Java tutorial
/* * Copyright (C) 2015 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.awesomeapp.messenger.ui; import android.content.ContentUris; import android.content.Context; import android.content.Intent; import android.database.Cursor; import android.database.DatabaseUtils; import android.net.Uri; import android.os.Bundle; import android.support.annotation.Nullable; import android.support.design.widget.Snackbar; import android.support.v4.app.Fragment; import android.support.v4.app.LoaderManager; import android.support.v4.content.CursorLoader; import android.support.v4.content.Loader; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.support.v7.widget.helper.ItemTouchHelper; import android.util.TypedValue; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import org.awesomeapp.messenger.provider.Imps; import java.sql.Date; import im.zom.messenger.R; //import com.bumptech.glide.Glide; public class GalleryListFragment extends Fragment { private MessageListRecyclerViewAdapter mAdapter = null; private Uri mUri; private MyLoaderCallbacks mLoaderCallbacks; private LoaderManager mLoaderManager; private int mLoaderId = 1001; private RecyclerView mRecView; private View mEmptyView; private View mEmptyViewImage; private int mByContactId = -1; @Nullable @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.awesome_fragment_gallery_list, container, false); if (getArguments() != null) mByContactId = getArguments().getInt("contactId", -1); mRecView = (RecyclerView) view.findViewById(R.id.recyclerview); mEmptyView = view.findViewById(R.id.empty_view); mEmptyViewImage = view.findViewById(R.id.empty_view_image); setupRecyclerView(mRecView); return view; } private void setupRecyclerView(RecyclerView recyclerView) { recyclerView.setLayoutManager(new LinearLayoutManager(recyclerView.getContext())); Uri baseUri = Imps.Messages.CONTENT_URI; if (mByContactId != -1) baseUri = Imps.Messages.getContentUriByThreadId(mByContactId); Uri.Builder builder = baseUri.buildUpon(); mUri = builder.build(); mLoaderManager = getLoaderManager(); mLoaderCallbacks = new MyLoaderCallbacks(); mLoaderManager.initLoader(mLoaderId, null, mLoaderCallbacks); Cursor cursor = null; mAdapter = new MessageListRecyclerViewAdapter(getActivity(), cursor); if (mAdapter.getItemCount() == 0) { mRecView.setVisibility(View.GONE); if (mByContactId == -1) { mEmptyView.setVisibility(View.VISIBLE); mEmptyViewImage.setVisibility(View.VISIBLE); } else { mEmptyView.setVisibility(View.GONE); mEmptyViewImage.setVisibility(View.GONE); } } else { mRecView.setVisibility(View.VISIBLE); mEmptyView.setVisibility(View.GONE); mEmptyViewImage.setVisibility(View.GONE); } } public static class MessageListRecyclerViewAdapter extends CursorRecyclerViewAdapter<GalleryMediaViewHolder> { private final TypedValue mTypedValue = new TypedValue(); private int mBackground; private Context mContext; public MessageListRecyclerViewAdapter(Context context, Cursor cursor) { super(context, cursor); context.getTheme().resolveAttribute(R.attr.selectableItemBackground, mTypedValue, true); mBackground = mTypedValue.resourceId; mContext = context; setHasStableIds(true); } @Override public long getItemId(int position) { Cursor c = getCursor(); c.moveToPosition(position); long chatId = c.getLong(3); //timestamp! id is first column return chatId; } @Override public GalleryMediaViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { GalleryListItem view = (GalleryListItem) LayoutInflater.from(parent.getContext()) .inflate(R.layout.gallery_item_view, parent, false); //view.setBackgroundResource(mBackground); GalleryMediaViewHolder viewHolder = (GalleryMediaViewHolder) view.getTag(); if (viewHolder == null) { viewHolder = new GalleryMediaViewHolder(view, view.getContext()); view.setTag(viewHolder); } return viewHolder; } @Override public void onBindViewHolder(GalleryMediaViewHolder viewHolder, Cursor cursor) { int id = cursor.getInt(0); String mimeType = "image/jpeg"; String nickname = cursor.getString(1); String body = cursor.getString(2); java.util.Date ts = new Date(cursor.getLong(3)); viewHolder.bind(id, mimeType, body, ts); } } class MyLoaderCallbacks implements LoaderManager.LoaderCallbacks<Cursor> { @Override public Loader<Cursor> onCreateLoader(int id, Bundle args) { StringBuilder buf = new StringBuilder(); buf.append(Imps.Messages.MIME_TYPE); buf.append(" LIKE "); buf.append("'image/jpeg'"); buf.append(" AND ").append(Imps.Messages.BODY).append(" IS NOT NULL) GROUP BY (") .append(Imps.Messages.BODY); //GROUP BY CursorLoader loader = new CursorLoader(getActivity(), mUri, MESSAGE_PROJECTION, buf == null ? null : buf.toString(), null, "maxDate DESC"); return loader; } @Override public void onLoadFinished(Loader<Cursor> loader, Cursor newCursor) { if (newCursor == null) return; // the app was quit or something while this was working newCursor.setNotificationUri(getActivity().getContentResolver(), mUri); mAdapter.changeCursor(newCursor); if (mRecView.getAdapter() == null) mRecView.setAdapter(mAdapter); if (mAdapter.getItemCount() == 0) { mRecView.setVisibility(View.GONE); if (mByContactId == -1) { mEmptyView.setVisibility(View.VISIBLE); mEmptyViewImage.setVisibility(View.VISIBLE); } else { mEmptyView.setVisibility(View.GONE); mEmptyViewImage.setVisibility(View.GONE); } } else if (mRecView.getVisibility() == View.GONE) { mRecView.setVisibility(View.VISIBLE); mEmptyView.setVisibility(View.GONE); mEmptyViewImage.setVisibility(View.GONE); } } @Override public void onLoaderReset(Loader<Cursor> loader) { mAdapter.swapCursor(null); } public final String[] MESSAGE_PROJECTION = { "MAX (" + Imps.Messages._ID + ") as _id", Imps.Messages.NICKNAME, Imps.Messages.BODY, "MAX (" + Imps.Messages.DATE + ") as maxDate" }; } }