// Write labels to the PDF
internal void WriteLabels()
{
if (!edited)
{
return;
}
// Grab the labels element, creating it if necessary
PdfDictionary labels_dict;
if (!pdf_elements.ContainsKey(name_labels))
{
labels_dict = new PdfDictionary(pdf_document);
pdf_elements.Add(name_labels, labels_dict);
}
else
{
labels_dict = pdf_elements.GetDictionary(name_labels);
}
labels_dict.Elements.Clear();
// Create the number tree
PdfArray number_tree = new PdfArray(pdf_document);
// Add the range-start, attrib-dict pairs
foreach (int range_start in page_labels.Keys)
{
number_tree.Elements.Add(new PdfInteger(range_start));
PageLabelFormat label_format = page_labels[range_start];
PdfDictionary r_attribs = new PdfDictionary(pdf_document);
if (label_format.number_style.Length > 0)
{
r_attribs.Elements.Add(name_fmt, new PdfName(label_format.number_style));
}
if (label_format.first_number > 1)
{
r_attribs.Elements.Add(name_start_at, new PdfInteger(label_format.first_number));
}
if (label_format.prefix.Length > 0)
{
r_attribs.Elements.Add(name_prefix, new PdfString(label_format.prefix));
}
number_tree.Elements.Add(r_attribs);
}
labels_dict.Elements.Add(name_numtree, number_tree);
}
internal PageLabels(PdfDocument document)
{
page_labels = new SortedDictionary <int, PageLabelFormat> ();
pdf_elements = document.Internals.Catalog.Elements;
pdf_document = document;
edited = false;
// Ignore documents that don't have labelling stuff defined
if (!pdf_elements.ContainsKey(name_labels))
{
return;
}
// Ignore documents that don't have a properly-defined PageLabelFmt section
PdfDictionary my_labels = pdf_elements.GetDictionary(name_labels);
if (!my_labels.Elements.ContainsKey(name_numtree))
{
return;
}
/* The number tree (not my term) is a PdfArray arranged as follows: [##, dict, ##, dict, ##, dict ...]
* ## represents the starting index of the page (0-based) and the following dict is a PdfDictionary
* containing formatting information regarding the range
*/
PdfArray number_tree = my_labels.Elements.GetArray(name_numtree);
for (int i = 0; i < number_tree.Elements.Count / 2; ++i)
{
Console.WriteLine("Range # {0}", i);
PageLabelFormat temp_label = new PageLabelFormat();
int range_start = number_tree.Elements.GetInteger(i * 2);
PdfDictionary label_data = number_tree.Elements.GetDictionary(i * 2 + 1);
// Set the prefix, default to ""
if (label_data.Elements.ContainsKey(name_prefix))
{
temp_label.prefix = label_data.Elements.GetString(name_prefix);
}
else
{
temp_label.prefix = "";
}
// Set the start number, default to 1
if (label_data.Elements.ContainsKey(name_start_at))
{
temp_label.first_number = label_data.Elements.GetInteger(name_start_at);
}
else
{
temp_label.first_number = 1;
}
// Set the format type, default to no numbering (only show the prefix)
if (label_data.Elements.ContainsKey(name_fmt))
{
temp_label.number_style = label_data.Elements.GetString(name_fmt);
}
else
{
temp_label.number_style = "";
}
page_labels.Add(range_start, temp_label);
}
}