LoadingListFragment.java

package com.alorma.github.ui.fragment.base;

import android.graphics.Color;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.widget.SwipeRefreshLayout;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.alorma.github.R;
import com.alorma.github.ui.adapter.base.RecyclerArrayAdapter;
import com.alorma.github.utils.AttributesUtils;
import com.mikepenz.iconics.IconicsDrawable;
import com.mikepenz.octicons_typeface_library.Octicons;
import java.util.ArrayList;
import java.util.List;
import tr.xip.errorview.ErrorView;

public abstract class LoadingListFragment<Adapter extends RecyclerArrayAdapter> extends BaseFragment
    implements SwipeRefreshLayout.OnRefreshListener, View.OnClickListener, RecyclerArrayAdapter.RecyclerAdapterContentListener,
    ErrorView.RetryListener {

  protected static final String USERNAME = "USERNAME";
  protected FloatingActionButton fab;
  protected RecyclerView recyclerView;
  protected Toolbar extraToolbar;
  protected boolean fromRetry = false;
  protected boolean refreshing;
  protected SwipeRefreshLayout swipe;
  private ErrorView error_view;
  private Adapter adapter;
  protected View loadingView;
  private boolean fromPaginated;
  private Integer page;
  private List<RecyclerView.ItemDecoration> listDecorators;

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

  @Override
  public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    super.onCreateView(inflater, container, savedInstanceState);

    return getThemedLayoutInflater(inflater).inflate(useFAB() ? R.layout.list_fragment_with_fab : R.layout.list_fragment, null, false);
  }

  public void setPage(Integer page) {
    this.page = page;
  }

  @Override
  public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    recyclerView = (RecyclerView) view.findViewById(R.id.recycler);
    extraToolbar = (Toolbar) view.findViewById(R.id.extraToolbar);

    loadingView = view.findViewById(R.id.loading_view);

    if (recyclerView != null) {
      recyclerView.setLayoutManager(getLayoutManager());
      recyclerView.setItemAnimator(getItemAnimator());
    }

    error_view = (ErrorView) view.findViewById(R.id.error_view);

    fab = (FloatingActionButton) view.findViewById(R.id.fabButton);

    checkFAB();

    swipe = (SwipeRefreshLayout) view.findViewById(R.id.swipe);

    if (swipe != null) {
      int accent = AttributesUtils.getAccentColor(getContext());
      swipe.setColorSchemeColors(accent);
      swipe.setOnRefreshListener(this);
    }

    if (autoStart()) {
      if (getAdapter() != null) {
        getAdapter().clear();

        setAdapter(null);
      }
      executeRequest();
    }
  }

  protected void showExtraToolbar() {
    extraToolbar.setVisibility(View.VISIBLE);
  }

  protected void hideExtraToolbar() {
    extraToolbar.setVisibility(View.GONE);
  }

  protected RecyclerView.LayoutManager getLayoutManager() {
    return new LinearLayoutManager(getContext());
  }

  protected RecyclerView.ItemAnimator getItemAnimator() {
    return new DefaultItemAnimator();
  }

  protected void addItemDecoration(RecyclerView.ItemDecoration itemDecoration) {
    if (recyclerView != null) {
      if (listDecorators == null) {
        listDecorators = new ArrayList<>();
      }
      listDecorators.add(itemDecoration);
      recyclerView.removeItemDecoration(itemDecoration);
      recyclerView.addItemDecoration(itemDecoration);
    }
  }

  public void removeDecorations() {
    if (recyclerView != null) {
      if (listDecorators != null) {
        for (RecyclerView.ItemDecoration listDecorator : listDecorators) {
          recyclerView.removeItemDecoration(listDecorator);
        }
        listDecorators.clear();
      }
    }
  }

  @Override
  public void onRefresh() {
    refreshing = true;
    executeRequest();
  }

  public void setRefreshing() {
    this.refreshing = true;
  }

  @Override
  public void loadMoreItems() {
    if (page != null) {
      executePaginatedRequest(page);
      page = null;
    }
  }

  protected void executeRequest() {
    startRefresh();
  }

  protected void executePaginatedRequest(int page) {
    fromPaginated = true;
    startRefresh();
  }

  protected void startRefresh() {
    hideEmpty();
    if (swipe != null && (fromRetry || fromPaginated)) {
      fromRetry = false;
      swipe.post(() -> swipe.setRefreshing(true));
    }

    if (!fromPaginated && loadingView != null && (getAdapter() == null || getAdapter().getItemCount() == 0)) {
      loadingView.setVisibility(View.VISIBLE);
    }
  }

  protected void stopRefresh() {
    if (swipe != null) {
      refreshing = false;
      fromRetry = false;
      swipe.post(() -> swipe.setRefreshing(false));
    }

    if (loadingView != null) {
      loadingView.setVisibility(View.GONE);
    }
  }

  protected void checkFAB() {
    if (getContext() != null && fab != null) {
      if (useFAB()) {
        fab.setVisibility(View.VISIBLE);
        fab.setOnClickListener(this);
        IconicsDrawable iconicsDrawable = new IconicsDrawable(getContext(), getFABGithubIcon());
        iconicsDrawable.color(Color.WHITE);
        iconicsDrawable.sizeDp(24);

        fab.setImageDrawable(iconicsDrawable);
      } else {
        fab.setVisibility(View.GONE);
      }
    }
  }

  protected abstract void loadArguments();

  protected boolean useFAB() {
    return false;
  }

  public void setEmpty() {
    if (getActivity() != null && isAdded()) {
      stopRefresh();
      if (getContext() != null) {
        if (error_view != null) {
          error_view.setVisibility(View.VISIBLE);
          error_view.setTitle(getNoDataText());
          error_view.showRetryButton(true);
          error_view.setOnRetryListener(this);
        }
      }

      if (recyclerView != null) {
        recyclerView.setLayoutManager(getLayoutManager());
        recyclerView.setItemAnimator(getItemAnimator());
      }
    }
  }

  public void setEmpty(boolean withError, int statusCode) {
    if (getContext() != null) {
      if (error_view != null) {
        error_view.setVisibility(View.VISIBLE);
        error_view.setError(statusCode);
        error_view.showRetryButton(withError);
        if (withError) {
          error_view.setOnRetryListener(this);
        }
      }
    }
  }

  public void hideEmpty() {
    if (getContext() != null) {
      stopRefresh();
      if (error_view != null) {
        error_view.setVisibility(View.GONE);
      }
    }
  }

  protected abstract Octicons.Icon getNoDataIcon();

  protected abstract int getNoDataText();

  @Override
  public void onClick(View v) {
    if (v.getId() == R.id.fabButton) {
      fabClick();
    }
  }

  protected void fabClick() {

  }

  protected Octicons.Icon getFABGithubIcon() {
    return Octicons.Icon.oct_squirrel;
  }

  public Adapter getAdapter() {
    return adapter;
  }

  public void setAdapter(Adapter adapter) {
    this.adapter = adapter;
    if (this.adapter != null) {
      try {
        adapter.setRecyclerAdapterContentListener(this);
      } catch (Exception e) {
        e.printStackTrace();
      }
    }
    if (recyclerView != null) {
      recyclerView.setAdapter(adapter);
    }
  }

  protected boolean autoStart() {
    return true;
  }

  @Override
  public void onRetry() {
    hideEmpty();
    fromRetry = true;
    executeRequest();
  }
}