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1package ${packageName};
2
3import android.app.Activity;
4import android.os.Bundle;
5import android.support.v4.app.ListFragment;
6import android.view.View;
7import android.widget.ArrayAdapter;
8import android.widget.ListView;
9
10import ${packageName}.dummy.DummyContent;
11
12/**
13 * A list fragment representing a list of ${objectKindPlural}. This fragment
14 * also supports tablet devices by allowing list items to be given an
15 * 'activated' state upon selection. This helps indicate which item is
16 * currently being viewed in a {@link ${DetailName}Fragment}.
17 * <p>
18 * Activities containing this fragment MUST implement the {@link Callbacks}
19 * interface.
20 */
21public class ${CollectionName}Fragment extends ListFragment {
22
23    /**
24     * The serialization (saved instance state) Bundle key representing the
25     * activated item position. Only used on tablets.
26     */
27    private static final String STATE_ACTIVATED_POSITION = "activated_position";
28
29    /**
30     * The fragment's current callback object, which is notified of list item
31     * clicks.
32     */
33    private Callbacks mCallbacks = sDummyCallbacks;
34
35    /**
36     * The current activated item position. Only used on tablets.
37     */
38    private int mActivatedPosition = ListView.INVALID_POSITION;
39
40    /**
41     * A callback interface that all activities containing this fragment must
42     * implement. This mechanism allows activities to be notified of item
43     * selections.
44     */
45    public interface Callbacks {
46        /**
47         * Callback for when an item has been selected.
48         */
49        public void onItemSelected(String id);
50    }
51
52    /**
53     * A dummy implementation of the {@link Callbacks} interface that does
54     * nothing. Used only when this fragment is not attached to an activity.
55     */
56    private static Callbacks sDummyCallbacks = new Callbacks() {
57        @Override
58        public void onItemSelected(String id) {
59        }
60    };
61
62    /**
63     * Mandatory empty constructor for the fragment manager to instantiate the
64     * fragment (e.g. upon screen orientation changes).
65     */
66    public ${CollectionName}Fragment() {
67    }
68
69    @Override
70    public void onCreate(Bundle savedInstanceState) {
71        super.onCreate(savedInstanceState);
72
73        // TODO: replace with a real list adapter.
74        setListAdapter(new ArrayAdapter<DummyContent.DummyItem>(
75                getActivity(),
76                android.R.layout.simple_list_item_activated_1,
77                android.R.id.text1,
78                DummyContent.ITEMS));
79    }
80
81    @Override
82    public void onViewCreated(View view, Bundle savedInstanceState) {
83        super.onViewCreated(view, savedInstanceState);
84
85        // Restore the previously serialized activated item position.
86        if (savedInstanceState != null
87                && savedInstanceState.containsKey(STATE_ACTIVATED_POSITION)) {
88            setActivatedPosition(savedInstanceState.getInt(STATE_ACTIVATED_POSITION));
89        }
90    }
91
92    @Override
93    public void onAttach(Activity activity) {
94        super.onAttach(activity);
95
96        // Activities containing this fragment must implement its callbacks.
97        if (!(activity instanceof Callbacks)) {
98            throw new IllegalStateException("Activity must implement fragment's callbacks.");
99        }
100
101        mCallbacks = (Callbacks) activity;
102    }
103
104    @Override
105    public void onDetach() {
106        super.onDetach();
107
108        // Reset the active callbacks interface to the dummy implementation.
109        mCallbacks = sDummyCallbacks;
110    }
111
112    @Override
113    public void onListItemClick(ListView listView, View view, int position, long id) {
114        super.onListItemClick(listView, view, position, id);
115
116        // Notify the active callbacks interface (the activity, if the
117        // fragment is attached to one) that an item has been selected.
118        mCallbacks.onItemSelected(DummyContent.ITEMS.get(position).id);
119    }
120
121    @Override
122    public void onSaveInstanceState(Bundle outState) {
123        super.onSaveInstanceState(outState);
124        if (mActivatedPosition != ListView.INVALID_POSITION) {
125            // Serialize and persist the activated item position.
126            outState.putInt(STATE_ACTIVATED_POSITION, mActivatedPosition);
127        }
128    }
129
130    /**
131     * Turns on activate-on-click mode. When this mode is on, list items will be
132     * given the 'activated' state when touched.
133     */
134    public void setActivateOnItemClick(boolean activateOnItemClick) {
135        // When setting CHOICE_MODE_SINGLE, ListView will automatically
136        // give items the 'activated' state when touched.
137        getListView().setChoiceMode(activateOnItemClick
138                ? ListView.CHOICE_MODE_SINGLE
139                : ListView.CHOICE_MODE_NONE);
140    }
141
142    private void setActivatedPosition(int position) {
143        if (position == ListView.INVALID_POSITION) {
144            getListView().setItemChecked(mActivatedPosition, false);
145        } else {
146            getListView().setItemChecked(position, true);
147        }
148
149        mActivatedPosition = position;
150    }
151}
152