Move Emf class to the printing library. Also creates a platform agnostic Nat...

chrome/common/gfx/emf.h

-// Copyright (c) 2006-2008 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 CHROME_COMMON_GFX_EMF_H__
-#define CHROME_COMMON_GFX_EMF_H__
-
-#include <windows.h>
-#include <vector>
-
-#include "base/basictypes.h"
-
-namespace gfx {
-
-class Rect;
-
-// Simple wrapper class that manage an EMF data stream and its virtual HDC.
-class Emf {
- public:
-  class Record;
-  class Enumerator;
-  struct EnumerationContext;
-
-  Emf();
-  ~Emf();
-
-  // Generates a virtual HDC that will record every GDI commands and compile it
-  // in a EMF data stream.
-  // hdc is used to setup the default DPI and color settings. hdc is optional.
-  // rect specifies the dimensions (in .01-millimeter units) of the EMF. rect is
-  // optional.
-  bool CreateDc(HDC sibling, const RECT* rect);
-
-  // Load a EMF data stream. buffer contains EMF data.
-  bool CreateFromData(const void* buffer, size_t size);
-
-  // TODO(maruel): CreateFromFile(). If ever used. Maybe users would like to
-  // have the ability to save web pages to an EMF file? Afterward, it is easy to
-  // convert to PDF or PS.
-
-  // Closes the HDC created by CreateDc() and generates the compiled EMF
-  // data.
-  bool CloseDc();
-
-  // Closes the EMF data handle when it is not needed anymore.
-  void CloseEmf();
-
-  // "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.
-  bool Playback(HDC hdc, const RECT* rect) const;
-
-  // 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.
-  bool SafePlayback(HDC hdc) const;
-
-  // Retrieves the bounds of the painted area by this EMF buffer. This value
-  // should be passed to Playback to keep the exact same size.
-  gfx::Rect GetBounds() const;
-
-  // Retrieves the EMF stream size.
-  unsigned GetDataSize() const;
-
-  // Retrieves the EMF stream.
-  bool GetData(void* buffer, size_t size) const;
-
-  // Retrieves the EMF stream. It is an helper function.
-  bool GetData(std::vector<uint8>* buffer) const;
-
-  HENHMETAFILE emf() const {
-    return emf_;
-  }
-
-  HDC hdc() const {
-    return hdc_;
-  }
-
-  // Saves the EMF data to a file as-is. It is recommended to use the .emf file
-  // extension but it is not enforced. This function synchronously writes to the
-  // file. For testing only.
-  bool SaveTo(const std::wstring& filename) const;
-
- private:
-  // Playbacks safely one EMF record.
-  static int CALLBACK SafePlaybackProc(HDC hdc,
-                                       HANDLETABLE* handle_table,
-                                       const ENHMETARECORD* record,
-                                       int objects_count,
-                                       LPARAM param);
-
-  // Compiled EMF data handle.
-  HENHMETAFILE emf_;
-
-  // Valid when generating EMF data through a virtual HDC.
-  HDC hdc_;
-
-  DISALLOW_EVIL_CONSTRUCTORS(Emf);
-};
-
-struct Emf::EnumerationContext {
-  HANDLETABLE* handle_table;
-  int objects_count;
-  HDC hdc;
-};
-
-// One EMF record. It keeps pointers to the EMF buffer held by Emf::emf_.
-// The entries become invalid once Emf::CloseEmf() is called.
-class Emf::Record {
- public:
-  Record();
-
-  // Plays the record.
-  bool Play() const;
-
-  // Plays the record working around quirks with SetLayout,
-  // SetWorldTransform and ModifyWorldTransform. See implementation for details.
-  bool SafePlayback(const XFORM* base_matrix) const;
-
-  // Access the underlying EMF record.
-  const ENHMETARECORD* record() const { return record_; }
-
- protected:
-  Record(const EnumerationContext* context,
-         const ENHMETARECORD* record);
-
- private:
-  friend class Emf;
-  friend class Enumerator;
-  const ENHMETARECORD* record_;
-  const EnumerationContext* context_;
-};
-
-// Retrieves individual records out of a Emf buffer. The main use is to skip
-// over records that are unsupported on a specific printer or to play back
-// only a part of an EMF buffer.
-class Emf::Enumerator {
- public:
-  // Iterator type used for iterating the records.
-  typedef std::vector<Record>::const_iterator const_iterator;
-
-  // Enumerates the records at construction time. |hdc| and |rect| are
-  // both optional at the same time or must both be valid.
-  // Warning: |emf| must be kept valid for the time this object is alive.
-  Enumerator(const Emf& emf, HDC hdc, const RECT* rect);
-
-  // Retrieves the first Record.
-  const_iterator begin() const;
-
-  // Retrieves the end of the array.
-  const_iterator end() const;
-
- private:
-  // Processes one EMF record and saves it in the items_ array.
-  static int CALLBACK EnhMetaFileProc(HDC hdc,
-                                      HANDLETABLE* handle_table,
-                                      const ENHMETARECORD* record,
-                                      int objects_count,
-                                      LPARAM param);
-
-  // The collection of every EMF records in the currently loaded EMF buffer.
-  // Initialized by Enumerate(). It keeps pointers to the EMF buffer held by
-  // Emf::emf_. The entries become invalid once Emf::CloseEmf() is called.
-  std::vector<Record> items_;
-
-  EnumerationContext context_;
-
-  DISALLOW_EVIL_CONSTRUCTORS(Enumerator);
-};
-
-}  // namespace gfx
-
-#endif  // CHROME_COMMON_GFX_EMF_H__