I am building an application like techcrunch. I am fetching data from server in JSON format and displaying the data in list view like article title,author name and image. I have applied pagination means when user scroll more articles load in a list view. My pagination works fine but there is an issue in the scroll function as the fresh or new data loads the scroll dose not aligns with the data. To clarify more in simple words my scroll-er goes at the top of the page when i am actually scrolling down this is my code :
public class OneFragment extends Fragment {
public OneFragment(){}
private static final String TAG = OneFragment.class.getSimpleName();
// Movies json url
private static String URL = "http:url&page=1";
private ProgressDialog pDialog;
private List<Movie> movieList = new ArrayList<Movie>();
private ListView listView;
private CustomListAdapter adapter;
int current_page = 1;
int mPreLast;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View rootView = inflater.inflate(R.layout.swip, container, false);
pDialog = new ProgressDialog(getActivity());
pDialog.setMessage("Loading...");
pDialog.show();
pDialog.setCancelable(false);
listView = (ListView) rootView.findViewById(R.id.list49);
listView.setOnScrollListener(new AbsListView.OnScrollListener()
{
@Override
public void onScrollStateChanged(AbsListView absListView, int i)
{
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount)
{
int lastItem = firstVisibleItem + visibleItemCount;
if(lastItem == totalItemCount){
if (mPreLast != lastItem)
{
mPreLast = lastItem;
onStart();
}
}
}
});
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> adapterView, View view, int Position,
long offset) {
// TODO Auto-generated method stub
Movie item = (Movie) adapter.getItem(Position);
Intent intent = new Intent(rootView.getContext(), SingleArticle.class);
single.date = item.getDate();
single.id = item.getId();
startActivity(intent);
}
});
//pDialog = new ProgressDialog(this);
// Showing progress dialog before making http request
return rootView;
}
@Override
public void onStart(){
super.onStart();
// calling adapter changes here, just
// to avoid getactivity()null
// increment current page
current_page += 1;
// Next page request
URL = "http:url&page=" + current_page;
//adapter = new CustomListAdapter(this, movieList);
// changing action bar color
//getActivity().getActionBar().setBackground(
//new ColorDrawable(Color.parseColor("#1b1b1b")));
// Creating volley request obj
JsonArrayRequest movieReq = new JsonArrayRequest(URL,
new Response.Listener<JSONArray>() {
@Override
public void onResponse(JSONArray response) {
Log.d(TAG, response.toString());
hidePDialog();
// Parsing json
for (int i = 0; i < response.length(); i++) {
try {
JSONObject obj = response.getJSONObject(i);
Movie movie = new Movie();
movie.setDate(obj.getString("date"));
movie.setId(obj.getString("id"));
movieList.add(movie);
int currentPosition = listView.getFirstVisiblePosition();
adapter = new CustomListAdapter(getActivity(), movieList);
adapter.notifyDataSetChanged();
listView.setAdapter(adapter);
listView.setSelectionFromTop(currentPosition + 1, 0);
} catch (JSONException e) {
e.printStackTrace();
}
}
}
},new Response.ErrorListener() {
@Override
public void onErrorResponse(VolleyError error) {
VolleyLog.d(TAG, "Error: " + error.getMessage());
new AlertDialog.Builder(getActivity())
.setTitle("No Connectivity ")
.setMessage("Please check your internet connectivity!")
.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// continue with delete
}
})
//.setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {
//public void onClick(DialogInterface dialog, int which) {
// do nothing
//}
//})
.setIcon(android.R.drawable.ic_dialog_alert)
.show();
hidePDialog();
}
});
AppController.getInstance().addToRequestQueue(movieReq);
listView.setAdapter(adapter);
}
private View getActionBar() {
// TODO Auto-generated method stub
return null;
}
@Override
public void onDestroy() {
super.onDestroy();
hidePDialog();
}
private void hidePDialog() {
if (pDialog != null) {
pDialog.dismiss();
pDialog = null;
}
}
}
