| // Copyright (c) 2010 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_EMF_WIN_H_ |
| #define PRINTING_EMF_WIN_H_ |
| |
| #include <windows.h> |
| #include <vector> |
| |
| #include "base/basictypes.h" |
| |
| class FilePath; |
| |
| namespace gfx { |
| class Rect; |
| } |
| |
| namespace printing { |
| |
| // Simple wrapper class that manage an EMF data stream and its virtual HDC. |
| class Emf { |
| public: |
| class Record; |
| class Enumerator; |
| struct EnumerationContext; |
| |
| Emf(); |
| ~Emf(); |
| |
| // Initializes the Emf with the data in |src_buffer|. Returns true on success. |
| bool Init(const void* src_buffer, uint32 src_buffer_size); |
| |
| // 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); |
| |
| // Similar to the above method but the metafile is backed by a file. |
| bool CreateFileBackedDc(HDC sibling, const RECT* rect, const FilePath& path); |
| |
| // Load an EMF file. |
| bool CreateFromFile(const FilePath& metafile_path); |
| |
| // 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. |
| uint32 GetDataSize() const; |
| |
| // Retrieves the EMF stream. |
| bool GetData(void* buffer, uint32 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_; |
| } |
| |
| // Inserts a custom GDICOMMENT records indicating StartPage/EndPage calls |
| // (since StartPage and EndPage do not work in a metafile DC). Only valid |
| // when hdc_ is non-NULL. |
| bool StartPage(); |
| bool EndPage(); |
| |
| // 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_COPY_AND_ASSIGN(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: |
| // 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_COPY_AND_ASSIGN(Enumerator); |
| }; |
| |
| } // namespace printing |
| |
| #endif // PRINTING_EMF_WIN_H_ |