1
2/*
3 * Copyright 2010 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#ifndef SkPDFCatalog_DEFINED
11#define SkPDFCatalog_DEFINED
12
13#include <sys/types.h>
14
15#include "SkPDFDocument.h"
16#include "SkPDFTypes.h"
17#include "SkRefCnt.h"
18#include "SkTDArray.h"
19
20/** \class SkPDFCatalog
21
22    The PDF catalog manages object numbers and file offsets.  It is used
23    to create the PDF cross reference table.
24*/
25class SkPDFCatalog {
26public:
27    /** Create a PDF catalog.
28     */
29    explicit SkPDFCatalog(SkPDFDocument::Flags flags);
30    ~SkPDFCatalog();
31
32    /** Add the passed object to the catalog.  Refs obj.
33     *  @param obj         The object to add.
34     *  @param onFirstPage Is the object on the first page.
35     *  @return The obj argument is returned.
36     */
37    SkPDFObject* addObject(SkPDFObject* obj, bool onFirstPage);
38
39    /** Inform the catalog of the object's position in the final stream.
40     *  The object should already have been added to the catalog.  Returns
41     *  the object's size.
42     *  @param obj         The object to add.
43     *  @param offset      The byte offset in the output stream of this object.
44     */
45    size_t setFileOffset(SkPDFObject* obj, off_t offset);
46
47    /** Output the object number for the passed object.
48     *  @param obj         The object of interest.
49     *  @param stream      The writable output stream to send the output to.
50     */
51    void emitObjectNumber(SkWStream* stream, SkPDFObject* obj);
52
53    /** Return the number of bytes that would be emitted for the passed
54     *  object's object number.
55     *  @param obj         The object of interest
56     */
57    size_t getObjectNumberSize(SkPDFObject* obj);
58
59    /** Return the document flags in effect for this catalog/document.
60     */
61    SkPDFDocument::Flags getDocumentFlags() const { return fDocumentFlags; }
62
63    /** Output the cross reference table for objects in the catalog.
64     *  Returns the total number of objects.
65     *  @param stream      The writable output stream to send the output to.
66     *  @param firstPage   If true, include first page objects only, otherwise
67     *                     include all objects not on the first page.
68     */
69    int32_t emitXrefTable(SkWStream* stream, bool firstPage);
70
71    /** Set substitute object for the passed object.
72     */
73    void setSubstitute(SkPDFObject* original, SkPDFObject* substitute);
74
75    /** Find and return any substitute object set for the passed object. If
76     *  there is none, return the passed object.
77     */
78    SkPDFObject* getSubstituteObject(SkPDFObject* object);
79
80    /** Set file offsets for the resources of substitute objects.
81     *  @param fileOffset Accumulated offset of current document.
82     *  @param firstPage  Indicate whether this is for the first page only.
83     *  @return           Total size of resources of substitute objects.
84     */
85    off_t setSubstituteResourcesOffsets(off_t fileOffset, bool firstPage);
86
87    /** Emit the resources of substitute objects.
88     */
89    void emitSubstituteResources(SkWStream* stream, bool firstPage);
90
91private:
92    struct Rec {
93        Rec(SkPDFObject* object, bool onFirstPage)
94            : fObject(object),
95              fFileOffset(0),
96              fObjNumAssigned(false),
97              fOnFirstPage(onFirstPage) {
98        }
99        SkPDFObject* fObject;
100        off_t fFileOffset;
101        bool fObjNumAssigned;
102        bool fOnFirstPage;
103    };
104
105    struct SubstituteMapping {
106        SubstituteMapping(SkPDFObject* original, SkPDFObject* substitute)
107            : fOriginal(original), fSubstitute(substitute) {
108        }
109        SkPDFObject* fOriginal;
110        SkPDFObject* fSubstitute;
111    };
112
113    // TODO(vandebo): Make this a hash if it's a performance problem.
114    SkTDArray<struct Rec> fCatalog;
115
116    // TODO(arthurhsu): Make this a hash if it's a performance problem.
117    SkTDArray<SubstituteMapping> fSubstituteMap;
118    SkTSet<SkPDFObject*> fSubstituteResourcesFirstPage;
119    SkTSet<SkPDFObject*> fSubstituteResourcesRemaining;
120
121    // Number of objects on the first page.
122    uint32_t fFirstPageCount;
123    // Next object number to assign (on page > 1).
124    uint32_t fNextObjNum;
125    // Next object number to assign on the first page.
126    uint32_t fNextFirstPageObjNum;
127
128    SkPDFDocument::Flags fDocumentFlags;
129
130    int findObjectIndex(SkPDFObject* obj) const;
131
132    int assignObjNum(SkPDFObject* obj);
133
134    SkTSet<SkPDFObject*>* getSubstituteList(bool firstPage);
135};
136
137#endif
138