Fetches list of image and video Albums using content provider along with path to thumbnail of an album.

GetAlbumListFromContentProvider.kt

package droidninja.filepicker

import android.content.ContentResolver
import android.provider.MediaStore
import android.util.Log

/*
~ Nilesh Deokar @nieldeokar on 03/06/19 9:57 AM
*/


class GetAlbumListFromContentProvider {

    private val MEDIA_TYPE_VIDEO = 3
    /*
 *
 *   mediaType could be one of
 *
 *   public static final int MEDIA_TYPE_IMAGE = 1;
 *   public static final int MEDIA_TYPE_VIDEO = 3;
 *
 *   From {@link android.provider.MediaStore}
 *
 */
    fun getAlbumList(mediaType: Int, contentResolver: ContentResolver) {
        val countColumnName = "count"
        var contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
        if (mediaType == MEDIA_TYPE_VIDEO) {
            contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI
        }

        val projection = arrayOf(MediaStore.Images.ImageColumns.BUCKET_ID, MediaStore.Images.ImageColumns.BUCKET_DISPLAY_NAME, MediaStore.Images.ImageColumns.DATE_TAKEN, MediaStore.Images.ImageColumns.DATA)
        val bucketGroupBy = "1) GROUP BY ${MediaStore.Images.ImageColumns.BUCKET_ID}, (${MediaStore.Images.ImageColumns.BUCKET_DISPLAY_NAME}"
        val bucketOrderBy = MediaStore.Images.Media.DATE_MODIFIED + " DESC"

        val cursor = contentResolver.query(contentUri, projection, bucketGroupBy, null, bucketOrderBy)

        /* This creates a query :
            SELECT bucket_id, bucket_display_name, datetaken, _data FROM images WHERE (1)
            GROUP BY bucket_id,(bucket_display_name) ORDER BY date_modified DESC
         */

        if (cursor != null) {
            while (cursor.moveToNext()) {
                val bucketId = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.ImageColumns.BUCKET_ID))
                val name = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.Images.ImageColumns.BUCKET_DISPLAY_NAME))
                val path = cursor.getString(cursor.getColumnIndexOrThrow(MediaStore.MediaColumns.DATA)) // Thumb image path

                val selection = MediaStore.Images.Media.BUCKET_ID + "='" + bucketId + "'"

                val countCursor = contentResolver.query(contentUri, arrayOf("$countColumnName(*) AS $countColumnName"), selection, null, null)

                var count = 0
                if (countCursor != null) {
                    countCursor.moveToFirst()
                    count = countCursor.getInt(countCursor.getColumnIndexOrThrow(countColumnName))
                    countCursor.close()
                }

                Log.d("AlbumScanner", "bucketId : $bucketId | name : $name | count : $count | path : $path")
            }
            cursor.close()

        }

    }
}

new android with kotlin, can not use this way now.