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

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.


Member Enumeration Documentation

The flags of this plugin.

See also:
flags()

Definition at line 89 of file thumbcreator.h.


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.


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