GradientPaint and TexturePaint supported when creating PDFs with jPDFWriter

Qoppa PDF Library jPDFWriter defines a PDFGraphics class which extends Java Graphics2D. Many of the Graphics2D functions are supported (though not all), allowing users to get a graphics object from a PDF page (calling page.createGraphics()) and then drawing onto the page in the same way you would draw to Graphics2D.

Graphics2D has a setPaint() method but in jPDFWriter subclass PDFGraphics, not all paints are supported. You can set the paint to GradientPaint or TexturePaint but LinearGradientPaint and RadialGradientPaint are not supported.

Texture Paint with a red ellipse
Gradient Paint with a red ellipse

 

See below for a sample Java program that creates a new PDF documents, add pages to it, sets the paint to either GradientPaint or TexturePaint and draws an oval onto the page.

// create a new PDF
PDFDocument pdfDoc = new PDFDocument();
 
// create a new page format
PageFormat pageFormat = new PageFormat();
int x = (int) pageFormat.getImageableX();
int y = (int) pageFormat.getImageableY();
int w = (int) pageFormat.getImageableWidth();
int h = (int) pageFormat.getImageableHeight();
 
// define paints array
Paint[] paints = new Paint[2];
 
// gradient paint
paints[0] = new GradientPaint(x, y, Color.BLUE, x, y + h, Color.YELLOW);
 
// texture paint
BufferedImage bi = new BufferedImage(5, 5, BufferedImage.TYPE_INT_RGB);
Graphics2D big = bi.createGraphics();
big.setColor(Color.blue);
big.fillRect(0, 0, 5, 5);
big.setColor(Color.lightGray);
big.fillOval(0, 0, 5, 5);
Rectangle r = new Rectangle(0, 0, 5, 5);
paints[1] = new TexturePaint(bi, r);
 
// linear gradient paint is NOT supported
//paints[2] = new LinearGradientPaint(x, y, x, y + h, new float[]{0f, 1f}, new Color[]{Color.BLUE, Color.YELLOW});
 
// radial gradient paint is NOT supported
//paints[3] = new RadialGradientPaint(x + w / 2, y + h / 2, w / 2, new float[]{0f, 1f}, new Color[]{Color.BLUE, Color.YELLOW});
 
// for each paint
for (Paint paint : paints)
{
// create and add a new page
PDFPage page = pdfDoc.createPage(pageFormat);
pdfDoc.addPage(page);
// get the graphics for this page
Graphics2D g = (Graphics2D) page.createGraphics();
// set paint
g.setPaint(paint);
g.fillRect(x, y, w, h);
g.setPaint(Color.RED);
// draw an oval
g.drawOval(x + 100, y + 100, w - 200, h - 200);
}
try
{
pdfDoc.saveDocument("C://test//Gradient.pdf");
}
catch(Throwable t)
{
t.printStackTrace();
}