1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef PRINTING_EMF_WIN_H_
6#define PRINTING_EMF_WIN_H_
7
8#include <windows.h>
9
10#include <vector>
11
12#include "base/basictypes.h"
13#include "base/compiler_specific.h"
14#include "base/gtest_prod_util.h"
15#include "printing/metafile.h"
16
17namespace base {
18class FilePath;
19}
20
21namespace gfx {
22class Rect;
23class Size;
24}
25
26namespace printing {
27
28// http://msdn2.microsoft.com/en-us/library/ms535522.aspx
29// Windows 2000/XP: When a page in a spooled file exceeds approximately 350
30// MB, it can fail to print and not send an error message.
31const size_t kMetafileMaxSize = 350*1024*1024;
32
33// Simple wrapper class that manage an EMF data stream and its virtual HDC.
34class PRINTING_EXPORT Emf : public Metafile {
35 public:
36  class Record;
37  class Enumerator;
38  struct EnumerationContext;
39
40  // Generates a virtual HDC that will record every GDI commands and compile
41  // it in a EMF data stream.
42  Emf();
43  virtual ~Emf();
44
45  // Generates a new metafile that will record every GDI command, and will
46  // be saved to |metafile_path|.
47  virtual bool InitToFile(const base::FilePath& metafile_path);
48
49  // Initializes the Emf with the data in |metafile_path|.
50  virtual bool InitFromFile(const base::FilePath& metafile_path);
51
52  // Metafile methods.
53  virtual bool Init() OVERRIDE;
54  virtual bool InitFromData(const void* src_buffer,
55                            uint32 src_buffer_size) OVERRIDE;
56
57  virtual SkBaseDevice* StartPageForVectorCanvas(
58      const gfx::Size& page_size, const gfx::Rect& content_area,
59      const float& scale_factor) OVERRIDE;
60  // Inserts a custom GDICOMMENT records indicating StartPage/EndPage calls
61  // (since StartPage and EndPage do not work in a metafile DC). Only valid
62  // when hdc_ is non-NULL. |page_size|, |content_area|, and |scale_factor| are
63  // ignored.
64  virtual bool StartPage(const gfx::Size& page_size,
65                         const gfx::Rect& content_area,
66                         const float& scale_factor) OVERRIDE;
67  virtual bool FinishPage() OVERRIDE;
68  virtual bool FinishDocument() OVERRIDE;
69
70  virtual uint32 GetDataSize() const OVERRIDE;
71  virtual bool GetData(void* buffer, uint32 size) const OVERRIDE;
72
73  // Saves the EMF data to a file as-is. It is recommended to use the .emf file
74  // extension but it is not enforced. This function synchronously writes to the
75  // file. For testing only.
76  virtual bool SaveTo(const base::FilePath& file_path) const OVERRIDE;
77
78  // Should be passed to Playback to keep the exact same size.
79  virtual gfx::Rect GetPageBounds(unsigned int page_number) const OVERRIDE;
80
81  virtual unsigned int GetPageCount() const OVERRIDE {
82    return page_count_;
83  }
84
85  virtual HDC context() const OVERRIDE {
86    return hdc_;
87  }
88
89  virtual bool Playback(HDC hdc, const RECT* rect) const OVERRIDE;
90  virtual bool SafePlayback(HDC hdc) const OVERRIDE;
91
92  virtual HENHMETAFILE emf() const OVERRIDE {
93    return emf_;
94  }
95
96  // Returns true if metafile contains alpha blend.
97  bool IsAlphaBlendUsed() const;
98
99  // Returns new metafile with only bitmap created by playback of the current
100  // metafile. Returns NULL if fails.
101  Emf* RasterizeMetafile(int raster_area_in_pixels) const;
102
103  // Returns new metafile where AlphaBlend replaced by bitmaps. Returns NULL
104  // if fails.
105  Emf* RasterizeAlphaBlend() const;
106
107 private:
108  FRIEND_TEST_ALL_PREFIXES(EmfTest, DC);
109  FRIEND_TEST_ALL_PREFIXES(EmfPrintingTest, PageBreak);
110  FRIEND_TEST_ALL_PREFIXES(EmfTest, FileBackedEmf);
111
112  // Retrieves the underlying data stream. It is a helper function.
113  bool GetDataAsVector(std::vector<uint8>* buffer) const;
114
115  // Playbacks safely one EMF record.
116  static int CALLBACK SafePlaybackProc(HDC hdc,
117                                       HANDLETABLE* handle_table,
118                                       const ENHMETARECORD* record,
119                                       int objects_count,
120                                       LPARAM param);
121
122  // Compiled EMF data handle.
123  HENHMETAFILE emf_;
124
125  // Valid when generating EMF data through a virtual HDC.
126  HDC hdc_;
127
128  int page_count_;
129
130  DISALLOW_COPY_AND_ASSIGN(Emf);
131};
132
133struct Emf::EnumerationContext {
134  EnumerationContext();
135
136  HANDLETABLE* handle_table;
137  int objects_count;
138  HDC hdc;
139  const XFORM* base_matrix;
140  int dc_on_page_start;
141};
142
143// One EMF record. It keeps pointers to the EMF buffer held by Emf::emf_.
144// The entries become invalid once Emf::CloseEmf() is called.
145class PRINTING_EXPORT Emf::Record {
146 public:
147  // Plays the record.
148  bool Play(EnumerationContext* context) const;
149
150  // Plays the record working around quirks with SetLayout,
151  // SetWorldTransform and ModifyWorldTransform. See implementation for details.
152  bool SafePlayback(EnumerationContext* context) const;
153
154  // Access the underlying EMF record.
155  const ENHMETARECORD* record() const { return record_; }
156
157 protected:
158  explicit Record(const ENHMETARECORD* record);
159
160 private:
161  friend class Emf;
162  friend class Enumerator;
163  const ENHMETARECORD* record_;
164};
165
166// Retrieves individual records out of a Emf buffer. The main use is to skip
167// over records that are unsupported on a specific printer or to play back
168// only a part of an EMF buffer.
169class PRINTING_EXPORT Emf::Enumerator {
170 public:
171  // Iterator type used for iterating the records.
172  typedef std::vector<Record>::const_iterator const_iterator;
173
174  // Enumerates the records at construction time. |hdc| and |rect| are
175  // both optional at the same time or must both be valid.
176  // Warning: |emf| must be kept valid for the time this object is alive.
177  Enumerator(const Emf& emf, HDC hdc, const RECT* rect);
178
179  // Retrieves the first Record.
180  const_iterator begin() const;
181
182  // Retrieves the end of the array.
183  const_iterator end() const;
184
185 private:
186  FRIEND_TEST_ALL_PREFIXES(EmfPrintingTest, Enumerate);
187
188  // Processes one EMF record and saves it in the items_ array.
189  static int CALLBACK EnhMetaFileProc(HDC hdc,
190                                      HANDLETABLE* handle_table,
191                                      const ENHMETARECORD* record,
192                                      int objects_count,
193                                      LPARAM param);
194
195  // The collection of every EMF records in the currently loaded EMF buffer.
196  // Initialized by Enumerate(). It keeps pointers to the EMF buffer held by
197  // Emf::emf_. The entries become invalid once Emf::CloseEmf() is called.
198  std::vector<Record> items_;
199
200  EnumerationContext context_;
201
202  DISALLOW_COPY_AND_ASSIGN(Enumerator);
203};
204
205}  // namespace printing
206
207#endif  // PRINTING_EMF_WIN_H_
208