Android - update ListView from a fragment to another

Question

I am trying to update listView from another fragment class after i delete an item from listView from current class. For example, i delete a consumer that has an expense, then the expense of that consumer will also be deleted. But consumer and expense is different page that using tab control, which is fragment, when i delete consumer, the expense list is not updated, until i go to previous page, then enter the page again. What can i do to update the expense list when consumer from consumer list is deleted? i heard of using broadcast receiver is able to do that, but how can i implement it in my code? I am new in android, please guide me.Thanks

Here is the code for consumer/participant list :

public class Participant extends ListFragment implements OnClickListener{

Intent intent;
TextView friendId;
Button addparticipant;
String eventId;
ListView lv;

public void onActivityCreated(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onActivityCreated(savedInstanceState);
    EventController controller = new EventController(getActivity());

    HashMap<String, String> queryValues = new HashMap<String, String>();
    Intent objIntent = getActivity().getIntent();
    eventId = objIntent.getStringExtra("eventId");
    queryValues.put("eventId", eventId);
    ArrayList<HashMap<String, String>> friendList = controller
            .getAllFriends(queryValues);
    if (friendList.size() != 0) {
        lv = getListView();
        lv.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                friendId = (TextView) view.findViewById(R.id.friendId);
                String valFriendId = friendId.getText().toString();
                Intent objIndent = new Intent(getActivity(),
                        EventPage.class);
                objIndent.putExtra("friendId", valFriendId);
                startActivity(objIndent);
            }
        });
        lv.setOnItemLongClickListener(new OnItemLongClickListener(){

            @Override
            public boolean onItemLongClick(AdapterView<?> arg0,
                    View arg1, int arg2, long arg3) {
                // TODO Auto-generated method stub
                friendId = (TextView) arg1.findViewById(R.id.friendId);
                registerForContextMenu(getListView());
                return false;
            }

        });
        SimpleAdapter adapter = new SimpleAdapter(getActivity(),
                friendList, R.layout.view_friend_entry, new String[] {
                        "friendId", "friendName", "friendSpending" },
                new int[] { R.id.friendId, R.id.friendName,
                        R.id.friendSpending });
        adapter.notifyDataSetChanged();
        setListAdapter(adapter);
    }
}

public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.participant, container, false);
    addparticipant = (Button) rootView.findViewById(R.id.addpart);
    addparticipant.setOnClickListener(this);
    return rootView;

}

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub
    Intent objIntent = new Intent(getActivity(),
            AddParticipant.class);
    objIntent.putExtra("eventId", eventId);
    startActivity(objIntent);
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v,
        ContextMenuInfo menuInfo) {
    String[] menuItems = getResources().getStringArray(R.array.menu);
    for (int i = 0; i < menuItems.length; i++) {
        menu.add(Menu.NONE, i, i, menuItems[i]);
    }
}

@Override
public boolean onContextItemSelected(MenuItem item) {
    int menuItemIndex = item.getItemId();
    EventController controller = new EventController(getActivity());
    switch (menuItemIndex) {
    case 0:
        String valFriendId = friendId.getText().toString();
        Intent objIndent = new Intent(getActivity(),
                EditParticipant.class);
        objIndent.putExtra("friendId", valFriendId);
        startActivity(objIndent);
        break;
    case 1:
        String valFriendId2 = friendId.getText().toString();
        controller.deleteFriend(valFriendId2);
        onResume();
    }

    return true;
}

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

    if (getListView() != null) {
        updateData();
    }
}

private void updateData() {
    EventController controller = new EventController(getActivity());
    HashMap<String, String> queryValues = new HashMap<String, String>();
    Intent objIntent = getActivity().getIntent();
    eventId = objIntent.getStringExtra("eventId");
    queryValues.put("eventId", eventId);
    SimpleAdapter adapter = new SimpleAdapter(getActivity(),
            controller.getAllFriends(queryValues),
            R.layout.view_friend_entry, new String[] { "friendId",
                    "friendName", "friendSpending" }, new int[] {
                    R.id.friendId, R.id.friendName, R.id.friendSpending });
    setListAdapter(adapter);
}

}

Here is the code for expense list:

public class Expense extends ListFragment implements OnClickListener {

Button addexp;
TextView expenseId;
ListView lv;
String eventId, friendId;

public void onActivityCreated(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onActivityCreated(savedInstanceState);
    EventController controller = new EventController(getActivity());

    HashMap<String, String> queryValues = new HashMap<String, String>();
    Intent objIntent = getActivity().getIntent();
    eventId = objIntent.getStringExtra("eventId");
    queryValues.put("eventId", eventId);
    ArrayList<HashMap<String, String>> expenseList = controller
            .getAllExpenses(queryValues);
    if (expenseList.size() != 0) {
        lv = getListView();
        lv.setOnItemClickListener(new OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                    int position, long id) {
                expenseId = (TextView) view.findViewById(R.id.expenseId);
                String valExpenseId = expenseId.getText().toString();
                Intent objIndent = new Intent(getActivity(),
                        EditExpense.class);
                objIndent.putExtra("expenseId", valExpenseId);
                startActivity(objIndent);
            }
        });
        SimpleAdapter adapter = new SimpleAdapter(getActivity(),
                expenseList, R.layout.view_expense_entry, new String[] {
                        "expenseId", "expenseName","expenseQuantity" }, new int[] {
                        R.id.expenseId, R.id.expenseName, R.id.expenseQuantity });
        adapter.notifyDataSetChanged();
        setListAdapter(adapter);
    }
}

public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.expense, container, false);
    addexp = (Button) rootView.findViewById(R.id.addexp);
    addexp.setOnClickListener(this);
    return rootView;

}

@Override
public void onClick(View v) {
    // TODO Auto-generated method stub
    Intent objIntent = new Intent(getActivity(), AddExpense.class);
    objIntent.putExtra("eventId", eventId);
    startActivity(objIntent);
}

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

    if (getListView() != null) {
        updateData();
    }
}

private void updateData() {
    EventController controller = new EventController(getActivity());
    HashMap<String, String> queryValues = new HashMap<String, String>();
    Intent objIntent = getActivity().getIntent();
    eventId = objIntent.getStringExtra("eventId");
    queryValues.put("eventId", eventId);
    SimpleAdapter adapter = new SimpleAdapter(getActivity(),
            controller.getAllExpenses(queryValues),
            R.layout.view_expense_entry, new String[] { "expenseId",
                    "expenseName", "expenseQuantity" }, new int[] { R.id.expenseId,
                    R.id.expenseName, R.id.expenseQuantity });
    setListAdapter(adapter);
}

}

Answer 1

Same scenario with me, if you used FragmentPagerAdapter , Try like this in FirstFragment

private void updateSecondFragment(){

    //Way to get TagName which generated by FragmentPagerAdapter
    String tagName = "android:switcher:" + R.id.pager + ":" + 1; // Your pager name & tab no of Second Fragment 

    //Get SecondFragment object from FirstFragment
    SecondFragment f2 = (SecondFragment)getActivity().getSupportFragmentManager().findFragmentByTag(tagName);

    //Then call your wish method from SecondFragment to update appropriate list
    f2.updateList();
}

I got that idea by reading this . Then edit a little !

Answer 2

One way could be creating the methods in the activity that contains the two fragments, and access to the fragments methods from the activity. You can update the database and reload the list in the same method.

For example, In the activity

public void updateFragment2(){ ... }

In fragment 1 you should call:

((ActivityClass)getActivity()).updateFragment2();

In the section "Communicating with the Activity" you can see the explanation of this example: http://developer.android.com/guide/components/fragments.html