292 lines
12 KiB
C#
292 lines
12 KiB
C#
#region PDFsharp - A .NET library for processing PDF
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//
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// Authors:
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// Stefan Lange
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//
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// Copyright (c) 2005-2016 empira Software GmbH, Cologne Area (Germany)
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//
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// http://www.PdfSharpCore.com
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// http://sourceforge.net/projects/pdfsharp
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//
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// Permission is hereby granted, free of charge, to any person obtaining a
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// copy of this software and associated documentation files (the "Software"),
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// to deal in the Software without restriction, including without limitation
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// the rights to use, copy, modify, merge, publish, distribute, sublicense,
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// and/or sell copies of the Software, and to permit persons to whom the
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// Software is furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included
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// in all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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// DEALINGS IN THE SOFTWARE.
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#endregion
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using System;
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using System.Diagnostics;
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using PdfSharpCore.Pdf.IO;
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using PdfSharpCore.Pdf.Security;
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using PdfSharpCore.Pdf.Internal;
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namespace PdfSharpCore.Pdf.Advanced
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{
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/// <summary>
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/// Represents a PDF trailer dictionary. Even though trailers are dictionaries they never have a cross
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/// reference entry in PdfReferenceTable.
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/// </summary>
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internal class PdfTrailer : PdfDictionary // Reference: 3.4.4 File Trailer / Page 96
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{
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/// <summary>
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/// Initializes a new instance of PdfTrailer.
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/// </summary>
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public PdfTrailer(PdfDocument document)
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: base(document)
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{
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_document = document;
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}
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/// <summary>
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/// Initializes a new instance of the <see cref="PdfTrailer"/> class from a <see cref="PdfCrossReferenceStream"/>.
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/// </summary>
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public PdfTrailer(PdfCrossReferenceStream trailer)
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: base(trailer._document)
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{
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_document = trailer._document;
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// /ID [<09F877EBF282E9408ED1882A9A21D9F2><2A4938E896006F499AC1C2EA7BFB08E4>]
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// /Info 7 0 R
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// /Root 1 0 R
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// /Size 10
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PdfReference iref = trailer.Elements.GetReference(Keys.Info);
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if (iref != null)
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Elements.SetReference(Keys.Info, iref);
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Elements.SetReference(Keys.Root, trailer.Elements.GetReference(Keys.Root));
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Elements.SetInteger(Keys.Size, trailer.Elements.GetInteger(Keys.Size));
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PdfArray id = trailer.Elements.GetArray(Keys.ID);
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if (id != null)
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Elements.SetValue(Keys.ID, id);
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}
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public int Size
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{
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get { return Elements.GetInteger(Keys.Size); }
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set { Elements.SetInteger(Keys.Size, value); }
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}
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// TODO: needed when linearized...
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//public int Prev
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//{
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// get {return Elements.GetInteger(Keys.Prev);}
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//}
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public PdfDocumentInformation Info
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{
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get { return (PdfDocumentInformation)Elements.GetValue(Keys.Info, VCF.CreateIndirect); }
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}
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/// <summary>
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/// (Required; must be an indirect reference)
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/// The catalog dictionary for the PDF document contained in the file.
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/// </summary>
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public PdfCatalog Root
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{
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get { return (PdfCatalog)Elements.GetValue(PdfTrailer.Keys.Root, VCF.CreateIndirect); }
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}
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/// <summary>
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/// Gets the first or second document identifier.
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/// </summary>
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public string GetDocumentID(int index)
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{
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if (index < 0 || index > 1)
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throw new ArgumentOutOfRangeException("index", index, "Index must be 0 or 1.");
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PdfArray array = Elements[Keys.ID] as PdfArray;
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if (array == null || array.Elements.Count < 2)
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return "";
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PdfItem item = array.Elements[index];
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if (item is PdfString)
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return ((PdfString)item).Value;
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return "";
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}
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/// <summary>
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/// Sets the first or second document identifier.
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/// </summary>
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public void SetDocumentID(int index, string value)
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{
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if (index < 0 || index > 1)
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throw new ArgumentOutOfRangeException("index", index, "Index must be 0 or 1.");
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PdfArray array = Elements[Keys.ID] as PdfArray;
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if (array == null || array.Elements.Count < 2)
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array = CreateNewDocumentIDs();
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array.Elements[index] = new PdfString(value, PdfStringFlags.HexLiteral);
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}
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/// <summary>
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/// Creates and sets two identical new document IDs.
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/// </summary>
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internal PdfArray CreateNewDocumentIDs()
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{
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PdfArray array = new PdfArray(_document);
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byte[] docID = Guid.NewGuid().ToByteArray();
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string id = PdfEncoders.RawEncoding.GetString(docID, 0, docID.Length);
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array.Elements.Add(new PdfString(id, PdfStringFlags.HexLiteral));
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array.Elements.Add(new PdfString(id, PdfStringFlags.HexLiteral));
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Elements[Keys.ID] = array;
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return array;
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}
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/// <summary>
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/// Gets the standard security handler.
