Adding an Annotation to a PdfFormXObject so the Annotation is reusable - pdf

I'm using iText 7 to construct reusable PDF components that I reuse across multiple pages within a document. I'm using iText-dotnet for this task (v7), using F# as the language. (This shouldn't be hard to follow for non-F# people as it's just iText calls :D)
I know how to add annotations to a Page, that isn't the issue. Adding the annotation to the page is as simple as page.AddAnnotation(newAnnotation).
Where I'm having difficulty, is that there is no "Page" associated with a Canvas when you are using a PdfFormXObject() to render a Pdf fragment.
let template = new PdfFormXObject(rect)
let templateCanvas = PdfCanvas(template, pageContext.Canvas.GetPdfDocument())
let newCanvas = new Canvas(templateCanvas, rect)
Once I have the new Canvas, I try to write to the Canvas and add the Annotation via Page.AddAnnotation(). The problem is that there is no Page attached to the PdfFormXObject!
// Create the destination and annotation (destPage is the pageNumber)
let dest = PdfExplicitDestination.CreateFitB(destPage)
let action = PdfAction.CreateGoTo(dest)
let annotation = PdfLinkAnnotation(rect)
let border = iText.Kernel.Pdf.PdfAnnotationBorder(0f, 0f, 0f)
// set up the Annotation with action and display information
annotation
.SetHighlightMode(PdfAnnotation.HIGHLIGHT_PUSH)
.SetAction(action)
.SetBorder(border)
|> ignore
// Try adding the annotation to the page BOOM! (There is *NO* page (null) associated with newCanvas)
newCanvas.GetPage().AddAnnotation(annotation) |> ignore // HELP HERE: Is there another way to do this?
The issue is that I do not know of a different way to set the Annotation on the canvas. Is there a way to render the annotation and just add the annotation directly to the canvas as raw PDF instructions?
Alternatively, is there a way create a different reusable PDF fragment in iText so I can also reuse the GoTo annotation.
N.B. I could split off the annotations and then apply them every time I use the PdfFormXObject() on a new page, but that sort of defeats the purpose of reusing Pdf fragments (template) in my final PDF to reduce it's size.
If you can point me in the right direction, that would be great.
Again, this is not how to add an annotation to a Page(), that's easy. It's how to add an annotation to a PdfFormXObject (or similar mechanism that I'm unaware of for constructing rusable Pdf fragments).
-- As per John's comments below:
I cannot seem to find any reference to single use annotations.
I'm aware of the following example link, so I modified it to look like this:
private static void Main(string[] args)
{
try
{
PdfDocument pdfDocument = new PdfDocument(new PdfWriter("TestMultiLink.pdf"));
Document document = new Document(pdfDocument);
string destinationName = "MyForwardDestination";
// Create a PdfStringDestination to use more than once.
var stringDestination = new PdfStringDestination(destinationName);
for (int page = 1; page <= 50; page++)
{
document.Add(new Paragraph().SetFontSize(100).Add($"{page}"));
switch (page)
{
case 1: // First use of PdfStringDestination
document.Add(new Paragraph(new Link("Click here for a forward jump", stringDestination).SetFontSize(20)));
break;
case 3: // Re-use the stringDestination
document.Add(new Paragraph(new Link("Click here for a forward jump", stringDestination).SetFontSize(10)));
break;
case 42:
pdfDocument.AddNamedDestination(destinationName, PdfExplicitDestination.CreateFit(pdfDocument.GetLastPage()).GetPdfObject());
break;
}
if (page < 50)
document.Add(new AreaBreak(AreaBreakType.NEXT_PAGE));
}
document.Close();
}
catch (Exception e)
{
Console.WriteLine($"Ouch: {e.Message}");
}
}
If you dig into the iText source for iText.Layout.Link, you'll see that the String Destination is added as an Annotation. Therefore, I'm not sure if John's answer is true anymore.
Does anyone know how I can convert the Annotation to a Dictionary and how I would go about adding the PdfDictionary (raw) info into the PftFormXObject?
Thanks

#johnwhitington is correct.
Per PDF specification, annotations can only be added to a page, they cannot be added to a form XObject. It is not a limitation of iText or any other PDF library.
Annotations cannot be reused, each annotation is a distinct object.

