1// Copyright 2018 Google LLC.
2// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3#ifndef SkPDFDocument_DEFINED
4#define SkPDFDocument_DEFINED
5
6#include "include/core/SkDocument.h"
7
8#include <vector>
9
10#include "include/core/SkColor.h"
11#include "include/core/SkMilestone.h"
12#include "include/core/SkScalar.h"
13#include "include/core/SkString.h"
14#include "include/core/SkTime.h"
15#include "include/private/SkNoncopyable.h"
16
17#define SKPDF_STRING(X) SKPDF_STRING_IMPL(X)
18#define SKPDF_STRING_IMPL(X) #X
19
20class SkExecutor;
21class SkPDFArray;
22class SkPDFTagTree;
23
24namespace SkPDF {
25
26/** Table 333 in PDF 32000-1:2008 ยง14.8.4.2
27*/
28enum class DocumentStructureType {
29 kDocument, //!< Document
30 kPart, //!< Part
31 kArt, //!< Article
32 kSect, //!< Section
33 kDiv, //!< Division
34 kBlockQuote, //!< Block quotation
35 kCaption, //!< Caption
36 kTOC, //!< Table of Contents
37 kTOCI, //!< Table of Contents Item
38 kIndex, //!< Index
39 kNonStruct, //!< Nonstructural element
40 kPrivate, //!< Private element
41 kH, //!< Heading
42 kH1, //!< Heading level 1
43 kH2, //!< Heading level 2
44 kH3, //!< Heading level 3
45 kH4, //!< Heading level 4
46 kH5, //!< Heading level 5
47 kH6, //!< Heading level 6
48 kP, //!< Paragraph
49 kL, //!< List
50 kLI, //!< List item
51 kLbl, //!< List item label
52 kLBody, //!< List item body
53 kTable, //!< Table
54 kTR, //!< Table row
55 kTH, //!< Table header cell
56 kTD, //!< Table data cell
57 kTHead, //!< Table header row group
58 kTBody, //!< Table body row group
59 kTFoot, //!< table footer row group
60 kSpan, //!< Span
61 kQuote, //!< Quotation
62 kNote, //!< Note
63 kReference, //!< Reference
64 kBibEntry, //!< Bibliography entry
65 kCode, //!< Code
66 kLink, //!< Link
67 kAnnot, //!< Annotation
68 kRuby, //!< Ruby annotation
69 kRB, //!< Ruby base text
70 kRT, //!< Ruby annotation text
71 kRP, //!< Ruby punctuation
72 kWarichu, //!< Warichu annotation
73 kWT, //!< Warichu text
74 kWP, //!< Warichu punctuation
75 kFigure, //!< Figure
76 kFormula, //!< Formula
77 kForm, //!< Form control (not like an HTML FORM element)
78};
79
80/** Attributes for nodes in the PDF tree. */
81class SK_API AttributeList : SkNoncopyable {
82public:
83 AttributeList();
84 ~AttributeList();
85
86 // Each attribute must have an owner (e.g. "Layout", "List", "Table", etc)
87 // and an attribute name (e.g. "BBox", "RowSpan", etc.) from PDF32000_2008 14.8.5,
88 // and then a value of the proper type according to the spec.
89 void appendInt(const char* owner, const char* name, int value);
90 void appendFloat(const char* owner, const char* name, float value);
91 void appendString(const char* owner, const char* name, const char* value);
92 void appendFloatArray(const char* owner,
93 const char* name,
94 const std::vector<float>& value);
95 void appendStringArray(const char* owner,
96 const char* name,
97 const std::vector<SkString>& value);
98
99private:
100 friend class ::SkPDFTagTree;
101
102 std::unique_ptr<SkPDFArray> fAttrs;
103};
104
105/** A node in a PDF structure tree, giving a semantic representation
106 of the content. Each node ID is associated with content
107 by passing the SkCanvas and node ID to SkPDF::SetNodeId() when drawing.
108 NodeIDs should be unique within each tree.
109*/
110struct StructureElementNode {
111 SkString fTypeString;
112 std::vector<std::unique_ptr<StructureElementNode>> fChildVector;
113 int fNodeId = 0;
114 std::vector<int> fAdditionalNodeIds;
115 AttributeList fAttributes;
116 SkString fAlt;
117 SkString fLang;
118
119 // Deprecated. Use fChildVector instead.
120 StructureElementNode* fChildren = nullptr;
121 size_t fChildCount = 0;
122
123 // Deprecated. Use fTypeString instead.
124 DocumentStructureType fType = DocumentStructureType::kNonStruct;
125};
126
127/** Optional metadata to be passed into the PDF factory function.
