PDFTron WebViewer

Class: PageLabel

Core.PDFNet. PageLabel

new PageLabel( [mp_obj] [, m_first_page] [, m_last_page])

PDF page labels can be used to describe a page. This is used to allow for non-sequential page numbering or the addition of arbitrary labels for a page (such as the inclusion of Roman numerals at the beginning of a book). PDFNet PageLabel object can be used to specify the numbering style to use (for example, upper- or lower-case Roman, decimal, and so forth), the starting number for the first page, and an arbitrary prefix to be pre-appended to each number (for example, "A-" to generate "A-1", "A-2", "A-3", and so forth.) PageLabel corresponds to the PDF Page Label object (Section 8.3.1, 'Page Labels' in the PDF Reference Manual. Each page in a PDF document is identified by an integer page index that expresses the page's relative position within the document. In addition, a document may optionally define page labels to identify each page visually on the screen or in print. Page labels and page indices need not coincide: the indices are fixed, running consecutively through the document starting from 1 for the first page, but the labels can be specified in any way that is appropriate for the particular document. For example, if the document begins with 12 pages of front matter numbered in roman numerals and the remainder of the document is numbered in Arabic, the first page would have a page index of 1 and a page label of i, the twelfth page would have index 12 and label xii, and the thirteenth page would have index 13 and label 1. For purposes of page labeling, a document can be divided into labeling ranges, each of which is a series of consecutive pages using the same numbering system. Pages within a range are numbered sequentially in ascending order. A page's label consists of a numeric portion based on its position within its labeling range, optionally preceded by a label prefix denoting the range itself. For example, the pages in an appendix might be labeled with decimal numeric portions prefixed with the string "A-" and the resulting page labels would be "A-1", "A-2", Note: There is no default numbering style; if no 'S' (Style) entry is present, page labels consist solely of a label prefix with no numeric portion. For example, if the 'P' entry (Prefix) specifies the label prefix "Appendix", each page is simply labeled "Appendix" with no page number. If the 'P' entry is also missing or empty, the page label is an empty string. Sample code (See PableLabelsTest sample project for examples): 
// Create a page labeling scheme that starts with the first page in 
// the document (page 1) and is using uppercase roman numbering 
// style. 
doc.SetPageLabel(1, PageLabel::Create(doc, PageLabel::e_roman_uppercase, "My Prefix ", 1));

// Create a page labeling scheme that starts with the fourth page in 
// the document and is using decimal Arabic numbering style. 
// Also the numeric portion of the first label should start with number 
// 4 (otherwise the first label would be "My Prefix 1"). 
PageLabel L2 = PageLabel::Create(doc, PageLabel::e_decimal, "My Prefix ", 4);
doc.SetPageLabel(4, L2);

// Create a page labeling scheme that starts with the seventh page in 
// the document and is using alphabetic numbering style. The numeric 
// portion of the first label should start with number 1. 
PageLabel L3 = PageLabel::Create(doc, PageLabel::e_alphabetic_uppercase, "My Prefix ", 1);
doc.SetPageLabel(7, L3);

// Read page labels from an existing PDF document.
PageLabel label;
for (int i=1; i<=doc.GetPageCount(); ++i) {
label = doc.GetPageLabel(i);
if (label.IsValid()) {
  UString title = label.GetLabelTitle(i);
}
Parameters:
Name Type Argument Description
mp_obj Core.PDFNet.Obj <optional>
m_first_page number <optional>
m_last_page number <optional>
Properties:
Name Type Description
mp_obj Core.PDFNet.Obj
m_first_page number
m_last_page number

Members

<static> Style

Type:
  • number
Properties:
Name Type Description
e_decimal number
e_roman_uppercase number
e_roman_lowercase number
e_alphabetic_uppercase number
e_alphabetic_lowercase number
e_none number

Methods

<static> create(doc, style [, prefix] [, start_at])

