Class OutputHandler from the extension package is the base class for all vector graphics file formats. It provides a common basis for the yExport output handlers that enhance the yFiles library. OutputHandler is a direct subclass of abstract class IOHandler from package y.io of the yFiles library. Figure 12.1, “Output handler hierarchy in yExport” illustrates the yExport output handler hierarchy.

Figure 12.1. Output handler hierarchy in yExport

The code fragment in Example 12.1, “Instantiating a PDFOutputHandler” shows how to instantiate and use a PDFOutputHandler to export the content of a given Graph2DView to a PDF-encoded file.

public void exportPDF(Graph2DView view) {
  // Instantiate a PDF output handler and export the view's content.
  try {
    IOHandler ioh = new PDFOutputHandler();
    ioh.write(view.getGraph2D(), "MyPDF.pdf");
  }
  catch (IOException ioEx) {
    // Something went wrong. Complain.
  }
}

PDFExportDemo.java presents an extensive tutorial demo application that shows how to export a view's contents to PDF.

Class OutputHandler supports passing rendering hints to the underlying rendering system. Rendering hints can be used to control the quality of text rendering, for example. The following method allows to specify the hints:

void addRenderingHint(RenderingHints.Key key, Object value)