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SwipeRefreshListFragment / src / com.example.android.swiperefreshlistfragment /

SwipeRefreshListFragmentFragment.java

       
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        /*
       
       
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        * Copyright 2014 The Android Open Source Project
       
       
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        *
       
       
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        * Licensed under the Apache License, Version 2.0 (the "License");
       
       
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        * you may not use this file except in compliance with the License.
       
       
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        * You may obtain a copy of the License at
       
       
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        *
       
       
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        *       http://www.apache.org/licenses/LICENSE-2.0
       
       
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        *
       
       
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        * Unless required by applicable law or agreed to in writing, software
       
       
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        * distributed under the License is distributed on an "AS IS" BASIS,
       
       
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        * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
       
       
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        * See the License for the specific language governing permissions and
       
       
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        * limitations under the License.
       
       
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        */
       
       
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        package com.example.android.swiperefreshlistfragment;
       
       
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        import com.example.android.common.dummydata.Cheeses;
       
       
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        import com.example.android.common.logger.Log;
       
       
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        import android.os.AsyncTask;
       
       
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        import android.os.Bundle;
       
       
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        import android.support.v4.widget.SwipeRefreshLayout;
       
       
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        import android.view.Menu;
       
       
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        import android.view.MenuInflater;
       
       
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        import android.view.MenuItem;
       
       
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        import android.view.View;
       
       
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        import android.widget.ArrayAdapter;
       
       
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        import android.widget.ListAdapter;
       
       
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        import java.util.List;
       
       
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        /**
       
       
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        * A sample which shows how to use {@link android.support.v4.widget.SwipeRefreshLayout} within a
       
       
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        * {@link android.support.v4.app.ListFragment} to add the 'swipe-to-refresh' gesture to a
       
       
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        * {@link android.widget.ListView}. This is provided through the provided re-usable
       
       
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        * {@link SwipeRefreshListFragment} class.
       
       
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        *
       
       
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        * <p>To provide an accessible way to trigger the refresh, this app also provides a refresh
       
       
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        * action item. This item should be displayed in the Action Bar's overflow item.
       
       
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        *
       
       
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        * <p>In this sample app, the refresh updates the ListView with a random set of new items.
       
       
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        *
       
       
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        * <p>This sample also provides the functionality to change the colors displayed in the
       
       
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        * {@link android.support.v4.widget.SwipeRefreshLayout} through the options menu. This is meant to
       
       
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        * showcase the use of color rather than being something that should be integrated into apps.
       
       
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        */
       
       
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        public class SwipeRefreshListFragmentFragment extends SwipeRefreshListFragment {
       
       
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        private static final String LOG_TAG = SwipeRefreshListFragmentFragment.class.getSimpleName();
       
       
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        private static final int LIST_ITEM_COUNT = 20;
       
       
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        @Override
       
       
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        public void onCreate(Bundle savedInstanceState) {
       
       
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        super.onCreate(savedInstanceState);
       
       
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        // Notify the system to allow an options menu for this fragment.
       
       
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        setHasOptionsMenu(true);
       
       
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        }
       
       
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        @Override
       
       
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        public void onViewCreated(View view, Bundle savedInstanceState) {
       
       
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        super.onViewCreated(view, savedInstanceState);
       
       
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        /**
       
       
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        * Create an ArrayAdapter to contain the data for the ListView. Each item in the ListView
       
       
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        * uses the system-defined simple_list_item_1 layout that contains one TextView.
       
       
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        */
       
       
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        ListAdapter adapter = new ArrayAdapter<String>(
       
       
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        getActivity(),
       
       
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        android.R.layout.simple_list_item_1,
       
       
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        android.R.id.text1,
       
       
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        Cheeses.randomList(LIST_ITEM_COUNT));
       
       
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        // Set the adapter between the ListView and its backing data.
       
       
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        setListAdapter(adapter);
       
       
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        /**
       
       
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        * Implement {@link SwipeRefreshLayout.OnRefreshListener}. When users do the "swipe to
       
       
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        * refresh" gesture, SwipeRefreshLayout invokes
       
       
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        * {@link SwipeRefreshLayout.OnRefreshListener#onRefresh onRefresh()}. In
       
       
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        * {@link SwipeRefreshLayout.OnRefreshListener#onRefresh onRefresh()}, call a method that
       
       
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        * refreshes the content. Call the same method in response to the Refresh action from the
       
       
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        * action bar.
       
       
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        */
       
       
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        setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
       
       
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        @Override
       
       
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        public void onRefresh() {
       
       
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        Log.i(LOG_TAG, "onRefresh called from SwipeRefreshLayout");
       
       
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        initiateRefresh();
       
       
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        }
       
       
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        });
       
       
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        }
       
       
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        @Override
       
       
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        public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
       
       
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        inflater.inflate(R.menu.main_menu, menu);
       
       
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        }
       
       
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        /**
       
       
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        * Respond to the user's selection of the Refresh action item. Start the SwipeRefreshLayout
       
       
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        * progress bar, then initiate the background task that refreshes the content.
       
