== Replacing the Category filter controls

The document category filter controls normally appear at the top of the
*recoll* GUI, either as checkboxes just above the result list, or as a
dropbox in the tool area.

By default, they are labeled _Media_, _Message_, _Spreadsheet_, _Text_,
etc. and each map to a document category.

The mapping used to be fixed. You could change the number and composition
of categories by redefining them inside the {{{mimeconf}}} configuration
file (you still can), but the filters always used document categories.

Categories can also be selected from the query language by using an
+rclcat:+ selector. E.g.: _rclcat:message_.

As of Recoll release 1.17, the filters are not hard-wired any more. They
map to query language fragments. This means that you can freely redefine
what they do. 

The associations are configured inside the 'mimeconf' file, in the
+[guifilters]+ section. Most GUI parameters are stored in the *Qt*
configuration file, so this is not entirely consistent, and you will have
to bear with my lazyness here.

A simple exemple will hopefuly make things clearer. If you add the 
following to your '~/.recoll/mimeconf' file:

----
[guifilters]

Big Books = dir:"~/My Books" size>10K
My Docs = dir:"~/My Documents"
Small Books = dir:"~/My Books" size<10K
System Docs = dir:/usr/share/doc

----

You will have four filter checkboxes, labelled _Big Books_, _My Docs_, etc.

The text after the equal sign must be a valid query language fragment, and
will be translated to a *Recoll* query and combined with the rest of the
query with an AND conjunction.

Any name text before a colon character will be erased in the display, but
used for sorting. You can use this to display the checkboxes in any order
you like. For exemple, the following would do exactly the same as above,
but ordering the checkboxes in the reverse order.

----
[guifilters]

d:Big Books = dir:"~/My Books" size>10K
c:My Docs = dir:"~/My Documents"
b:Small Books = dir:"~/My Books" size<10K
a:System Docs = dir:/usr/share/doc

----