CODEWITHSUNDEEP
javaandroidandroid-recyclerview
Jungle
Jungle

Reputation: 247

How to add items to recyclerView in android

In my application i want add some list from server into my recyclerView.
My list items size has 10, but i want add last 7 item to this RecyclerView. I don't want add first 3 item to this recyclerView

I write below code : 

        Call<ListCartResponse> call = apIs.getListCardResponse(jwtToken);
        call.enqueue(new Callback<ListCartResponse>() {
            @Override
            public void onResponse(Call<ListCartResponse> call, Response<ListCartResponse> response) {
                if (response.body() != null) {

                                if (response.body().getRes().getCarts() != null) {
                                    if (response.body().getRes().getCarts().size() > 0) {
                                        model.clear();
                                        model.addAll(response.body().getRes().getCarts());
                                        adapter.notifyDataSetChanged();

            }

            @Override
            public void onFailure(Call<ListCartResponse> call, Throwable t) {
            }
        });

But in my above codes add all of 10 items to recyclerView.
I want add just last 7 items and remove 3 first items.

My recyclerView items now : 1 2 3 4 5 6 7 8 9 10 But i want : 4 5 6 7 8 9 10

How can i it?

Upvotes: 1

Views: 409

Answers (3)

Jeel Vankhede
Jeel Vankhede

Reputation: 12118

You can use subList() method of List interface:

For your example :

model.clear();
model.addAll(response.body().getRes().getCarts().subList(3, 9));

Note: Beware that if your list from server is less than 10 items and you still need last 7 items, then you should pass index dynamically instead (Above solution will crash for that instance)

Reference

subList(int fromIndex, int toIndex)

Returns a view of the portion of this list between the specified fromIndex, inclusive, and toIndex, exclusive. (If fromIndex and toIndex are equal, the returned list is empty.) The returned list is backed by this list, so non-structural changes in the returned list are reflected in this list, and vice-versa. The returned list supports all of the optional list operations supported by this list.

This method eliminates the need for explicit range operations (of the sort that commonly exist for arrays). Any operation that expects a list can be used as a range operation by passing a subList view instead of a whole list. For example, the following idiom removes a range of elements from a list:

list.subList(from, to).clear();

Similar idioms may be constructed for indexOf and lastIndexOf, and all of the algorithms in the Collections class can be applied to a subList.

The semantics of the list returned by this method become undefined if the backing list (i.e., this list) is structurally modified in any way other than via the returned list. (Structural modifications are those that change the size of this list, or otherwise perturb it in such a fashion that iterations in progress may yield incorrect results.)

Parameters:

fromIndex - low endpoint (inclusive) of the subList

toIndex - high endpoint (exclusive) of the subList

Returns:

a view of the specified range within this list

Upvotes: 2

aminography
aminography

Reputation: 22832

I think it is because of the model in response part does not refer to model in your adapter class. Add this to your SupportListAdapter class, the use it when response has received:

public void replaceModelList(List<Res> newModel){
     model.clear();
     model.addAll(newModel);
     notifyDataSetChanged();
}

When result has received:

if (response.body().getRes().getCarts() != null) {
     if (response.body().getRes().getCarts().size() > 0)
          adapter.replaceModelList(response.body().getRes().getCarts());

Upvotes: 0

rahul kumar
rahul kumar

Reputation: 53

Add this:

   if (response.body().getRes().getCarts().size() > 0) 
    {
      model.clear();
      model.addAll(response.body().getRes().getCarts());
      model.remove(0);
      model.remove(0);
      model.remove(0);
      adapter.notifyDataSetChanged();        
                }

Upvotes: 1

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