In one of my projects I use JUNG2 to visualize a very large multiple-parent hierarchy graph, displayed in an applet. I would need to export the whole/parts of the graph to high resolution still images, since screenshots look hideous when printed (especially if the graph has been zoomed out).
The code I use currently is as follows:
public void writeToDisk(File saveToFolder, String filename) {
//Dimension loDims = getGraphLayout().getSize();
Dimension vsDims = getSize();
int width = vsDims.width;
int height = vsDims.height;
Color bg = getBackground();
BufferedImage im = new BufferedImage(width,height,BufferedImage.TYPE_INT_BGR);
Graphics2D graphics = im.createGraphics();
graphics.setColor(bg);
graphics.fillRect(0,0, width, height);
paintComponent(graphics);
try{
ImageIO.write(im,"png",new File(saveToFolder,filename));
}catch(Exception e){
e.printStackTrace();
}
}
This creates PNG images which are not particularly high resolution. So my questions are as follows:
Thanks in advance,
Thanks for the suggestions but I have managed to get FreeHEP Vector Graphics library working the way I want to. I am sharing the code below in case anyone runs into the same questions.
The above-named library has a very nice built-in export menu, which handles the export to a bunch of different formats. Code excerpt from the modified ´ModelGraphMouse´ class:
protected void handlePopup(MouseEvent e) {
final VisualizationViewer<MyNode, MyEdge> vv = (VisualizationViewer<MyNode, MyEdge>)e.getSource();
Point2D p = e.getPoint();
GraphElementAccessor<MyNode, MyEdge> pickSupport = vv.getPickSupport();
if(pickSupport != null) {
final MyNode v = pickSupport.getVertex(vv.getGraphLayout(), p.getX(), p.getY());
// if clicked on a vertex -> show info popup
// else show contexual menu
if(v != null) {
JFrame popup = new JFrame("Node: " + v.getId());
popup.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
...
} else{
JPopupMenu menu = new JPopupMenu();
JMenuItem exportGraphMenuItem = new JMenuItem("Export graph to vector image...");
exportGraphMenuItem.addActionListener(new ExportActionListener((WritingVisualizationViewer<V, E>) vv));
menu.add(exportGraphMenuItem);
menu.show(e.getComponent(), e.getX(), e.getY());
}
}
}
and the action listener:
public class ExportActionListener implements ActionListener{
private VisualizationViewer<V, E> wvv;
public ExportActionListener(VisualizationViewer<V, E> vv) {
this.wvv = vv;
}
@Override
public void actionPerformed(ActionEvent e) {
ExportDialog export = new ExportDialog();
export.showExportDialog(wvv, "Export view as ...", wvv, "export");
}
}
Basically a PNG suffices. The dimension of resolution in a BufferedImage is pixels, not dpi. So you need to double/triple your width
and height
to receive a better resolution.
Graphics2D could scale too for the JUNG graphs.
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