EndlessScrollListener

EndlessScrollListener.java

import android.widget.AbsListView;

/**
 * Classe controla a atualização da Lista conforme a mesma chega ao fim
 */
public class EndlessScrollListener implements AbsListView.OnScrollListener{

    //    private int visibleThreshold = ;
    private int currentPage = -1; // incia em 0
    private int currentTotalItens = 0;
    //    private int firstItemPageIndex = 0;
    private boolean loading = false;

    private boolean nextPage = true;



    private OnLoadMoreListener onLoadMoreListener;

    public EndlessScrollListener(final OnLoadMoreListener onLoadMoreListener)
    {
        this.onLoadMoreListener = onLoadMoreListener;
    }

    @Override
    public void onScrollStateChanged(AbsListView view, int scrollState)
    {

    }

    @Override
    public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount)
    {

        if(!nextPage)
            return;

        if(totalItemCount < currentTotalItens)
        {
            this.currentPage = 0;
            this.currentTotalItens = totalItemCount;
            if( totalItemCount == 0 ){ this.loading = true; }
        }

        if( loading && (totalItemCount > currentTotalItens) )
        {
            loading = false;
            currentTotalItens = totalItemCount;
            currentPage++;
        }

        if (!loading && (totalItemCount - visibleItemCount) <= (firstVisibleItem + 3))
        {
            onLoadMoreListener.onLoadMore(currentPage+1, totalItemCount);
            loading = true;
        }
    }

    public void setNextPage(boolean nextPage)
    {
        this.nextPage = nextPage;
    }


    public interface OnLoadMoreListener {
        void onLoadMore(int page, int totalItemsCount);
    }
}