Solución:
Clase de actividad con recylcerview en archivo de diseño xml
public class WallpaperActivity extends AppCompatActivity implements OnTaskCompleted
private static final String TAG = "WallpaperActivity";
private Toolbar toolbar;
private RecyclerView mRecyclerView;
private WallPaperDataAdapter mAdapter;
private LinearLayoutManager mLayoutManager;
// to keep track which pages loaded and next pages to load
public static int pageNumber;
private List wallpaperImagesList;
protected Handler handler;
@Override
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.wallpaper_main);
toolbar = (Toolbar) findViewById(R.id.toolbar);
mRecyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
pageNumber = 1;
wallpaperImagesList = new ArrayList();
handler = new Handler();
if (toolbar != null)
setSupportActionBar(toolbar);
getSupportActionBar().setTitle("WallPapers");
// use this setting to improve performance if you know that changes
// in content do not change the layout size of the RecyclerView
mRecyclerView.setHasFixedSize(true);
mLayoutManager = new LinearLayoutManager(this);
// use a linear layout manager
mRecyclerView.setLayoutManager(mLayoutManager);
// create an Object for Adapter
mAdapter = new WallPaperDataAdapter(wallpaperImagesList, mRecyclerView);
// set the adapter object to the Recyclerview
mRecyclerView.setAdapter(mAdapter);
getWebServiceData();
mAdapter.setOnLoadMoreListener(new OnLoadMoreListener()
@Override
public void onLoadMore()
//add null , so the adapter will check view_type and show progress bar at bottom
wallpaperImagesList.add(null);
mAdapter.notifyItemInserted(wallpaperImagesList.size() - 1);
++pageNumber;
getWebServiceData();
);
public void getWebServiceData()
BackGroundTask backGroundTask = new BackGroundTask(this, this, pageNumber);
backGroundTask.execute();
@Override
public void onTaskCompleted(String response)
parsejosnData(response);
public void parsejosnData(String response)
try
JSONObject jsonObject = new JSONObject(response);
// String json = jsonObject.toString();
JSONArray jsonArray = jsonObject.getJSONArray("wallpapers");
if (jsonArray != null)
// looping through All albums
if (pageNumber > 1)
wallpaperImagesList.remove(wallpaperImagesList.size() - 1);
mAdapter.notifyItemRemoved(wallpaperImagesList.size());
for (int i = 0; i < jsonArray.length(); i++)
JSONObject c = jsonArray.getJSONObject(i);
// Storing each json item values in variable
String id = c.getString("id");
String orig_url = c.getString("orig_url");
String thumb_url = c.getString("thumb_url");
String downloads = c.getString("downloads");
String fav = c.getString("fav");
// Creating object for each product
WallPaper singleWall = new WallPaper(id, orig_url, thumb_url, downloads, fav);
// adding HashList to ArrayList
wallpaperImagesList.add(singleWall);
handler.post(new Runnable()
@Override
public void run()
mAdapter.notifyItemInserted(wallpaperImagesList.size());
);
mAdapter.setLoaded();
else
Log.d("Wallpapers: ", "null");
catch (JSONException e)
e.printStackTrace();
Clase de adaptador
public class WallPaperDataAdapter extends RecyclerView.Adapter
private final int VIEW_ITEM = 1;
private final int VIEW_PROG = 0;
private List imagesList;
// The minimum amount of items to have below your current scroll position
// before loading more.
private int visibleThreshold = 5;
private int lastVisibleItem, totalItemCount;
private boolean loading;
private OnLoadMoreListener onLoadMoreListener;
public WallPaperDataAdapter(List imagesList1, RecyclerView recyclerView)
imagesList = imagesList1;
if (recyclerView.getLayoutManager() instanceof LinearLayoutManager)
final LinearLayoutManager linearLayoutManager = (LinearLayoutManager) recyclerView
.getLayoutManager();
recyclerView
.addOnScrollListener(new RecyclerView.OnScrollListener()
@Override
public void onScrolled(RecyclerView recyclerView,
int dx, int dy)
super.onScrolled(recyclerView, dx, dy);
totalItemCount = linearLayoutManager.getItemCount();
lastVisibleItem = linearLayoutManager
.findLastVisibleItemPosition();
if (!loading
&& totalItemCount <= (lastVisibleItem + visibleThreshold))
// End has been reached
// Do something
if (onLoadMoreListener != null)
onLoadMoreListener.onLoadMore();
loading = true;
);
@Override
public int getItemViewType(int position)
return imagesList.get(position) != null ? VIEW_ITEM : VIEW_PROG;
@Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType)
RecyclerView.ViewHolder vh;
if (viewType == VIEW_ITEM)
View v = LayoutInflater.from(parent.getContext()).inflate(
R.layout.wallpaper_row, parent, false);
vh = new WallPaperViewHolder(v);
else
View v = LayoutInflater.from(parent.getContext()).inflate(
R.layout.progress_item, parent, false);
vh = new ProgressViewHolder(v);
return vh;
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position)
if (holder instanceof WallPaperViewHolder)
WallPaper singleWallPaper = (WallPaper) imagesList.get(position);
Glide.with(((WallPaperViewHolder) holder).thumbIcon.getContext())
.load(singleWallPaper.getThumbUrl())
.centerCrop()
.placeholder(R.drawable.bg)
.crossFade()
.into(((WallPaperViewHolder) holder).thumbIcon);
else
((ProgressViewHolder) holder).progressBar.setIndeterminate(true);
public void setLoaded()
loading = false;
@Override
public int getItemCount()
return imagesList.size();
public void setOnLoadMoreListener(OnLoadMoreListener onLoadMoreListener)
this.onLoadMoreListener = onLoadMoreListener;
//
public static class WallPaperViewHolder extends RecyclerView.ViewHolder
