How to make fragments load faster?

Question

I am currently developing a fragment which contains lists of albums. The structure is pretty simple:

Horizontal slider contains LinearLayour (horizontal). In order to add an album with songs list I have created a separate view which consists of cover image and a listview. The listview is custom as well where items are linearlayout with 3 textviews. Then I inflate it, populate list, and add to the Horizontal slider.

The issue occurs if I have more than 2 album lists. It takes some time to open a fragment.

Another thing is when I try to scroll (horizontally), sometimes it stops for a short moment, which makes bad user experience.

What I am trying to say is that I have seen similar views and they work quickly and with no lags. Is it possible somehow to optimize it? Or is it possible so that the fragment opens straight away and then the lists load afterwards (kind of lazyload).

LISTVIEW ITEM:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:background="#ccffffff"
    android:padding="10dp" >

        <TextView
            android:id="@+id/album_list_item_number"
            android:layout_width="30dp"
            android:layout_height="wrap_content"
            android:text=""
            android:gravity="center|center_vertical"
            android:layout_gravity="center|center_vertical"
            android:textColor="#333333"
            android:textAppearance="?android:attr/textAppearanceMedium" />





        <TextView
            android:id="@+id/album_list_item_title"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:text=""
            android:layout_weight="1"
            android:gravity="left|center_vertical"
            android:layout_gravity="left|center_vertical"
            android:textColor="#333333"
            android:textAppearance="?android:attr/textAppearanceMedium" />

        <TextView
            android:id="@+id/album_list_item_time"
            android:layout_width="90dp"
            android:layout_height="wrap_content"
            android:text=""
            android:gravity="center|center_vertical"
            android:layout_gravity="center|center_vertical"
            android:textColor="#333333"
            android:textAppearance="?android:attr/textAppearanceMedium" />

</LinearLayout>

POPULATING THE LIST AND ADDING VIEW TO THE HORIZONTAL SLIDER:

    View albumView = inflater.inflate(R.layout.artist_album_col, container, false);
    //setting cover
    ImageView albumCover = (ImageView) albumView.findViewById(R.id.artistAlbumCover);
    albumCover.setImageDrawable(getResources().getDrawable(R.drawable.albumcover)); //cover

    ListView albumList = (ListView) albumView.findViewById(R.id.artistSongList);


    // create the grid item mapping
    String[] from = new String[] {"num", "title", "time"};
    int[] to = new int[] { R.id.album_list_item_number, R.id.album_list_item_title, R.id.album_list_item_time};

    // prepare the list of all records
    List<HashMap<String, String>> fillMaps = new ArrayList<HashMap<String, String>>();
    for(int i = 0; i < 24; i++){
        HashMap<String, String> map = new HashMap<String, String>();
        map.put("num", "" + i);
        map.put("title", "title title title title title title title title title " + i);
        map.put("time", "time " + i);
        fillMaps.add(map);
    }

    // fill in the grid_item layout
    SimpleAdapter adapter = new SimpleAdapter(mContext, fillMaps, R.layout.album_list_item, from, to);
    albumList.setAdapter(adapter);

    albumContainer.addView(albumView);

Answer 1

You can use Async Task to perform the time-consuming tasks and take them off the UI thread. This will allow the fragment to load quickly and the list to populate "lazily".

Call with:

new LoadingTask().execute(""); 

And you can stick a class like this in your fragment class (warning! not tested):

private class LoadingTask extends AsyncTask<Void, Void, Void> {
   SimpleAdapter adapter;

   protected void doInBackground(Void... values) {

       // do your work in background thread 
       // create the grid item mapping                       
       String[] from = new String[] {"num", "title", "time"};                       
       int[] to = new int[] { R.id.album_list_item_number, R.id.album_list_item_title, R.id.album_list_item_time};

       // prepare the list of all records                         
       List<HashMap<String, String>> fillMaps = new ArrayList<HashMap<String, String>>();                         
       for(int i = 0; i < 24; i++){                             
       HashMap<String, String> map = new HashMap<String, String>();                             
       map.put("num", "" + i);                             
       map.put("title", "title title title title title title title title title " + i);                             
       map.put("time", "time " + i);                             
       fillMaps.add(map);                         
     }                                              
     // fill in the grid_item layout                         
     adapter = new SimpleAdapter(mContext, fillMaps, R.layout.album_list_item, from, to); 
       return;
   }

   protected void onPostExecute(Void value) {

      // back in UI thread after task is done   
      ListView albumList = (ListView) getActivity().findViewById(R.id.artistSongList);     
      albumList.setAdapter(adapter);
   }
}

Another example here.