       
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        *
       
       
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        * <p>A color scheme menu item used for demonstrating the use of SwipeRefreshLayout's color
       
       
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        * scheme functionality. This kind of menu item should not be incorporated into your app,
       
       
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        * it just to demonstrate the use of color. Instead you should choose a color scheme based
       
       
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        * off of your application's branding.
       
       
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        */
       
       
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        @Override
       
       
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        public boolean onOptionsItemSelected(MenuItem item) {
       
       
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        switch (item.getItemId()) {
       
       
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        case R.id.menu_refresh:
       
       
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        Log.i(LOG_TAG, "Refresh menu item selected");
       
       
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        // We make sure that the SwipeRefreshLayout is displaying it's refreshing indicator
       
       
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        if (!isRefreshing()) {
       
       
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        setRefreshing(true);
       
       
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        }
       
       
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        // Start our refresh background task
       
       
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        initiateRefresh();
       
       
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        return true;
       
       
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        case R.id.menu_color_scheme_1:
       
       
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        Log.i(LOG_TAG, "setColorScheme #1");
       
       
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        item.setChecked(true);
       
       
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        // Change the colors displayed by the SwipeRefreshLayout by providing it with 4
       
       
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        // color resource ids
       
       
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        setColorScheme(R.color.color_scheme_1_1, R.color.color_scheme_1_2,
       
       
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        R.color.color_scheme_1_3, R.color.color_scheme_1_4);
       
       
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        return true;
       
       
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        case R.id.menu_color_scheme_2:
       
       
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        Log.i(LOG_TAG, "setColorScheme #2");
       
       
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        item.setChecked(true);
       
       
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        // Change the colors displayed by the SwipeRefreshLayout by providing it with 4
       
       
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        // color resource ids
       
       
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        setColorScheme(R.color.color_scheme_2_1, R.color.color_scheme_2_2,
       
       
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        R.color.color_scheme_2_3, R.color.color_scheme_2_4);
       
       
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        return true;
       
       
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        case R.id.menu_color_scheme_3:
       
       
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        Log.i(LOG_TAG, "setColorScheme #3");
       
       
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        item.setChecked(true);
       
       
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        // Change the colors displayed by the SwipeRefreshLayout by providing it with 4
       
       
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        // color resource ids
       
       
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        setColorScheme(R.color.color_scheme_3_1, R.color.color_scheme_3_2,
       
       
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        R.color.color_scheme_3_3, R.color.color_scheme_3_4);
       
       
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        return true;
       
       
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        }
       
       
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        return super.onOptionsItemSelected(item);
       
       
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        }
       
       
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        /**
       
       
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        * By abstracting the refresh process to a single method, the app allows both the
       
       
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        * SwipeGestureLayout onRefresh() method and the Refresh action item to refresh the content.
       
       
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        */
       
       
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        private void initiateRefresh() {
       
       
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        Log.i(LOG_TAG, "initiateRefresh");
       
       
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        /**
       
       
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        * Execute the background task, which uses {@link android.os.AsyncTask} to load the data.
       
       
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        */
       
       
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        new DummyBackgroundTask().execute();
       
       
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        }
       
       
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        /**
       
       
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        * When the AsyncTask finishes, it calls onRefreshComplete(), which updates the data in the
       
       
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        * ListAdapter and turns off the progress bar.
       
       
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        */
       
       
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        private void onRefreshComplete(List<String> result) {
       
       
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        Log.i(LOG_TAG, "onRefreshComplete");
       
       
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        // Remove all items from the ListAdapter, and then replace them with the new items
       
       
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        ArrayAdapter<String> adapter = (ArrayAdapter<String>) getListAdapter();
       
       
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        adapter.clear();
       
       
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        for (String cheese : result) {
       
       
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        adapter.add(cheese);
       
       
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        }
       
       
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        // Stop the refreshing indicator
       
       
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        setRefreshing(false);
       
       
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        }
       
       
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        /**
       
       
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        * Dummy {@link AsyncTask} which simulates a long running task to fetch new cheeses.
       
       
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        */
       
       
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        private class DummyBackgroundTask extends AsyncTask<Void, Void, List<String>> {
       
       
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        static final int TASK_DURATION = 3 * 1000; // 3 seconds
       
       
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        @Override
       
       
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        protected List<String> doInBackground(Void... params) {
       
       
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        // Sleep for a small amount of time to simulate a background-task
       
       
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        try {
       
       
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        Thread.sleep(TASK_DURATION);
       
       
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        } catch (InterruptedException e) {
       
       
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        e.printStackTrace();
       
       
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        }
       
       
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        // Return a new random list of cheeses
       
       
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        return Cheeses.randomList(LIST_ITEM_COUNT);
       
       
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        }
       
       
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        @Override
       
       
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        protected void onPostExecute(List<String> result) {
       
       
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        super.onPostExecute(result);
       
       
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        // Tell the Fragment that the refresh has completed
       
       
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        onRefreshComplete(result);
       
       
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        }
       
       
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        }
       
       
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        }