Add progress bar in ListView

app/src/main/java/fr/free/nrw/commons/nearby/NearbyListFragment.java

@@ -2,12 +2,17 @@ package fr.free.nrw.commons.nearby;
 
 
 import android.os.Bundle;
+import android.provider.ContactsContract;
 import android.support.v4.app.Fragment;
 import android.support.v4.app.ListFragment;
+import android.support.v4.view.ViewPager;
+import android.support.v4.widget.SimpleCursorAdapter;
 import android.util.Log;
+import android.view.Gravity;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
+import android.widget.ProgressBar;
 
 import fr.free.nrw.commons.R;
 
@@ -31,6 +36,72 @@ public class NearbyListFragment extends ListFragment {
         View view = inflater.inflate(R.layout.fragment_nearby, container, false);
 
 
+        // Create a progress bar to display while the list loads
+        ProgressBar progressBar = new ProgressBar(getActivity());
+        progressBar.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
+                ViewGroup.LayoutParams.WRAP_CONTENT));
+        progressBar.setIndeterminate(true);
+        getListView().setEmptyView(progressBar);
+        // Must add the progress bar to the root of the layout
+        ViewGroup root = (ViewGroup) view.getRootView();
+        root.addView(progressBar);
+
+        // For the cursor adapter, specify which columns go into which views
+        String[] fromColumns = {ContactsContract.Data.DISPLAY_NAME};
+        int[] toViews = {android.R.id.text1}; // The TextView in simple_list_item_1
+
+        // Create an empty adapter we will use to display the loaded data.
+        // We pass null for the cursor, then update it in onLoadFinished()
+        mAdapter = new SimpleCursorAdapter(this,
+                android.R.layout.simple_list_item_1, null,
+                fromColumns, toViews, 0);
+        setListAdapter(mAdapter);
+
+        // Prepare the loader.  Either re-connect with an existing one,
+        // or start a new one.
+        getLoaderManager().initLoader(0, null, this);
         return view;
     }
+
+
+    // This is the Adapter being used to display the list's data
+    SimpleCursorAdapter mAdapter;
+
+    // These are the Contacts rows that we will retrieve
+    static final String[] PROJECTION = new String[] {ContactsContract.Data._ID,
+            ContactsContract.Data.DISPLAY_NAME};
+
+    // This is the select criteria
+    static final String SELECTION = "((" +
+            ContactsContract.Data.DISPLAY_NAME + " NOTNULL) AND (" +
+            ContactsContract.Data.DISPLAY_NAME + " != '' ))";
+
+
+    // Called when a new Loader needs to be created
+    public Loader<Cursor> onCreateLoader(int id, Bundle args) {
+        // Now create and return a CursorLoader that will take care of
+        // creating a Cursor for the data being displayed.
+        return new CursorLoader(this, ContactsContract.Data.CONTENT_URI,
+                PROJECTION, SELECTION, null, null);
+    }
+
+    // Called when a previously created loader has finished loading
+    public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
+        // Swap the new cursor in.  (The framework will take care of closing the
+        // old cursor once we return.)
+        mAdapter.swapCursor(data);
+    }
+
+    // Called when a previously created loader is reset, making the data unavailable
+    public void onLoaderReset(Loader<Cursor> loader) {
+        // This is called when the last Cursor provided to onLoadFinished()
+        // above is about to be closed.  We need to make sure we are no
+        // longer using it.
+        mAdapter.swapCursor(null);
+    }
+
+    @Override
+    public void onListItemClick(ListView l, View v, int position, long id) {
+        // Do something when a list item is clicked
+    }
 }