everburning

I’ve been doing some more fiddling with EWL the last few days. Came up with
an idea for an IO manager thats been commited to CVS.

Basically, it abstracts out the need for reading/writting data to get
specific EWL types back. The code currently has a hack in it to determine
mime types at the moment. This will eventually get changed to have correct
mime type lookups.

If you want to see an example of using the IO manager take a look at the
ewl/src/bin/tests/ewl_io_manager.c file. The test provides a file
dialog to select your data and uses the IO manager to read the data.

It currently supports plain text and images. We’ll hopefully get more
plugins in the future to read different file types.

The simple magic behind the IO manager test is the line:

t = ewl_io_manager_uri_read(path)

This will then return either an Ewl_Text widget setup with the contents of
the file, an Ewl_Image widget if it’s an image or NULL if the URI can’t be
read in for some reason. It’s that simple. You can do other things with the IO
manager, map extensions to their icon names, lookup mime types for files,
etc.

Along with the input portion of this, you can also save using the IO
manager. To write out a file you’ll pass in the widget that contains the
information, the URI to write too and the mime type to write the data out
as. You should be able to save both plain text and images through the IO
manager at the moment. (You should also be able to convert image types this
way, read in a JPG and write out a PNG should, in theory, work
correctly.)

What are these plugins I’m talking about? Well, the IO manager works by
taking the mime type and loading in a chunk of code to handle that mime
type. So, for a text/plain mime type it will look for the
ewl_io_manager_text_plain_plugin.so, failing that it
will look for the
ewl_io_manager_text_plugin.so
(it falls back down the mime type). These
plugins are located in PACKAGE_LIB_DIR/plugins.

Because these plugins aren’t tied with EWL, developers can write their own
plugins and install them into the lib directory. They’ll then get picked up
automatically by any application that uses the IO manager.

Plugins are fairly simple to write, you can take a look in the
ewl/src/plugins directory for
two examples, one for text and one for images.

If you’d like to help out, there are a few ways. Send an email to
the enlightenment-devel mailing list, join #ewl on irc.freenode.net or add
your bugs/patches to the bug tracker at xcomputerman.com/bugs.