src/graphics/GraphicsImage.h

   1 // -*- C++ -*-
   2 /**
   3  * \file GraphicsImage.h
   4  * This file is part of LyX, the document processor.
   5  * Licence details can be found in the file COPYING.
   6  *
   7  * \author Baruch Even
   8  * \author Angus Leeming
   9  *
  10  * Full author contact details are available in file CREDITS.
  11  *
  12  * An abstract base class for the images themselves.
  13  * Allows the user to retrieve the pixmap, once loaded and to issue commands
  14  * to modify it.
  15  *
  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.
  19  *
  20  * The loading process can be asynchronous, but cropping, rotating and
  21  * scaling block execution.
  22  */
  23
  24 #ifndef GRAPHICSIMAGE_H
  25 #define GRAPHICSIMAGE_H
  26
  27 #include <boost/function.hpp>
  28 #include <boost/shared_ptr.hpp>
  29 #include <boost/signal.hpp>
  30
  31 #include <vector>
  32 #include <utility>
  33
  34 namespace lyx {
  35
  36 namespace support { class FileName; }
  37
  38 namespace graphics {
  39
  40 class Params;
  41
  42 class Image {
  43 public:
  44         /** This is to be connected to a function that will return a new
  45          *  instance of a viable derived class.
  46          */
  47         typedef boost::shared_ptr<Image> ImagePtr;
  48         ///
  49         static boost::function<ImagePtr()> newImage;
  50
  51         ///
  52         typedef std::vector<std::string> FormatList;
  53         /// Return the list of loadable formats.
  54         static boost::function<FormatList()> loadableFormats;
  55
  56         ///
  57         virtual ~Image() {}
  58
  59         /// Create a copy
  60         Image * clone() const;
  61
  62         /// Get the image width
  63         unsigned int getWidth() const;
  64
  65         /// Get the image height
  66         unsigned int getHeight() const;
  67
  68         /// Is the image drawable ?
  69         bool isDrawable() const;
  70
  71         /** At the end of the loading process inform the outside world
  72          *  by emitting a signal
  73          */
  74         typedef boost::signal<void(bool)> SignalType;
  75         ///
  76         SignalType finishedLoading;
  77
  78         /** Start loading the image file.
  79          *  The caller should expect this process to be asynchronous and
  80          *  so should connect to the "finished" signal above.
  81          */
  82         void load(support::FileName const & filename);
  83
  84         /** Generate the pixmap.
  85          *  Uses the params to decide on color, grayscale etc.
  86          *  Returns true if the pixmap is created.
  87          */
  88         bool setPixmap(Params const & params);
  89
  90         /// Clip the image using params.
  91         void clip(Params const & params);
  92
  93         /// Rotate the image using params.
  94         void rotate(Params const & params);
  95
  96         /// Scale the image using params.
  97         void scale(Params const & params);
  98
  99 protected:
 100         /// Must define default c-tor explicitly as we define a copy c-tor.
 101         Image() {}
 102         /// Don't copy the signal finishedLoading
 103         Image(Image const &) {}
 104
 105         /** Uses the params to ascertain the dimensions of the scaled image.
 106          *  Returned as make_pair(width, height).
 107          *  If something goes wrong, returns make_pair(getWidth(), getHeight())
 108          */
 109         std::pair<unsigned int, unsigned int>
 110         getScaledDimensions(Params const & params) const;
 111
 112 private:
 113         /// Create a copy
 114         virtual Image * clone_impl() const = 0;
 115         /// Get the image width
 116         virtual unsigned int getWidth_impl() const = 0;
 117
 118         /// Get the image height
 119         virtual unsigned int getHeight_impl() const = 0;
 120
 121         /// is the image drawable ?
 122         virtual bool isDrawable_impl() const = 0;
 123
 124         /** Start loading the image file.
 125          *  The caller should expect this process to be asynchronous and
 126          *  so should connect to the "finished" signal above.
 127          */
 128         virtual void load_impl(support::FileName const & filename) = 0;
 129
 130         /** Generate the pixmap.
 131          *  Uses the params to decide on color, grayscale etc.
 132          *  Returns true if the pixmap is created.
 133          */
 134         virtual bool setPixmap_impl(Params const & params) = 0;
 135
 136         /// Clip the image using params.
 137         virtual void clip_impl(Params const & params) = 0;
 138
 139         /// Rotate the image using params.
 140         virtual void rotate_impl(Params const & params) = 0;
 141
 142         /// Scale the image using params.
 143         virtual void scale_impl(Params const & params) = 0;
 144 };
 145
 146
 147 inline
 148 Image * Image::clone() const
 149 {
 150         return clone_impl();
 151 }
 152
 153
 154 inline
 155 unsigned int Image::getWidth() const
 156 {
 157         return getWidth_impl();
 158 }
 159
 160
 161 inline
 162 unsigned int Image::getHeight() const
 163 {
 164         return getHeight_impl();
 165 }
 166
 167
 168 inline
 169 bool Image::isDrawable() const
 170 {
 171         return isDrawable_impl();
 172 }
 173
 174
 175 inline
 176 void Image::load(support::FileName const & filename)
 177 {
 178         return load_impl(filename);
 179 }
 180
 181
 182 inline
 183 bool Image::setPixmap(Params const & params)
 184 {
 185         return setPixmap_impl(params);
 186 }
 187
 188
 189 inline
 190 void Image::clip(Params const & params)
 191 {
 192         return clip_impl(params);
 193 }
 194
 195
 196 inline
 197 void Image::rotate(Params const & params)
 198 {
 199         return rotate_impl(params);
 200 }
 201
 202
 203 inline
 204 void Image::scale(Params const & params)
 205 {
 206         return scale_impl(params);
 207 }
 208
 209 } // namespace graphics
 210 } // namespace lyx
 211
 212 #endif // GRAPHICSIMAGE_H