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/* This file is part of the KDE libraries
Copyright (C) 2000 Malte Starostik <malte@kde.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
along with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#ifndef _THUMBCREATOR_H_
#define _THUMBCREATOR_H_
#include <qstring.h>
class QString;
class QImage;
/**
* This is the baseclass for "thumbnail-plugins" in KDE. Using the class
* KIO::PreviewJob allows you to generate small images (thumbnails)
* for any kind of file, where a "ThumbCreator" is available. Have a look
* at kdebase/kioslave/thumbnail/ for existing ThumbCreators.
*
* What you need to do to create and register a ThumbCreator:
* @li Inherit from this class and reimplement the create() method to
* generate a thumbnail for the given file-path.
* @li Provide a factory method in your implementation file to instantiate
* your plugin, e.g.:
* \code
* extern "C"
* {
* ThumbCreator *new_creator()
* {
* return new YourThumbCreator();
* }
* };
* \endcode
*
* Compile your ThumbCreator as a module. The contents of Makefile.am
* need to look like this:
* \code
* INCLUDES = $(all_includes)
* kde_module_LTLIBRARIES = yourthumbcreator.la
* yourthumbcreator_la_SOURCES = yourthumbcreator.cpp
* yourthumbcreator_la_LIBADD = $(LIB_KIO)
* yourthumbcreator_la_LDFLAGS = $(all_libraries) -module $(KDE_PLUGIN)
* kde_services_DATA = yourthumbcreator.desktop
* \endcode
*
* @li Create a file yourthumbcreator.desktop with the following contents:
* \code
* [Desktop Entry]
* Encoding=UTF-8
* Type=Service
* Name=Name of the type of files your ThumbCreator supports
* ServiceTypes=ThumbCreator
* MimeTypes=application/x-somemimetype
* CacheThumbnail=true
* X-KDE-Library=yourthumbcreator
* \endcode
*
* You can supply a comma-separated list of mimetypes to the MimeTypes entry,
* naming all mimetypes your ThumbCreator supports. You can also use simple
* wildcards, like (where you see [slash], put a /)
* \code
* text[slash]* or image[slash]*.
* \endcode
*
* If your plugin is rather inexpensive (e.g. like the text preview ThumbCreator),
* you can set CacheThumbnail=false to prevent your thumbnails from being cached
* on disk.
*
* @short Baseclass for thumbnail-generating plugins.
*/
class ThumbCreator
{
public:
/**
* The flags of this plugin.
* @see flags()
*/
enum Flags { None = 0, DrawFrame = 1, BlendIcon = 2 };
virtual ~ThumbCreator() {}
/**
* Creates a thumbnail
* Note that the width and height parameters should not be used
* for scaling. Only plugins that create an image "from scratch",
* like the TextCreator should directly use the specified size.
* If the resulting preview is larger than width x height, it will be
* scaled down.
*
* @param path the (always local) file path to create a preview for
* @param width maximum width for the preview
* @param height maximum height for the preview
* @param img this image will contain the preview on success
*
* @return true if preview generation succeeded
*/
virtual bool create(const QString &path, int width, int height, QImage &img) = 0;
/**
* The flags of this plugin:
* @li None nothing special
* @li DrawFrame a frame should be painted around the preview
* @li BlendIcon the mimetype icon should be blended over the preview
*
* @return flags for this plugin
*/
virtual Flags flags() const { return None; }
};
typedef ThumbCreator *(*newCreator)();
#endif
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