/// <summary>
/// Recursively converts the page tree into a flat array.
/// </summary>
PDFDictionary[] GetKids(PDFReference iref, PDFPage.InheritedValues values, PDFDictionary parent)
{
// TODO: inherit inheritable keys...
PDFDictionary kid = (PDFDictionary)iref.Value;
#if true
string type = kid.Elements.GetName(Keys.Type);
if (type == "/Page")
{
PDFPage.InheritValues(kid, values);
return(new PDFDictionary[] { kid });
}
if (String.IsNullOrEmpty(type))
{
// Type is required. If type is missing, assume it is "/Page" and hope it will work.
// TODO Implement a "Strict" mode in PDFSharp and don't do this in "Strict" mode.
PDFPage.InheritValues(kid, values);
return(new PDFDictionary[] { kid });
}
#else
if (kid.Elements.GetName(Keys.Type) == "/Page")
{
PDFPage.InheritValues(kid, values);
return(new PDFDictionary[] { kid });
}
#endif
Debug.Assert(kid.Elements.GetName(Keys.Type) == "/Pages");
PDFPage.InheritValues(kid, ref values);
List <PDFDictionary> list = new List <PDFDictionary>();
PDFArray kids = kid.Elements["/Kids"] as PDFArray;
if (kids == null)
{
if (kid.Elements["/Kids"] is PDFReference xref3)
{
kids = xref3.Value as PDFArray;
}
}
foreach (PDFReference xref2 in kids)
{
list.AddRange(GetKids(xref2, values, kid));
}
int count = list.Count;
Debug.Assert(count == kid.Elements.GetInteger("/Count"));
return(list.ToArray());
}
/// <summary>
/// Replaces the page tree by a flat array of indirect references to the pages objects.
/// </summary>
internal void FlattenPageTree()
{
// Acrobat creates a balanced tree if the number of pages is roughly more than ten. This is
// not difficult but obviously also not necessary. I created a document with 50000 pages with
// PDF4NET and Acrobat opened it in less than 2 seconds.
//PDFReference xrefRoot = Document.Catalog.Elements[PDFCatalog.Keys.Pages] as PDFReference;
//PDFDictionary[] pages = GetKids(xrefRoot, null);
// Promote inheritable values down the page tree
PDFPage.InheritedValues values = new PDFPage.InheritedValues();
PDFPage.InheritValues(this, ref values);
PDFDictionary[] pages = GetKids(Reference, values, null);
// Replace /Pages in catalog by this object
// xrefRoot.Value = this;
PDFArray array = new PDFArray(Owner);
foreach (PDFDictionary page in pages)
{
// Fix the parent
page.Elements[PDFPage.Keys.Parent] = Reference;
array.Elements.Add(page.Reference);
}
Elements.SetName(Keys.Type, "/Pages");
#if true
// Direct array.
Elements.SetValue(Keys.Kids, array);
#else
// Indirect array.
Document.xrefTable.Add(array);
Elements.SetValue(Keys.Kids, array.XRef);
#endif
Elements.SetInteger(Keys.Count, array.Elements.Count);
}
