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