Create a Factory for NativeMetafile.

printing/pdf_ps_metafile_cairo.h

Index: printing/pdf_ps_metafile_cairo.h
diff --git a/printing/pdf_ps_metafile_cairo.h b/printing/pdf_ps_metafile_cairo.h
index e56b64c65f8563e00baa835b70c402e003485b69..7e45288079a303ba3b338033f5cad12b1bcd9c0c 100644
--- a/printing/pdf_ps_metafile_cairo.h
+++ b/printing/pdf_ps_metafile_cairo.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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.
 
@@ -8,6 +8,8 @@
 #include <string>
 
 #include "base/basictypes.h"
+#include "printing/native_metafile_factory.h"
+#include "printing/native_metafile_linux.h"
 
 typedef struct _cairo_surface cairo_surface_t;
 typedef struct _cairo cairo_t;
@@ -22,46 +24,33 @@ namespace printing {
 
 // This class uses Cairo graphics library to generate PostScript/PDF stream
 // and stores rendering results in a string buffer.
-class PdfPsMetafile {
+class PdfPsMetafile : public NativeMetafile  {
  public:
-  enum FileFormat {
-    PDF,
-    PS,
-  };
-
-  PdfPsMetafile();
-
-  // In the renderer process, callers should also call Init(void) to see if the
-  // metafile can obtain all necessary rendering resources.
-  // In the browser process, callers should also call Init(const void*, uint32)
-  // to initialize the buffer |data_| to use SaveTo().
-  explicit PdfPsMetafile(const FileFormat& format);
-
-  ~PdfPsMetafile();
+  virtual ~PdfPsMetafile();
 
   // Initializes to a fresh new metafile. Returns true on success.
   // Note: Only call in the renderer to allocate rendering resources.
-  bool Init();
+  virtual bool Init();
 
   // Initializes a copy of metafile from PDF/PS stream data.
   // Returns true on success.
   // |src_buffer| should point to the shared memory which stores PDF/PS
   // contents generated in the renderer.
   // Note: Only call in the browser to initialize |data_|.
-  bool Init(const void* src_buffer, uint32 src_buffer_size);
+  virtual bool Init(const void* src_buffer, uint32 src_buffer_size);
 
   // Sets raw PS/PDF data for the document. This is used when a cairo drawing
   // surface has already been created. This method will cause all subsequent
   // drawing on the surface to be discarded (in Close()). If Init() has not yet
   // been called this method simply calls the second version of Init.
-  bool SetRawData(const void* src_buffer, uint32 src_buffer_size);
+  virtual bool SetRawData(const void* src_buffer, uint32 src_buffer_size);
 
-  FileFormat GetFileFormat() const { return format_; }

[vandebo (ex-Chrome), 2011/02/24 22:42:50]

Since you removed the constructor that takes the file format, you can also
remove this accessor, and the FileFormat enum from native_metafile_linux.h  Then
again, maybe better to do this in a different CL.

+  virtual FileFormat GetFileFormat() const { return format_; }
 
   // Prepares a new cairo surface/context for rendering a new page.
   // The unit is in point (=1/72 in).
   // Returns NULL when failed.
-  cairo_t* StartPage(double width_in_points,
+  virtual cairo_t* StartPage(double width_in_points,
                      double height_in_points,
                      double margin_top_in_points,
                      double margin_right_in_points,
@@ -71,24 +60,24 @@ class PdfPsMetafile {
   // Destroys the surface and the context used in rendering current page.
   // The results of current page will be appended into buffer |data_|.
   // Returns true on success.
-  bool FinishPage();
+  virtual bool FinishPage();
 
   // Closes resulting PDF/PS file. No further rendering is allowed.
-  void Close();
+  virtual void Close();
 
   // Returns size of PDF/PS contents stored in buffer |data_|.
   // This function should ONLY be called after PDF/PS file is closed.
-  uint32 GetDataSize() const;
+  virtual uint32 GetDataSize() const;
 
   // Copies PDF/PS contents stored in buffer |data_| into |dst_buffer|.
   // This function should ONLY be called after PDF/PS file is closed.
   // Returns true only when success.
-  bool GetData(void* dst_buffer, uint32 dst_buffer_size) const;
+  virtual bool GetData(void* dst_buffer, uint32 dst_buffer_size) const;
 
   // Saves PDF/PS contents stored in buffer |data_| into the file
   // associated with |fd|.
   // This function should ONLY be called after PDF/PS file is closed.
-  bool SaveTo(const base::FileDescriptor& fd) const;
+  virtual bool SaveTo(const base::FileDescriptor& fd) const;
 
   // The hardcoded margins, in points. These values are based on 72 dpi,
   // with 0.25 margins on top, left, and right, and 0.56 on bottom.
@@ -98,10 +87,15 @@ class PdfPsMetafile {
   static const double kLeftMarginInInch;
 
   // Returns the PdfPsMetafile object that owns the given context. Returns NULL
-  // if the context was not created by a PdfPdMetafile object.
+  // if the context was not created by a PdfPsMetafile object.
   static PdfPsMetafile* FromCairoContext(cairo_t* context);
 
+ protected:
+  PdfPsMetafile();
+
  private:
+  friend class NativeMetafileFactory;
+
   // Cleans up all resources.
   void CleanUpAll();