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Revision as of 10:40, 24 April 2009

For the following recipes you need to install HPDF, a pure Haskell PDF generation library.

1 Creating an empty PDF file

runPdf generates a PDF file in the file system. You need to pass it four things:

• a name for the PDF file
• document information, an instance of PDFDocumentInfo. You can use the data generated by standardDocInfo.
• the default page size, an instance of PDFRect.
• a PDF Action

Let's create an empty PDF file with the name "test1.pdf". We use addPage to add an empty page.

import Graphics.PDF
 
main :: IO ()
main = do
  let outputFileName= "test1.pdf"
  let documentInfo = standardDocInfo 
  let defaultPageSize = PDFRect 0 0 200 300
 
  runPdf outputFileName documentInfo defaultPageSize $ do
    addPage Nothing

2 Pages with different sizes

If you pass "Nothing" to addPage, the default page size will be used for the size of the new page. We can pass it a different size (an instance of PDFRect).

Let’s create three pages, the last two pages with different dimensions:

import Graphics.PDF
 
main :: IO ()
main = do
  let outputFileName= "test2.pdf"
  let documentInfo = standardDocInfo 
  let defaultPageSize = PDFRect 0 0 200 300
 
  runPdf outputFileName documentInfo defaultPageSize $ do
    addPage Nothing
    addPage $ Just $ PDFRect 0 0 100 100
    addPage $ Just $ PDFRect 0 0 150 150

3 Drawing a simple text

To draw a simple text you need to take the following steps:

• convert the text to a PDFString using toPDFString
• create a PDFFont, passing it
  • a FontName
  • a font size
• create a PDFText using text, passing it
  • the PDFFont from above
  • a x,y-coordinate
  • the PDFString from above
• create a Draw action using drawText and the PDFText from above
• draw on a given page using drawWithPage and the Draw action from above

Example:

import Graphics.PDF
 
main :: IO ()
main = do
  let outputFileName= "test3.pdf"
  let documentInfo = standardDocInfo 
  let defaultPageSize = PDFRect 0 0 200 300
 
  let pdfString = toPDFString "Hello World!"
  let pdfFont = PDFFont Times_Roman 32
  let pdfText = text pdfFont 10.0 10.0 pdfString
 
  runPdf outputFileName documentInfo defaultPageSize $ do
    page <- addPage Nothing
 
    drawWithPage page $ do
      drawText pdfText