Audinaut-subsonic-app-android/app/src/main/java/net/nullsum/audinaut/fragments/SelectRecyclerFragment.java

/*
  This file is part of Subsonic.
    Subsonic 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.
    Subsonic 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 Subsonic. If not, see <http://www.gnu.org/licenses/>.
    Copyright 2015 (C) Scott Jackson
*/

package net.nullsum.audinaut.fragments;

import android.os.Bundle;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.View;
import android.view.ViewGroup;

import net.nullsum.audinaut.R;
import net.nullsum.audinaut.adapter.SectionAdapter;
import net.nullsum.audinaut.service.MusicService;
import net.nullsum.audinaut.service.MusicServiceFactory;
import net.nullsum.audinaut.util.Constants;
import net.nullsum.audinaut.util.ProgressListener;
import net.nullsum.audinaut.util.TabBackgroundTask;
import net.nullsum.audinaut.view.FastScroller;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

public abstract class SelectRecyclerFragment<T> extends SubsonicFragment implements SectionAdapter.OnItemClickedListener<T> {
    private static final String TAG = SelectRecyclerFragment.class.getSimpleName();
    RecyclerView recyclerView;
    SectionAdapter<T> adapter;
    List<T> objects;
    boolean serialize = true;
    boolean largeAlbums = false;
    boolean pullToRefresh = true;
    boolean backgroundUpdate = true;
    private FastScroller fastScroller;
    private UpdateTask currentTask;

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

        if (bundle != null && serialize) {
            objects = (List<T>) bundle.getSerializable(Constants.FRAGMENT_LIST);
        }
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        if (serialize) {
            outState.putSerializable(Constants.FRAGMENT_LIST, (Serializable) objects);
        }
    }

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

        refreshLayout = rootView.findViewById(R.id.refresh_layout);
        refreshLayout.setOnRefreshListener(this);

        recyclerView = rootView.findViewById(R.id.fragment_recycler);
        fastScroller = rootView.findViewById(R.id.fragment_fast_scroller);
        setupLayoutManager();

        if (pullToRefresh) {
            setupScrollList(recyclerView);
        } else {
            refreshLayout.setEnabled(false);
        }

        if (objects == null) {
            refresh(false);
        } else {
            recyclerView.setAdapter(adapter = getAdapter(objects));
        }

        return rootView;
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater menuInflater) {
        if (!primaryFragment) {
            return;
        }

        menuInflater.inflate(getOptionsMenu(), menu);
        onFinishSetupOptionsMenu(menu);
    }

    @Override
    public void setIsOnlyVisible(boolean isOnlyVisible) {
        boolean update = this.isOnlyVisible != isOnlyVisible;
        super.setIsOnlyVisible(isOnlyVisible);
        if (update && adapter != null) {
            RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
            if (layoutManager instanceof GridLayoutManager) {
                ((GridLayoutManager) layoutManager).setSpanCount(getRecyclerColumnCount());
            }
        }
    }

    @Override
    void refresh(final boolean refresh) {
        int titleRes = getTitleResource();
        if (titleRes != 0) {
            setTitle(getTitleResource());
        }
        if (backgroundUpdate) {
            recyclerView.setVisibility(View.GONE);
        }

        // Cancel current running task before starting another one
        if (currentTask != null) {
            currentTask.cancel();
        }

        currentTask = new UpdateTask(this, refresh);

        if (backgroundUpdate) {
            currentTask.execute();
        } else {
            objects = new ArrayList<>();

            try {
                objects = getObjects(null, refresh, null);
            } catch (Exception x) {
                Log.e(TAG, "Failed to load", x);
            }

            currentTask.done(objects);
        }
    }

    public SectionAdapter getCurrentAdapter() {
        return adapter;
    }

    private void setupLayoutManager() {
        setupLayoutManager(recyclerView, largeAlbums);
    }

    protected abstract int getOptionsMenu();

    protected abstract SectionAdapter<T> getAdapter(List<T> objs);

    protected abstract List<T> getObjects(MusicService musicService, boolean refresh, ProgressListener listener) throws Exception;

    protected abstract int getTitleResource();

    void onFinishRefresh() {

    }

    private class UpdateTask extends TabBackgroundTask<List<T>> {
        private final boolean refresh;

        public UpdateTask(SubsonicFragment fragment, boolean refresh) {
            super(fragment);
            this.refresh = refresh;
        }

        @Override
        public List<T> doInBackground() throws Exception {
            MusicService musicService = MusicServiceFactory.getMusicService(context);

            objects = new ArrayList<>();

            try {
                objects = getObjects(musicService, refresh, this);
            } catch (Exception x) {
                Log.e(TAG, "Failed to load", x);
            }

            return objects;
        }

        @Override
        public void done(List<T> result) {
            if (result != null && !result.isEmpty()) {
                recyclerView.setAdapter(adapter = getAdapter(result));
                if (!fastScroller.isAttached()) {
                    fastScroller.attachRecyclerView(recyclerView);
                }

                onFinishRefresh();
                recyclerView.setVisibility(View.VISIBLE);
            } else {
                setEmpty(true);
            }

            currentTask = null;
        }
    }
}