SortedFragment.java

/***
  Copyright (c) 2008-2015 CommonsWare, LLC
  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.
  
  Covered in detail in the book _The Busy Coder's Guide to Android Development_
    https://commonsware.com/Android
*/

package com.commonsware.android.recyclerview.sorted;

import android.os.AsyncTask;
import android.os.Bundle;
import android.os.SystemClock;
import android.support.v7.util.SortedList;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;

public class SortedFragment extends RecyclerViewFragment {
  private static final String[] items={"lorem", "ipsum", "dolor",
          "sit", "amet",
          "consectetuer", "adipiscing", "elit", "morbi", "vel",
          "ligula", "vitae", "arcu", "aliquet", "mollis",
          "etiam", "vel", "erat", "placerat", "ante",
          "porttitor", "sodales", "pellentesque", "augue", "purus"};
  private SortedList<String> model=null;
  private AddStringTask task=null;
  private IconicAdapter adapter=null;

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

    setRetainInstance(true);

    model=new SortedList<String>(String.class, sortCallback);

    task=new AddStringTask();
    task.execute();
  }

  @Override
  public void onViewCreated(View view, Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);

    setLayoutManager(new LinearLayoutManager(getActivity()));
    adapter=new IconicAdapter();
    setAdapter(adapter);
  }

  @Override
  public void onDestroy() {
    if (task != null) {
      task.cancel(false);
    }

    super.onDestroy();
  }

  private SortedList.Callback<String> sortCallback=new SortedList.Callback<String>() {
    @Override
    public int compare(String o1, String o2) {
      return o1.compareTo(o2);
    }

    @Override
    public boolean areContentsTheSame(String oldItem, String newItem) {
      return(areItemsTheSame(oldItem, newItem));
    }

    @Override
    public boolean areItemsTheSame(String oldItem, String newItem) {
      return(compare(oldItem, newItem)==0);
    }

    @Override
    public void onInserted(int position, int count) {
      adapter.notifyItemRangeInserted(position, count);
    }

    @Override
    public void onRemoved(int position, int count) {
      adapter.notifyItemRangeRemoved(position, count);
    }

    @Override
    public void onMoved(int fromPosition, int toPosition) {
      adapter.notifyItemMoved(fromPosition, toPosition);
    }

    @Override
    public void onChanged(int position, int count) {
      adapter.notifyItemRangeChanged(position, count);
    }
  };

  class IconicAdapter extends RecyclerView.Adapter<RowController> {
    @Override
    public RowController onCreateViewHolder(ViewGroup parent, int viewType) {
      return(new RowController(getActivity().getLayoutInflater()
                                .inflate(R.layout.row, parent, false)));
    }

    @Override
    public void onBindViewHolder(RowController holder, int position) {
      holder.bindModel(model.get(position));
    }

    @Override
    public int getItemCount() {
      return(model.size());
    }
  }

  private class AddStringTask extends AsyncTask<Void, String, Void> {
    @Override
    protected Void doInBackground(Void... unused) {
      for (String item : items) {
        if (isCancelled())
          break;

        publishProgress(item);
        SystemClock.sleep(400);
      }

      return(null);
    }

    @Override
    protected void onProgressUpdate(String... item) {
      if (!isCancelled()) {
        model.add(item[0]);
      }
    }

    @Override
    protected void onPostExecute(Void unused) {
      Toast.makeText(getActivity(), R.string.done, Toast.LENGTH_SHORT)
          .show();

      task=null;
    }
  }
}