Related

PdfFormField simply does not hide when setting the visibility to HIDDEN

I'm setting the visibility of a PdfFormField to HIDDEN using the setVisibility() method with parameter PdfFormField.HIDDEN. Still, on flattening it, the field does not hide. Below is the code to do so.
File file = new File("path to PDF file");
baos = new ByteArrayOutputStream();
pdfDoc = new PdfDocument(new PdfReader(file.getAbsolutePath()), new PdfWriter("path to flattened PDF file"));
//This function removes all the permissions.
removePdfPermissions();
form = PdfAcroForm.getAcroForm(pdfDoc, true);
fields = form.getFormFields();
fields.get("HumanSubjectsText").setVisibility(PdfFormField.HIDDEN);
fields.get("HumanSubjects").setVisibility(PdfFormField.HIDDEN);
form.flattenFields();
pdfDoc.close();
Setting the values of the fields to empty string "" is a workaround, but not the proper way.
The fields "HumanSubjects" and "HumanSubjectsText" correspond to a checkbox and its correspond text on page 2. (Human Subjects)
Link to PDF file
The fields could not be hidden using iText library. In contrast to Bruno's comment, one of the methods from iText library worked well, the setValue(). I'm not quite sure why the setVisibility() fails.
However, I was able to hide the field using Master PDF editor tool. I've attached a screenshot of this tool, where you can change the visibility for a form field from the General tab.
An observation: In the com.itextpdf.forms.fields.PdfFormField some of the constants defined are as follows:
public static final int HIDDEN = 1;
public static final int VISIBLE_BUT_DOES_NOT_PRINT = 2;
public static final int HIDDEN_BUT_PRINTABLE = 3;
public static final int VISIBLE = 4;
The Master PDF editor also has similar options to hide a field. Please refer to the attached screenshot.
NOTE: My requirement was just to simply hide the field. It could be achieved programmatically by using a library like iText or with some PDF editor tool.

Why is flying saucer always printing PDF on A4 paper?

I'm trying to save an html document to PDF using flyingsaucer but the generated document always ends up having an A4 dimension when I look at the Document Properties from Adobe Reader (Page Size: 8.26 x 11.69 in).
I did read the documentation and I'm passing the css #page {size: letter;} style. And while it does have an effect on the output, the page size always remains 8.26 x 11.69 in Adobe Reader. For example, if I set the page size to legal, my PDF is still the size of a A4 but the top of the document is missing as if it had fell off the "paper".
I'm not sure if the problem falls on the itext side or the flying saucer side. I was using a fairly old version so my first step was to upgrade to the latest 9.1.6 version of flying saucer. I also moved from itext 2.0.8 to openPDF 1.0.1 but I'm still getting the same behavior.
I also traced in the debugger up to the com.lowagie.text.Document creation in ITextRenderer and at this point the document size passed is correct. That makes me think that the issue might be in openPDF / iText but I can't find what I'm doing wrong.
It turns out the PDF generation was correctly using the #page size declaration and the problem was occurring later in our software. What I had not noticed is that after the generation of the PDF another method was called to merge multiple PDFs into one. This method should probably not have been called, but that's another story.
The bottom line is this method created a new com.lowagie.text.Document(), which by default creates an A4 sized document, and then was iterating over all pages of the pdf, adding the pages to the new document using pdfWriter.getImportedPage(pdfReader, currentPage++). These imported pages did not retain their original size.
I fixed it by passing the page size of the fist page when creating the merged document object:
document = new Document(pdfReader.getPageSize(1));
The real problem is that you're (unwittingly) using software that is no longer supported. Anything that still has the namespace lowagie (the founder and CTO of iText) is really outdated.
If you simply want to convert HTML to pdf, why not use iText directly and cut out the middle-man?
We have multiple options for you.
XMLWorker (iText5 based code that converts HTML to pdf)
pdfHTML (iText7 based add-on that converts HTML5/CSS3 to pdf)
This is a rather extensive code-sample for using pdfHTML:
public void createPdf(String src, String dest, String resources) throws IOException {
try {
FileOutputStream outputStream = new FileOutputStream(dest);
WriterProperties writerProperties = new WriterProperties();
//Add metadata
writerProperties.addXmpMetadata();
PdfWriter pdfWriter = new PdfWriter(outputStream, writerProperties);
PdfDocument pdfDoc = new PdfDocument(pdfWriter);
pdfDoc.getCatalog().setLang(new PdfString("en-US"));
//Set the document to be tagged
pdfDoc.setTagged();
pdfDoc.getCatalog().setViewerPreferences(new PdfViewerPreferences().setDisplayDocTitle(true));
//Set meta tags
PdfDocumentInfo pdfMetaData = pdfDoc.getDocumentInfo();
pdfMetaData.setAuthor("Joris Schellekens");
pdfMetaData.addCreationDate();
pdfMetaData.getProducer();
pdfMetaData.setCreator("iText Software");
pdfMetaData.setKeywords("example, accessibility");
pdfMetaData.setSubject("PDF accessibility");
//Title is derived from html
// pdf conversion
ConverterProperties props = new ConverterProperties();
FontProvider fp = new FontProvider();
fp.addStandardPdfFonts();
fp.addDirectory(resources);//The noto-nashk font file (.ttf extension) is placed in the resources
props.setFontProvider(fp);
props.setBaseUri(resources);
//Setup custom tagworker factory for better tagging of headers
DefaultTagWorkerFactory tagWorkerFactory = new AccessibilityTagWorkerFactory();
props.setTagWorkerFactory(tagWorkerFactory);
HtmlConverter.convertToPdf(new FileInputStream(src), pdfDoc, props);
pdfDoc.close();
} catch (Exception e) {
e.printStackTrace();
}
}
You can find more information at http://itextpdf.com/itext7/pdfHTML

