Create a Factory for NativeMetafile.

printing/pdf_metafile_mac.h

 // Copyright (c) 2009 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_MAC_H_
 #define PRINTING_PDF_METAFILE_MAC_H_
 
 #include <ApplicationServices/ApplicationServices.h>
 #include <CoreFoundation/CoreFoundation.h>
 
 #include "base/basictypes.h"
 #include "base/mac/scoped_cftyperef.h"
+#include "printing/metafile_factory.h"
+#include "printing/native_metafile_mac.h"
 
 namespace gfx {
 class Rect;
 class Size;
 class Point;
 }
 class FilePath;
 
 namespace printing {
 
 // This class creates a graphics context that renders into a PDF data stream.
-class PdfMetafile {
+class PdfMetafile: public NativeMetafile {
+
+  friend class MetafileFactory;

[Avi (use Gerrit), 2011/02/22 19:00:07]

friends are private.

[dpapad, 2011/02/22 19:29:10]

Done.

+
  public:
-  // To create PDF data, callers should also call Init() to set up the
-  // rendering context.
-  // To create a metafile from existing Data, callers should also call
-  // Init(const void*, uint32).
-  PdfMetafile();
 
-  ~PdfMetafile();
+  virtual ~PdfMetafile();
 
   // Initializes a new metafile, and returns a drawing context for rendering
   // into the PDF. Returns NULL on failure.
   // 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 Init();
+  virtual CGContextRef Init();
 
   // Initializes a copy of metafile from PDF data. Returns true on success.
-  bool Init(const void* src_buffer, uint32 src_buffer_size);
+  virtual bool Init(const void* src_buffer, uint32 src_buffer_size);
 
   // Prepares a new pdf page at specified |content_origin| with the given
   // |page_size| and a |scale_factor| to use for the drawing.
-  CGContextRef StartPage(const gfx::Size& page_size,
+  virtual CGContextRef StartPage(const gfx::Size& page_size,
                          const gfx::Point& content_origin,
                          const float& scale_factor);
 
   // Closes the current page.
-  void FinishPage();
+  virtual void FinishPage();
 
   // Closes the PDF file; no further rendering is allowed.
-  void Close();
+  virtual void Close();
 
   // Renders the given page into |rect| in the given context.
   // Pages use a 1-based index. The rendering uses the following arguments
   // to determine scaling and translation factors.
   // |shrink_to_fit| specifies whether the output should be shrunk to fit the
   // supplied |rect| if the page size is larger than |rect| in any dimension.
   // If this is false, parts of the PDF page that lie outside the bounds will be
   // clipped.
   // |stretch_to_fit| specifies whether the output should be stretched to fit
   // the supplied bounds if the page size is smaller than |rect| in all
   // dimensions.
   // |center_horizontally| specifies whether the final image (after any scaling
   // is done) should be centered horizontally within the given |rect|.
   // |center_vertically| specifies whether the final image (after any scaling
   // is done) should be centered vertically within the given |rect|.
   // Note that all scaling preserves the original aspect ratio of the page.
-  bool RenderPage(unsigned int page_number, CGContextRef context,
+  virtual bool RenderPage(unsigned int page_number, CGContextRef context,
                   const CGRect rect, bool shrink_to_fit, bool stretch_to_fit,
                   bool center_horizontally, bool center_vertically) const;
-  unsigned int GetPageCount() const;
+  virtual unsigned int GetPageCount() const;
 
   // Returns the bounds of the given page.
   // Pages use a 1-based index.
-  gfx::Rect GetPageBounds(unsigned int page_number) const;
+  virtual  gfx::Rect GetPageBounds(unsigned int page_number) const;
 
   // Returns the size of the underlying PDF data. Only valid after Close() has
   // been called.
-  uint32 GetDataSize() const;
+  virtual uint32 GetDataSize() const;
 
   // Copies the first |dst_buffer_size| bytes of the PDF data into |dst_buffer|.
   // Only valid after Close() has been called.
   // Returns true if the copy succeeds.
-  bool GetData(void* dst_buffer, uint32 dst_buffer_size) const;
+  virtual bool GetData(void* dst_buffer, uint32 dst_buffer_size) const;
 
   // Saves the raw PDF data to the given file. For testing only.
   // Returns true if writing succeeded.
-  bool SaveTo(const FilePath& file_path) const;
+  virtual bool SaveTo(const FilePath& file_path) const;
+
+ protected:
+  // To create PDF data, callers should also call Init() to set up the
+  // rendering context.
+  // To create a metafile from existing Data, callers should also call
+  // Init(const void*, uint32).
+  PdfMetafile();
 
  private:
   // Returns a CGPDFDocumentRef version of pdf_data_.
-  CGPDFDocumentRef GetPDFDocument() const;
+  virtual CGPDFDocumentRef GetPDFDocument() const;
 
   // Context for rendering to the pdf.
   base::mac::ScopedCFTypeRef<CGContextRef> context_;
 
   // PDF backing store.
   base::mac::ScopedCFTypeRef<CFMutableDataRef> pdf_data_;
 
   // Lazily-created CGPDFDocument representation of pdf_data_.
   mutable base::mac::ScopedCFTypeRef<CGPDFDocumentRef> pdf_doc_;
 
   // Whether or not a page is currently open.
   bool page_is_open_;
 
   DISALLOW_COPY_AND_ASSIGN(PdfMetafile);
 };
 
 }  // namespace printing
 
 #endif  // PRINTING_PDF_METAFILE_MAC_H_