TubeLab-App-Android/app/src/main/java/app/fedilab/fedilabtube/fragment/DisplayAccountsFragment.java

package app.fedilab.fedilabtube.fragment;
/* Copyright 2020 Thomas Schneider
 *
 * This file is a part of TubeLab
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation; either version 3 of the
 * License, or (at your option) any later version.
 *
 * TubeLab is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even
 * the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 * Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with TubeLab; if not,
 * see <http://www.gnu.org/licenses>. */

import android.content.Context;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RelativeLayout;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.DividerItemDecoration;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;

import java.util.ArrayList;
import java.util.List;

import app.fedilab.fedilabtube.R;
import app.fedilab.fedilabtube.asynctasks.RetrieveAccountsAsyncTask;
import app.fedilab.fedilabtube.client.APIResponse;
import app.fedilab.fedilabtube.client.entities.Account;
import app.fedilab.fedilabtube.drawer.AccountsListAdapter;
import app.fedilab.fedilabtube.interfaces.OnRetrieveAccountsInterface;
import es.dmoral.toasty.Toasty;


public class DisplayAccountsFragment extends Fragment implements OnRetrieveAccountsInterface {

    private boolean flag_loading;
    private Context context;
    private AsyncTask<Void, Void, Void> asyncTask;
    private AccountsListAdapter accountsListAdapter;
    private String max_id;
    private List<Account> accounts;
    private RelativeLayout mainLoader, nextElementLoader, textviewNoAction;
    private boolean firstLoad;
    private SwipeRefreshLayout swipeRefreshLayout;
    private String targetedId, name;
    private boolean swiped;
    private RecyclerView lv_accounts;
    private View rootView;

    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        rootView = inflater.inflate(R.layout.fragment_accounts, container, false);

        context = getContext();
        Bundle bundle = this.getArguments();
        accounts = new ArrayList<>();
        if (bundle != null) {
            if (bundle.containsKey("tag"))
                targetedId = bundle.getString("tag", null);
            else
                targetedId = bundle.getString("targetedid", null);
            name = bundle.getString("name", null);
        }
        max_id = null;
        firstLoad = true;
        flag_loading = true;
        swiped = false;

        swipeRefreshLayout = rootView.findViewById(R.id.swipeContainer);


        lv_accounts = rootView.findViewById(R.id.lv_accounts);
        lv_accounts.addItemDecoration(new DividerItemDecoration(context, DividerItemDecoration.VERTICAL));
        mainLoader = rootView.findViewById(R.id.loader);
        nextElementLoader = rootView.findViewById(R.id.loading_next_accounts);
        textviewNoAction = rootView.findViewById(R.id.no_action);
        mainLoader.setVisibility(View.VISIBLE);
        nextElementLoader.setVisibility(View.GONE);
        accountsListAdapter = new AccountsListAdapter(targetedId, this.accounts);
        lv_accounts.setAdapter(accountsListAdapter);

        final LinearLayoutManager mLayoutManager;
        mLayoutManager = new LinearLayoutManager(context);
        lv_accounts.setLayoutManager(mLayoutManager);
        lv_accounts.addOnScrollListener(new RecyclerView.OnScrollListener() {
            public void onScrolled(@NonNull RecyclerView recyclerView, int dx, int dy) {
                if (dy > 0) {
                    int visibleItemCount = mLayoutManager.getChildCount();
                    int totalItemCount = mLayoutManager.getItemCount();
                    int firstVisibleItem = mLayoutManager.findFirstVisibleItemPosition();
                    if (firstVisibleItem + visibleItemCount == totalItemCount) {
                        if (!flag_loading) {
                            flag_loading = true;
                            asyncTask = new RetrieveAccountsAsyncTask(context, name, DisplayAccountsFragment.this).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
                            nextElementLoader.setVisibility(View.VISIBLE);
                        }
                    } else {
                        nextElementLoader.setVisibility(View.GONE);
                    }
                }
            }
        });
        swipeRefreshLayout.setOnRefreshListener(this::pullToRefresh);

        asyncTask = new RetrieveAccountsAsyncTask(context, name, DisplayAccountsFragment.this).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
        return rootView;
    }

    @Override
    public void onDestroyView() {
        super.onDestroyView();
        rootView = null;
    }

    @Override
    public void onCreate(Bundle saveInstance) {
        super.onCreate(saveInstance);
    }


    @Override
    public void onAttach(@NonNull Context context) {
        super.onAttach(context);
        this.context = context;
    }

    public void onDestroy() {
        super.onDestroy();
        if (asyncTask != null && asyncTask.getStatus() == AsyncTask.Status.RUNNING)
            asyncTask.cancel(true);
    }

    public void scrollToTop() {
        if (lv_accounts != null)
            lv_accounts.setAdapter(accountsListAdapter);
    }

    @Override
    public void onRetrieveAccounts(APIResponse apiResponse) {
        mainLoader.setVisibility(View.GONE);
        nextElementLoader.setVisibility(View.GONE);
        if (apiResponse.getError() != null) {
            Toasty.error(context, apiResponse.getError().getError(), Toast.LENGTH_LONG).show();
            swipeRefreshLayout.setRefreshing(false);
            swiped = false;
            flag_loading = false;
            return;
        }
        flag_loading = (apiResponse.getMax_id() == null);

        List<Account> accounts = apiResponse.getAccounts();
        if (!swiped && firstLoad && (accounts == null || accounts.size() == 0))
            textviewNoAction.setVisibility(View.VISIBLE);
        else
            textviewNoAction.setVisibility(View.GONE);

        max_id = apiResponse.getMax_id();

        if (swiped) {
            accountsListAdapter = new AccountsListAdapter(targetedId, this.accounts);
            lv_accounts.setAdapter(accountsListAdapter);
            swiped = false;
        }
        if (accounts != null && accounts.size() > 0) {
            int currentPosition = this.accounts.size();
            this.accounts.addAll(accounts);
            accountsListAdapter.notifyItemRangeChanged(currentPosition, accounts.size());
        }
        swipeRefreshLayout.setRefreshing(false);
        firstLoad = false;
    }

    public void pullToRefresh() {
        max_id = null;
        accounts = new ArrayList<>();
        firstLoad = true;
        flag_loading = true;
        swiped = true;
        swipeRefreshLayout.setRefreshing(true);
        asyncTask = new RetrieveAccountsAsyncTask(context, name, DisplayAccountsFragment.this).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
    }

}