src/graphics/PreviewedInset.C

   1 // -*- C++ -*-
   2 /**
   3  *  \file PreviewedInset.C
   4  *  Copyright 2002 the LyX Team
   5  *  Read the file COPYING
   6  *
   7  * \author Angus Leeming <leeming@lyx.org>
   8  */
   9
  10 #ifdef __GNUG__
  11 #pragma implementation
  12 #endif
  13
  14 #include <config.h>
  15
  16 #include "PreviewedInset.h"
  17
  18 #include "BufferView.h"
  19
  20 #include "GraphicsImage.h"
  21 #include "PreviewLoader.h"
  22 #include "PreviewImage.h"
  23 #include "Previews.h"
  24
  25 #include <boost/bind.hpp>
  26
  27
  28 namespace grfx {
  29
  30 bool PreviewedInset::activated()
  31 {
  32         return Previews::activated();
  33 }
  34
  35
  36 void PreviewedInset::generatePreview() const
  37 {
  38         if (!Previews::activated() || !previewWanted() ||
  39             !view() || !view()->buffer())
  40                 return;
  41
  42         grfx::Previews & previews = grfx::Previews::get();
  43         grfx::PreviewLoader & loader = previews.loader(view()->buffer());
  44         addPreview(loader);
  45         loader.startLoading();
  46 }
  47
  48
  49 void PreviewedInset::addPreview(grfx::PreviewLoader & ploader) const
  50 {
  51         if (!Previews::activated() || !previewWanted())
  52                 return;
  53
  54         // Generate the LaTeX snippet.
  55         string const snippet = latexString();
  56
  57         pimage_ = ploader.preview(snippet);
  58         if (pimage_)
  59                 return;
  60
  61         // If this is the first time of calling, connect to the
  62         // grfx::PreviewLoader signal that'll inform us when the preview image
  63         // is ready for loading.
  64         if (!connection_.connected()) {
  65                 connection_ = ploader.connect(
  66                         boost::bind(&PreviewedInset::imageReady, this, _1));
  67         }
  68
  69         ploader.add(snippet);
  70 }
  71
  72
  73 bool PreviewedInset::previewReady() const
  74 {
  75         if (!grfx::Previews::activated() || !previewWanted() ||
  76             !view() || !view()->buffer())
  77                 return false;
  78
  79         // If the cached grfx::PreviewImage is invalid, update it.
  80         string const snippet = latexString();
  81
  82         if (!pimage_ || snippet != pimage_->snippet()) {
  83                 grfx::PreviewLoader & ploader =
  84                         grfx::Previews::get().loader(view()->buffer());
  85                 pimage_ = ploader.preview(snippet);
  86         }
  87
  88         if (!pimage_)
  89                 return false;
  90
  91         return pimage_->image(inset_, *view());
  92 }
  93
  94
  95 void PreviewedInset::imageReady(grfx::PreviewImage const & pimage) const
  96 {
  97         // Check snippet against the Inset's current contents
  98         if (latexString() != pimage.snippet())
  99                 return;
 100
 101         pimage_ = &pimage;
 102         if (view())
 103                 view()->updateInset(&inset_, false);
 104 }
 105
 106 } // namespace grfx