Added grid image for playlist

app/src/main/java/code/name/monkey/retromusic/adapter/playlist/PlaylistAdapter.kt

@@ -1,7 +1,9 @@
 package code.name.monkey.retromusic.adapter.playlist
 
+import android.graphics.Bitmap
 import android.graphics.Color
 import android.graphics.drawable.Drawable
+import android.os.AsyncTask
 import android.text.TextUtils
 import android.view.LayoutInflater
 import android.view.MenuItem
@@ -28,6 +30,7 @@ import code.name.monkey.retromusic.model.Playlist
 import code.name.monkey.retromusic.model.Song
 import code.name.monkey.retromusic.model.smartplaylist.AbsSmartPlaylist
 import code.name.monkey.retromusic.model.smartplaylist.LastAddedPlaylist
+import code.name.monkey.retromusic.util.AutoGeneratedPlaylistBitmap
 import code.name.monkey.retromusic.util.MusicUtil
 import code.name.monkey.retromusic.util.NavigationUtil
 import java.util.*
@@ -86,6 +89,7 @@ class PlaylistAdapter(
         } else {
             holder.menu?.show()
         }
+        PlaylistBitmapLoader(this, holder, playlist).execute()
     }
 
     private fun getIconRes(playlist: Playlist): Drawable {
@@ -225,6 +229,23 @@ class PlaylistAdapter(
         }
     }
 
+    class PlaylistBitmapLoader(
+        private var adapter: PlaylistAdapter,
+        private var viewHolder: ViewHolder,
+        private var playlist: Playlist
+    ) : AsyncTask<Void, Void, Bitmap>() {
+
+        override fun doInBackground(vararg params: Void?): Bitmap {
+            val songs = PlaylistSongsLoader.getPlaylistSongList(adapter.activity, playlist)
+            return AutoGeneratedPlaylistBitmap.getBitmap(adapter.activity, songs, false, false)
+        }
+
+        override fun onPostExecute(result: Bitmap?) {
+            super.onPostExecute(result)
+            viewHolder.image?.setImageBitmap(result)
+        }
+    }
+
     companion object {
         val TAG: String = PlaylistAdapter::class.java.simpleName
         private const val SMART_PLAYLIST = 0