Thursday, November 8, 2007

Episode selector dialog for gPodder

Today after University, I decided to hack a feature into gPodder that I have thought about for a while - the episode selector dialog. It should be used in several user interaction situations where a simple binary question is not specific enough ("delete old episodes?" vs "which of these old episodes do you really want to remove?"). So I set out implementing this neat little feature and when I looked at the watch and decided that I had to leave for math classes, most of the episodes selector has been implemented, with quite some fancy features and options. I used the last two hours to look through the my working copy diff to fix some obvious omissions, but as of now, the code of the new episode selector is already in SVN. I've attached some screenshots so you can see how it looks.

Thanks to lambda expressions, PyGTK coolness and getattr, i.e. accessing attributes by name, this dialog is now quite customizable and the code is still readable and (compared to what other languages would have yielded), small. If you are using gPodder, be sure to check out the current SVN trunk head.

One feature I used several times was enumerate() - you give an iterable as parameter, and get a generator that yields tuples with two elements - a zero-based index and the values you would normally get from the iterables directly. So, instead of writing code like this:
index = 0
for item in items:
print 'item %d is %s' % ( index, item )
index += 1
you can simply write
for index, item in enumerate( items):
print 'item %d is %s' % ( index, item )
which isn't only nicer, but you save two lines and the code is IMHO more readable (you instantly recognize "index" as being related to the for loop in the second code snippet).

1 comment:

Roel said...

This looks like a nice improvement!
I'm updating SVN as we speak... :-)

Keep up the good work!