fedilab-Android-App/app/src/main/java/fr/gouv/etalab/mastodon/fragments/DisplayMediaFragment.java

package fr.gouv.etalab.mastodon.fragments;
/* Copyright 2018 Thomas Schneider
 *
 * This file is a part of Mastalab
 *
 * 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.
 *
 * Mastalab 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 Mastalab; if not,
 * see <http://www.gnu.org/licenses>. */

import android.content.Context;
import android.content.SharedPreferences;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.support.annotation.NonNull;
import android.support.v4.app.Fragment;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.RelativeLayout;
import android.widget.Toast;
import java.util.ArrayList;
import java.util.List;
import fr.gouv.etalab.mastodon.R;
import fr.gouv.etalab.mastodon.asynctasks.RetrieveFeedsAsyncTask;
import fr.gouv.etalab.mastodon.client.APIResponse;
import fr.gouv.etalab.mastodon.client.Entities.Attachment;
import fr.gouv.etalab.mastodon.client.Entities.Status;
import fr.gouv.etalab.mastodon.drawers.ImageAdapter;
import fr.gouv.etalab.mastodon.helper.Helper;
import fr.gouv.etalab.mastodon.interfaces.OnRetrieveFeedsInterface;



/**
 * Created by Thomas on 05/09/2018.
 * Fragment to display media related to status
 */
public class DisplayMediaFragment extends Fragment implements OnRetrieveFeedsInterface {


    private boolean flag_loading;
    private Context context;
    private AsyncTask<Void, Void, Void> asyncTask;
    private String max_id;
    private RelativeLayout mainLoader, nextElementLoader, textviewNoAction;
    private boolean firstLoad;
    private String targetedId;
    private boolean showMediaOnly, showPinned, showReply;
    boolean firstTootsLoaded;
    private SharedPreferences sharedpreferences;
    private ArrayList<Attachment> attachments;
    private ImageAdapter gridAdaper;

    public DisplayMediaFragment(){
    }

    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_status_media, container, false);

        context = getContext();
        Bundle bundle = this.getArguments();
        showMediaOnly = true;
        //Will allow to load first toots if bookmark != null
        firstTootsLoaded = true;
        showPinned = false;
        max_id = null;
        flag_loading = true;
        showReply = false;
        firstLoad = true;
        assert context != null;
        sharedpreferences = context.getSharedPreferences(Helper.APP_PREFS, Context.MODE_PRIVATE);
        mainLoader =  rootView.findViewById(R.id.loader);
        nextElementLoader = rootView.findViewById(R.id.loading_next_status);
        textviewNoAction =  rootView.findViewById(R.id.no_action);
        mainLoader.setVisibility(View.VISIBLE);
        nextElementLoader.setVisibility(View.GONE);
        if (bundle != null) {
            targetedId = bundle.getString("targetedId", null);
        }

        attachments = new ArrayList<>();
        gridAdaper = new ImageAdapter(context, attachments);
        RecyclerView gridview = rootView.findViewById(R.id.gridview_media);

        gridview.setAdapter(gridAdaper);

        GridLayoutManager gvLayout = new GridLayoutManager(context, 3);
        gridview.setLayoutManager(gvLayout);

        gridview.addOnScrollListener(new RecyclerView.OnScrollListener() {
            public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                int firstVisibleItem = gvLayout.findFirstVisibleItemPosition();
                if (dy > 0) {
                    int visibleItemCount = gvLayout.getChildCount();
                    int totalItemCount = gvLayout.getItemCount();


                    if (firstVisibleItem + visibleItemCount == totalItemCount && context != null) {
                        if (!flag_loading) {
                            flag_loading = true;
                            asyncTask = new RetrieveFeedsAsyncTask(context, RetrieveFeedsAsyncTask.Type.USER, targetedId, max_id, showMediaOnly, showPinned, showReply, DisplayMediaFragment.this).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
                            nextElementLoader.setVisibility(View.VISIBLE);
                        }
                    } else {
                        nextElementLoader.setVisibility(View.GONE);
                    }
                }
            }
        });


        if( context != null) {
            asyncTask = new RetrieveFeedsAsyncTask(context, RetrieveFeedsAsyncTask.Type.USER, targetedId, max_id, showMediaOnly, showPinned, showReply,DisplayMediaFragment.this).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
        }else {
            new Handler(Looper.getMainLooper()).postDelayed(new Runnable() {
                @Override
                public void run() {
                    if( context != null){
                        asyncTask = new RetrieveFeedsAsyncTask(context, RetrieveFeedsAsyncTask.Type.USER, targetedId, max_id, showMediaOnly, showPinned, showReply,DisplayMediaFragment.this).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
                    }
                }
            }, 500);
        }

        return rootView;
    }


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



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

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



    @Override
    public void onRetrieveFeeds(APIResponse apiResponse) {
        mainLoader.setVisibility(View.GONE);
        nextElementLoader.setVisibility(View.GONE);
        //Discards 404 - error which can often happen due to toots which have been deleted
        if( apiResponse.getError() != null && apiResponse.getError().getStatusCode() != 404 ){
            Toast.makeText(context, apiResponse.getError().getError(),Toast.LENGTH_LONG).show();
            flag_loading = false;
            return;
        }
        List<Status> statuses = apiResponse.getStatuses();
        max_id = apiResponse.getMax_id();
        if( attachments == null)
            attachments = new ArrayList<>();
        int previousPosition = this.attachments.size();
        flag_loading = (max_id == null );
        if( firstLoad && (statuses == null || statuses.size() == 0))
            textviewNoAction.setVisibility(View.VISIBLE);
        else
            textviewNoAction.setVisibility(View.GONE);
        if( statuses != null && statuses.size() > 0) {
            for(Status status: statuses){
                if( status.getMedia_attachments() != null && status.getMedia_attachments().size() > 0) {
                    attachments.addAll(status.getMedia_attachments());
                    gridAdaper.notifyItemRangeInserted(previousPosition, attachments.size());
                }
            }
        }
        firstLoad = false;
    }


}