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/// </summary>
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public PdfStandardSecurityHandler SecurityHandler
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{
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get
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{
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if (_securityHandler == null)
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_securityHandler = (PdfStandardSecurityHandler)Elements.GetValue(Keys.Encrypt, VCF.CreateIndirect);
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return _securityHandler;
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}
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}
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internal PdfStandardSecurityHandler _securityHandler;
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internal override void WriteObject(PdfWriter writer)
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{
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// Delete /XRefStm entry, if any.
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// HACK:
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_elements.Remove(Keys.XRefStm);
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// Don't encrypt myself
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PdfStandardSecurityHandler securityHandler = writer.SecurityHandler;
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writer.SecurityHandler = null;
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base.WriteObject(writer);
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writer.SecurityHandler = securityHandler;
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}
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/// <summary>
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/// Replace temporary irefs by their correct counterparts from the iref table.
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/// </summary>
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internal void Finish()
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{
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// /Root
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PdfReference iref = _document._trailer.Elements[Keys.Root] as PdfReference;
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if (iref != null && iref.Value == null)
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{
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iref = _document._irefTable[iref.ObjectID];
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Debug.Assert(iref.Value != null);
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_document._trailer.Elements[Keys.Root] = iref;
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}
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// /Info
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iref = _document._trailer.Elements[PdfTrailer.Keys.Info] as PdfReference;
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if (iref != null && iref.Value == null)
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{
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iref = _document._irefTable[iref.ObjectID];
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Debug.Assert(iref.Value != null);
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_document._trailer.Elements[Keys.Info] = iref;
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}
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// /Encrypt
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iref = _document._trailer.Elements[Keys.Encrypt] as PdfReference;
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if (iref != null)
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{
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_document._irefTable.Remove(_document._irefTable[iref.ObjectID]);
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_document._irefTable.Add(_document._trailer._securityHandler);
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_document._trailer.Elements[Keys.Encrypt] = _document._trailer._securityHandler;
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}
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Elements.Remove(Keys.Prev);
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Debug.Assert(_document._irefTable.IsUnderConstruction == false);
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_document._irefTable.IsUnderConstruction = false;
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}
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/// <summary>
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/// Predefined keys of this dictionary.
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/// </summary>
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internal class Keys : KeysBase // Reference: TABLE 3.13 Entries in the file trailer dictionary / Page 97
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{
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/// <summary>
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/// (Required; must not be an indirect reference) The total number of entries in the file’s
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/// cross-reference table, as defined by the combination of the original section and all
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/// update sections. Equivalently, this value is 1 greater than the highest object number
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/// used in the file.
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/// Note: Any object in a cross-reference section whose number is greater than this value is
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/// ignored and considered missing.
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/// </summary>
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[KeyInfo(KeyType.Integer | KeyType.Required)]
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public const string Size = "/Size";
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/// <summary>
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/// (Present only if the file has more than one cross-reference section; must not be an indirect
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/// reference) The byte offset from the beginning of the file to the beginning of the previous
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/// cross-reference section.
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/// </summary>
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[KeyInfo(KeyType.Integer | KeyType.Optional)]
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public const string Prev = "/Prev";
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/// <summary>
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/// (Required; must be an indirect reference) The catalog dictionary for the PDF document
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/// contained in the file.
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/// </summary>
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[KeyInfo(KeyType.Dictionary | KeyType.Required, typeof(PdfCatalog))]
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public const string Root = "/Root";
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/// <summary>
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/// (Required if document is encrypted; PDF 1.1) The document’s encryption dictionary.
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/// </summary>
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[KeyInfo(KeyType.Dictionary | KeyType.Optional, typeof(PdfStandardSecurityHandler))]
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public const string Encrypt = "/Encrypt";
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/// <summary>
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/// (Optional; must be an indirect reference) The document’s information dictionary.
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/// </summary>
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[KeyInfo(KeyType.Dictionary | KeyType.Optional, typeof(PdfDocumentInformation))]
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public const string Info = "/Info";
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/// <summary>
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/// (Optional, but strongly recommended; PDF 1.1) An array of two strings constituting
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/// a file identifier for the file. Although this entry is optional,
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/// its absence might prevent the file from functioning in some workflows
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/// that depend on files being uniquely identified.
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/// </summary>
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[KeyInfo(KeyType.Array | KeyType.Optional)]
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public const string ID = "/ID";
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/// <summary>
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/// (Optional) The byte offset from the beginning of the file of a cross-reference stream.
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/// </summary>
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[KeyInfo(KeyType.Integer | KeyType.Optional)]
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public const string XRefStm = "/XRefStm";
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/// <summary>
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/// Gets the KeysMeta for these keys.
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/// </summary>
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public static DictionaryMeta Meta
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{
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get { return _meta ?? (_meta = CreateMeta(typeof(Keys))); }
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}
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static DictionaryMeta _meta;
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}
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/// <summary>
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/// Gets the KeysMeta of this dictionary type.
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/// </summary>
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internal override DictionaryMeta Meta
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{
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get { return Keys.Meta; }
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}
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}
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}
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