3 * \file PreviewedInset.h
4 * This file is part of LyX, the document processor.
5 * Licence details can be found in the file COPYING.
7 * \author Angus Leeming
9 * Full author contact details are available in file CREDITS
11 * grfx::PreviewedInset is an abstract base class that can help insets to
12 * generate previews. The daughter class must instantiate three small
13 * methods. The Inset would own an instance of this daughter class.
16 #ifndef PREVIEWEDINSET_H
17 #define PREVIEWEDINSET_H
20 #include <boost/signals/trackable.hpp>
21 #include <boost/signals/connection.hpp>
32 class PreviewedInset : public boost::signals::trackable {
34 /// a wrapper for Previews::activated()
35 static bool activated();
38 PreviewedInset(Inset & inset) : inset_(inset), pimage_(0) {}
40 virtual ~PreviewedInset() {}
42 /** Find the PreviewLoader, add a LaTeX snippet to it and
43 * start the loading process.
45 void generatePreview();
47 /** Add a LaTeX snippet to the PreviewLoader but do not start the
50 void addPreview(PreviewLoader & ploader);
52 /** Remove a snippet from the cache of previews.
53 * Useful if previewing the contents of a file that has changed.
57 /// The preview has been generated and is ready to use.
58 bool previewReady() const;
60 /// If !previewReady() returns 0.
61 PreviewImage const * pimage() const { return pimage_; }
64 /// Allow the daughter classes to cast up to the parent inset.
65 Inset * inset() const { return &inset_; }
67 BufferView * view() const;
70 /** This method is connected to the grfx::PreviewLoader::imageReady
73 void imageReady(PreviewImage const &) const;
75 /// Does the owning inset want a preview?
76 virtual bool previewWanted() const = 0;
77 /// a wrapper to Inset::latex
78 virtual string const latexString() const = 0;
85 /// We don't own this. Cached for efficiency reasons.
86 mutable PreviewImage const * pimage_;
88 boost::signals::connection connection_;
91 } // namespace graphics
94 #endif // PREVIEWEDINSET_H