printing/pdf_metafile_cg_mac.h

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef PRINTING_PDF_METAFILE_CG_MAC_H_
#define PRINTING_PDF_METAFILE_CG_MAC_H_

#include <ApplicationServices/ApplicationServices.h>
#include <CoreFoundation/CoreFoundation.h>
#include <stdint.h>

#include "base/mac/scoped_cftyperef.h"
#include "base/macros.h"
#include "printing/metafile.h"

namespace gfx {
class Rect;
class Size;
}

namespace printing {

// This class creates a graphics context that renders into a PDF data stream.
class PRINTING_EXPORT PdfMetafileCg : public Metafile {
 public:
  PdfMetafileCg();
  ~PdfMetafileCg() override;

  // Metafile methods.
  bool Init() override;
  bool InitFromData(const void* src_buffer, size_t src_buffer_size) override;
  void StartPage(const gfx::Size& page_size,
                 const gfx::Rect& content_area,
                 const float& scale_factor) override;
  bool FinishPage() override;
  bool FinishDocument() override;

  uint32_t GetDataSize() const override;
  bool GetData(void* dst_buffer, uint32_t dst_buffer_size) const override;

  gfx::Rect GetPageBounds(unsigned int page_number) const override;
  unsigned int GetPageCount() const override;

  // Note: The returned context *must not be retained* past Close(). If it is,
  // the data returned from GetData will not be valid PDF data.
  CGContextRef context() const override;

  // |shrink_to_fit| specifies whether the output should be shrunk to fit a
  // destination page if the source PDF is bigger than the destination page in
  // any dimension. If this is false, parts of the source PDF page that lie
  // outside the bounds will be clipped.
  //
  // |stretch_to_fit| specifies whether the output should be stretched to fit
  // the destination page if the source page size is smaller in all dimensions.
  //
  // |center_horizontally| specifies whether the output (after any scaling is
  // done) should be centered horizontally within the destination page.
  //
  // |center_vertically| specifies whether the output (after any scaling is
  // done) should be centered vertically within the destination page.
  // Note that all scaling preserves the original aspect ratio of the page.
  //
  // |autorotate| specifies whether the source PDF should be autorotated to fit
  // on the destination page.
  struct RenderPageParams {
    bool shrink_to_fit = false;
    bool stretch_to_fit = false;
    bool center_horizontally = false;
    bool center_vertically = false;
    bool autorotate = false;
  };
  // Renders the given page from this metafile into |rect| in the given context.
  // Pages use a 1-based index. The rendering uses the arguments in
  // |params| to determine scaling, translation, and rotation.
  bool OnRenderPage(unsigned int page_number,
                    CGContextRef context,
                    const CGRect rect,
                    const RenderPageParams& params);

  // Renders the given page from |src_buffer| into |rect| in the given context.
  // Pages use a 1-based index. The rendering uses the arguments in
  // |params| to determine scaling, translation, and rotation.
  static bool RenderPage(const std::vector<char>& src_buffer,
                         unsigned int page_number,
                         CGContextRef context,
                         const CGRect rect,
                         const RenderPageParams& params);

 private:
  // Returns a CGPDFDocumentRef version of |pdf_data_|.
  CGPDFDocumentRef GetPDFDocument() const;

  // Context for rendering to the pdf.
  base::ScopedCFTypeRef<CGContextRef> context_;

  // PDF backing store.
  base::ScopedCFTypeRef<CFMutableDataRef> pdf_data_;

  // Lazily-created CGPDFDocument representation of |pdf_data_|.
  mutable base::ScopedCFTypeRef<CGPDFDocumentRef> pdf_doc_;

  // Whether or not a page is currently open.
  bool page_is_open_;

  DISALLOW_COPY_AND_ASSIGN(PdfMetafileCg);
};

}  // namespace printing

#endif  // PRINTING_PDF_METAFILE_CG_MAC_H_