printing/metafile.h

   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_METAFILE_H_
   6 #define PRINTING_METAFILE_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "build/build_config.h"
  12 #include "printing/printing_export.h"
  13 #include "ui/gfx/native_widget_types.h"
  14
  15 #if defined(OS_WIN)
  16 #include <windows.h>
  17 #elif defined(OS_MACOSX)
  18 #include <ApplicationServices/ApplicationServices.h>
  19 #include <CoreFoundation/CoreFoundation.h>
  20 #include "base/mac/scoped_cftyperef.h"
  21 #endif
  22
  23 namespace base {
  24 class File;
  25 }
  26
  27 namespace gfx {
  28 class Rect;
  29 class Size;
  30 }
  31
  32 class SkBaseDevice;
  33
  34 namespace printing {
  35
  36 // This class plays metafiles from data stream (usually PDF or EMF).
  37 class PRINTING_EXPORT MetafilePlayer {
  38  public:
  39 #if defined(OS_MACOSX)
  40   // |shrink_to_fit| specifies whether the output should be shrunk to fit a
  41   // destination page if the source PDF is bigger than the destination page in
  42   // any dimension. If this is false, parts of the source PDF page that lie
  43   // outside the bounds will be clipped.
  44   // |stretch_to_fit| specifies whether the output should be stretched to fit
  45   // the destination page if the source page size is smaller in all dimensions.
  46   // |center_horizontally| specifies whether the output (after any scaling is
  47   // done) should be centered horizontally within the destination page.
  48   // |center_vertically| specifies whether the output (after any scaling is
  49   // done) should be centered vertically within the destination page.
  50   // Note that all scaling preserves the original aspect ratio of the page.
  51   // |autorotate| specifies whether the source PDF should be autorotated to fit
  52   // on the destination page.
  53   struct MacRenderPageParams {
  54     MacRenderPageParams()
  55         : shrink_to_fit(false),
  56           stretch_to_fit(false),
  57           center_horizontally(false),
  58           center_vertically(false),
  59           autorotate(false) {
  60     }
  61
  62     bool shrink_to_fit;
  63     bool stretch_to_fit;
  64     bool center_horizontally;
  65     bool center_vertically;
  66     bool autorotate;
  67   };
  68 #endif  // defined(OS_MACOSX)
  69   MetafilePlayer();
  70   virtual ~MetafilePlayer();
  71
  72 #if defined(OS_WIN)
  73   // The slow version of Playback(). It enumerates all the records and play them
  74   // back in the HDC. The trick is that it skip over the records known to have
  75   // issue with some printers. See Emf::Record::SafePlayback implementation for
  76   // details.
  77   virtual bool SafePlayback(gfx::NativeDrawingContext hdc) const = 0;
  78
  79 #elif defined(OS_MACOSX)
  80   // Renders the given page into |rect| in the given context.
  81   // Pages use a 1-based index. The rendering uses the arguments in
  82   // |params| to determine scaling, translation, and rotation.
  83   virtual bool RenderPage(unsigned int page_number,
  84                           gfx::NativeDrawingContext context,
  85                           const CGRect rect,
  86                           const MacRenderPageParams& params) const = 0;
  87 #endif  // if defined(OS_WIN)
  88
  89   // Saves the underlying data to the given file. This function should ONLY be
  90   // called after the metafile is closed. Returns true if writing succeeded.
  91   virtual bool SaveTo(base::File* file) const = 0;
  92
  93  private:
  94   DISALLOW_COPY_AND_ASSIGN(MetafilePlayer);
  95 };
  96
  97 // This class creates a graphics context that renders into a data stream
  98 // (usually PDF or EMF).
  99 class PRINTING_EXPORT Metafile : public MetafilePlayer {
 100  public:
 101   Metafile();
 102   virtual ~Metafile();
 103
 104   // Initializes a fresh new metafile for rendering. Returns false on failure.
 105   // Note: It should only be called from within the renderer process to allocate
 106   // rendering resources.
 107   virtual bool Init() = 0;
 108
 109   // Initializes the metafile with the data in |src_buffer|. Returns true
 110   // on success.
 111   // Note: It should only be called from within the browser process.
 112   virtual bool InitFromData(const void* src_buffer, uint32 src_buffer_size) = 0;
 113
 114   // This method calls StartPage and then returns an appropriate
 115   // VectorPlatformDevice implementation bound to the context created by
 116   // StartPage or NULL on error.
 117   virtual SkBaseDevice* StartPageForVectorCanvas(const gfx::Size& page_size,
 118                                                  const gfx::Rect& content_area,
 119                                                  const float& scale_factor) = 0;
 120
 121   // Prepares a context for rendering a new page with the given |page_size|,
 122   // |content_area| and  a |scale_factor| to use for the drawing. The units are
 123   // in points (=1/72 in). Returns true on success.
 124   virtual bool StartPage(const gfx::Size& page_size,
 125                          const gfx::Rect& content_area,
 126                          const float& scale_factor) = 0;
 127
 128   // Closes the current page and destroys the context used in rendering that
 129   // page. The results of current page will be appended into the underlying
 130   // data stream. Returns true on success.
 131   virtual bool FinishPage() = 0;
 132
 133   // Closes the metafile. No further rendering is allowed (the current page
 134   // is implicitly closed).
 135   virtual bool FinishDocument() = 0;
 136
 137   // Returns the size of the underlying data stream. Only valid after Close()
 138   // has been called.
 139   virtual uint32 GetDataSize() const = 0;
 140
 141   // Copies the first |dst_buffer_size| bytes of the underlying data stream into
 142   // |dst_buffer|. This function should ONLY be called after Close() is invoked.
 143   // Returns true if the copy succeeds.
 144   virtual bool GetData(void* dst_buffer, uint32 dst_buffer_size) const = 0;
 145
 146   virtual gfx::Rect GetPageBounds(unsigned int page_number) const = 0;
 147   virtual unsigned int GetPageCount() const = 0;
 148
 149   virtual gfx::NativeDrawingContext context() const = 0;
 150
 151 #if defined(OS_WIN)
 152   // "Plays" the EMF buffer in a HDC. It is the same effect as calling the
 153   // original GDI function that were called when recording the EMF. |rect| is in
 154   // "logical units" and is optional. If |rect| is NULL, the natural EMF bounds
 155   // are used.
 156   // Note: Windows has been known to have stack buffer overflow in its GDI
 157   // functions, whether used directly or indirectly through precompiled EMF
 158   // data. We have to accept the risk here. Since it is used only for printing,
 159   // it requires user intervention.
 160   virtual bool Playback(gfx::NativeDrawingContext hdc,
 161                         const RECT* rect) const = 0;
 162 #endif  // OS_WIN
 163
 164   bool GetDataAsVector(std::vector<char>* buffer) const;
 165
 166   virtual bool SaveTo(base::File* file) const OVERRIDE;
 167
 168  private:
 169   DISALLOW_COPY_AND_ASSIGN(Metafile);
 170 };
 171
 172 }  // namespace printing
 173
 174 #endif  // PRINTING_METAFILE_H_