iTextSharp rotated PDF page reverts orientation when file is rasterized at print house

Using iTextSharp I am creating a PDF composed of a collection of existing PDFs, some of the included PDFs are landscape orientation and need to be rotated. So, I do the following:
private static void AdjustRotationIfNeeded(PdfImportedPage pdfImportedPage, PdfReader reader, int documentPage)
{
float width = pdfImportedPage.Width;
float height = pdfImportedPage.Height;
if (pdfImportedPage.Rotation != 0)
{
PdfDictionary pageDict = reader.GetPageN(documentPage);
pageDict.Put(PdfName.ROTATE, new PdfNumber(0));
}
if (width > height)
{
PdfDictionary pageDict = reader.GetPageN(documentPage);
pageDict.Put(PdfName.ROTATE, new PdfNumber(270));
}
}
This works great. The included PDFs rotated to portrait orientation if needed. The PDF prints correctly on my local printer.
This file is sent to a fulfillment house, and unfortunately, the landscape included files do not print properly when going through their printer and rasterization process. They use Kodak (Creo) NexRip 11.01 or Kodak (Creo) Prinergy 6.1. machines. The fulfillment house's suggestion is to: "generate a new PDF file after we rotate pages or make any changes to a PDF. It is as easy as exporting out to a PostScript and distilling back to a PDF."
I know iTextSharp doesn't support PostScript. Is there another way iTextSharp can rotate included PDFs to hold the orientation when rasterized?
First let me assure you that changing the rotation in the page dictionary is the correct procedure to achieve what you want. As far as I can see your code, there's nothing wrong with it. You are doing the right thing.
Unfortunately, you are faced with a third party product over which you have no control that is not doing the right thing. How to solve this?
I have written an example called IncorrectExample. I have named it that way because I don't want it to be used in a context that is different from yours. You can safely ignore all the warnings I added: they are not meant for you. This example is very specific to your problem.
Please try the following code:
public void manipulatePdf(String src, String dest)
throws IOException, DocumentException {
// Creating a reader
PdfReader reader = new PdfReader(src);
// step 1
Rectangle pagesize = getPageSize(reader, 1);
Document document = new Document(pagesize);
// step 2
PdfWriter writer
= PdfWriter.getInstance(document, new FileOutputStream(dest));
// step 3
document.open();
// step 4
PdfContentByte cb = writer.getDirectContent();
for (int i = 1; i <= reader.getNumberOfPages(); i++) {
pagesize = getPageSize(reader, i);
document.setPageSize(pagesize);
document.newPage();
PdfImportedPage page = writer.getImportedPage(reader, i);
if (isPortrait(reader, i)) {
cb.addTemplate(page, 0, 0);
}
else {
cb.addTemplate(page, 0, 1, -1, 0, pagesize.getWidth(), 0);
}
}
// step 4
document.close();
reader.close();
}
public Rectangle getPageSize(PdfReader reader, int pagenumber) {
Rectangle pagesize = reader.getPageSizeWithRotation(pagenumber);
return new Rectangle(
Math.min(pagesize.getWidth(), pagesize.getHeight()),
Math.max(pagesize.getWidth(), pagesize.getHeight()));
}
public boolean isPortrait(PdfReader reader, int pagenumber) {
Rectangle pagesize = reader.getPageSize(pagenumber);
return pagesize.getHeight() > pagesize.getWidth();
}
I have taken the pages.pdf file as an example. This file is special in the sense that it has two pages in landscape that are created in a different way:
one page is a page of which the width is smaller than the height (sounds like it's a page in portrait), but as there's a /Rotate value of 90 added to the page dictionary, it is shown in landscape.
the other page isn't rotated, but it has a height that is smaller than the width.
In my example, I am using the classes Document and PdfWriter to create a copy of the original document. This is wrong in general because it throws away all interaction. I should use PdfStamper or PdfCopy instead, but it is right in your specific case because you don't need the interactivity: the final purpose of the PDF is to be printed.
With Document, I create new pages using a new Rectangle that uses the lowest value of the dimensions of the existing page as the width and the highest value as the height. This way, the page will always be in portrait. Note that I use the method getPageSizeWithRotation() to make sure I get the correct width and height, taking into account any possible rotation.
I then add a PdfImportedPage to the direct content of the writer. I use the isPortrait() method to find out if I need to rotate the page or not. Observe that the isPortrait() method looks at the page size without taking into account the rotation. If we did take into account the rotation, we'd rotate pages that don't need rotating.
The resulting PDF can be found here: pages_changed.pdf
As you can see, some information got lost: there was an annotation on the final page: it's gone. There were specific viewer preferences defined for the original document: they're gone. But that shouldn't matter in your specific case, because all that matters for you is that the pages are printed correctly.

