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