Module org.sejda.sambox
Package org.sejda.sambox.pdmodel

Class PDPageTree

java.lang.Object
org.sejda.sambox.pdmodel.PDPageTree
All Implemented Interfaces:
Iterable<PDPage>, COSObjectable
public class PDPageTree extends Object implements COSObjectable, Iterable<PDPage>
The page tree, which defines the ordering of pages in the document in an efficient manner.

  • Field Details

    • LOG

      private static final org.slf4j.Logger LOG

    • root

      private final COSDictionary root

    • document

      private final PDDocument document

  • Constructor Details

    • PDPageTree

      public PDPageTree()
      Constructor for embedding.

    • PDPageTree

      public PDPageTree(COSDictionary root)
      Constructor for reading.
      Parameters:
      root - A page tree root.

    • PDPageTree

      PDPageTree(COSDictionary root, PDDocument document)
      Constructor for reading.
      Parameters:
      root - A page tree root.
      document - The document which contains "root".

  • Method Details

    • getInheritableAttribute

      public static <T extends COSBase> COSBase getInheritableAttribute(COSDictionary node, COSName key, Class<T> clazz)
      Similar to getInheritableAttribute(COSDictionary, COSName) but also checks the returned element matches the expected type class
      Type Parameters:
      T -
      Parameters:
      node -
      key -
      clazz - expected type class
      Returns:

    • getInheritableAttribute

      public static COSBase getInheritableAttribute(COSDictionary node, COSName key)
      Returns the given attribute, inheriting from parent tree nodes if necessary.
      Parameters:
      node - page object
      key - the key to look up
      Returns:
      COS value for the given key

    • getInheritableAttribute

      public static COSBase getInheritableAttribute(COSDictionary node, COSName key, Set<String> visitedObjectIds)

    • iterator

      public Iterator<PDPage> iterator()
      Returns an iterator which walks all pages in the tree, in order.
      Specified by:
      iterator in interface Iterable<PDPage>

    • stream

      public Stream<PDPage> stream()
      Returns:
      a sequential Stream over the pages of this page tree.

    • streamNodes

      public Stream<COSDictionary> streamNodes()
      Returns:
      a sequential Stream over the nodes of this page tree.

    • getKids

      private List<COSDictionary> getKids(COSDictionary node)
      Helper to get kids from malformed PDFs.
      Parameters:
      node - page tree node
      Returns:
      list of kids

    • get

      public PDPage get(int index)
      Returns the page at the given index.
      Parameters:
      index - zero-based index

    • sanitizeType

      private static void sanitizeType(COSDictionary dictionary)

    • get

      private PDPageTree.PageAndPageTreeParent get(int pageNum, COSDictionary node, int encountered, COSDictionary pageTreeParent, Set<COSDictionary> visited)
      Returns the given COS page using a depth-first search.
      Parameters:
      pageNum - 1-based page number
      node - page tree node to search
      encountered - number of pages encountered so far
      pageTreeParent - the parent node, as determined traversing the page tree top -> down
      Returns:
      COS dictionary of the Page object

    • getSourcePath

      private String getSourcePath()

    • isPageTreeNode

      public static boolean isPageTreeNode(COSDictionary node)
      Returns:
      true if the node is a page tree node (i.e. and intermediate).

    • indexOf

      public int indexOf(PDPage page)
      Returns the index of the given page, or -1 if it does not exist.
      Parameters:
      page - The page to search for.
      Returns:
      the zero-based index of the given page, or -1 if the page is not found.

    • findPage

      private boolean findPage(PDPageTree.SearchContext context, COSDictionary node)

    • getCount

      public int getCount()
      Returns the number of leaf nodes (page objects) that are descendants of this root within the page tree.

    • getCOSObject

      public COSDictionary getCOSObject()
      Specified by:
      getCOSObject in interface COSObjectable
      Returns:
      The COSBase that matches this Java object.

    • remove

      public void remove(int index)
      Removes the page with the given index from the page tree.
      Parameters:
      index - zero-based page index

    • remove

      public void remove(PDPage page)
      Removes the given page from the page tree.
      Parameters:
      page - The page to remove.

    • remove

      private void remove(COSDictionary node)
      Removes the given COS page.

    • remove

      private void remove(COSDictionary node, COSDictionary knownParent)
      Removes the given COS page.

    • add

      public void add(PDPage page)
      Adds the given page to this page tree.
      Parameters:
      page - The page to add.

    • insertBefore

      public void insertBefore(PDPage newPage, PDPage nextPage)
      Insert a page before another page within a page tree.
      Parameters:
      newPage - the page to be inserted.
      nextPage - the page that is to be after the new page.
      Throws:
      IllegalArgumentException - if one attempts to insert a page that isn't part of a page tree.

    • insertAfter

      public void insertAfter(PDPage newPage, PDPage prevPage)
      Insert a page after another page within a page tree.
      Parameters:
      newPage - the page to be inserted.
      prevPage - the page that is to be before the new page.
      Throws:
      IllegalArgumentException - if one attempts to insert a page that isn't part of a page tree.

    • increaseParents

      private void increaseParents(COSDictionary parentDict)