PdfPages is the PDF Pages-object.
*
* The Pages of a document are accessible through a tree of nodes known as the Pages tree.
* This tree defines the ordering of the pages in the document.
* This object is described in the 'Portable Document Format Reference Manual version 1.3'
* section 6.3 (page 71-73)
*
* @see PdfPageElement
* @see PdfPage
*/
public class PdfPages {
private ArrayList pages = new ArrayList();
private ArrayList parents = new ArrayList();
private int leafSize = 10;
private PdfWriter writer;
private PdfIndirectReference topParent;
// constructors
/**
* Constructs a PdfPages-object.
*/
internal PdfPages(PdfWriter writer) {
this.writer = writer;
}
internal void AddPage(PdfDictionary page) {
if ((pages.Count % leafSize) == 0)
parents.Add(writer.PdfIndirectReference);
PdfIndirectReference parent = (PdfIndirectReference)parents[parents.Count - 1];
page.Put(PdfName.PARENT, parent);
PdfIndirectReference current = writer.CurrentPage;
writer.AddToBody(page, current);
pages.Add(current);
}
internal PdfIndirectReference AddPageRef(PdfIndirectReference pageRef) {
if ((pages.Count % leafSize) == 0)
parents.Add(writer.PdfIndirectReference);
pages.Add(pageRef);
return (PdfIndirectReference)parents[parents.Count - 1];
}
// returns the top parent to include in the catalog
internal PdfIndirectReference WritePageTree() {
if (pages.Count == 0)
throw new IOException("The document has no pages.");
int leaf = 1;
ArrayList tParents = parents;
ArrayList tPages = pages;
ArrayList nextParents = new ArrayList();
while (true) {
leaf *= leafSize;
int stdCount = leafSize;
int rightCount = tPages.Count % leafSize;
if (rightCount == 0)
rightCount = leafSize;
for (int p = 0; p < tParents.Count; ++p) {
int count;
int thisLeaf = leaf;
if (p == tParents.Count - 1) {
count = rightCount;
thisLeaf = pages.Count % leaf;
if (thisLeaf == 0)
thisLeaf = leaf;
}
else
count = stdCount;
PdfDictionary top = new PdfDictionary(PdfName.PAGES);
top.Put(PdfName.COUNT, new PdfNumber(thisLeaf));
PdfArray kids = new PdfArray();
ArrayList intern = kids.ArrayList;
intern.AddRange(tPages.GetRange(p * stdCount, count));
top.Put(PdfName.KIDS, kids);
if (tParents.Count > 1) {
if ((p % leafSize) == 0)
nextParents.Add(writer.PdfIndirectReference);
top.Put(PdfName.PARENT, (PdfIndirectReference)nextParents[p / leafSize]);
}
writer.AddToBody(top, (PdfIndirectReference)tParents[p]);
}
if (tParents.Count == 1) {
topParent = (PdfIndirectReference)tParents[0];
return topParent;
}
tPages = tParents;
tParents = nextParents;
nextParents = new ArrayList();
}
}
internal PdfIndirectReference TopParent {
get {
return topParent;
}
}
internal void SetLinearMode(PdfIndirectReference topParent) {
if (parents.Count > 1)
throw new Exception("Linear page mode can only be called with a single parent.");
if (topParent != null) {
this.topParent = topParent;
parents.Clear();
parents.Add(topParent);
}
leafSize = 10000000;
}
internal void AddPage(PdfIndirectReference page) {
pages.Add(page);
}
internal int ReorderPages(int[] order) {
if (order == null)
return pages.Count;
if (parents.Count > 1)
throw new DocumentException("Page reordering requires a single parent in the page tree. Call PdfWriter.SetLinearMode() after open.");
if (order.Length != pages.Count)
throw new DocumentException("Page reordering requires an array with the same size as the number of pages.");
int max = pages.Count;
bool[] temp = new bool[max];
for (int k = 0; k < max; ++k) {
int p = order[k];
if (p < 1 || p > max)
throw new DocumentException("Page reordering requires pages between 1 and " + max + ". Found " + p + ".");
if (temp[p - 1])
throw new DocumentException("Page reordering requires no page repetition. Page " + p + " is repeated.");
temp[p - 1] = true;
}
Object[] copy = pages.ToArray();
for (int k = 0; k < max; ++k) {
pages[k] = copy[order[k] - 1];
}
return max;
}
}
}