3 * \file GraphicsLoader.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 * The public face of the graphics cache.
13 * * The user supplies an image file and the display parameters.
14 * * He can change the file or the display parameters through a reset() method.
15 * * He must start the loading process explicitly with startLoading().
16 * * If he is connected through the connect() method, then he'll be informed
17 * when the loading status changes.
18 * * When (status() == Ready), he can use image() to access the loaded image
19 * and pass it to the Painter.
21 * What could be simpler?
24 #ifndef GRAPHICSLOADER_H
25 #define GRAPHICSLOADER_H
31 #include "GraphicsTypes.h"
34 #include <boost/signals/signal0.hpp>
35 #include <boost/scoped_ptr.hpp>
47 /// Must use the reset methods to make this instance usable.
49 /// The image is not transformed, just displayed as-is.
50 Loader(string const & file_with_path, DisplayType = ColorDisplay);
51 /// The image is transformed before display.
52 Loader(string const & file_with_path, Params const &);
54 /// Define an empty d-tor out-of-line to keep boost::scoped_ptr happy.
57 /// The file can be changed, or the display params, or both.
58 void reset(string const & file_with_path,
59 DisplayType = ColorDisplay) const;
61 void reset(string const & file_with_path, Params const &) const;
63 void reset(Params const &) const;
65 /// Returns the absolute path of the loaded (loading?) file.
66 string const & filename() const;
68 bool empty() const { return filename().empty(); }
70 /// We are explicit about when we begin the loading process.
71 void startLoading() const;
73 /** starting loading of the image is conditional upon the
74 * inset being visible or not.
76 void startLoading(Inset const &, BufferView const &) const;
78 /** Monitor any changes to the file.
79 * There is no point monitoring the file before startLoading() is
82 void startMonitoring() const;
84 bool monitoring() const;
85 /** Returns the check sum of filename() so that, for example, you can
86 * ascertain whether to output a new PostScript version of the file
89 unsigned long checksum() const;
91 /// How far have we got in loading the image?
92 ImageStatus status() const;
94 /** Connect and you'll be informed when the loading status of the image
97 typedef boost::signal0<void>::slot_type slot_type;
99 boost::signals::connection connect(slot_type const &) const;
101 /** The loaded image with Pixmap set.
102 * If the Pixmap is not yet set (see status() for why...), returns 0.
104 Image const * image() const;
107 /// Use the Pimpl idiom to hide the internals.
109 /// The pointer never changes although *pimpl_'s contents may.
110 boost::scoped_ptr<Impl> const pimpl_;
115 #endif // GRAPHICSLOADER_H