lyx_mirror/src/graphics/GraphicsImage.h

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// -*- C++ -*-
/**
* \file GraphicsImage.h
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Baruch Even
* \author Angus Leeming
*
* Full author contact details are available in file CREDITS.
*
* An abstract base class for the images themselves.
* Allows the user to retrieve the pixmap, once loaded and to issue commands
* to modify it.
*
* The boost::functions newImage and loadableFormats are connected to the
* appropriate derived classes elsewhere, allowing the graphics cache to
* access them without knowing anything about their instantiation.
*
* The loading process can be asynchronous, but cropping, rotating and
* scaling block execution.
*/
#ifndef GRAPHICSIMAGE_H
#define GRAPHICSIMAGE_H
#include <boost/function.hpp>
#include <boost/shared_ptr.hpp>
#include <boost/signal.hpp>
#include <vector>
#include <utility>
namespace lyx {
namespace graphics {
class Params;
class Image {
public:
/** This is to be connected to a function that will return a new
* instance of a viable derived class.
*/
typedef boost::shared_ptr<Image> ImagePtr;
///
static boost::function<ImagePtr()> newImage;
///
typedef std::vector<std::string> FormatList;
/// Return the list of loadable formats.
static boost::function<FormatList()> loadableFormats;
///
virtual ~Image() {}
/// Create a copy
Image * clone() const;
/// Get the image width
unsigned int getWidth() const;
/// Get the image height
unsigned int getHeight() const;
/// Is the image drawable ?
bool isDrawable() const;
/** At the end of the loading process inform the outside world
* by emitting a signal
*/
typedef boost::signal<void(bool)> SignalType;
///
SignalType finishedLoading;
/** Start loading the image file.
* The caller should expect this process to be asynchronous and
* so should connect to the "finished" signal above.
*/
void load(std::string const & filename);
/** Generate the pixmap.
* Uses the params to decide on color, grayscale etc.
* Returns true if the pixmap is created.
*/
bool setPixmap(Params const & params);
/// Clip the image using params.
void clip(Params const & params);
/// Rotate the image using params.
void rotate(Params const & params);
/// Scale the image using params.
void scale(Params const & params);
protected:
/// Must define default c-tor explicitly as we define a copy c-tor.
Image() {}
/// Don't copy the signal finishedLoading
Image(Image const &) {}
/** Uses the params to ascertain the dimensions of the scaled image.
* Returned as make_pair(width, height).
* If something goes wrong, returns make_pair(getWidth(), getHeight())
*/
std::pair<unsigned int, unsigned int>
getScaledDimensions(Params const & params) const;
private:
/// Create a copy
virtual Image * clone_impl() const = 0;
/// Get the image width
virtual unsigned int getWidth_impl() const = 0;
/// Get the image height
virtual unsigned int getHeight_impl() const = 0;
/// is the image drawable ?
virtual bool isDrawable_impl() const = 0;
/** Start loading the image file.
* The caller should expect this process to be asynchronous and
* so should connect to the "finished" signal above.
*/
virtual void load_impl(std::string const & filename) = 0;
/** Generate the pixmap.
* Uses the params to decide on color, grayscale etc.
* Returns true if the pixmap is created.
*/
virtual bool setPixmap_impl(Params const & params) = 0;
/// Clip the image using params.
virtual void clip_impl(Params const & params) = 0;
/// Rotate the image using params.
virtual void rotate_impl(Params const & params) = 0;
/// Scale the image using params.
virtual void scale_impl(Params const & params) = 0;
};
inline
Image * Image::clone() const
{
return clone_impl();
}
inline
unsigned int Image::getWidth() const
{
return getWidth_impl();
}
inline
unsigned int Image::getHeight() const
{
return getHeight_impl();
}
inline
bool Image::isDrawable() const
{
return isDrawable_impl();
}
inline
void Image::load(std::string const & filename)
{
return load_impl(filename);
}
inline
bool Image::setPixmap(Params const & params)
{
return setPixmap_impl(params);
}
inline
void Image::clip(Params const & params)
{
return clip_impl(params);
}
inline
void Image::rotate(Params const & params)
{
return rotate_impl(params);
}
inline
void Image::scale(Params const & params)
{
return scale_impl(params);
}
} // namespace graphics
} // namespace lyx
#endif // GRAPHICSIMAGE_H