I create a PDF using iText. The content consists of text and I need to draw a line to delimit this text every 25 words as shown in the following image:
I'm aware there's a way of that I can extract text and text positions once I have a finished PDF, but considering I'm writing the text to the PDF file, I guess there could be a way of adding these lines during the creation process without really having to find the text position, right?
Posted on StackOverflow on Feb 25, 2015 by Matias Bello
Please take a look at the Every25Words example. In that example, I read a text file into a String with the readFile() method. I then split the text into words based on the occurrence of spaces, and I add each word one by one:
public void createPdf(String dest) throws IOException, DocumentException { Document document = new Document(); PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(dest)); writer.setPageEvent(new WordCounter()); writer.setInitialLeading(16); document.open(); String[] words = readFile().split("\\s+"); Chunk chunk = null; for (String word : words) { if (chunk != null) { document.add(new Chunk(" ")); } chunk = new Chunk(word); chunk.setGenericTag(""); document.add(chunk); } document.close(); }
The magic happens in this line:
writer.setPageEvent(new WordCounter()); ... chunk.setGenericTag("");
First we declare an instance of the WordCounter event. You may choose a better name for that class, as not only does it count words, it also draws a dashed line:
public class WordCounter extends PdfPageEventHelper { public int count = 0; @Override public void onGenericTag( PdfWriter writer, Document document, Rectangle rect, String text) { count++; if (count % 25 == 0) { PdfContentByte canvas = writer.getDirectContent(); canvas.saveState(); canvas.setLineDash(5, 5); canvas.moveTo(document.left(), rect.getBottom()); canvas.lineTo(rect.getRight(), rect.getBottom()); canvas.lineTo(rect.getRight(), rect.getTop()); canvas.lineTo(document.right(), rect.getTop()); canvas.stroke(); canvas.restoreState(); } } }
Do you see what we do between the saveState() and restoreState() method? We define a dash pattern, we move to the left of the page, we construct a path to the right of the word, then we draw a short upwards line, to finish the path with a line to the right. Once the path is constructed, we stroke the line.
This onGenericTag() method will be triggered every time a Chunk is added on which we used the setGenericTag method.
This is what the result looks like every25words.pdf:
Screen shot of result
Click this link if you want to see how to answer this question in iText 7.