Conditions:
I have an Activity and I'm creating PagerAdapter extends FragmentPagerAdapter with one Fragment class. TabLayout includes 10 tabs. I have TabLayout.addOnTabSelectedListener and there in onTabSelected() I am updating some custom variable in app's SharedPreferences which depends on current tab name and tab index. Tab's names are not static - there are loading from server too.
My task:
With this value I should make a retrofit2 Call to my server and load values in adapter with recyclerview for my Fragment.
My problem:
I am loading the same data for the different tabs, which should contatin different data! I am understand that this happens because in all cases I have the same SharedPreferences variable's value so I am making retrofit Call with same conditions.
setOffscreenPageLimit() can't be setted to 0 - default is 1 according documentation:
https://developer.android.com/reference/kotlin/androidx/viewpager/widget/ViewPager#setoffscreenpagelimit;
setUserVisibleHint() on SO I've found this like some variant for solving my problem, but it can't be overrided because is deprecated now.
Solution:
I think I should save previous and next tab name in some way and then I can make different parallel retrofit Calls with different conditions. When tab selected I can get current, previous and next tab name. But how, where and when I should make two more retrofit calls?
UPD 08.02.2022: Still thinking about this problem.
Code:
SomeActivity.java
public class SomeActivity extends BaseActivity {
private String TAG="SomeActivity";
private Context context;
private TabLayout tabs;
private ViewPager viewpager;
private ProgressBar PBLoading;
private PagerAdapter_SomePAdapter adapter;
List<String> names = new ArrayList<>();
private String[] tabTitles;
public String previousTabName;
public String nextTabName;
public int counterForPreviousTabName;
public int counterForNextTabName;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_layout);
context = getApplicationContext();
String categories = AppPreferences.getCategories(context);
tabTitles = categories.split(";");
tabs = findViewById(R.id.tabs);
viewpager = findViewById(R.id.viewpager);
PBLoading = findViewById(R.id.PBLoading);
tabs.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabUnselected(TabLayout.Tab tab) {
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
}
@Override
public void onTabSelected(TabLayout.Tab tab) {
Log.d(TAG, "onTabSelected");
AppPreferences.setCurrentValueForRetrofit(getApplicationContext(), tab.getPosition());
counterForPreviousTabName = tmpTab.getPosition() - 1;
counterForNextTabName = tmpTab.getPosition() + 1;
//here I can get tab names.
}
});
adapter = new PagerAdapter_SomePAdapter(getSupportFragmentManager(), SomeActivity.this);
viewpager.setAdapter(adapter);
adapter.updateTitleData(tabTitles);
tabs.setupWithViewPager(viewpager);
adapter.notifyDataSetChanged();
}
}
PagerAdapter_SomePAdapter.java:
public class PagerAdapter_SomePAdapter extends FragmentPagerAdapter {
int PAGE_COUNT = 2;
private String[] tabTitles = new String[] { "", ""};
private Context mContext;
Fragment_fragment fragment_fragment;
String TAG = "PagerAdapter_SomePAdapter";
public PagerAdapter_SomePAdapter(FragmentManager fm, Context context) {
super(fm, BEHAVIOR_RESUME_ONLY_CURRENT_FRAGMENT);
mContext = context;
fragment_fragment = new Fragment_fragment();
}
@Override public int getCount() {
return PAGE_COUNT;
}
@Override public Fragment getItem(int position) {
return fragment_fragment.newInstance(position + 1, tabTitles[position]);
}
@Override public CharSequence getPageTitle(int position) {
return tabTitles[position];
}
public void updateTitleData(String[] tabTitlesNew) {
tabTitles = tabTitlesNew;
PAGE_COUNT = tabTitlesNew.length;
notifyDataSetChanged();
}
}
Fragment_fragment.java:
public class Fragment_fragment extends Fragment {
private String TAG = "Fragment_fragment";
private static final String ARG_PAGE = "ARG_PAGE";
private int mPage;
private View rootView;
private RecyclerView RV;
private Adapter_Items adapter;
public static Fragment_fragment newInstance(int page, String tabName) {
Bundle args = new Bundle();
args.putInt(ARG_PAGE, page);
Fragment_fragment fragment = new Fragment_fragment();
fragment.setArguments(args);
return fragment;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mPage = getArguments().getInt(ARG_PAGE);
}
}
@Override
public void onAttach(@NonNull Context context) {
super.onAttach(context);
mContext=context;
}
@SuppressLint("ClickableViewAccessibility")
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.content_list, container, false);
RV = rootView.findViewById(R.id.recycler_view);
new loadDataAS().execute();
return rootView;
}
private void loadData(){
//retrofit call code;
}
class loadDataAS extends AsyncTask<Void, Void, Void> {
final ProgressDialog progress = new ProgressDialog(mContext);
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected Void doInBackground(Void... arg0) {
loadData();
return null;
}
@Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
adapter = new Adapter_Items(arguments, arguments2, arguments3);
RV.setAdapter(adapter);
adapter.notifyDataSetChanged();
}
}
}
Adapter_Items:
public class Adapter_Items extends RecyclerView.Adapter<Adapter_Items.ViewHolder>{
private LayoutInflater mInflater;
private Context mContext;
private static String TAG = "Adapter_Items";
public Adapter_Items(List<Integer>arguments, List<String>arguments2, List<String>arguments3){
//initializing arguments
}
// inflates the row layout from xml when needed
@NotNull
@Override
public ViewHolder onCreateViewHolder(@NotNull ViewGroup parent, int viewType) {
View view = mInflater.inflate(R.layout.recycle_item, parent, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
//setting view's information
}
@Override
public int getItemCount() {
return arguments.size();
}
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
ViewHolder(View itemView) {
super(itemView);
itemView.setOnClickListener(this);
}
@Override
public void onClick(View view) {
}
}
}
