PDFTron WebViewer

Class: NumberTree

PDFNet. NumberTree

new NumberTree()

A NumberTree is a common data structure in PDF. See section 3.8.6 'Number Trees' in PDF Reference Manual for more details. A number tree serves a similar purpose to a dictionary - associating keys and values - but by different means. NumberTrees allow efficient storage of very large association collections (number/Obj* maps). A NumberTree can have many more entries than a SDF/Cos dictionary can. Sample code: 
  PDFDoc doc("../Data/test.pdf");
  NumberTree labels(doc.GetRoot().Get("PageLabels").Value());
  if (labels.IsValid()) {
    // Traversing the NumberTree 
    for (NumberTreeIterator i = labels.GetIterator(); i.HasNext(); i.Next()) 
        cout << "Key: " << i.Key().GetNumber() << endl;
  }

Methods

<static> create(number_tree)

Create a high level NumberTree wrapper around an existing SDF/Cos NumberTree. This does not copy the object.
Parameters:
Name Type Description
number_tree PDFNet.Obj SDF/Cos root of the NumberTree object.
Returns:
A promise that resolves to an object of type: "PDFNet.NumberTree"
Type
Promise.<PDFNet.NumberTree>

copy()

Copy Constructor
Returns:
A promise that resolves to an object of type: "PDFNet.NumberTree"
Type
Promise.<PDFNet.NumberTree>

erase(pos)

Removes the NumberTree entry pointed by the iterator.
Parameters:
Name Type Description
pos PDFNet.DictIterator dictionary iterator object that points to the NumberTree entry to be removed
Returns:
Type
Promise.<void>

eraseKey(key)

Removes the specified object from the tree. Does nothing if no object with that number exists.
Parameters:
Name Type Description
key number A number representing the key of the entry to be removed.
Returns:
Type
Promise.<void>

getIterator(key)

Search for the specified key in the NumberTree.
Parameters:
Name Type Description
key number the number representing the key to be found. Sample code: NumberTreeIterator i = dests.Find(5); if (i.HasNext()) { cout << "Key: " << i.GetKey()->GetNumber() << endl; cout << "Value: " << i.GetValue()->GetType() << endl; }
Returns:
A promise that resolves to if the key is present the function returns a NumberTreeIterator the points to the given Key/Value pair. If the key is not found the function returns End() (a non-valid) iterator.
Type
Promise.<PDFNet.DictIterator>

getIteratorBegin()

Returns:
A promise that resolves to an iterator to the first key/value pair (i.e. NNTreeData) in the document. You can use the Next method on the returned iterator to traverse all entries stored under the NumberTree. Sample code: for (NumberTreeIterator i = dests.GetIterator(); i.HasNext(); i.Next()) cout << "Key: " << i.GetKey().GetNumber() << endl;
Type
Promise.<PDFNet.DictIterator>

getSDFObj()

Returns:
A promise that resolves to the object to the underlying SDF/Cos object. If the NumberTree.IsValid() returns false the SDF/Cos object is NULL.
Type
Promise.<PDFNet.Obj>

getValue(key)

Parameters:
Name Type Description
key number
Returns:
A promise that resolves to an object of type: "PDFNet.Obj"
Type
Promise.<PDFNet.Obj>

isValid()

Returns:
A promise that resolves to whether this is a valid (non-null) NumberTree. If the function returns false the underlying SDF/Cos object is null and the NumberTree object should be treated as null as well.
Type
Promise.<boolean>

put(key, value)

Puts a new entry in the name tree. If an entry with this number is already in the tree, it is replaced.
Parameters:
Name Type Description
key number A number representing the key of the new entry.
value PDFNet.Obj the value associated with the key. It can be any SDF::Obj.
Returns:
Type
Promise.<void>