/*
* Copyright 2014 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 com.example.android.swiperefreshmultipleviews;
import com.example.android.common.dummydata.Cheeses;
import com.example.android.common.logger.Log;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.widget.SwipeRefreshLayout;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.GridView;
import java.util.List;
/**
* A sample which shows how to use {@link android.support.v4.widget.SwipeRefreshLayout} to add
* the 'swipe-to-refresh' gesture to a layout with multiple children. In this sample,
* SwipeRefreshLayout contains a scrollable {@link android.widget.GridView}, along with a
* {@link android.widget.TextView} empty view.
*
* <p>To provide an accessible way to trigger the refresh, this app also provides a refresh
* action item.
*
* <p>In this sample app, the refresh updates the GridView with a random set of new items.
*/
public class SwipeRefreshMultipleViewsFragment extends Fragment {
private static final String LOG_TAG = SwipeRefreshMultipleViewsFragment.class.getSimpleName();
private static final int LIST_ITEM_COUNT = 40;
/**
* The {@link MultiSwipeRefreshLayout} that detects swipe gestures and triggers callbacks in
* the app.
*/
private MultiSwipeRefreshLayout mSwipeRefreshLayout;
/**
* The {@link android.widget.GridView} that displays the content that should be refreshed.
*/
private GridView mGridView;
/**
* The {@link android.widget.ListAdapter} used to populate the {@link android.widget.GridView}
* defined in the previous statement.
*/
private ArrayAdapter<String> mListAdapter;
/**
* The {@link View} which is displayed when the GridView is empty.
*/
private View mEmptyView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Notify the system to allow an options menu for this fragment.
setHasOptionsMenu(true);
}
// BEGIN_INCLUDE (inflate_view)
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_sample, container, false);
// Retrieve the SwipeRefreshLayout and GridView instances
mSwipeRefreshLayout = (MultiSwipeRefreshLayout) view.findViewById(R.id.swiperefresh);
// BEGIN_INCLUDE (change_colors)
// Set the color scheme of the SwipeRefreshLayout by providing 4 color resource ids
mSwipeRefreshLayout.setColorScheme(
R.color.swipe_color_1, R.color.swipe_color_2,
R.color.swipe_color_3, R.color.swipe_color_4);
// END_INCLUDE (change_colors)
// Retrieve the GridView
mGridView = (GridView) view.findViewById(android.R.id.list);
// Retrieve the empty view
mEmptyView = view.findViewById(android.R.id.empty);
return view;
}
// END_INCLUDE (inflate_view)
// BEGIN_INCLUDE (setup_views)
@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
/**
* Create an ArrayAdapter to contain the data for the GridView. Each item in the GridView
* uses the system-defined simple_list_item_1 layout that contains one TextView. Initially
*/
mListAdapter = new ArrayAdapter<String>(
getActivity(),
android.R.layout.simple_list_item_1,
android.R.id.text1);
// Set the adapter between the GridView and its backing data.
mGridView.setAdapter(mListAdapter);
// Set the empty view so that it is displayed as needed
mGridView.setEmptyView(mEmptyView);
// BEGIN_INCLUDE (setup_swipeable_children)
// Tell the MultiSwipeRefreshLayout which views are swipeable. In this case, the GridView
// and empty view.
mSwipeRefreshLayout.setSwipeableChildren(android.R.id.list, android.R.id.empty);
// END_INCLUDE (setup_swipeable_children)
// BEGIN_INCLUDE (setup_refreshlistener)
/**
* Implement {@link SwipeRefreshLayout.OnRefreshListener}. When users do the "swipe to
* refresh" gesture, SwipeRefreshLayout invokes
* {@link SwipeRefreshLayout.OnRefreshListener#onRefresh onRefresh()}. In
* {@link SwipeRefreshLayout.OnRefreshListener#onRefresh onRefresh()}, call a method that
* refreshes the content. Call the same method in response to the Refresh action from the
* action bar.
*/
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
Log.i(LOG_TAG, "onRefresh called from SwipeRefreshLayout");
initiateRefresh();
}
});
// END_INCLUDE (setup_refreshlistener)
}
// END_INCLUDE (setup_views)
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.main_menu, menu);
}
// BEGIN_INCLUDE (setup_refresh_menu_listener)
/**
* Respond to the user's selection of the Refresh action item. Start the SwipeRefreshLayout
* progress bar, then initiate the background task that refreshes the content.
*/
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_clear:
Log.i(LOG_TAG, "Clear menu item selected");
mListAdapter.clear();
return true;
case R.id.menu_refresh:
Log.i(LOG_TAG, "Refresh menu item selected");
// We make sure that the SwipeRefreshLayout is displaying it's refreshing indicator
if (!mSwipeRefreshLayout.isRefreshing()) {
mSwipeRefreshLayout.setRefreshing(true);
}
// Start our refresh background task
initiateRefresh();
return true;
}
return super.onOptionsItemSelected(item);
}
// END_INCLUDE (setup_refresh_menu_listener)
// BEGIN_INCLUDE (initiate_refresh)
/**
* By abstracting the refresh process to a single method, the app allows both the
* SwipeGestureLayout onRefresh() method and the Refresh action item to refresh the content.
*/
private void initiateRefresh() {
Log.i(LOG_TAG, "initiateRefresh");
/**
* Execute the background task, which uses {@link android.os.AsyncTask} to load the data.
*/
new DummyBackgroundTask().execute();
}
// END_INCLUDE (initiate_refresh)
// BEGIN_INCLUDE (refresh_complete)
/**
* When the AsyncTask finishes, it calls onRefreshComplete(), which updates the data in the
* ListAdapter and turns off the progress bar.
*/
private void onRefreshComplete(List<String> result) {
Log.i(LOG_TAG, "onRefreshComplete");
// Remove all items from the ListAdapter, and then replace them with the new items
mListAdapter.clear();
for (String cheese : result) {
mListAdapter.add(cheese);
}
// Stop the refreshing indicator
mSwipeRefreshLayout.setRefreshing(false);
}
// END_INCLUDE (refresh_complete)
/**
* Dummy {@link AsyncTask} which simulates a long running task to fetch new cheeses.
*/
private class DummyBackgroundTask extends AsyncTask<Void, Void, List<String>> {
static final int TASK_DURATION = 3 * 1000; // 3 seconds
@Override
protected List<String> doInBackground(Void... params) {
// Sleep for a small amount of time to simulate a background-task
try {
Thread.sleep(TASK_DURATION);
} catch (InterruptedException e) {
e.printStackTrace();
}
// Return a new random list of cheeses
return Cheeses.randomList(LIST_ITEM_COUNT);
}
@Override
protected void onPostExecute(List<String> result) {
super.onPostExecute(result);
// Tell the Fragment that the refresh has completed
onRefreshComplete(result);
}
}
}