3 * \file GraphicsImage.h
4 * This file is part of LyX, the document processor.
5 * Licence details can be found in the file COPYING.
8 * \author Angus Leeming
10 * Full author contact details are available in file CREDITS.
12 * An abstract base class for the images themselves.
13 * Allows the user to retrieve the pixmap, once loaded and to issue commands
16 * The boost::functions newImage and loadableFormats are connected to the
17 * appropriate derived classes elsewhere, allowing the graphics cache to
18 * access them without knowing anything about their instantiation.
20 * The loading process can be asynchronous, but cropping, rotating and
21 * scaling block execution.
24 #ifndef GRAPHICSIMAGE_H
25 #define GRAPHICSIMAGE_H
27 #include <boost/function.hpp>
28 #include <boost/signal.hpp>
35 namespace support { class FileName; }
43 /** This is to be connected to a function that will return a new
44 * instance of a viable derived class.
46 static boost::function<Image *()> newImage;
49 typedef std::vector<std::string> FormatList;
50 /// Return the list of loadable formats.
51 static boost::function<FormatList()> loadableFormats;
57 virtual Image * clone() const = 0;
59 /// Get the image width
60 virtual unsigned int getWidth() const = 0;
62 /// Get the image height
63 virtual unsigned int getHeight() const = 0;
65 /// Is the image drawable ?
66 virtual bool isDrawable() const = 0;
68 /** At the end of the loading process inform the outside world
69 * by emitting a signal
71 typedef boost::signal<void(bool)> SignalType;
73 SignalType finishedLoading;
75 /** Start loading the image file.
76 * The caller should expect this process to be asynchronous and
77 * so should connect to the "finished" signal above.
79 virtual void load(support::FileName const & filename) = 0;
81 /** Generate the pixmap.
82 * Uses the params to decide on color, grayscale etc.
83 * Returns true if the pixmap is created.
85 virtual bool setPixmap(Params const & params) = 0;
87 /// Clip the image using params.
88 virtual void clip(Params const & params) = 0;
90 /// Rotate the image using params.
91 virtual void rotate(Params const & params) = 0;
93 /// Scale the image using params.
94 virtual void scale(Params const & params) = 0;
97 /// Must define default c-tor explicitly as we define a copy c-tor.
99 /// Don't copy the signal finishedLoading
100 Image(Image const &) {}
102 /** Uses the params to ascertain the dimensions of the scaled image.
103 * Returned as make_pair(width, height).
104 * If something goes wrong, returns make_pair(getWidth(), getHeight())
106 std::pair<unsigned int, unsigned int>
107 getScaledDimensions(Params const & params) const;
111 } // namespace graphics
114 #endif // GRAPHICSIMAGE_H