I am using PagerSlidingTabStrip to create a sliding tabs. I was successfully able to use this library in my project.
Based on selected/clicked tab, the application should send a get request to server to fetch data and populate the list view. Every-time the tab is selected, http call would be made to server and list view will be updated.
I just modify SuperAwesomeCardFragment.java in the sample:
public class SuperAwesomeCardFragment extends ListFragment {
private ListView listView;
private ArrayList<User> arrayOfUsers = new ArrayList<User>();
private UsersAdapter useradapter;
ProgressDialog mProgressDialog;
ArrayList<HashMap<String, String>> arraylist;
JSONObject jsonobject;
JSONArray ja;
private static final String ARG_POSITION = "position";
private int position;
public static SuperAwesomeCardFragment newInstance(int position) {
SuperAwesomeCardFragment f = new SuperAwesomeCardFragment();
Bundle b = new Bundle();
b.putInt(ARG_POSITION, position);
f.setArguments(b);
return f;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
position = getArguments().getInt(ARG_POSITION);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
new DownloadJSON().execute();
View rootView = inflater.inflate(R.layout.fragment,
container, false);
listView = (ListView) rootView.findViewById(android.R.id.list);
useradapter = new UsersAdapter(getActivity(), android.R.id.list, arrayOfUsers);
listView.setAdapter(useradapter);
//Return the View for the fragment's UI
return rootView;
}
// DownloadJSON AsyncTask
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(getActivity());
// Set progressdialog title
mProgressDialog.setTitle("Connecting to server");
// Set progressdialog message
mProgressDialog.setMessage("Serving...");
mProgressDialog.setIndeterminate(false);
// Show progressdialog
mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
String statusStr;
switch (position) {
case 0:
statusStr = "UNREAD";
break;
case 1:
statusStr = "PROCCC";
break;
case 2:
statusStr = "COMPLETE";
break;
default:
statusStr = "UNKNOWN";
}
arraylist = new ArrayList<HashMap<String, String>>();
jsonobject = JSONfunctions
.getJSONfromURL("http://example.com/?id=" + statusStr);
try {
// Locate the array name in JSON
ja = jsonobject.getJSONArray("all_orders");
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
arrayOfUsers.clear();
arrayOfUsers.addAll(User.fromJson(ja));
System.out.println(arrayOfUsers.toString());
listView.setAdapter(useradapter);
// Close the progressbar
mProgressDialog.dismiss();
useradapter.notifyDataSetChanged();
}
}
} Didn't touch any other file.
Here is the custom adapter(UserAdapter.java) which I have created:
public class UsersAdapter extends ArrayAdapter<User> {
private Context context;
private List<User> objects;
public UsersAdapter(Context context, int textViewResourceId, List<User> objects) {
super(context, textViewResourceId, objects);
// TODO Auto-generated constructor stub
this.objects=objects;
this.context = context;
}
private class ViewHolder {
TextView name;
TextView home;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder; // view lookup cache stored in tag
// Get the data item for this position
User user = getItem(position);
// Check if an existing view is being reused, otherwise inflate the view
LayoutInflater mInflater = (LayoutInflater) context
.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
if (convertView == null) {
viewHolder = new ViewHolder();
convertView = mInflater.inflate(R.layout.list_row, null);
viewHolder.name = (TextView) convertView.findViewById(R.id.tvName);
viewHolder.home = (TextView) convertView.findViewById(R.id.tvHome);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
// Populate the data into the template view using tYiuhe data object
viewHolder.name.setText(user.ord_name);
viewHolder.home.setText(user.ord_id);
// Return the completed view to render on screen
return convertView;
}
I was able to run the application successfully(Didn't see any error or exceptions in Log Cat). However, the behaviour is quite abrupt:
- Load App For the first time: When I press Tab 1 and Tab 2, then its fetches the data and populate the list-view(Expected). However, it do not refresh/fetch data from server when I press last tab(Tab 3).
- Once I finished clicking all three tabs: Tab 1 and Tab 3 do not fetch data, neither load list. The fragment is blank. Only Tab 2 shows list view, but do not refresh data from server. The total number of tab equals 3.
Behaviour 2 is repeated every time, whatever combination I try.
I am quite new to Android development, so not able debug this behaviour.
Any help is appreciated.
UPD: I was able to bring desired behaviour by over-riding setUserVisibleHint:
public void setUserVisibleHint(boolean isVisibleToUser) {
super.setUserVisibleHint(isVisibleToUser);
if (isVisibleToUser) {
new DownloadJSON().execute();
Log.d("MyFragment", "Fragment is visible.");
}
else {
Log.d("MyFragment", "Fragment is not visible.");
}
}
Is this the prescribed way?
