter(String svgFilePath) throws TranscoderException {
// Initialize the SVGConverter with the path to the SVG file
TranscoderInput input = new TranscoderInput(svgFilePath);
this.transcode(input, null);
}
public BufferedImage toBufferedImage() {
return this.image;
}
public Image toImage() {
// Convert the BufferedImage to a JavaFX Image
return SwingFXUtils.toFXImage(this.toBufferedImage(), null);
}
@Override
public BufferedImage createImage(int width, int height) {
// Create a new BufferedImage with the specified width and height
return new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
}
@Override
public void writeImage(BufferedImage img, TranscoderOutput output) throws TranscoderException {
// Store the converted image in the 'image' variable
image = img;
}
}In this code, the SVGConverter class provides a method toImage() to convert an SVG to a JavaFX Image. It utilizes the SwingFXUtils class to perform the conversion.
By converting SVG to an Image, you gain the flexibility to use JavaFX’s extensive set of features for image manipulation and integration into your user interface. This approach allows you to apply transformations, create thumbnails, or use the SVG as part of a larger composition within your JavaFX application.
Conclusion
In this article, we’ve delved into the world of SVG images in JavaFX. We explored the benefits of using SVG as a versatile and responsive image format and introduced the Batik library, a powerful tool for working with SVG in Java applications.
We demonstrated how to load and display SVG files in JavaFX using Batik, creating a simple SVG viewer. Additionally, we covered the process of converting SVG to images, allowing for further manipulation or integration into your JavaFX applications.
With this knowledge in hand, you’re well-equipped to create visually engaging and responsive user interfaces in JavaFX using SVG images. Whether it’s interactive maps, icons, diagrams, or any other graphical content, JavaFX and Batik provide the tools to bring your vision to life. Start exploring the world of SVG in JavaFX and unlock new possibilities in your software development journey.
I hope you found this article informative and useful. If you would like to receive more content, please consider subscribing to our newsletter.
