{"id":111,"date":"2015-12-08T10:39:10","date_gmt":"2015-12-08T15:39:10","guid":{"rendered":"http:\/\/jsevy.com\/wordpress\/?page_id=111"},"modified":"2022-03-08T12:22:55","modified_gmt":"2022-03-08T17:22:55","slug":"android-pdf-library","status":"publish","type":"page","link":"https:\/\/jsevy.com\/wordpress\/index.php\/java-and-android\/android-apps-and-libraries\/android-pdf-library\/","title":{"rendered":"Android PDF Library (GnuAPDF)"},"content":{"rendered":"

The GnuAPDF library provides support for generation of PDF files using standard Android “draw” commands. The library provides a special Canvas subclass, PDFCanvas, that is associated with a PDF document and that renders draw commands into PDF syntax. A sequence of Android Canvas drawing method calls will thus create a structured PDF document that, when viewed with a standard PDF reader, will display the corresponding image. Note that Android version 5.0 has this functionality as part of the standard API; however, earlier versions did not provide PDF generation, and the Android support library didn’t include this as of the time of this writing.<\/p>\n

This library is derived from the GnuJPDF library<\/a>, which provides similar functionality for the Java AWT graphics system, and as such is similarly released under the LGPL License<\/a>.<\/p>\n

 <\/p>\n

Basic Workflow<\/h2>\n

The class PDFCanvas implements the graphics operations defined by the standard Android Canvas class. To draw something into a PDF document, you use the standard Android Canvas drawing calls (including drawing, transformations, clips, etc.) on an instance of PDFCanvas. The PDFCanvas will encode these as PDF drawing commands.<\/p>\n

A PDFCanvas is associated with a PDFPage, which is part of a PDFDocument. The basic workflow is:<\/p>\n

\/\/ Create a PDF document, a page in the document, and get that page’s PDFCanvas
\nPDFDocument pdfDoc = new PDFDocument();
\nPDFPage page = new PDFPage(PageFormat.LETTER);
\npdfDoc.add(page);
\nPDFCanvas pdfCanvas = page.getCanvas();<\/p>\n

\/\/ do drawing commands as on any other Canvas
\nPaint paint = new Paint();
\npaint.setColor(Color.RED);
\npaint.setTypeface(Typeface.SERIF);
\npaint.setTextSize(38);
\npaint.setStyle(Style.STROKE);
\npdfCanvas.drawLine(0, 0,100, 100, paint);
\npdfCanvas.drawRect(120, 180, 400, 400, paint);
\npdfCanvas.drawText(“Some text”, 200, 600, paint);
\npaint.setStyle(Style.FILL);
\npdfCanvas.drawCircle(300, 300, 100, paint);<\/p>\n

\/\/ write the PDF content for the page to a file
\nBufferedOutputStream fileStream = new BufferedOutputStream(new FileOutputStream(file));
\npdfDoc.write(outStream);
\nfileStream.flush();
\nfileStream.close();<\/p>\n

Features<\/h2>\n

The GnuAPDF library provides most of the drawing operations available in the standard Canvas class. However, certain methods are unimplemented due to lack of support in PDF; these will throw an UnsupportedOperationException if used. Some additional features currently have no or limited support, as indicated below.<\/p>\n

Supported operations<\/h3>\n