Possible to put HTML annotations on PDF?

I know that we can now put text, links and videos..but can we put HTML as annotation as well?
If there's a SDK, please point me to it as well.
I have tried to search as much as possible but couldn't find anything on it.
Updated: okay, here are more details. I'm creating a script to create a PDF from an image, and at the same time have to place annotations on top of the image. When the person click the annotation, the HTML will be shown. I understand there are link annotations and shape annotation, but what I'm looking for is the ability to place HTML markup/codes in the annotation. For example, i would be able to design a simple form or style some text or even a embed YouTube video.
I hope I'm clear.
Thanks!
Here goes a very basic sample code : Please add Itext jar in your project
Code :
import com.itextpdf.text.Document;
import com.itextpdf.text.PageSize;
import com.itextpdf.text.Rectangle;
import com.itextpdf.text.pdf.PdfWriter;
import com.itextpdf.text.Image;
//input is image in String format
public void createfromimage(String input){
Document document = new Document(PageSize.A4.rotate());
document.setMargins(0,0,0,0);
String output = "C:/Users/username/Downloads/text.pdf";
try {
FileOutputStream fileOutputStream = new FileOutputStream(output);
PdfWriter pdfWriter = PdfWriter.getInstance(document, fileOutputStream);
Image image = Image.getInstance(input);
document.setPageSize(new Rectangle(image.getWidth(),image.getHeight()));
document.open();
pdfWriter.open();
document.add(image);
document.close();
pdfWriter.close();
} catch (Exception e){
e.printStackTrace();
}
}
You can add annotations in above way, and for Link annotations, refer to link below :
https://pdfbox.apache.org/apidocs/org/apache/pdfbox/pdmodel/interactive/annotation/PDAnnotationLink.html
please note, this is just a simple example.

iText Pdf Header Removal for particular page

I'm generating a PDF with iText, in that I'm displaying a header and footer.
Now i want to remove header for a particular page.
For eg: If I'm generating a 50 pages pdf, for the final 50th I don't want to show header,
how could this be achieved?
Here's my code where I'm generating footer (header part removed).
public class HeaderAndFooter extends PdfPageEventHelper {
public void onEndPage (PdfWriter writer, Document document) {
Rectangle rect = writer.getBoxSize("art");
switch(writer.getPageNumber() % 2) {
case 0:
case 1:
ColumnText.showTextAligned(writer.getDirectContent(),
Element.ALIGN_CENTER, new Phrase(String.format("%d", writer.getPageNumber())),
300f, 62f, 0);
break;
}
}
}
Any suggestions? Thanks in advance.
You can use a 2-pass approach:
1st pass : generate the PDF file without header
2nd pass : stamp the header on all but the last page
Have a look at this example taken from the iText book. You'll just have to adapt the second pass by only going through the N-1 first pages:
int n = reader.getNumberOfPages() - 1;
instead of
int n = reader.getNumberOfPages();
I was also in need to do the same. I want to share how I resolved this issue.
The Idea is, for the automatic generation of header footer, we set page event on PDFWriter like:
HeaderAndFooter event= new HeaderAndFooter(); //HeaderAndFooter is the implementation of PdfPageEventHelper class
writer.setPageEvent(event);// writer is the instance of PDFWriter
So, before the content of the last page, We can remove the event:
event=null;
writer.setPageEvent(event);
It works for me without any error or exception.