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      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 SkDevice;
     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 SkDevice* 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_
    169