ThumbCreator Class Reference

This is the baseclass for "thumbnail-plugins" in KDE. More...

#include <thumbcreator.h>

List of all members.

Public Types
enum	Flags { None = 0, DrawFrame = 1, BlendIcon = 2 }
Public Member Functions
virtual bool	create (const QString &path, int width, int height, QImage &img)=0
virtual Flags	flags () const
virtual	~ThumbCreator ()

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Detailed Description

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:

• Inherit from this class and reimplement the create() method to generate a thumbnail for the given file-path.
• Provide a factory method in your implementation file to instantiate your plugin, e.g.:

   extern "C"
   {
     ThumbCreator *new_creator()
     {
       return new YourThumbCreator();
     }
   };
  

Compile your ThumbCreator as a module. The contents of Makefile.am need to look like this:

 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

• Create a file yourthumbcreator.desktop with the following contents:

   [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
  

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 /)

              text[slash]* or image[slash]*.

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.

Baseclass for thumbnail-generating plugins.

Definition at line 82 of file thumbcreator.h.

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Member Enumeration Documentation

enum ThumbCreator::Flags

The flags of this plugin.

See also:

flags()

Enumerator:

None
DrawFrame
BlendIcon

Definition at line 89 of file thumbcreator.h.

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Constructor & Destructor Documentation

virtual ThumbCreator::~ThumbCreator

(

)

[inline, virtual]

Definition at line 90 of file thumbcreator.h.

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Member Function Documentation

virtual bool ThumbCreator::create	(	const QString &	path,
		int	width,
		int	height,
		QImage &	img
	)			[pure virtual]

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.

Parameters:

	path	the (always local) file path to create a preview for
	width	maximum width for the preview
	height	maximum height for the preview
	img	this image will contain the preview on success

Returns:

true if preview generation succeeded

virtual Flags ThumbCreator::flags

(

)

const [inline, virtual]

The flags of this plugin:.

• None nothing special
• DrawFrame a frame should be painted around the preview
• BlendIcon the mimetype icon should be blended over the preview

Returns:

flags for this plugin

Definition at line 117 of file thumbcreator.h.

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The documentation for this class was generated from the following file:

• thumbcreator.h