Bookmarks in Flutter PDF

5 May 20216 minutes to read

The Syncfusion Flutter PDF provides support to add bookmarks to a PDF document to navigate interactively from one part of the document to another. It provides customization such as title font, color, size and more. It also provides support to insert, remove, and modify the bookmarks in an existing PDF Document.

Adding bookmarks to a PDF

The PdfBookmarkBase collection represents the bookmarks in a PDF document. You can add a bookmark to a new PDF document using PdfBookmark class. Refer to the following code example.

  • dart
  • //Create a new PDF document
    PdfDocument document = PdfDocument();
    
    //Creates document bookmark
    PdfBookmark bookmark = document.bookmarks.add('page 1');
    
    //Sets the destination page and destination location
    bookmark.destination = PdfDestination(document.pages.add(), Offset(100, 100));
    
    //Sets the text style
    bookmark.textStyle = [PdfTextStyle.bold];
    
    //Sets the bookmark color(RGB)
    bookmark.color = PdfColor(255, 0, 0);
    
    //Save the document
    File('Output.pdf').writeAsBytes(document.save());
    
    //Dispose the document
    document.dispose();

    Adding a child to the bookmarks

    You can add a child bookmark by using the insert or add method. Refer to the following code example.

  • dart
  • //Create a new PDF document
    PdfDocument document = PdfDocument();
    
    //Add a page
    PdfPage page = document.pages.add();
    
    //Creates document bookmark
    PdfBookmark bookmark = document.bookmarks.add('page 1');
    
    //Inserts the child bookmark
    PdfBookmark childBookmark1 = bookmark.insert(0, 'heading 1');
    
    //Adds the child bookmark
    PdfBookmark childBookmark2 = bookmark.add('heading 2');
    
    //Sets the text style
    childBookmark1.textStyle = [PdfTextStyle.bold, PdfTextStyle.italic];
    childBookmark2.textStyle = [PdfTextStyle.italic];
    
    //Sets the destination page and destination location
    childBookmark1.destination = PdfDestination(page, Offset(100, 100));
    childBookmark2.destination = PdfDestination(page, Offset(100, 400));
    
    //Sets the bookmark color(RGB)
    childBookmark1.color = PdfColor(0, 255, 0);
    childBookmark2.color = PdfColor(0, 0, 255);
    
    //Saves the bookmark
    File('Output.pdf').writeAsBytes(document.save());
    
    //Dispose the document
    document.dispose();

    Adding bookmarks in an existing PDF document

    To add bookmarks in an existing PDF document, use the following code example.

  • dart
  • //Loads an existing PDF document
    PdfDocument document =
        PdfDocument(inputBytes: File('input.pdf').readAsBytesSync());
    
    //Creates a document bookmark
    PdfBookmark bookmark = document.bookmarks.add('Page 1');
    
    //Sets the destination page and location
    bookmark.destination = PdfDestination(document.pages[0], Offset(20, 20));
    
    //Sets the bookmark color
    bookmark.color = PdfColor(255, 0, 0);
    
    //Sets the text style
    bookmark.textStyle = [PdfTextStyle.bold];
    
    //Saves the document
    File('output.pdf').writeAsBytes(document.save());
      
    //Disposes the document
    document.dispose();

    Inserting bookmarks in an existing PDF

    When loading an existing document, the Syncfusion Flutter PDF loads all bookmarks of the document.

    Each loaded bookmark is represented by the PdfBookmark object. The following code example explains how to insert new bookmarks in the existing PDF document.

  • dart
  • //Loads an existing PDF document
    PdfDocument document =
        PdfDocument(inputBytes: File('input.pdf').readAsBytesSync());
    
    //Creates a document bookmark
    PdfBookmark bookmark = document.bookmarks.insert(1, 'New Bookmark');
    
    //Sets the destination page and location
    bookmark.destination = PdfDestination(document.pages[0], Offset(40, 40));
    
    //Saves the document
    File('output.pdf').writeAsBytes(document.save());
    
    //Disposes the document
    document.dispose();

    Removing bookmarks from an existing PDF

    You can also remove bookmarks from the existing PDF document by using the remove method. Please refer to the following code example.

  • dart
  • //Loads an existing PDF document
    PdfDocument document =
        PdfDocument(inputBytes: File('input.pdf').readAsBytesSync());
    
    //Gets all the bookmarks
    PdfBookmarkBase bookmark = document.bookmarks;
    
    //Removes bookmark by index
    bookmark.removeAt(1);
    
    //Removes bookmark by bookmark name
    bookmark.remove('Page 1');
    
    //Saves the document
    File('output.pdf').writeAsBytes(document.save());
    
    //Disposes the document
    document.dispose();

    Modifying bookmarks in an existing PDF

    The Syncfusion Flutter PDF allows you to modify the bookmarks in the existing PDF document. The following modifications can be done to bookmarks in an existing document.

    • Modify the bookmark style, color, title, and destination.
    • Add or insert new bookmarks into the root collection.
    • Add or insert new bookmarks as a child of another bookmark.
    • Assign the destination of the added bookmarks to a loaded page or a new page of the document.

    The following code example shows how to modify the destination, color, textStyle and title of the existing bookmark collection.

  • dart
  • //Loads an existing PDF document
    PdfDocument document =
        PdfDocument(inputBytes: File('input.pdf').readAsBytesSync());
    
    //Loads an existing PDF page
    PdfPage page = document.pages[1];
    
    //Gets all the bookmarks
    PdfBookmarkBase collection = document.bookmarks;
    
    //Gets the first bookmark and changes the properties of the bookmark
    PdfBookmark bookmark = collection[0];
    bookmark.color = PdfColor(0, 0, 255);
    bookmark.destination = PdfDestination(page, Offset(20, 20));
    bookmark.textStyle = [PdfTextStyle.italic];
    bookmark.title = 'Changed Title';
    
    //Adds a child to the existing bookmark
    PdfBookmark childBookmark = bookmark.add('Child Bookmark');
    childBookmark.destination = PdfDestination(page, Offset(100, 100));
    
    //Saves the document
    File('output.pdf').writeAsBytes(document.save());
    
    //Disposes the document
    document.dispose();