268 lines
9.1 KiB
C#
268 lines
9.1 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) 2005-2017 empira Software GmbH, Cologne Area (Germany)
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//
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// http://www.pdfsharp.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.Collections.Generic;
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using System.Diagnostics;
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using System.Collections;
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using PdfSharp.Pdf.Content.Objects;
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using PdfSharp.Pdf.IO;
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namespace PdfSharp.Pdf.Advanced
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{
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/// <summary>
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/// Represents an array of PDF content streams of a page.
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/// </summary>
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public sealed class PdfContents : PdfArray
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{
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/// <summary>
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/// Initializes a new instance of the <see cref="PdfContents"/> class.
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/// </summary>
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/// <param name="document">The document.</param>
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public PdfContents(PdfDocument document)
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: base(document)
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{ }
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internal PdfContents(PdfArray array)
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: base(array)
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{
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int count = Elements.Count;
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for (int idx = 0; idx < count; idx++)
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{
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// Convert the references from PdfDictionary to PdfContent
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PdfItem item = Elements[idx];
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PdfReference iref = item as PdfReference;
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if (iref != null && iref.Value is PdfDictionary)
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{
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// The following line is correct!
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new PdfContent((PdfDictionary)iref.Value);
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}
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else
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throw new InvalidOperationException("Unexpected item in a content stream array.");
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}
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}
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/// <summary>
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/// Appends a new content stream and returns it.
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/// </summary>
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public PdfContent AppendContent()
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{
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Debug.Assert(Owner != null);
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SetModified();
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PdfContent content = new PdfContent(Owner);
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Owner._irefTable.Add(content);
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Debug.Assert(content.Reference != null);
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Elements.Add(content.Reference);
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return content;
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}
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/// <summary>
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/// Prepends a new content stream and returns it.
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/// </summary>
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public PdfContent PrependContent()
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{
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Debug.Assert(Owner != null);
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SetModified();
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PdfContent content = new PdfContent(Owner);
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Owner._irefTable.Add(content);
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Debug.Assert(content.Reference != null);
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Elements.Insert(0, content.Reference);
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return content;
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}
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/// <summary>
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/// Creates a single content stream with the bytes from the array of the content streams.
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/// This operation does not modify any of the content streams in this array.
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/// </summary>
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public PdfContent CreateSingleContent()
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{
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byte[] bytes = new byte[0];
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byte[] bytes1;
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byte[] bytes2;
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foreach (PdfItem iref in Elements)
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{
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PdfDictionary cont = (PdfDictionary)((PdfReference)iref).Value;
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bytes1 = bytes;
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bytes2 = cont.Stream.UnfilteredValue;
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bytes = new byte[bytes1.Length + bytes2.Length + 1];
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bytes1.CopyTo(bytes, 0);
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bytes[bytes1.Length] = (byte)'\n';
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bytes2.CopyTo(bytes, bytes1.Length + 1);
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}
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PdfContent content = new PdfContent(Owner);
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content.Stream = new PdfDictionary.PdfStream(bytes, content);
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return content;
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}
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/// <summary>
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/// Replaces the current content of the page with the specified content sequence.
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/// </summary>
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public PdfContent ReplaceContent(CSequence cseq)
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{
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if (cseq == null)
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throw new ArgumentNullException(nameof(cseq));
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return ReplaceContent(cseq.ToContent());
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}
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/// <summary>
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/// Replaces the current content of the page with the specified bytes.
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/// </summary>
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PdfContent ReplaceContent(byte[] contentBytes)
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{
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Debug.Assert(Owner != null);
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PdfContent content = new PdfContent(Owner);
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content.CreateStream(contentBytes);
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Owner._irefTable.Add(content);
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Elements.Clear();
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Elements.Add(content.Reference);
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return content;
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}
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void SetModified()
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{
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if (!_modified)
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{
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_modified = true;
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int count = Elements.Count;
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if (count == 1)
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{
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PdfContent content = (PdfContent)((PdfReference)Elements[0]).Value;
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content.PreserveGraphicsState();
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}
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else if (count > 1)
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{
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// Surround content streams with q/Q operations
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byte[] value;
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int length;
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PdfContent content = (PdfContent)((PdfReference)Elements[0]).Value;
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if (content != null && content.Stream != null)
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{
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length = content.Stream.Length;
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value = new byte[length + 2];
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value[0] = (byte)'q';
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value[1] = (byte)'\n';
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Array.Copy(content.Stream.Value, 0, value, 2, length);
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content.Stream.Value = value;
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content.Elements.SetInteger("/Length", length + 2);
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}
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content = (PdfContent)((PdfReference)Elements[count - 1]).Value;
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if (content != null && content.Stream != null)
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{
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length = content.Stream.Length;
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value = new byte[length + 3];
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Array.Copy(content.Stream.Value, 0, value, 0, length);
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value[length] = (byte)' ';
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value[length + 1] = (byte)'Q';
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value[length + 2] = (byte)'\n';
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content.Stream.Value = value;
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content.Elements.SetInteger("/Length", length + 3);
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}
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}
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}
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}
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bool _modified;
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internal override void WriteObject(PdfWriter writer)
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{
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// Save two bytes in PDF stream...
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if (Elements.Count == 1)
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Elements[0].WriteObject(writer);
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else
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base.WriteObject(writer);
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}
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/// <summary>
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/// Gets the enumerator.
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/// </summary>
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public new IEnumerator<PdfContent> GetEnumerator()
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{
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return new PdfPageContentEnumerator(this);
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}
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class PdfPageContentEnumerator : IEnumerator<PdfContent>
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{
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internal PdfPageContentEnumerator(PdfContents list)
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{
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_contents = list;
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_index = -1;
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}
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public bool MoveNext()
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{
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if (_index < _contents.Elements.Count - 1)
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{
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_index++;
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_currentElement = (PdfContent)((PdfReference)_contents.Elements[_index]).Value;
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return true;
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}
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_index = _contents.Elements.Count;
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return false;
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}
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public void Reset()
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{
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_currentElement = null;
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_index = -1;
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}
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object IEnumerator.Current
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{
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get { return Current; }
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}
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public PdfContent Current
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{
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get
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{
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if (_index == -1 || _index >= _contents.Elements.Count)
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throw new InvalidOperationException(PSSR.ListEnumCurrentOutOfRange);
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return _currentElement;
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}
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}
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public void Dispose()
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{
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// Nothing to do.
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}
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PdfContent _currentElement;
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int _index;
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readonly PdfContents _contents;
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}
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}
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}
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