// -*- C++ -*-
-/* This file is part of
- * =================================================
- *
- * LyX, The Document Processor
- * Copyright 1995 Matthias Ettrich.
- * Copyright 1995-2000 The LyX Team.
+/**
+ * \file GraphicsCacheItem.h
+ * This file is part of LyX, the document processor.
+ * Licence details can be found in the file COPYING.
*
- * This file Copyright 2000 Baruch Even
- * ================================================= */
+ * \author Baruch Even
+ * \author Angus Leeming
+ *
+ * Full author contact details are available in file CREDITS
+ *
+ * The graphics cache is a container of grfx::CacheItems.
+ * Each grfx::CacheItem, defined here represents a separate image file.
+ *
+ * The routines here can be used to load the graphics file into memory at
+ * which point (status() == grfx::Loaded).
+ * The user is then free to access image() in order to copy it and to then
+ * transform the copy (rotate, scale, clip) and to generate the pixmap.
+ *
+ * The graphics cache supports fully asynchronous:
+ * file conversion to a loadable format;
+ * file loading.
+ *
+ * Whether you get that, of course, depends on grfx::Converter and on the
+ * grfx::Image-derived image class.
+ */
#ifndef GRAPHICSCACHEITEM_H
#define GRAPHICSCACHEITEM_H
-#ifdef __GNUG__
-#pragma interface
-#endif
+#include "GraphicsTypes.h"
+#include "LString.h"
+
+#include <boost/utility.hpp>
+#include <boost/scoped_ptr.hpp>
+#include <boost/signals/signal0.hpp>
+
+class InsetGraphics;
+
+namespace grfx {
+
+class Image;
+class Converter;
-class GraphicsCacheItem {
+/// A grfx::Cache item holder.
+class CacheItem : boost::noncopyable {
public:
- ~GraphicsCacheItem() {}
-
+ ///
+ CacheItem(string const & file);
+
+ /// Define an empty d-tor out-of-line to keep boost::scoped_ptr happy.
+ ~CacheItem();
+
+ ///
+ string const & filename() const;
+
+ /// It's in the cache. Now start the loading process.
+ 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;
+
+ /** Get the image associated with filename().
+ * If the image is not yet loaded, returns 0.
+ * This routine returns a pointer to const; if you want to modify it,
+ * create a copy and modify that.
+ */
+ Image const * image() 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;
+
private:
- GraphicsCacheItem() {}
+ /// Use the Pimpl idiom to hide the internals.
+ class Impl;
- friend class GraphicsCache;
+ /// The pointer never changes although *pimpl_'s contents may.
+ boost::scoped_ptr<Impl> const pimpl_;
};
-#endif
+} // namespace grfx
+
+#endif // GRAPHICSCACHEITEM_H