Added contextual empty view around network status.

app/src/main/AndroidManifest.xml

@@ -28,6 +28,10 @@
     <uses-permission
         android:name="android.permission.AUTHENTICATE_ACCOUNTS"/>
 
+    <!-- Permissions required to make our UI more friendly -->
+    <uses-permission
+        android:name="android.permission.ACCESS_NETWORK_STATE" />
+
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"

app/src/main/java/com/example/android/sunshine/app/ForecastFragment.java

@@ -32,6 +32,7 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AdapterView;
 import android.widget.ListView;
+import android.widget.TextView;
 
 import com.example.android.sunshine.app.data.WeatherContract;
 import com.example.android.sunshine.app.sync.SunshineSyncAdapter;
@@ -255,6 +256,7 @@ public class ForecastFragment extends Fragment implements LoaderManager.LoaderCa
             // to, do so now.
             mListView.smoothScrollToPosition(mPosition);
         }
+        updateEmptyView();
     }
 
     @Override
@@ -268,4 +270,22 @@ public class ForecastFragment extends Fragment implements LoaderManager.LoaderCa
             mForecastAdapter.setUseTodayLayout(mUseTodayLayout);
         }
     }
+
+    /*
+        Updates the empty list view with contextually relevant information that the user can
+        use to determine why they aren't seeing weather.
+     */
+    private void updateEmptyView() {
+        if ( mForecastAdapter.getCount() == 0 ) {
+            TextView tv = (TextView) getView().findViewById(R.id.listview_forecast_empty);
+            if ( null != tv ) {
+                // if cursor is empty, why? do we have an invalid location
+                int message = R.string.empty_forecast_list;
+                if (!Utility.isNetworkAvailable(getActivity()) ) {
+                    message = R.string.empty_forecast_list_no_network;
+                }
+                tv.setText(message);
+            }
+        }
+    }
 }

app/src/main/java/com/example/android/sunshine/app/Utility.java

@@ -17,6 +17,8 @@ package com.example.android.sunshine.app;
 
 import android.content.Context;
 import android.content.SharedPreferences;
+import android.net.ConnectivityManager;
+import android.net.NetworkInfo;
 import android.preference.PreferenceManager;
 import android.text.format.Time;
 
@@ -246,4 +248,19 @@ public class Utility {
         }
         return -1;
     }
+
+    /**
+     * Returns true if the network is available or about to become available.
+     *
+     * @param c Context used to get the ConnectivityManager
+     * @return
+     */
+    static public boolean isNetworkAvailable(Context c) {
+        ConnectivityManager cm =
+                (ConnectivityManager)c.getSystemService(Context.CONNECTIVITY_SERVICE);
+
+        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
+        return activeNetwork != null &&
+                activeNetwork.isConnectedOrConnecting();
+    }
 }

app/src/main/res/values/strings.xml

@@ -111,5 +111,7 @@
 
     <!-- Empty Weather Database -->
     <string name="empty_forecast_list">No Weather Information Available</string>
+    <string name="empty_forecast_list_no_network">No weather information available. The network is not available to fetch weather data.</string>
+
 
 </resources>