130 lines
6.6 KiB
C#
130 lines
6.6 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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namespace PdfSharp.Pdf.Advanced
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{
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/// <summary>
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/// Represents a PDF transparency group XObject.
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/// </summary>
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public sealed class PdfTransparencyGroupAttributes : PdfGroupAttributes
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{
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internal PdfTransparencyGroupAttributes(PdfDocument thisDocument)
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: base(thisDocument)
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{
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Elements.SetName(Keys.S, "/Transparency");
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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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public sealed new class Keys : PdfGroupAttributes.Keys
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{
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/// <summary>
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/// (Sometimes required, as discussed below)
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/// The group color space, which is used for the following purposes:
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/// <20> As the color space into which colors are converted when painted into the group
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/// <20> As the blending color space in which objects are composited within the group
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/// <20> As the color space of the group as a whole when it in turn is painted as an object onto its backdrop
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/// The group color space may be any device or CIE-based color space that
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/// treats its components as independent additive or subtractive values in the
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/// range 0.0 to 1.0, subject to the restrictions described in Section 7.2.3, <20>Blending Color Space.<2E>
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/// These restrictions exclude Lab and lightness-chromaticity ICCBased color spaces,
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/// as well as the special color spaces Pattern, Indexed, Separation, and DeviceN.
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/// Device color spaces are subject to remapping according to the DefaultGray,
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/// DefaultRGB, and DefaultCMYK entries in the ColorSpace subdictionary of the
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/// current resource dictionary.
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/// Ordinarily, the CS entry is allowed only for isolated transparency groups
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/// (those for which I, below, is true), and even then it is optional. However,
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/// this entry is required in the group attributes dictionary for any transparency
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/// group XObject that has no parent group or page from which to inherit <20> in
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/// particular, one that is the value of the G entry in a soft-mask dictionary of
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/// subtype Luminosity.
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/// In addition, it is always permissible to specify CS in the group attributes
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/// dictionary associated with a page object, even if I is false or absent. In the
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/// normal case in which the page is imposed directly on the output medium,
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/// the page group is effectively isolated regardless of the I value, and the
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/// specified CS value is therefore honored. But if the page is in turn used as an
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/// element of some other page and if the group is non-isolated, CS is ignored
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/// and the color space is inherited from the actual backdrop with which the
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/// page is composited.
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/// Default value: the color space of the parent group or page into which this
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/// transparency group is painted. (The parent<6E>s color space in turn can be
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/// either explicitly specified or inherited.)
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/// </summary>
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[KeyInfo(KeyType.NameOrArray | KeyType.Optional)]
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public const string CS = "/CS";
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/// <summary>
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/// (Optional) A flag specifying whether the transparency group is isolated.
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/// If this flag is true, objects within the group are composited against a fully
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/// transparent initial backdrop; if false, they are composited against the
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/// group<75>s backdrop.
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/// Default value: false.
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/// In the group attributes dictionary for a page, the interpretation of this
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/// entry is slightly altered. In the normal case in which the page is imposed
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/// directly on the output medium, the page group is effectively isolated and
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/// the specified I value is ignored. But if the page is in turn used as an
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/// element of some other page, it is treated as if it were a transparency
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/// group XObject; the I value is interpreted in the normal way to determine
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/// whether the page group is isolated.
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/// </summary>
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[KeyInfo(KeyType.Boolean | KeyType.Optional)]
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public const string I = "/I";
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/// <summary>
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/// (Optional) A flag specifying whether the transparency group is a knockout
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/// group. If this flag is false, later objects within the group are composited
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/// with earlier ones with which they overlap; if true, they are composited with
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/// the group<75>s initial backdrop and overwrite (<28>knock out<75>) any earlier
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/// overlapping objects.
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/// Default value: false.
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/// </summary>
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[KeyInfo(KeyType.Boolean | KeyType.Optional)]
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public const string K = "/K";
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/// <summary>
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/// Gets the KeysMeta for these keys.
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/// </summary>
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internal static new 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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