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