128*/
129struct Metadata {
130 /** The document's title.
131 */
132 SkString fTitle;
133
134 /** The name of the person who created the document.
135 */
136 SkString fAuthor;
137
138 /** The subject of the document.
139 */
140 SkString fSubject;
141
142 /** Keywords associated with the document. Commas may be used to delineate
143 keywords within the string.
144 */
145 SkString fKeywords;
146
147 /** If the document was converted to PDF from another format,
148 the name of the conforming product that created the
149 original document from which it was converted.
150 */
151 SkString fCreator;
152
153 /** The product that is converting this document to PDF.
154 */
155 SkString fProducer = SkString("Skia/PDF m" SKPDF_STRING(SK_MILESTONE));
156
157 /** The date and time the document was created.
158 The zero default value represents an unknown/unset time.
159 */
160 SkTime::DateTime fCreation = {0, 0, 0, 0, 0, 0, 0, 0};
161
162 /** The date and time the document was most recently modified.
163 The zero default value represents an unknown/unset time.
164 */
165 SkTime::DateTime fModified = {0, 0, 0, 0, 0, 0, 0, 0};
166
167 /** The DPI (pixels-per-inch) at which features without native PDF support
168 will be rasterized (e.g. draw image with perspective, draw text with
169 perspective, ...) A larger DPI would create a PDF that reflects the
170 original intent with better fidelity, but it can make for larger PDF
171 files too, which would use more memory while rendering, and it would be
172 slower to be processed or sent online or to printer.
173 */
174 SkScalar fRasterDPI = SK_ScalarDefaultRasterDPI;
175
176 /** If true, include XMP metadata, a document UUID, and sRGB output intent
177 information. This adds length to the document and makes it
178 non-reproducable, but are necessary features for PDF/A-2b conformance
179 */
180 bool fPDFA = false;
181
182 /** Encoding quality controls the trade-off between size and quality. By
183 default this is set to 101 percent, which corresponds to lossless
184 encoding. If this value is set to a value <= 100, and the image is
185 opaque, it will be encoded (using JPEG) with that quality setting.
186 */
187 int fEncodingQuality = 101;
188
189 /** An optional tree of structured document tags that provide
190 a semantic representation of the content. The caller
191 should retain ownership.
192 */
193 StructureElementNode* fStructureElementTreeRoot = nullptr;
194
195 /** Executor to handle threaded work within PDF Backend. If this is nullptr,
196 then all work will be done serially on the main thread. To have worker
197 threads assist with various tasks, set this to a valid SkExecutor
198 instance. Currently used for executing Deflate algorithm in parallel.
199
200 If set, the PDF output will be non-reproducible in the order and
201 internal numbering of objects, but should render the same.
202
203 Experimental.
204 */
205 SkExecutor* fExecutor = nullptr;
206
207 /** Preferred Subsetter. Only respected if both are compiled in.
208
209 The Sfntly subsetter is deprecated.
210
211 Experimental.
212 */
213 enum Subsetter {
214 kHarfbuzz_Subsetter,
215 kSfntly_Subsetter,
216 } fSubsetter = kHarfbuzz_Subsetter;
217};
218
219/** Associate a node ID with subsequent drawing commands in an
220 SkCanvas. The same node ID can appear in a StructureElementNode
221 in order to associate a document's structure element tree with
222 its content.
223
224 A node ID of zero indicates no node ID.
225
226 @param canvas The canvas used to draw to the PDF.
227 @param nodeId The node ID for subsequent drawing commands.
228*/
229SK_API void SetNodeId(SkCanvas* dst, int nodeID);
230
231/** Create a PDF-backed document, writing the results into a SkWStream.
232
233 PDF pages are sized in point units. 1 pt == 1/72 inch == 127/360 mm.
234
235 @param stream A PDF document will be written to this stream. The document may write
236 to the stream at anytime during its lifetime, until either close() is
237 called or the document is deleted.
238 @param metadata a PDFmetadata object. Any fields may be left empty.
239
240 @returns NULL if there is an error, otherwise a newly created PDF-backed SkDocument.
241*/
242SK_API sk_sp<SkDocument> MakeDocument(SkWStream* stream, const Metadata& metadata);
243
244static inline sk_sp<SkDocument> MakeDocument(SkWStream* stream) {
245 return MakeDocument(stream, Metadata());
246}
247
248} // namespace SkPDF
249
250#undef SKPDF_STRING
251#undef SKPDF_STRING_IMPL
252#endif // SkPDFDocument_DEFINED
253