[Thunar-dev] Something weird with thumbnailers (transparency and no drop shadow)

[Stefan Stuhr]

On Tue, 2007-08-14 at 15:53 +0100, Erlend Davidson wrote:
> I've written a thumbnailer for OpenDocument files (which doesn't need 
> libgsf), but I notice thunar isn't putting the nice border shadow around 
> the icons thumbnailed using this.  Furthermore, if I go into 
> ~/.thumbnails/normal and find the actual thumbnail image it has 
> transparent parts!  The background colour (white) has been made 
> transparent somehow.
> 
> My thumbnailer isn't doing it AFAIK, it simply does:
> unzip -p "$ifile" Thumbnails/thumbnail.png | convert - -scale 
> "$sizex$size" "png:$ofile"
> 
> and the original thumbnail.png files in the ODF are not transparent.

I have just looked in an ODF document on my computer, and the
Thumbnails/thumbnail.png file (in my document file, at least) definitely
have a transparent background.

Try this:
unzip -p "$ifile" Thumbnails/thumbnail.png | convert - +matte -scale "$sizex$size" "png:$ofile"

>From the ImageMagick documentation[1]:

-matte

        store matte channel if the image has one.
        
        If the image does not have a matte channel, create an opaque
        one.
        
        Use +matte to ignore the matte channel and to avoid writing a
        matte channel in the output file.

[1]: http://www.imagemagick.org/script/command-line-options.php#matte

>   My 
> guess is that the transparency is somehow killing the border.
> 
> Erlend

Stefan