Android: Select first item by default in ListView in Master Detail template

Question

I program a RSS reader with Master Detail flow with a list view on the left, and a detail view on the right.

When the screen is created the right side is empty and no item on the left is selected. How can I load the first item by default?

I found this post which is similar to my problem: Select the first item by default in a Master Detail flow

The code in my ListFragment looks like this:

@Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        // Set a listener to be invoked when the list should be refreshed.
        listView = (PullToRefreshListView) getListView();

        listView.setOnRefreshListener(new OnRefreshListener() {
            @Override
            public void onRefresh() {
                //refresh list
                refresh_list();
            }
        });

        listView.setVerticalFadingEdgeEnabled(true);

        // Set custom list adapter to the ListView
        adapter = new CustomListAdapter(getActivity(), feed);
        listView.setAdapter(adapter);

        //create button, on click go to website
        final Button btnAddMore = new Button(getActivity());
        btnAddMore.setText(R.string.button_text_end_list);
        btnAddMore.setBackgroundColor(getResources().getColor(R.color.white));
        btnAddMore.setOnClickListener(new OnClickListener() {
               @Override
               public void onClick(View v) {
                    // go to website on click
                    String url = "http://www.test.de";
                    Intent web = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
                    startActivity(web);
               }
              });
        //add button at the end of the listview
        listView.addFooterView(btnAddMore);
    }

    @Override
    public void onViewCreated(View view, Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        // Restore the previously serialized activated item position.
        if (savedInstanceState != null
                && savedInstanceState.containsKey(STATE_ACTIVATED_POSITION)) {
            setActivatedPosition(savedInstanceState
                    .getInt(STATE_ACTIVATED_POSITION));
        }

        //select the first item in the listview by default
        listView.requestFocusFromTouch();
        listView.setSelection(0);
        listView.performItemClick(listView
                .getAdapter().getView(0, view, null), 0, 0);
    }

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    Log.d(TAG, "Hallo in ItemListFragment");

    // show ActionBar
    setHasOptionsMenu(true);

    // get reference to activity
    myApp = getActivity().getApplication();

    // check if intent from ItemListActivity is null
    Bundle be = getActivity().getIntent().getExtras();
    if (be == null) {
        // if null read local feed
        feed = ReadFeed(fileName);
        Log.d(TAG, "Lese Feed lokal :" + feed);
    } else {
        // else get extras from the intent
        feed = (RSSFeed) getActivity().getIntent().getExtras().get("feed");
        Log.d(TAG,
                "Intent von ItemListActivity an ItemListFragment vorhanden");
    }
}

But I receive this error:

01-19 06:39:14.723: E/AndroidRuntime(1921): Caused by: java.lang.NullPointerException
01-19 06:39:14.723: E/AndroidRuntime(1921):     at ItemListFragment.onViewCreated(ItemListFragment.java:185)

in the line

listView.requestFocusFromTouch();

Please help me!

CustomListAdapter

public class CustomListAdapter extends BaseAdapter {

    private LayoutInflater layoutInflater;
    public ImageLoader imageLoader;
    public RSSFeed _feed;
    public Date pDate;

    public CustomListAdapter(Activity activity, RSSFeed feed) {

        _feed = feed;

        layoutInflater = (LayoutInflater) activity
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        imageLoader = new ImageLoader(activity.getApplicationContext());
    }

    public void setNewFeed(RSSFeed feed) {
        // set new Feed list, after refresh
        _feed = feed;
    }

    @Override
    public int getCount() {
        // Set the total list item count
        return _feed.getItemCount();
    }

    @Override
    public Object getItem(int position) {
        return position;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        // Inflate the item layout and set the views
        View listItem = convertView;
        int pos = position;
        if (listItem == null) {
            listItem = layoutInflater.inflate(R.layout.list_item, null);
        }

        // Initialize the views in the layout
        ImageView iv = (ImageView) listItem.findViewById(R.id.thumb);
        TextView tvTitle = (TextView) listItem.findViewById(R.id.title);
        TextView tvDate = (TextView) listItem.findViewById(R.id.date);
        TextView comment_bubble = (TextView) listItem.findViewById(R.id.comment_bubble);

        // Set the views in the layout
        imageLoader.DisplayImage(_feed.getItem(pos).getImage(), iv);
        tvTitle.setText(_feed.getItem(pos).getTitle());

        // calculate the time difference to the actual system time
        String pubDate = _feed.getItem(pos).getDate();
        SimpleDateFormat df = new SimpleDateFormat(
                "EEE, dd MMM yyyy HH:mm:ss",Locale.ENGLISH);
        try {
            try {
                pDate = df.parse(pubDate);
            } catch (java.text.ParseException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            pubDate = "Vor "
                    + DateUtils.getDateDifference(pDate);
        } catch (ParseException e) {
            Log.e("DATE PARSING", "Error parsing date..");

        }
        //set time difference
        tvDate.setText(pubDate);

        //set comment in bubble
        comment_bubble.setText(_feed.getItem(pos).getComment());

        return listItem;
    }
}

Answer 1

I solved it this way inside my ListFragment:

    @Override
    public void onStart() {
        super.onStart();

        //set first item activated by default
        onListItemClick(listView, getView(), 1, 0);
    }
/**
 * Turns on activate-on-click mode. When this mode is on, list items will be
 * given the 'activated' state when touched.
 */
public void setActivateOnItemClick(boolean activateOnItemClick) {
    // When setting CHOICE_MODE_SINGLE, ListView will automatically
    // give items the 'activated' state when touched.
    listView.setChoiceMode(activateOnItemClick ? ListView.CHOICE_MODE_SINGLE
            : ListView.CHOICE_MODE_NONE);
}