skia2/include/pdf/SkPDFPage.h
2011-02-24 23:22:30 +00:00

98 lines
4.0 KiB
C++

/*
* Copyright (C) 2010 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SkPDFPage_DEFINED
#define SkPDFPage_DEFINED
#include "SkPDFTypes.h"
#include "SkPDFStream.h"
#include "SkRefCnt.h"
#include "SkTDArray.h"
class SkPDFCatalog;
class SkPDFDevice;
class SkWStream;
/** \class SkPDFPage
A SkPDFPage contains meta information about a page, is used in the page
tree and points to the content of the page.
*/
class SkPDFPage : public SkPDFDict {
public:
/** Create a PDF page with the passed PDF device. The device need not
* have content on it yet.
* @param content The page content.
*/
explicit SkPDFPage(const SkRefPtr<SkPDFDevice>& content);
~SkPDFPage();
/** Before a page and its contents can be sized and emitted, it must
* be finalized. No changes to the PDFDevice will be honored after
* finalizePage has been called. This function adds the page content
* to the passed catalog, so it must be called for each document
* that the page is part of.
* @param catalog The catalog to add page content objects to.
* @param firstPage Indicate if this is the first page of a document.
* @param resourceObjects The resource objects used on the page are added
* to this array. This gives the caller a chance
* to deduplicate resources across pages.
*/
void finalizePage(SkPDFCatalog* catalog, bool firstPage,
SkTDArray<SkPDFObject*>* resourceObjects);
/** Determine the size of the page content and store to the catalog
* the offsets of all nonresource-indirect objects that make up the page
* content. This must be called before emitPage(), but after finalizePage.
* @param catalog The catalog to add the object offsets to.
* @param fileOffset The file offset where the page content will be
* emitted.
*/
off_t getPageSize(SkPDFCatalog* catalog, off_t fileOffset);
/** Output the page content to the passed stream.
* @param stream The writable output stream to send the content to.
* @param catalog The active object catalog.
*/
void emitPage(SkWStream* stream, SkPDFCatalog* catalog);
/** Generate a page tree for the passed vector of pages. New objects are
* added to the catalog. The pageTree vector is populated with all of
* the 'Pages' dictionaries as well as the 'Page' objects. Page trees
* have both parent and children links, creating reference cycles, so
* it must be torn down explicitly. The first page is not added to
* the pageTree dictionary array so the caller can handle it specially.
* @param pages The ordered vector of page objects.
* @param catalog The catalog to add new objects into.
* @param pageTree An output vector with all of the internal and leaf
* nodes of the pageTree.
* @param rootNode An output parameter set to the root node.
*/
static void generatePageTree(const SkTDArray<SkPDFPage*>& pages,
SkPDFCatalog* catalog,
SkTDArray<SkPDFDict*>* pageTree,
SkPDFDict** rootNode);
private:
// Multiple pages may reference the content.
SkRefPtr<SkPDFDevice> fDevice;
// Once the content is finalized, put it into a stream for output.
SkRefPtr<SkPDFStream> fContentStream;
};
#endif