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// 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_METAFILE_H_
#define PRINTING_METAFILE_H_
#include "base/basictypes.h"
#include "build/build_config.h"
#include "printing/printing_export.h"
#include "ui/gfx/native_widget_types.h"
#if defined(OS_WIN)
#include <windows.h>
#elif defined(OS_MACOSX)
#include <ApplicationServices/ApplicationServices.h>
#include <CoreFoundation/CoreFoundation.h>
#include "base/mac/scoped_cftyperef.h"
#endif
class FilePath;
namespace gfx {
class Rect;
class Size;
}
class SkDevice;
#if defined(OS_CHROMEOS)
namespace base {
struct FileDescriptor;
}
#endif
namespace printing {
// This class creates a graphics context that renders into a data stream
// (usually PDF or EMF).
class PRINTING_EXPORT Metafile {
public:
virtual ~Metafile() {}
// Initializes a fresh new metafile for rendering. Returns false on failure.
// Note: It should only be called from within the renderer process to allocate
// rendering resources.
virtual bool Init() = 0;
// Initializes the metafile with the data in |src_buffer|. Returns true
// on success.
// Note: It should only be called from within the browser process.
virtual bool InitFromData(const void* src_buffer, uint32 src_buffer_size) = 0;
// This method calls StartPage and then returns an appropriate
// VectorPlatformDevice implementation bound to the context created by
// StartPage or NULL on error.
virtual SkDevice* StartPageForVectorCanvas(
const gfx::Size& page_size,
const gfx::Rect& content_area,
const float& scale_factor) = 0;
// Prepares a context for rendering a new page with the given |page_size|,
// |content_area| and a |scale_factor| to use for the drawing. The units are
// in points (=1/72 in). Returns true on success.
virtual bool StartPage(const gfx::Size& page_size,
const gfx::Rect& content_area,
const float& scale_factor) = 0;
// Closes the current page and destroys the context used in rendering that
// page. The results of current page will be appended into the underlying
// data stream. Returns true on success.
virtual bool FinishPage() = 0;
// Closes the metafile. No further rendering is allowed (the current page
// is implicitly closed).
virtual bool FinishDocument() = 0;
// Returns the size of the underlying data stream. Only valid after Close()
// has been called.
virtual uint32 GetDataSize() const = 0;
// Copies the first |dst_buffer_size| bytes of the underlying data stream into
// |dst_buffer|. This function should ONLY be called after Close() is invoked.
// Returns true if the copy succeeds.
virtual bool GetData(void* dst_buffer, uint32 dst_buffer_size) const = 0;
// Saves the underlying data to the given file. This function should ONLY be
// called after the metafile is closed. Returns true if writing succeeded.
virtual bool SaveTo(const FilePath& file_path) 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;
virtual unsigned int GetPageCount() const = 0;
// Get the context for rendering to the PDF.
virtual gfx::NativeDrawingContext context() const = 0;
#if defined(OS_WIN)
// "Plays" the EMF buffer in a HDC. It is the same effect as calling the
// original GDI function that were called when recording the EMF. |rect| is in
// "logical units" and is optional. If |rect| is NULL, the natural EMF bounds
// are used.
// Note: Windows has been known to have stack buffer overflow in its GDI
// functions, whether used directly or indirectly through precompiled EMF
// data. We have to accept the risk here. Since it is used only for printing,
// it requires user intervention.
virtual bool Playback(gfx::NativeDrawingContext hdc,
const RECT* rect) const = 0;
// The slow version of Playback(). It enumerates all the records and play them
// back in the HDC. The trick is that it skip over the records known to have
// issue with some printers. See Emf::Record::SafePlayback implementation for
// details.
virtual bool SafePlayback(gfx::NativeDrawingContext hdc) const = 0;
virtual HENHMETAFILE emf() const = 0;
#elif defined(OS_MACOSX)
// 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,
gfx::NativeDrawingContext context,
const CGRect rect,
bool shrink_to_fit,
bool stretch_to_fit,
bool center_horizontally,
bool center_vertically) const = 0;
#elif defined(OS_CHROMEOS)
// Saves the underlying data to the file associated with fd. This function
// should ONLY be called after the metafile is closed.
// Returns true if writing succeeded.
virtual bool SaveToFD(const base::FileDescriptor& fd) const = 0;
#endif // if defined(OS_CHROMEOS)
};
} // namespace printing
#endif // PRINTING_METAFILE_H_