Get, Update and Expand a Bookmark
Get Bookmarks
The Document object’s OutlineCollection collection contains all a PDF file’s bookmarks. This article explains how to get bookmarks from a PDF file, and how to get which page a particular bookmark is on.
To get the bookmarks, loop through the OutlineCollection collection and get each bookmark in the OutlineItemCollection. The OutlineItemCollection provides access to all the bookmark’s attributes. The following code snippet shows you how to get bookmarks from the PDF file.
void GettingBookmarks() {
String _dataDir("C:\\Samples\\Bookmarks\\");
// Open document
auto pdfDocument = MakeObject<Document>(_dataDir + u"UpdateBookmarks.pdf");
// Loop through all the bookmarks
for (auto outlineItem : pdfDocument->get_Outlines()) {
Console::WriteLine(u"Title :- " + outlineItem->get_Title());
Console::WriteLine(u"Is Italic :- " + outlineItem->get_Italic());
Console::WriteLine(u"Is Bold :- " + outlineItem->get_Bold());
Console::WriteLine(u"Color :- {0}", outlineItem->get_Color());
}
}
Getting a Bookmark’s Page Number
Once you have added a bookmark you can find out what page it is on by getting the destination PageNumber associated with the Bookmark object.
void GettingBookmarksPageNumber() {
String _dataDir("C:\\Samples\\Bookmarks\\");
// Create PdfBookmarkEditor
auto bookmarkEditor = MakeObject<Aspose::Pdf::Facades::PdfBookmarkEditor>();
// Open PDF file
bookmarkEditor->BindPdf(_dataDir + u"UpdateBookmarks.pdf");
// Extract bookmarks
auto bookmarks = bookmarkEditor->ExtractBookmarks();
for (auto bookmark : bookmarks) {
String strLevelSeprator("");
for (int i = 1; i < bookmark->get_Level(); i++) {
strLevelSeprator += u"---- ";
}
Console::WriteLine(u"Title :- " + strLevelSeprator + bookmark->get_Title());
Console::WriteLine(u"Page Number :- " + strLevelSeprator + bookmark->get_PageNumber());
Console::WriteLine(u"Page Action :- " + strLevelSeprator + bookmark->get_Action());
}
}
Update Bookmarks in a PDF Document
To update a bookmark in a PDF file, first, get the particular bookmark from the Document object’s OutlineColletion collection by specifying the bookmark’s index. Once you have retrieved the bookmark into OutlineItemCollection object, you can update its properties and then save the updated PDF file using the Save method. The following code snippets show how to update bookmarks in a PDF document.
void UpdateBookmarksInPDFDocument() {
String _dataDir("C:\\Samples\\Bookmarks\\");
// Open document
auto pdfDocument = MakeObject<Document>(_dataDir + u"UpdateBookmarks.pdf");
// Get a bookmark object
auto pdfOutline = pdfDocument->get_Outlines()->idx_get(1);
// Update the bookmark object
pdfOutline->set_Title(u"Updated Outline");
pdfOutline->set_Italic(true);
pdfOutline->set_Bold(true);
// Set the target page as 2
pdfOutline->set_Destination(MakeObject<Aspose::Pdf::Annotations::GoToAction>(pdfDocument->get_Pages()->idx_get(2)));
// Save output
pdfDocument->Save(_dataDir + u"Bookmarkupdated_output.pdf");
}
Update Child Bookmarks in a PDF Document
To update a child bookmark:
- Retrieve the child bookmark you want to update from the PDF file by first getting the parent bookmark and then the child bookmark using appropriate index values.
- Save the updated PDF file using the Save method.
The following code snippet shows you how to update child bookmarks in a PDF document.
void UpdateChildBookmarksInPDFDocument() {
String _dataDir("C:\\Samples\\Bookmarks\\");
// Open document
auto pdfDocument = MakeObject<Document>(_dataDir + u"UpdateBookmarks.pdf");
// Get a bookmark object
auto pdfOutline = pdfDocument->get_Outlines()->idx_get(1);
// Get child bookmark object
auto childOutline = pdfOutline->idx_get(1);
// Update the bookmark object
childOutline->set_Title(u"Updated Outline");
childOutline->set_Italic(true);
childOutline->set_Bold(true);
// Set the target page as 2
childOutline->set_Destination(MakeObject<Aspose::Pdf::Annotations::GoToAction>(pdfDocument->get_Pages()->idx_get(2)));
// Save output
pdfDocument->Save(_dataDir + u"Bookmarkupdated_output.pdf");
}
Expanded Bookmarks when viewing document
Bookmarks are held in the Document object’s OutlineItemCollection collection, itself in the OutlineCollection collection. However, we may have a requirement to have all the bookmarks expanded when viewing the PDF file.
In order to accomplish this requirement, we can set open status for each outline/bookmark item as Open. The following code snippet shows you how to set the open status for each bookmark as expanded in a PDF document.
void ExpandedBookmarks() {
String _dataDir("C:\\Samples\\Bookmarks\\");
auto doc = MakeObject<Document>(_dataDir + u"UpdateBookmarks.pdf");
// set page view mode i.e. show thumbnails, full-screen, show attachment panel
doc->set_PageMode(PageMode::UseOutlines);
// print total count of Bookmarks in PDF file
Console::WriteLine(doc->get_Outlines()->get_Count());
// traverse through each Outline item in outlines collection of PDF file
for (int counter = 1; counter <= doc->get_Outlines()->get_Count(); counter++) {
// set open status for outline item
doc->get_Outlines()->idx_get(counter)->set_Open(true);
}
// save the PDF file
doc->Save(_dataDir + u"Bookmarks_Expanded.pdf");
}