1 /*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "SkPDFCatalog.h"
18 #include "SkPDFDevice.h"
19 #include "SkPDFPage.h"
20 #include "SkStream.h"
21
SkPDFPage(const SkRefPtr<SkPDFDevice> & content)22 SkPDFPage::SkPDFPage(const SkRefPtr<SkPDFDevice>& content)
23 : SkPDFDict("Page"),
24 fDevice(content) {
25 }
26
~SkPDFPage()27 SkPDFPage::~SkPDFPage() {}
28
finalizePage(SkPDFCatalog * catalog,bool firstPage,SkTDArray<SkPDFObject * > * resourceObjects)29 void SkPDFPage::finalizePage(SkPDFCatalog* catalog, bool firstPage,
30 SkTDArray<SkPDFObject*>* resourceObjects) {
31 if (fContentStream.get() == NULL) {
32 insert("Resources", fDevice->getResourceDict().get());
33 insert("MediaBox", fDevice->getMediaBox().get());
34
35 SkRefPtr<SkStream> content = fDevice->content();
36 content->unref(); // SkRefPtr and content() both took a reference.
37 fContentStream = new SkPDFStream(content.get());
38 fContentStream->unref(); // SkRefPtr and new both took a reference.
39 insert("Contents", new SkPDFObjRef(fContentStream.get()))->unref();
40 }
41 catalog->addObject(fContentStream.get(), firstPage);
42 fDevice->getResources(resourceObjects);
43 }
44
getPageSize(SkPDFCatalog * catalog,off_t fileOffset)45 off_t SkPDFPage::getPageSize(SkPDFCatalog* catalog, off_t fileOffset) {
46 SkASSERT(fContentStream.get() != NULL);
47 catalog->setFileOffset(fContentStream.get(), fileOffset);
48 return fContentStream->getOutputSize(catalog, true);
49 }
50
emitPage(SkWStream * stream,SkPDFCatalog * catalog)51 void SkPDFPage::emitPage(SkWStream* stream, SkPDFCatalog* catalog) {
52 SkASSERT(fContentStream.get() != NULL);
53 fContentStream->emitObject(stream, catalog, true);
54 }
55
56 // static
generatePageTree(const SkTDArray<SkPDFPage * > & pages,SkPDFCatalog * catalog,SkTDArray<SkPDFDict * > * pageTree,SkPDFDict ** rootNode)57 void SkPDFPage::generatePageTree(const SkTDArray<SkPDFPage*>& pages,
58 SkPDFCatalog* catalog,
59 SkTDArray<SkPDFDict*>* pageTree,
60 SkPDFDict** rootNode) {
61 // PDF wants a tree describing all the pages in the document. We arbitrary
62 // choose 8 (kNodeSize) as the number of allowed children. The internal
63 // nodes have type "Pages" with an array of children, a parent pointer, and
64 // the number of leaves below the node as "Count." The leaves are passed
65 // into the method, have type "Page" and need a parent pointer. This method
66 // builds the tree bottom up, skipping internal nodes that would have only
67 // one child.
68 static const int kNodeSize = 8;
69
70 SkRefPtr<SkPDFName> kidsName = new SkPDFName("Kids");
71 kidsName->unref(); // SkRefPtr and new both took a reference.
72 SkRefPtr<SkPDFName> countName = new SkPDFName("Count");
73 countName->unref(); // SkRefPtr and new both took a reference.
74 SkRefPtr<SkPDFName> parentName = new SkPDFName("Parent");
75 parentName->unref(); // SkRefPtr and new both took a reference.
76
77 // curNodes takes a reference to its items, which it passes to pageTree.
78 SkTDArray<SkPDFDict*> curNodes;
79 curNodes.setReserve(pages.count());
80 for (int i = 0; i < pages.count(); i++) {
81 SkSafeRef(pages[i]);
82 curNodes.push(pages[i]);
83 }
84
85 // nextRoundNodes passes its references to nodes on to curNodes.
86 SkTDArray<SkPDFDict*> nextRoundNodes;
87 nextRoundNodes.setReserve((pages.count() + kNodeSize - 1)/kNodeSize);
88
89 int treeCapacity = kNodeSize;
90 do {
91 for (int i = 0; i < curNodes.count(); ) {
92 if (i > 0 && i + 1 == curNodes.count()) {
93 nextRoundNodes.push(curNodes[i]);
94 break;
95 }
96
97 SkPDFDict* newNode = new SkPDFDict("Pages");
98 SkRefPtr<SkPDFObjRef> newNodeRef = new SkPDFObjRef(newNode);
99 newNodeRef->unref(); // SkRefPtr and new both took a reference.
100
101 SkRefPtr<SkPDFArray> kids = new SkPDFArray;
102 kids->unref(); // SkRefPtr and new both took a reference.
103 kids->reserve(kNodeSize);
104
105 int count = 0;
106 for (; i < curNodes.count() && count < kNodeSize; i++, count++) {
107 curNodes[i]->insert(parentName.get(), newNodeRef.get());
108 kids->append(new SkPDFObjRef(curNodes[i]))->unref();
109
110 // TODO(vandebo) put the objects in strict access order.
111 // Probably doesn't matter because they are so small.
112 if (curNodes[i] != pages[0]) {
113 pageTree->push(curNodes[i]); // Transfer reference.
114 catalog->addObject(curNodes[i], false);
115 } else {
116 SkSafeUnref(curNodes[i]);
117 }
118 }
119
120 newNode->insert(kidsName.get(), kids.get());
121 int pageCount = treeCapacity;
122 if (count < kNodeSize) {
123 pageCount = pages.count() % treeCapacity;
124 }
125 newNode->insert(countName.get(), new SkPDFInt(pageCount))->unref();
126 nextRoundNodes.push(newNode); // Transfer reference.
127 }
128
129 curNodes = nextRoundNodes;
130 nextRoundNodes.rewind();
131 treeCapacity *= kNodeSize;
132 } while(curNodes.count() > 1);
133
134 pageTree->push(curNodes[0]); // Transfer reference.
135 catalog->addObject(curNodes[0], false);
136 if (rootNode)
137 *rootNode = curNodes[0];
138 }
139
getFontResources() const140 const SkTDArray<SkPDFFont*>& SkPDFPage::getFontResources() const {
141 return fDevice->getFontResources();
142 }
143