Specifying thumbnailers as a service

[Philip Van Hoof]

On Fri, 2008-08-29 at 13:59 +0200, Philip Van Hoof wrote:
> On Fri, 2008-08-29 at 11:03 +0100, Bastien Nocera wrote:
> > On Fri, 2008-08-29 at 11:25 +0200, Philip Van Hoof wrote:
> > > 
> > >       <arg type="i" name="size_x" direction="in" />
> > >       <arg type="i" name="size_y" direction="in" />
> > 
> > In the libgnomeui API, you only set one of those, and aspect ratio is
> > preserved. The size passed is the maximum width and height.
> 
> Or we make it even more simply and have "normal", "big", "small" only.

Or we make it even more simple, and we don't deal with sizes at all.

The thumbnailer must make all sizes it supports. It's actually an
implementation detail of the thumbnailer vs. the library for accessing
them.

This DBus specification is only about "requesting the creation of a
thumbnail". It's the responsibility of a library to do the final
resizing operation and pass it as a toolkit specific pixbuf instance to
the application developer (in gtk+ that's for example GdkPixBuf).

We don't pass pixbufs over DBus, that makes no sense.

Which also means that we don't return any uri. That client library
calculate that path by following the thumbnail-spec [1].

Therefore isn't the uri of the thumbnail itself relevant for DBus.



That, combined with Rob Taylor's proposal, brings me to this DBus API:

<node name="/">

foreach ([mime-part] in supported_mime_parts) {

  <interface name="org.freedesktop.Thumbnailer.[mime-part]">  
    <method name="Create">
      <annotation name="org.freedesktop.DBus.GLib.Async" value="true"/>
      <arg type="as" name="uris" direction="in" />
    </method>
    <method name="Move">
      <annotation name="org.freedesktop.DBus.GLib.Async" value="true"/>
      <arg type="as" name="from_uris" direction="in" />
      <arg type="as" name="to_uris" direction="in" />
    </method>
    <method name="Delete">
      <annotation name="org.freedesktop.DBus.GLib.Async" value="true"/>
      <arg type="as" name="uris" direction="in" />
    </method>
  </interface>

}

</node>


--- footnotes
[1] http://jens.triq.net/thumbnail-spec/index.html


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Philip Van Hoof, freelance software developer
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