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

printing/native_metafile_mac.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_NATIVE_METAFILE_MAC_H_
-#define PRINTING_NATIVE_METAFILE_MAC_H_
-
-#include <ApplicationServices/ApplicationServices.h>
-#include <CoreFoundation/CoreFoundation.h>
-
-#include "base/basictypes.h"
-#include "base/mac/scoped_cftyperef.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 NativeMetafile {
- public:
-
-  virtual ~NativeMetafile() {}
-
-  // 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.
-  virtual CGContextRef Init() = 0;
-
-  // Initializes a copy of metafile from PDF data. Returns true on success.
-  virtual bool Init(const void* src_buffer, uint32 src_buffer_size) = 0;
-
-  // Prepares a new pdf page at specified |content_origin| with the given
-  // |page_size| and a |scale_factor| to use for the drawing.
-  virtual CGContextRef StartPage(const gfx::Size& page_size,
-                         const gfx::Point& content_origin,
-                         const float& scale_factor) = 0;
-
-  // Closes the current page.
-  virtual void FinishPage() = 0;
-
-  // Closes the PDF file; no further rendering is allowed.
-  virtual void Close() = 0;
-
-  // 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.
-  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 = 0;
-  virtual unsigned int GetPageCount() const = 0;
-
-  // Returns the bounds of the given page.
-  // Pages use a 1-based index.
-  virtual gfx::Rect GetPageBounds(unsigned int page_number) const = 0;
-
-  // Returns the size of the underlying PDF data. Only valid after Close() has
-  // been called.
-  virtual uint32 GetDataSize() const = 0;
-
-  // 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.
-  virtual bool GetData(void* dst_buffer, uint32 dst_buffer_size) const = 0;
-
-  // Saves the raw PDF data to the given file. For testing only.
-  // Returns true if writing succeeded.
-  virtual bool SaveTo(const FilePath& file_path) const = 0;
-};
-
-}  // namespace printing
-
-#endif  // PRINTING_NATIVE_METAFILE_MAC_H_