Creates a new PageLabel.
Parameters:
Name Type Argument Description
doc Core.PDFNet.PDFDoc | Core.PDFNet.SDFDoc | Core.PDFNet.FDFDoc A document to which the page label is added.
style number 
PDFNet.PageLabel.Style = {
	e_decimal : 0
	e_roman_uppercase : 1
	e_roman_lowercase : 2
	e_alphabetic_uppercase : 3
	e_alphabetic_lowercase : 4
	e_none : 5
}
The numbering style for the label.
prefix string <optional>
 The string used to prefix the numeric portion of the page label.
start_at number <optional>
 the value to use when generating the numeric portion of the first label in this range; must be greater than or equal to 1.
Returns:
A promise that resolves to newly created PageLabel object.
Type
Promise.<Core.PDFNet.PageLabel>

<static> createFromObj( [l] [, first_page] [, last_page])

Create a PageLabel and initialize it using given Cos/SDF object. Note: The constructor does not copy any data, but is instead the logical equivalent of a type cast.
Parameters:
Name Type Argument Description
l Core.PDFNet.Obj <optional>
first_page number <optional>
last_page number <optional>
Returns:
A promise that resolves to an object of type: "PDFNet.PageLabel"
Type
Promise.<Core.PDFNet.PageLabel>

compare(d)

Compares two PageLabel-s for equality. The comparison will return true only if both labels share the same underlying SDF/Cos object. Two labels are also equivalent if they have the same style, starting number (numeric value of the first page associated with the label), and prefix strings which are the same byte-for-byte.
Parameters:
Name Type Description
d Core.PDFNet.PageLabel
Returns:
A promise that resolves to an object of type: "boolean"
Type
Promise.<boolean>

getFirstPageNum()

Returns:
A promise that resolves to the first page in the range associated with this label or -1 if the label is not associated with any page.
Type
Promise.<number>

getLabelTitle(page_num)

Parameters:
Name Type Description
page_num number
Returns:
A promise that resolves to the full label title that is in effect for the given page. If there is no label object in effect, this method returns an empty string.
Type
Promise.<string>

getLastPageNum()

Returns:
A promise that resolves to the last page in the range associated with this label or -1 if the label is not associated with any page.
Type
Promise.<number>

getPrefix()

Returns:
A promise that resolves to the string used to prefix the numeric portion of the page label
Type
Promise.<string>

getSDFObj()

Returns:
A promise that resolves to the pointer to the underlying SDF/Cos object.
Type
Promise.<Core.PDFNet.Obj>

getStart()

Returns:
A promise that resolves to the value to use when generating the numeric portion of the first label in this range; must be greater than or equal to 1.
Type
Promise.<number>

getStyle()

Returns:
A promise that resolves to page numbering style.
Type
Promise.<number>
Example
Return value enum:
<pre>
PDFNet.PageLabel.Style = {
	e_decimal : 0
	e_roman_uppercase : 1
	e_roman_lowercase : 2
	e_alphabetic_uppercase : 3
	e_alphabetic_lowercase : 4
	e_none : 5
}
</pre>

isValid()

Returns:
A promise that resolves to whether this is a valid (non-null) PageLabel. If the function returns false the underlying SDF/Cos object is null or is not valid and the PageLabel object should be treated as null as well.
Type
Promise.<boolean>

setPrefix(prefix)

Parameters:
Name Type Description
prefix string the string used to prefix the numeric portion of the page label.
Returns:
Type
Promise.<void>

setStart(start_at)

Parameters:
Name Type Description
start_at number the value to use when generating the numeric portion of the first label in this range; must be greater than or equal to 1.
Returns:
Type
Promise.<void>

setStyle(style)

Sets the numbering style for the label.
Parameters:
Name Type Description
style number 
PDFNet.PageLabel.Style = {
	e_decimal : 0
	e_roman_uppercase : 1
	e_roman_lowercase : 2
	e_alphabetic_uppercase : 3
	e_alphabetic_lowercase : 4
	e_none : 5
}
the numbering style for the label. You may use label style to customize the page numbering schemes used throughout a document. There are three numbering formats: decimal (often used for normal page ranges) roman (often used for front matter such as a preface) alphabetic (often used for back matter such as appendices) Note: There is no default numbering style; if no 'S' (Style) entry is present, page labels consist solely of a label prefix with no numeric portion.
Returns:
Type
Promise.<void>