Batik Swing components

The goal of the Batik Swing component module is to provide a Swing component that can used to display SVG documents. With the JSVGCanvas class, you can easily display an SVG document (from a URI or a DOM tree) and allow the user to manipulate it, such as rotating, zooming, panning, selecting text or activating hyperlinks. First this document explains how to create a JSVGCanvas and integrate it in to a Swing application. Then, it descibes some advanced features such as the listener mechanism used to track all events that occurred while displaying or manipulating an SVG document.

Creating a JSVGCanvas

The following example illustrates how to create a JSVGCanvas , which is a Swing component that follows the Swing design rule. This means that the component is not thread safe and all operations on the component or the document it is displaying must be performed as described in the Swing tutorial . The JSVGCanvas is also a JavaBean , so it can be used in visual application builders. If you try this example, do not forget to set your CLASSPATH so that it contains the Batik classes and resources, as well as Xerces ( lib/xerces_2_5_0.jar ) and the XML APIs jars ( lib/xml-apis.jar and lib/xml-apis-ext.jar ).

import java.awt.;
import java.awt.event.;
import java.io.*;
import javax.swing.*;

import org.apache.batik.swing.JSVGCanvas;
import org.apache.batik.swing.gvt.GVTTreeRendererAdapter;
import org.apache.batik.swing.gvt.GVTTreeRendererEvent;
import org.apache.batik.swing.svg.SVGDocumentLoaderAdapter;
import org.apache.batik.swing.svg.SVGDocumentLoaderEvent;
import org.apache.batik.swing.svg.GVTTreeBuilderAdapter;
import org.apache.batik.swing.svg.GVTTreeBuilderEvent;

public class SVGApplication {

public static void main(String[] args) {
// Create a new JFrame.
JFrame f = new JFrame("Batik");
SVGApplication app = new SVGApplication(f);

// Add components to the frame.
f.getContentPane().add(app.createComponents());

// Display the frame.
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
f.setSize(400, 400);
f.setVisible(true);
}

// The frame.
protected JFrame frame;

// The "Load" button, which displays up a file chooser upon clicking.
protected JButton button = new JButton("Load...");

// The status label.
protected JLabel label = new JLabel();

// The SVG canvas.
protected JSVGCanvas svgCanvas = new JSVGCanvas();

public SVGApplication(JFrame f) {
frame = f;
}

public JComponent createComponents() {
// Create a panel and add the button, status label and the SVG canvas.
final JPanel panel = new JPanel(new BorderLayout());

JPanel p = new JPanel(new FlowLayout(FlowLayout.LEFT));
p.add(button);
p.add(label);

panel.add("North", p);
panel.add("Center", svgCanvas);

// Set the button action.
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
JFileChooser fc = new JFileChooser(".");
int choice = fc.showOpenDialog(panel);
if (choice == JFileChooser.APPROVE_OPTION) {
File f = fc.getSelectedFile();
try {
svgCanvas.setURI(f.toURL().toString());
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
});

// Set the JSVGCanvas listeners.
svgCanvas.addSVGDocumentLoaderListener(new SVGDocumentLoaderAdapter() {
public void documentLoadingStarted(SVGDocumentLoaderEvent e) {
label.setText("Document Loading...");
}
public void documentLoadingCompleted(SVGDocumentLoaderEvent e) {
label.setText("Document Loaded.");
}
});

svgCanvas.addGVTTreeBuilderListener(new GVTTreeBuilderAdapter() {
public void gvtBuildStarted(GVTTreeBuilderEvent e) {
label.setText("Build Started...");
}
public void gvtBuildCompleted(GVTTreeBuilderEvent e) {
label.setText("Build Done.");
frame.pack();
}
});

svgCanvas.addGVTTreeRendererListener(new GVTTreeRendererAdapter() {
public void gvtRenderingPrepare(GVTTreeRendererEvent e) {
label.setText("Rendering Started...");
}
public void gvtRenderingCompleted(GVTTreeRendererEvent e) {
label.setText("");
}
});

return panel;
}
}

Adding an Interactor

The JSVGCanvas provides a set of build-in interactors that let the users manipulate the displayed document, including ones for zooming, panning and rotating. Interactors catch user input to the JSVGCanvas component and translate them into behaviour. If you want to add new behaviors to the JSVGCanvas , you can implement the Interactor interface. Then, you can register this new interactor to the component by adding an element to the List returned by the getInteractors() method of the canvas.