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#include "SkPDFCatalog.h"
11#include "SkPDFDevice.h"
12#include "SkPDFPage.h"
13#include "SkPDFResourceDict.h"
14#include "SkStream.h"
15
16SkPDFPage::SkPDFPage(SkPDFDevice* content)
17    : SkPDFDict("Page"),
18      fDevice(content) {
19  SkSafeRef(content);
20}
21
22SkPDFPage::~SkPDFPage() {}
23
24void SkPDFPage::finalizePage(SkPDFCatalog* catalog, bool firstPage,
25                             const SkTSet<SkPDFObject*>& knownResourceObjects,
26                             SkTSet<SkPDFObject*>* newResourceObjects) {
27    SkPDFResourceDict* resourceDict = fDevice->getResourceDict();
28    if (fContentStream.get() == NULL) {
29        insert("Resources", resourceDict);
30        SkSafeUnref(this->insert("MediaBox", fDevice->copyMediaBox()));
31        if (!SkToBool(catalog->getDocumentFlags() &
32                      SkPDFDocument::kNoLinks_Flags)) {
33            SkPDFArray* annots = fDevice->getAnnotations();
34            if (annots && annots->size() > 0) {
35                insert("Annots", annots);
36            }
37        }
38
39        SkAutoTUnref<SkStream> content(fDevice->content());
40        fContentStream.reset(new SkPDFStream(content.get()));
41        insert("Contents", new SkPDFObjRef(fContentStream.get()))->unref();
42    }
43    catalog->addObject(fContentStream.get(), firstPage);
44    resourceDict->getReferencedResources(knownResourceObjects,
45                                         newResourceObjects,
46                                         true);
47}
48
49off_t SkPDFPage::getPageSize(SkPDFCatalog* catalog, off_t fileOffset) {
50    SkASSERT(fContentStream.get() != NULL);
51    catalog->setFileOffset(fContentStream.get(), fileOffset);
52    return fContentStream->getOutputSize(catalog, true);
53}
54
55void SkPDFPage::emitPage(SkWStream* stream, SkPDFCatalog* catalog) {
56    SkASSERT(fContentStream.get() != NULL);
57    fContentStream->emitObject(stream, catalog, true);
58}
59
60// static
61void SkPDFPage::GeneratePageTree(const SkTDArray<SkPDFPage*>& pages,
62                                 SkPDFCatalog* catalog,
63                                 SkTDArray<SkPDFDict*>* pageTree,
64                                 SkPDFDict** rootNode) {
65    // PDF wants a tree describing all the pages in the document.  We arbitrary
66    // choose 8 (kNodeSize) as the number of allowed children.  The internal
67    // nodes have type "Pages" with an array of children, a parent pointer, and
68    // the number of leaves below the node as "Count."  The leaves are passed
69    // into the method, have type "Page" and need a parent pointer. This method
70    // builds the tree bottom up, skipping internal nodes that would have only
71    // one child.
72    static const int kNodeSize = 8;
73
74    SkAutoTUnref<SkPDFName> kidsName(new SkPDFName("Kids"));
75    SkAutoTUnref<SkPDFName> countName(new SkPDFName("Count"));
76    SkAutoTUnref<SkPDFName> parentName(new SkPDFName("Parent"));
77
78    // curNodes takes a reference to its items, which it passes to pageTree.
79    SkTDArray<SkPDFDict*> curNodes;
80    curNodes.setReserve(pages.count());
81    for (int i = 0; i < pages.count(); i++) {
82        SkSafeRef(pages[i]);
83        curNodes.push(pages[i]);
84    }
85
86    // nextRoundNodes passes its references to nodes on to curNodes.
87    SkTDArray<SkPDFDict*> nextRoundNodes;
88    nextRoundNodes.setReserve((pages.count() + kNodeSize - 1)/kNodeSize);
89
90    int treeCapacity = kNodeSize;
91    do {
92        for (int i = 0; i < curNodes.count(); ) {
93            if (i > 0 && i + 1 == curNodes.count()) {
94                nextRoundNodes.push(curNodes[i]);
95                break;
96            }
97
98            SkPDFDict* newNode = new SkPDFDict("Pages");
99            SkAutoTUnref<SkPDFObjRef> newNodeRef(new SkPDFObjRef(newNode));
100
101            SkAutoTUnref<SkPDFArray> kids(new SkPDFArray);
102            kids->reserve(kNodeSize);
103
104            int count = 0;
105            for (; i < curNodes.count() && count < kNodeSize; i++, count++) {
106                curNodes[i]->insert(parentName.get(), newNodeRef.get());
107                kids->append(new SkPDFObjRef(curNodes[i]))->unref();
108
109                // TODO(vandebo): put the objects in strict access order.
110                // Probably doesn't matter because they are so small.
111                if (curNodes[i] != pages[0]) {
112                    pageTree->push(curNodes[i]);  // Transfer reference.
113                    catalog->addObject(curNodes[i], false);
114                } else {
115                    SkSafeUnref(curNodes[i]);
116                    catalog->addObject(curNodes[i], true);
117                }
118            }
119
120            // treeCapacity is the number of leaf nodes possible for the
121            // current set of subtrees being generated. (i.e. 8, 64, 512, ...).
122            // It is hard to count the number of leaf nodes in the current
123            // subtree. However, by construction, we know that unless it's the
124            // last subtree for the current depth, the leaf count will be
125            // treeCapacity, otherwise it's what ever is left over after
126            // consuming treeCapacity chunks.
127            int pageCount = treeCapacity;
128            if (i == curNodes.count()) {
129                pageCount = ((pages.count() - 1) % treeCapacity) + 1;
130            }
131            newNode->insert(countName.get(), new SkPDFInt(pageCount))->unref();
132            newNode->insert(kidsName.get(), kids.get());
133            nextRoundNodes.push(newNode);  // Transfer reference.
134        }
135
136        curNodes = nextRoundNodes;
137        nextRoundNodes.rewind();
138        treeCapacity *= kNodeSize;
139    } while (curNodes.count() > 1);
140
141    pageTree->push(curNodes[0]);  // Transfer reference.
142    catalog->addObject(curNodes[0], false);
143    if (rootNode) {
144        *rootNode = curNodes[0];
145    }
146}
147
148const SkTDArray<SkPDFFont*>& SkPDFPage::getFontResources() const {
149    return fDevice->getFontResources();
150}
151
152const SkPDFGlyphSetMap& SkPDFPage::getFontGlyphUsage() const {
153    return fDevice->getFontGlyphUsage();
154}
155
156void SkPDFPage::appendDestinations(SkPDFDict* dict) {
157    fDevice->appendDestinations(dict, this);
158}
159