blob: fa274091f20f4e8715fe9b985c76ca2a5d2d0bd2 [file] [log] [blame]
// Copyright (c) 2012 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.
#include <windows.h>
#include <vector>
#include "base/basictypes.h"
#include "base/compiler_specific.h"
#include "base/gtest_prod_util.h"
#include "printing/metafile.h"
namespace base {
class FilePath;
namespace gfx {
class Rect;
class Size;
namespace printing {
// Windows 2000/XP: When a page in a spooled file exceeds approximately 350
// MB, it can fail to print and not send an error message.
const size_t kMetafileMaxSize = 350*1024*1024;
// Simple wrapper class that manage an EMF data stream and its virtual HDC.
class PRINTING_EXPORT Emf : public Metafile {
class Record;
class Enumerator;
struct EnumerationContext;
// Generates a virtual HDC that will record every GDI commands and compile
// it in a EMF data stream.
virtual ~Emf();
// Generates a new metafile that will record every GDI command, and will
// be saved to |metafile_path|.
virtual bool InitToFile(const base::FilePath& metafile_path);
// Initializes the Emf with the data in |metafile_path|.
virtual bool InitFromFile(const base::FilePath& metafile_path);
// Metafile methods.
virtual bool Init() OVERRIDE;
virtual bool InitFromData(const void* src_buffer,
uint32 src_buffer_size) OVERRIDE;
virtual SkBaseDevice* StartPageForVectorCanvas(
const gfx::Size& page_size, const gfx::Rect& content_area,
const float& scale_factor) OVERRIDE;
// 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. |page_size|, |content_area|, and |scale_factor| are
// ignored.
virtual bool StartPage(const gfx::Size& page_size,
const gfx::Rect& content_area,
const float& scale_factor) OVERRIDE;
virtual bool FinishPage() OVERRIDE;
virtual bool FinishDocument() OVERRIDE;
virtual uint32 GetDataSize() const OVERRIDE;
virtual bool GetData(void* buffer, uint32 size) const OVERRIDE;
// 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.
virtual bool SaveTo(const base::FilePath& file_path) const OVERRIDE;
// Should be passed to Playback to keep the exact same size.
virtual gfx::Rect GetPageBounds(unsigned int page_number) const OVERRIDE;
virtual unsigned int GetPageCount() const OVERRIDE {
return page_count_;
virtual HDC context() const OVERRIDE {
return hdc_;
virtual bool Playback(HDC hdc, const RECT* rect) const OVERRIDE;
virtual bool SafePlayback(HDC hdc) const OVERRIDE;
virtual HENHMETAFILE emf() const OVERRIDE {
return emf_;
// Returns true if metafile contains alpha blend.
bool IsAlphaBlendUsed() const;
// Returns new metafile with only bitmap created by playback of the current
// metafile. Returns NULL if fails.
Emf* RasterizeMetafile(int raster_area_in_pixels) const;
// Returns new metafile where AlphaBlend replaced by bitmaps. Returns NULL
// if fails.
Emf* RasterizeAlphaBlend() const;
FRIEND_TEST_ALL_PREFIXES(EmfPrintingTest, PageBreak);
// Retrieves the underlying data stream. It is a helper function.
bool GetDataAsVector(std::vector<uint8>* buffer) const;
// 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.
// Valid when generating EMF data through a virtual HDC.
HDC hdc_;
int page_count_;
struct Emf::EnumerationContext {
HANDLETABLE* handle_table;
int objects_count;
HDC hdc;
const XFORM* base_matrix;
int dc_on_page_start;
// One EMF record. It keeps pointers to the EMF buffer held by Emf::emf_.
// The entries become invalid once Emf::CloseEmf() is called.
class PRINTING_EXPORT Emf::Record {
// Plays the record.
bool Play(EnumerationContext* context) const;
// Plays the record working around quirks with SetLayout,
// SetWorldTransform and ModifyWorldTransform. See implementation for details.
bool SafePlayback(EnumerationContext* context) const;
// Access the underlying EMF record.
const ENHMETARECORD* record() const { return record_; }
explicit Record(const ENHMETARECORD* record);
friend class Emf;
friend class Enumerator;
const ENHMETARECORD* record_;
// 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 PRINTING_EXPORT Emf::Enumerator {
// 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;
FRIEND_TEST_ALL_PREFIXES(EmfPrintingTest, Enumerate);
// 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_;
} // namespace printing