Java tutorial
package com.luorrak.ouroboros.gallery; import android.Manifest; import android.app.AlertDialog; import android.app.Fragment; import android.content.DialogInterface; import android.content.pm.PackageManager; import android.database.Cursor; import android.os.Bundle; import android.support.design.widget.Snackbar; import android.support.v4.app.ActivityCompat; import android.support.v4.content.ContextCompat; import android.support.v7.widget.GridLayoutManager; import android.support.v7.widget.RecyclerView; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import com.luorrak.ouroboros.R; import com.luorrak.ouroboros.util.DbContract; import com.luorrak.ouroboros.util.InfiniteDbHelper; import com.luorrak.ouroboros.util.Media; import com.luorrak.ouroboros.util.NetworkHelper; import com.luorrak.ouroboros.util.Util; import java.util.ArrayList; import java.util.Collection; /** * Ouroboros - An 8chan browser * Copyright (C) 2015 Luorrak * * 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. * * This program 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 this program. If not, see <http://www.gnu.org/licenses/>. */ public class GalleryFragment extends Fragment { private RecyclerView recyclerView; private GridLayoutManager gridLayoutManager; private GalleryAdapter galleryAdapter; private String boardName; private String resto; private InfiniteDbHelper infiniteDbHelper; private NetworkHelper networkHelper; public GalleryFragment() { } public GalleryFragment newInstance(String boardName, String resto) { GalleryFragment frag = new GalleryFragment(); Bundle args = new Bundle(); args.putString("boardName", boardName); args.putString("resto", resto); frag.setArguments(args); return frag; } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { super.onCreateView(inflater, container, savedInstanceState); setHasOptionsMenu(true); infiniteDbHelper = new InfiniteDbHelper(getActivity()); networkHelper = new NetworkHelper(); ArrayList<Media> mediaArrayList = new ArrayList<>(); View view = inflater.inflate(R.layout.fragment_gallery, container, false); getActivity().setTitle("Gallery"); if (getArguments() != null) { boardName = getArguments().getString("boardName"); resto = getArguments().getString("resto"); } Cursor cursor = infiniteDbHelper.getThreadCursor(resto); do { byte[] serializedPostMedia = cursor .getBlob(cursor.getColumnIndex(DbContract.ThreadEntry.COLUMN_THREAD_MEDIA_FILES)); if (serializedPostMedia != null) { mediaArrayList.addAll((Collection<? extends Media>) Util.deserializeObject(serializedPostMedia)); } } while (cursor.moveToNext()); cursor.close(); recyclerView = (RecyclerView) view.findViewById(R.id.gallery_list); gridLayoutManager = new GridLayoutManager(getActivity(), 3); recyclerView.setLayoutManager(gridLayoutManager); galleryAdapter = new GalleryAdapter(mediaArrayList, boardName, resto, getActivity()); recyclerView.setAdapter(galleryAdapter); return view; } @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { MenuItem saveAllImagesButton = menu.findItem(R.id.action_save_all_images); saveAllImagesButton.setVisible(true); super.onCreateOptionsMenu(menu, inflater); } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.action_save_all_images: { if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED || ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) { ActivityCompat .requestPermissions(getActivity(), new String[] { Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE }, Util.REQUEST_STORAGE_PERMISSION); } else { showDownloadAllDialog(); } break; } } return super.onOptionsItemSelected(item); } public void showDownloadAllDialog() { new AlertDialog.Builder(getActivity()).setTitle("Download All Images") .setMessage("Are you sure you want to download all images?") .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { startDownload(); } }).setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { } }).show(); } public void startDownload() { Cursor imageCursor = infiniteDbHelper.getGalleryCursor(resto); do { ArrayList<Media> mediaArrayList = (ArrayList<Media>) Util.deserializeObject(imageCursor .getBlob(imageCursor.getColumnIndex(DbContract.ThreadEntry.COLUMN_THREAD_MEDIA_FILES))); for (Media mediaItem : mediaArrayList) { networkHelper.downloadFile(boardName, mediaItem.fileName, mediaItem.ext, getActivity()); } } while (imageCursor.moveToNext()); imageCursor.close(); } @Override public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) { switch (requestCode) { case Util.REQUEST_STORAGE_PERMISSION: { // If request is cancelled, the result arrays are empty. if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { // permission was granted, yay! Do the task you need to do. showDownloadAllDialog(); } else { // permission denied, boo! Disable the // functionality that depends on this permission. Snackbar.make(getView(), "Requires Permission", Snackbar.LENGTH_LONG).show(); } break; } // other 'case' lines to check for other // permissions this app might request } } }