JavaFX 8 scale node for printing without changing displayed node - javafx

Question

In JavaFX 8, I am printing a node (e.g., ScatterChart) with printerJob.printPage(). Without scaling, the printed node is cropped. If I scale for printing, then the printed node is correctly fit to the page, but the displayed node is scaled. A simple solution would be to make a copy/clone of the node, but it appears that isn't supported. Is there a better solution than scaling the node and then removing the scaling (which causes the displayed node to briefly rescale, which is unsightly)? It would seem that printing a graph would be a basic operation for JavaFX.

Answer 1

You can play with this app. It creates a PNG of the chart. It then prints the chart. I didn't scale the image. The actual image is located in your source folder. You can also open it using Paint and print from there. You can also code the printer settings so that the printer dialog shows up before printing.
import java.awt.Graphics;
import java.awt.print.PageFormat;
import java.awt.print.Printable;
import static java.awt.print.Printable.NO_SUCH_PAGE;
import static java.awt.print.Printable.PAGE_EXISTS;
import java.awt.print.PrinterException;
import java.awt.print.PrinterJob;
import java.io.File;
import java.io.IOException;
import javafx.application.Application;
import javafx.embed.swing.SwingFXUtils;
import javafx.scene.Scene;
import javafx.scene.SnapshotParameters;
import javafx.scene.chart.BarChart;
import javafx.scene.chart.CategoryAxis;
import javafx.scene.chart.NumberAxis;
import javafx.scene.chart.XYChart;
import javafx.scene.control.Button;
import javafx.scene.image.Image;
import javafx.scene.image.WritableImage;
import javafx.scene.layout.StackPane;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javax.imageio.ImageIO;
/**
*
* #author blj0011
*/
public class JavaFXApplication145 extends Application
{
final static String itemA = "A";
final static String itemB = "B";
final static String itemC = "F";
#Override
public void start(Stage stage) {
final NumberAxis xAxis = new NumberAxis();
final CategoryAxis yAxis = new CategoryAxis();
final BarChart<Number, String> bc = new BarChart<Number, String>(xAxis, yAxis);
bc.setTitle("Summary");
xAxis.setLabel("Value");
xAxis.setTickLabelRotation(90);
yAxis.setLabel("Item");
XYChart.Series series1 = new XYChart.Series();
series1.setName("2003");
series1.getData().add(new XYChart.Data(2, itemA));
series1.getData().add(new XYChart.Data(20, itemB));
series1.getData().add(new XYChart.Data(10, itemC));
XYChart.Series series2 = new XYChart.Series();
series2.setName("2004");
series2.getData().add(new XYChart.Data(50, itemA));
series2.getData().add(new XYChart.Data(41, itemB));
series2.getData().add(new XYChart.Data(45, itemC));
XYChart.Series series3 = new XYChart.Series();
series3.setName("2005");
series3.getData().add(new XYChart.Data(45, itemA));
series3.getData().add(new XYChart.Data(44, itemB));
series3.getData().add(new XYChart.Data(18, itemC));
Button button = new Button("Print Chart");
button.setOnAction((event)->{printImage(saveAsPng(bc));});//Create the image and print it.
VBox vbox = new VBox();
vbox.getChildren().add(bc);
StackPane stackPane = new StackPane();
stackPane.getChildren().add(button);
vbox.getChildren().add(stackPane);
Scene scene = new Scene(vbox, 800, 600);
bc.getData().addAll(series1, series2, series3);
stage.setScene(scene);
stage.show();
}
/**
* #param args the command line arguments
*/
public static void main(String[] args)
{
launch(args);
}
public File saveAsPng(BarChart barChart) {
WritableImage image = barChart.snapshot(new SnapshotParameters(), null);
// TODO: probably use a file chooser here
File file = new File("chart.png");
try {
ImageIO.write(SwingFXUtils.fromFXImage(image, null), "png", file);
} catch (IOException e) {
// TODO: handle exception here
}
return file;
}
private void printImage(File file) {
Image image = new Image(file.toURI().toString());
java.awt.image.BufferedImage bufferedImage = SwingFXUtils.fromFXImage(image, null);
PrinterJob printJob = PrinterJob.getPrinterJob();
printJob.setPrintable(new Printable() {
#Override
public int print(Graphics graphics, PageFormat pageFormat, int pageIndex) throws PrinterException {
// Get the upper left corner that it printable
int x = (int) Math.ceil(pageFormat.getImageableX());
int y = (int) Math.ceil(pageFormat.getImageableY());
if (pageIndex != 0) {
return NO_SUCH_PAGE;
}
graphics.drawImage(bufferedImage, x, y, bufferedImage.getWidth(), bufferedImage.getHeight(), null);
return PAGE_EXISTS;
}
});
try {
printJob.print();
} catch (PrinterException e1) {
e1.printStackTrace();
}
}
}