Create a Factory for NativeMetafile.

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_