3 * \file PreviewLoader.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 * graphics::PreviewLoader collects latex snippets together. Then, on a
12 * startLoading() call, these are dumped to file and processed, converting
13 * each snippet to a separate bitmap image file. Once a bitmap file is ready
14 * to be loaded back into LyX, the PreviewLoader emits a signal to inform
15 * the initiating process.
18 #ifndef PREVIEWLOADER_H
19 #define PREVIEWLOADER_H
21 #include "ColorCode.h"
22 #include "support/signals.h"
36 class PreviewLoader : public QObject {
39 /** We need buffer because we require the preamble to the
42 PreviewLoader(Buffer const & buffer);
44 /** Is there an image already associated with this snippet of LaTeX?
45 * If so, returns a pointer to it, else returns 0.
47 PreviewImage const * preview(std::string const & latex_snippet) const;
61 /// How far have we got in loading the image?
62 Status status(std::string const & latex_snippet) const;
64 /// Add a snippet of LaTeX to the queue for processing.
65 void add(std::string const & latex_snippet) const;
67 /// Remove this snippet of LaTeX from the PreviewLoader.
68 void remove(std::string const & latex_snippet) const;
70 /** We have accumulated several latex snippets with status "InQueue".
71 * Initiate their transformation into bitmap images.
73 void startLoading(bool wait = false) const;
75 /** Connect and you'll be informed when the bitmap image file
76 * has been created and is ready for loading through
77 * lyx::graphics::PreviewImage::image().
79 typedef signal<void(PreviewImage const &)> sig;
80 typedef sig::slot_type slot;
82 connection connect(slot const &) const;
84 /** When PreviewImage has finished loading the image file into memory,
85 * it tells the PreviewLoader to tell the outside world
87 void emitSignal(PreviewImage const &) const;
89 /// Which buffer owns this loader.
90 Buffer const & buffer() const;
91 /// The background color used
92 static ColorCode backgroundColor() { return Color_background; }
93 /// The foreground color used
94 static ColorCode foregroundColor() { return Color_preview; }
96 double displayPixelRatio() const ;
100 void refreshPreviews();
104 PreviewLoader(PreviewLoader const &);
105 void operator=(PreviewLoader const &);
107 /// Use the Pimpl idiom to hide the internals.
109 /// The pointer never changes although *pimpl_'s contents may.
110 std::shared_ptr<Impl> const pimpl_;
113 } // namespace graphics
116 #endif // PREVIEWLOADER_H