Update content in ListFragment on menu click

Question

I have a ListFragment with some data. I am trying to sort the content of my list depending on which item I select from the menu. How can I update the content of the list when I select one option from the menu? I don't want to create another fragment, I just want to sort by name or by date the info that I have in the list so when I click one item in the menu the list updates immediately depending on whether I click sort by name or sort by date.

public class MainActivity extends AppCompatActivity{

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main_menu, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_sort_by_name) {
        Fragment currentFragment =        this.getFragmentManager().findFragmentById(R.id.fragment1);
        ArrayAdapter adapter = ArrayAdapter.createFromResource(this, R.array.Months, android.R.layout.simple_list_item_1);
        setListAdapter(adapter);
    }
    return super.onOptionsItemSelected(item);
}

And then I have the java class for the fragment:

public class EventsListFragment extends ListFragment implements     OnItemClickListener {
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.list_fragment, container, false);
    return view;
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    ArrayAdapter adapter = ArrayAdapter.createFromResource(getActivity(), R.array.Planets, android.R.layout.simple_list_item_1);
    setListAdapter(adapter);
    getListView().setOnItemClickListener(this);
}

@Override
public void onItemClick(AdapterView<?> parent, View view, int position,long id) {
    Toast.makeText(getActivity(), "Item: " + position, Toast.LENGTH_SHORT).show();
}

Looks like you can update the sort for an [ArrayAdapter](https://developer.android.com/reference/android/widget/ArrayAdapter.html#sort%28java.util.Comparator%3C?%20super%20T%3E%29) — zec, May 23 '16 at 17:50

score 0 · Accepted Answer · edited May 23 '17 at 12:07

use a Sort (by comparator) or by Filter on array or custom adapter - depending on the complexity of the adapter object

some examples and references:

basic example for array adapter:

Adapter.sort(new Comparator<Item>() {
    @Override
    public int compare(Item lhs, Item rhs) {
        return lhs.compareTo(rhs);   //Your sorting algorithm
    }
});

*Item - class definition for adapter item

array adapter doc ref:

https://developer.android.com/reference/android/widget/ArrayAdapter.html

complete solution for your case:

http://www.worldbestlearningcenter.com/tips/Android-sort-ListView.htm

Update content in ListFragment on menu click

1 Answers1