content: /*
   * Copyright 2017 Google Inc. All rights reserved.
   *
   * 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 com.example.networksecurity;
  
  import android.os.Bundle;
  import android.util.Log;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.ProgressBar;
  
  import androidx.annotation.NonNull;
  import androidx.coordinatorlayout.widget.CoordinatorLayout;
  import androidx.fragment.app.Fragment;
  import androidx.recyclerview.widget.LinearLayoutManager;
  import androidx.recyclerview.widget.RecyclerView;
  
  import com.example.networksecurity.model.Post;
  import com.example.networksecurity.ui.PostAdapter;
  import com.google.android.material.snackbar.Snackbar;
  
  public class MainFragment extends Fragment implements MainContract.View {
  
      private static final String TAG = MainFragment.class.getSimpleName();
      private MainContract.Presenter mPresenter;
  
      private ProgressBar mProgressBar;
      private CoordinatorLayout mLayout;
      private RecyclerView mPostList;
      private PostAdapter mPostAdapter;
      private View mEmptyView;
      private Snackbar mErrorSnackbar;
  
      public MainFragment() {
          // Required empty public constructor
      }
  
      public static MainFragment newInstance() {
          return new MainFragment();
      }
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
      }
  
      @Override
      public View onCreateView(LayoutInflater inflater, ViewGroup container,
                               Bundle savedInstanceState) {
  
  
          PostAdapter.PostAdapterCallback mPostLoadingListener = new PostAdapter.PostAdapterCallback() {
  
              @Override
              public void onPostImageLoadingError(String error, Exception e) {
                  mPresenter.onLoadPostImageError(error, e);
              }
          };
          mPostAdapter = new PostAdapter(getContext(), mPostLoadingListener);
  
          // Inflate the layout for this fragment
          View layout = inflater.inflate(R.layout.fragment_main, container, false);
          mProgressBar = (ProgressBar) layout.findViewById(R.id.progressBar);
          mLayout = (CoordinatorLayout) layout.findViewById(R.id.layout_coordinator);
          mPostList = (RecyclerView) layout.findViewById(R.id.post_list);
          mEmptyView = layout.findViewById(R.id.empty_view);
  
          LinearLayoutManager layoutManager = new LinearLayoutManager(getContext());
          layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
          mPostList.setLayoutManager(layoutManager);
          mPostList.setAdapter(mPostAdapter);
  
          layout.findViewById(R.id.load_posts).setOnClickListener(new View.OnClickListener() {
              @Override
              public void onClick(View v) {
                  onLoadPostsClick();
              }
          });
  
          return layout;
      }
  
      @Override
      public void onResume() {
          super.onResume();
          mPresenter.start();
      }
  
      private void onLoadPostsClick() {
          if (mPresenter == null) {
              return;
          }
          mPresenter.loadPosts();
      }
  
      @Override
      public void setPresenter(MainContract.Presenter presenter) {
          mPresenter = presenter;
      }
  
      @Override
      public void setLoadingPosts(boolean isLoading) {
          mProgressBar.setVisibility(isLoading ? View.VISIBLE : View.GONE);
      }
  
      @Override
      public void setPosts(Post[] posts) {
          mPostAdapter.setPosts(posts);
          if (posts == null || posts.length < 1) {
              mPostList.setVisibility(View.GONE);
          } else {
              mPostList.setVisibility(View.VISIBLE);
  
          }
      }
  
      @Override
      public void showError(@NonNull String title, String error) {
          Log.e(TAG, error != null ? error : title);
          mErrorSnackbar = Snackbar.make(mLayout, title, Snackbar.LENGTH_INDEFINITE);
          mErrorSnackbar.show();
  
      }
  
      @Override
      public void hideError() {
          if (mErrorSnackbar != null) {
              mErrorSnackbar.dismiss();
          }
      }
  
      @Override
      public void showNoPostsMessage(boolean showMessage) {
          mEmptyView.setVisibility(showMessage ? View.VISIBLE : View.GONE);
      }
  }
  