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      1 package ${packageName};
      2 
      3 import android.app.Activity;
      4 import android.os.Bundle;
      5 import android.support.v4.app.ListFragment;
      6 import android.view.View;
      7 import android.widget.ArrayAdapter;
      8 import android.widget.ListView;
      9 
     10 import ${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  */
     21 public 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