Unifying NativeMetafile class interface (as much as possible) for Linux, Mac, Win

printing/pdf_ps_metafile_cairo.h

 // 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.
 
 #ifndef PRINTING_PDF_PS_METAFILE_CAIRO_H_
 #define PRINTING_PDF_PS_METAFILE_CAIRO_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
-#include "printing/native_metafile_linux.h"
-
-typedef struct _cairo_surface cairo_surface_t;
-typedef struct _cairo cairo_t;
-
-namespace base {
-struct FileDescriptor;
-}
-
-class FilePath;
+#include "printing/native_metafile.h"
 
 namespace printing {
 
-// This class uses Cairo graphics library to generate PostScript/PDF stream
-// and stores rendering results in a string buffer.
-class PdfPsMetafile : public NativeMetafile  {
+// Implementing NativeMetafile

[Lei Zhang, 2011/03/04 12:02:36]

nit: Unnecessary comment. Same for all the other metafile formats. The old
comments are more descriptive.

[dpapad, 2011/03/04 19:19:43]

When attempting to unify the interfaces, the comments were merged and moved to
native_metafile.h (Some platform specific comments have been kept in
pdf_metafile_mac.h/emf_win.h/pdf_ps_metafile_cairo.h). Also, in a previous CL
you suggested this -->
http://codereview.chromium.org/6544028/diff/38071/printing/pdf_ps_metafile_ca...

[Lei Zhang, 2011/03/04 19:36:40]

Imagine someone who has never read the code before. They don't know what
"PdfPsMetafile" is based on just the class name. The comment that was here is a
good description. With your change, that knowledge has been lost. It hasn't been
transfered into native_metafile.h either.

[dpapad, 2011/03/04 21:48:19]

Done.

+class PdfPsMetafile : public NativeMetafile {
  public:
   virtual ~PdfPsMetafile();
-
-  // Initializes to a fresh new metafile. Returns true on success.
-  // Note: Only call in the renderer to allocate rendering resources.
   virtual bool Init();
-
-  // Initializes a copy of metafile from PDF stream data.
-  // Returns true on success.
-  // |src_buffer| should point to the shared memory which stores PDF
-  // contents generated in the renderer.
-  // Note: Only call in the browser to initialize |data_|.
   virtual bool Init(const void* src_buffer, uint32 src_buffer_size);
 
-  // Sets raw 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.
+  virtual uint32 GetDataSize() const;
+  virtual bool GetData(void* dst_buffer, uint32 dst_buffer_size) const;
+
+  virtual bool FinishPage();
+  virtual void Close();
+
+  virtual bool SaveTo(const FilePath& file_path) const;
+
   virtual bool SetRawData(const void* src_buffer, uint32 src_buffer_size);
-
-  // Prepares a new cairo surface/context for rendering a new page.
-  // The unit is in point (=1/72 in).
-  // Returns NULL when failed.
   virtual cairo_t* StartPage(double width_in_points,
                              double height_in_points,
                              double margin_top_in_points,
                              double margin_right_in_points,
                              double margin_bottom_in_points,
                              double margin_left_in_points);
 
-  // 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.
-  virtual bool FinishPage();
-
-  // Closes resulting PDF file. No further rendering is allowed.
-  virtual void Close();
-
-  // Returns size of PDF contents stored in buffer |data_|.
-  // This function should ONLY be called after PDF file is closed.
-  virtual uint32 GetDataSize() const;
-
-  // Copies PDF contents stored in buffer |data_| into |dst_buffer|.
-  // This function should ONLY be called after PDF file is closed.
-  // Returns true only when success.
-  virtual bool GetData(void* dst_buffer, uint32 dst_buffer_size) const;
-
-  // Saves PDF contents stored in buffer |data_| into the file
-  // associated with |fd|.
-  // This function should ONLY be called after PDF file is closed.
-  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.
   static const double kTopMarginInInch;
   static const double kRightMarginInInch;
   static const double kBottomMarginInInch;
   static const double kLeftMarginInInch;
 
   // Returns the PdfPsMetafile object that owns the given context. Returns NULL
   // if the context was not created by a PdfPsMetafile object.
   static PdfPsMetafile* FromCairoContext(cairo_t* context);
@@ skipping 16 matching lines @@
   std::string data_;
   // Buffer stores raw PDF contents set by SetRawPageData.
   std::string raw_override_data_;
 
   DISALLOW_COPY_AND_ASSIGN(PdfPsMetafile);
 };
 
 }  // namespace printing
 
 #endif  // PRINTING_PDF_PS_METAFILE_CAIRO_H_