Question

Suppose I have an Android block of code that looks something like this:

String[] proj = {MediaStore.Audio.Media.ARTIST, MediaStore.Audio.Media._ID};
int[] to = new int[] { R.id.artist_name };
Cursor musiccursor = managedQuery(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, proj, null, null, MediaStore.Audio.Media.ARTIST);
ListView musiclist = (ListView) findViewById(R.id.mylist);

SimpleCursorAdapter mAdapter = new SimpleCursorAdapter(getApplicationContext(), R.layout.songitem, musiccursor, proj, to);
musiclist.setAdapter(mAdapter);

But what I want, is this:

String selection = MediaStore.Audio.Media.FILE_PATH + " ilike '%audio%books%'";

String[] proj = {MediaStore.Audio.Media.ARTIST, MediaStore.Audio.Media._ID};
int[] to = new int[] { R.id.artist_name };
Cursor musiccursor = managedQuery(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, proj, selection, null, MediaStore.Audio.Media.ARTIST);
ListView musiclist = (ListView) findViewById(R.id.mylist);

SimpleCursorAdapter mAdapter = new SimpleCursorAdapter(getApplicationContext(), R.layout.songitem, musiccursor, proj, to);
musiclist.setAdapter(mAdapter);

The only problem, of course, is that FILE_PATH is not actually a column I can use, and as far as I can tell, no such column exists.

So I’m wondering:

1. Is there a way to query only for music in a certain directory? If so, how?
2. If that’s not an option, should I make a ListAdapter that filters by directory? If so, again, how would I go about in doing that?

Thanks for any advice.

Answer 1

OK, after many iterations of trying, I finally have an example that works and I thought I’d share it. My example queries the images MediaStore, then obtains the thumbnail for each image to display in a view. A few tweaks should provide you with the code needed to query the audio MediaStore instead. I am loading my images into a Gallery object, but that is not a requirement for this code to work:

Make sure you have a Cursor and int for the column index defined at the class level so that the Gallery’s ImageAdapter has access to them:

private Cursor cursor;
private int columnIndex;

First, obtain a cursor of image IDs located in the folder:

Gallery g = (Gallery) findViewById(R.id.gallery);
// request only the image ID to be returned
String[] projection = {MediaStore.Images.Media._ID};
// Create the cursor pointing to the SDCard
cursor = managedQuery( MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
        projection, 
        MediaStore.Images.Media.DATA + " like ? ",
        new String[] {"%myimagesfolder%"},  
        null);
// Get the column index of the image ID
columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Media._ID);
g.setAdapter(new ImageAdapter(this));

Then, in the ImageAdapter for the Gallery, obtain the thumbnail to display:

public View getView(int position, View convertView, ViewGroup parent) {
    ImageView i = new ImageView(context);
    // Move cursor to current position
    cursor.moveToPosition(position);
    // Get the current value for the requested column
    int imageID = cursor.getInt(columnIndex);
    // obtain the image URI
    Uri uri = Uri.withAppendedPath( MediaStore.Images.Media.EXTERNAL_CONTENT_URI, Integer.toString(imageID) );
    String url = uri.toString();
    // Set the content of the image based on the image URI
    int originalImageId = Integer.parseInt(url.substring(url.lastIndexOf("/") + 1, url.length()));
    Bitmap b = MediaStore.Images.Thumbnails.getThumbnail(getContentResolver(),
                    originalImageId, MediaStore.Images.Thumbnails.MINI_KIND, null);
    i.setImageBitmap(b);
    i.setLayoutParams(new Gallery.LayoutParams(150, 100));
    i.setScaleType(ImageView.ScaleType.FIT_XY);
    i.setBackgroundResource(mGalleryItemBackground);
    return i;
}

I guess the most important section of this code is the managedQuery that demonstrates how to use MediaStore queries to filter a list of image files in a specific folder.