[android-developers] Re: Filter specific data from cursor before ListView. How?

Thanks once again Kostya,

I came up with a cleaner solution that still has one thing left to
work:

Instead of using Media.Audio.Album I got to using only
Media.Audio.Media. It works as expected but the lack of the "_id"
column now is giving my a big headache when loading the Adapter.
I tried to use

String[] cols = new String[] {
"distinct " + MediaStore.Audio.Media.ALBUM_ID + " as _id",
MediaStore.Audio.Media.ALBUM,
MediaStore.Audio.Media.ARTIST
};

But it simply doesn´t work. How can I fix the Adapter dependency of
_id so my expandablelistview works?

Thanks,
Gabriel Simões

On May 22, 2:42 pm, Kostya Vasilyev <kmans...@gmail.com> wrote:
> 22.05.2011 21:13, Gabriel Simões пишет:
>
> > My second approach was to find a way to block the displaying of some
> > entries creating a custom adapter but while I can change the
> > information I couldn´t find a way to not display full entries.
>
> Ok, here is how you could do filtering on the fly.
>
> Assume the data set you get from CP in a cursor is like this:
>
> 0 - mp3
> 1 - mp3
> 2 - no mp3
> 3 - mp3
> 4 - no mp3
>
> Look through the cursor, checking for mp3s, and create a parallel index
> array like this:
>
> [ 0, 1, 3 ]
>
> The array has the cursor positions where albums have mp3.
>
> Now you have the count for the adapter's getCount method, which is the
> length of this array. The positions as seen by the list view are 0
> through 2.
>
> In getView / bindView, use the table above to find out the position for
> the original cursor: the 0th item is remapped to 0, 1 is mapped to 1,
> but 2 is mapped to 3.
>
> -- Kostya
>
> --
> Kostya Vasilyev --http://kmansoft.wordpress.com

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