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