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 SkPDFPage_DEFINED
11#define SkPDFPage_DEFINED
12
13#include "SkPDFTypes.h"
14#include "SkPDFStream.h"
15#include "SkRefCnt.h"
16#include "SkTDArray.h"
17
18class SkPDFCatalog;
19class SkPDFDevice;
20class SkWStream;
21
22/** \class SkPDFPage
23
24    A SkPDFPage contains meta information about a page, is used in the page
25    tree and points to the content of the page.
26*/
27class SkPDFPage : public SkPDFDict {
28    SK_DECLARE_INST_COUNT(SkPDFPage)
29public:
30    /** Create a PDF page with the passed PDF device.  The device need not
31     *  have content on it yet.
32     *  @param content    The page content.
33     */
34    explicit SkPDFPage(SkPDFDevice* content);
35    ~SkPDFPage();
36
37    /** Before a page and its contents can be sized and emitted, it must
38     *  be finalized.  No changes to the PDFDevice will be honored after
39     *  finalizePage has been called.  This function adds the page content
40     *  to the passed catalog, so it must be called for each document
41     *  that the page is part of.
42     *  @param catalog         The catalog to add page content objects to.
43     *  @param firstPage       Indicate if this is the first page of a document.
44     *  @param newResourceObjects All the resource objects (recursively) used on
45     *                         the page are added to this array.  This gives
46     *                         the caller a chance to deduplicate resources
47     *                         across pages.
48     *  @param knownResourceObjects  The set of resources to be ignored.
49     */
50    void finalizePage(SkPDFCatalog* catalog, bool firstPage,
51                      const SkTSet<SkPDFObject*>& knownResourceObjects,
52                      SkTSet<SkPDFObject*>* newResourceObjects);
53
54    /** Add destinations for this page to the supplied dictionary.
55     *  @param dict       Dictionary to add destinations to.
56     */
57    void appendDestinations(SkPDFDict* dict);
58
59    /** Determine the size of the page content and store to the catalog
60     *  the offsets of all nonresource-indirect objects that make up the page
61     *  content.  This must be called before emitPage(), but after finalizePage.
62     *  @param catalog    The catalog to add the object offsets to.
63     *  @param fileOffset The file offset where the page content will be
64     *                    emitted.
65     */
66    off_t getPageSize(SkPDFCatalog* catalog, off_t fileOffset);
67
68    /** Output the page content to the passed stream.
69     *  @param stream     The writable output stream to send the content to.
70     *  @param catalog    The active object catalog.
71     */
72    void emitPage(SkWStream* stream, SkPDFCatalog* catalog);
73
74    /** Generate a page tree for the passed vector of pages.  New objects are
75     *  added to the catalog.  The pageTree vector is populated with all of
76     *  the 'Pages' dictionaries as well as the 'Page' objects.  Page trees
77     *  have both parent and children links, creating reference cycles, so
78     *  it must be torn down explicitly.  The first page is not added to
79     *  the pageTree dictionary array so the caller can handle it specially.
80     *  @param pages      The ordered vector of page objects.
81     *  @param catalog    The catalog to add new objects into.
82     *  @param pageTree   An output vector with all of the internal and leaf
83     *                    nodes of the pageTree.
84     *  @param rootNode   An output parameter set to the root node.
85     */
86    static void GeneratePageTree(const SkTDArray<SkPDFPage*>& pages,
87                                 SkPDFCatalog* catalog,
88                                 SkTDArray<SkPDFDict*>* pageTree,
89                                 SkPDFDict** rootNode);
90
91    /** Get the fonts used on this page.
92     */
93    const SkTDArray<SkPDFFont*>& getFontResources() const;
94
95    /** Returns a SkPDFGlyphSetMap which represents glyph usage of every font
96     *  that shows on this page.
97     */
98    const SkPDFGlyphSetMap& getFontGlyphUsage() const;
99
100private:
101    // Multiple pages may reference the content.
102    SkAutoTUnref<SkPDFDevice> fDevice;
103
104    // Once the content is finalized, put it into a stream for output.
105    SkAutoTUnref<SkPDFStream> fContentStream;
106    typedef SkPDFDict INHERITED;
107};
108
109#endif
110