src/graphics/Previews.h

   1 // -*- C++ -*-
   2 /**
   3  * \file Previews.h
   4  * This file is part of LyX, the document processor.
   5  * Licence details can be found in the file COPYING.
   6  *
   7  * \author Angus Leeming
   8  *
   9  * Full author contact details are available in file CREDITS.
  10  *
  11  * lyx::graphics::Previews is a singleton class that stores the
  12  * lyx::graphics::PreviewLoader for each buffer requiring one.
  13  */
  14
  15 #ifndef PREVIEWS_H
  16 #define PREVIEWS_H
  17
  18 #include <boost/noncopyable.hpp>
  19 #include <boost/scoped_ptr.hpp>
  20
  21 namespace lyx {
  22
  23 class Buffer;
  24 class LyXRC_PreviewStatus;
  25
  26 namespace graphics {
  27
  28 class PreviewLoader;
  29
  30 class Previews : boost::noncopyable {
  31 public:
  32         /// a wrapper for lyxrc.preview
  33         static LyXRC_PreviewStatus status();
  34
  35         /// This is a singleton class. Get the instance.
  36         static Previews & get();
  37
  38         /** Returns the PreviewLoader for this buffer.
  39          *  Used by individual insets to update their own preview.
  40          */
  41         PreviewLoader & loader(Buffer const & buffer) const;
  42
  43         /// Called from the Buffer d-tor.
  44         void removeLoader(Buffer const & buffer) const;
  45
  46         /** For a particular buffer, initiate the generation of previews
  47          *  for each and every snippet of LaTeX that's of interest with
  48          *  a single forked process.
  49          */
  50         void generateBufferPreviews(Buffer const & buffer) const;
  51
  52 private:
  53         /** Make the c-tor, d-tor private so we can control how many objects
  54          *  are instantiated.
  55          */
  56         Previews();
  57         ~Previews();
  58
  59         /// Use the Pimpl idiom to hide the internals.
  60         class Impl;
  61         /// The pointer never changes although *pimpl_'s contents may.
  62         boost::scoped_ptr<Impl> const pimpl_;
  63 };
  64
  65 } // namespace graphics
  66 } // namespace lyx
  67
  68 #endif // PREVIEWS_H