public ImageView thumbIcon;
public WallPaperViewHolder(View v)
super(v);
thumbIcon = (ImageView) v.findViewById(R.id.thumbIcon);
public static class ProgressViewHolder extends RecyclerView.ViewHolder
public ProgressBar progressBar;
public ProgressViewHolder(View v)
super(v);
progressBar = (ProgressBar) v.findViewById(R.id.progressBar1);
wallpaper_row.xml
progress_item.xml
BackGroundTask.java independiente
public class BackGroundTask extends AsyncTask
private ProgressDialog pDialog;
public OnTaskCompleted listener = null;//Call back interface
Context context;
int pageNumber;
public BackGroundTask(Context context1, OnTaskCompleted listener1, int pageNumber)
context = context1;
listener = listener1; //Assigning call back interface through constructor
this.pageNumber = pageNumber;
@Override
protected void onPreExecute()
super.onPreExecute();
@Override
protected String doInBackground(Object... params)
//My Background tasks are written here
synchronized (this)
String url = Const.URL_WALLPAPERS_HD + pageNumber;
String jsonStr = ServiceHandler.makeServiceCall(url, ServiceHandler.GET);
Log.i("Url: ", "> " + url);
Log.i("Response: ", "> " + jsonStr);
return jsonStr;
@Override
protected void onPostExecute(String result)
super.onPostExecute(result);
listener.onTaskCompleted(result);
ServiceHanlder.java
public class ServiceHandler
static String response = null;
public final static int GET = 1;
public final static int POST = 2;
public ServiceHandler()
/**
* Making service call
*
* @url - url to make request
* @method - http request method
*/
public static String makeServiceCall(String url, int method)
return makeServiceCall(url, method, null);
/**
* Making service call
*
* @url - url to make request
* @method - http request method
* @params - http request params
*/
public static String makeServiceCall(String url, int method,
List params)
try
// http client
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpEntity httpEntity = null;
HttpResponse httpResponse = null;
// Checking http request method type
if (method == POST)
HttpPost httpPost = new HttpPost(url);
// adding post params
if (params != null)
httpPost.setEntity(new UrlEncodedFormEntity(params));
Log.e("Selltis Request URL", url);
httpResponse = httpClient.execute(httpPost);
else if (method == GET)
// appending params to url
if (params != null)
String paramString = URLEncodedUtils
.format(params, "utf-8");
url += paramString;
Log.i("Request URL", url);
HttpGet httpGet = new HttpGet(url);
httpResponse = httpClient.execute(httpGet);
httpEntity = httpResponse.getEntity();
response = EntityUtils.toString(httpEntity);
catch (UnsupportedEncodingException e)
e.printStackTrace();
return "Fail";
catch (ClientProtocolException e)
e.printStackTrace();
return "Fail";
catch (IOException e)
e.printStackTrace();
return "Fail";
return response;
Interfaz para cargar más
public interface OnLoadMoreListener
void onLoadMore();
Interfaz para conocer los datos del servicio web cargados desde asynctask
public interface OnTaskCompleted
void onTaskCompleted(String response);
Por favor, avíseme si esto funciona o si tiene algún problema. Es mejor usar las bibliotecas Volley u okHttp para redes.
Para ImageLoading utilicé Glide Library.
Así es como detecto si RecyclerView debería actualizar por OnScrollListener, mira esto:
recyclerView.setOnScrollListener(new RecyclerView.OnScrollListener()
int ydy = 0;
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState)
super.onScrollStateChanged(recyclerView, newState);
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy)
super.onScrolled(recyclerView, dx, dy);
int offset = dy - ydy;
ydy = dy;
boolean shouldRefresh = (linearLayoutManager.findFirstCompletelyVisibleItemPosition() == 0)
&& (recyclerView.getScrollState() == RecyclerView.SCROLL_STATE_DRAGGING) && offset > 30;
if (shouldRefresh)
//swipeRefreshLayout.setRefreshing(true);
//Refresh to load data here.
return;
boolean shouldPullUpRefresh = linearLayoutManager.findLastCompletelyVisibleItemPosition() == linearLayoutManager.getChildCount() - 1
&& recyclerView.getScrollState() == RecyclerView.SCROLL_STATE_DRAGGING && offset < -30;
if (shouldPullUpRefresh)
//swipeRefreshLayout.setRefreshing(true);
//refresh to load data here.
return;
swipeRefreshLayout.setRefreshing(false);
);
Espero que se sienta inspirado. Buena suerte ~
Otro ejemplo. Configure su barra de progreso en la parte inferior y cambie su visibilidad de acuerdo con el desplazamiento / carga y sus registros. Nota: debe llamar a notifyDataSetChanged (); método para agregar / actualizar datos al adaptador
recyclerView.setOnScrollListener(new RecyclerView.OnScrollListener()
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy)
super.onScrolled(recyclerView, dx, dy);
int total = linearLayoutManager.getItemCount();
int firstVisibleItemCount = linearLayoutManager.findFirstVisibleItemPosition();
int lastVisibleItemCount = linearLayoutManager.findLastVisibleItemPosition();
//to avoid multiple calls to loadMore() method
//maintain a boolean value (isLoading). if loadMore() task started set to true and completes set to false
if (!isLoading)
if (total > 0)
if ((total - 1) == lastVisibleItemCount)
loadMore();//your HTTP stuff goes in this method
loadingProgress.setVisibility(View.VISIBLE);
else
loadingProgress.setVisibility(View.GONE);
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState)
super.onScrollStateChanged(recyclerView, newState);
);
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