lyx_mirror/src/graphics/GraphicsLoader.h
Angus Leeming 236ea81bc5 Replace LString.h with support/std_string.h,
Lsstream.h with support/std_sstream.h,
support/LIstream.h with support/std_istream.h,
support/LOstream.h with support/std_ostream.h.


git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@7685 a592a061-630c-0410-9148-cb99ea01b6c8
2003-09-05 17:23:11 +00:00

114 lines
3.1 KiB
C++

// -*- C++ -*-
/**
* \file GraphicsLoader.h
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Angus Leeming
*
* Full author contact details are available in file CREDITS.
*
* The public face of the graphics cache.
*
* * The user supplies an image file and the display parameters.
* * He can change the file or the display parameters through a reset() method.
* * He must start the loading process explicitly with startLoading().
* * If he is connected through the connect() method, then he'll be informed
* when the loading status changes.
* * When (status() == Ready), he can use image() to access the loaded image
* and pass it to the Painter.
*
* What could be simpler?
*/
#ifndef GRAPHICSLOADER_H
#define GRAPHICSLOADER_H
#include "GraphicsTypes.h"
#include "support/std_string.h"
#include <boost/signals/signal0.hpp>
#include <boost/scoped_ptr.hpp>
class InsetOld;
namespace lyx {
namespace graphics {
class Image;
class Params;
class Loader {
public:
/// Must use the reset methods to make this instance usable.
Loader();
/// The image is not transformed, just displayed as-is.
Loader(string const & file_with_path, DisplayType = ColorDisplay);
/// The image is transformed before display.
Loader(string const & file_with_path, Params const &);
///
Loader(Loader const &);
/// Define an empty d-tor out-of-line to keep boost::scoped_ptr happy.
~Loader();
Loader & operator=(Loader const &);
/// The file can be changed, or the display params, or both.
void reset(string const & file_with_path,
DisplayType = ColorDisplay) const;
///
void reset(string const & file_with_path, Params const &) const;
///
void reset(Params const &) const;
/// Returns the absolute path of the loaded (loading?) file.
string const & filename() const;
///
bool empty() const { return filename().empty(); }
/** starting loading of the image is done by a urgency-based
* decision. Here we only call LoaderQueue::touch to request it.
*/
void startLoading() const;
/** Monitor any changes to the file.
* There is no point monitoring the file before startLoading() is
* invoked.
*/
void startMonitoring() const;
///
bool monitoring() const;
/** Returns the check sum of filename() so that, for example, you can
* ascertain whether to output a new PostScript version of the file
* for a LaTeX run.
*/
unsigned long checksum() const;
/// How far have we got in loading the image?
ImageStatus status() const;
/** Connect and you'll be informed when the loading status of the image
* changes.
*/
typedef boost::signal0<void>::slot_type slot_type;
///
boost::signals::connection connect(slot_type const &) const;
/** The loaded image with Pixmap set.
* If the Pixmap is not yet set (see status() for why...), returns 0.
*/
Image const * image() const;
private:
/// Use the Pimpl idiom to hide the internals.
class Impl;
/// The pointer never changes although *pimpl_'s contents may.
boost::scoped_ptr<Impl> const pimpl_;
};
} // namespace graphics
} // namespace lyx
#endif // GRAPHICSLOADER_H