Show appropriate message when search results are empty

Closes #512.

F-Droid/AndroidManifest.xml

@@ -105,6 +105,7 @@
         <activity
             android:name=".FDroid"
             android:launchMode="singleTop"
+            android:windowSoftInputMode="adjustResize"
             android:configChanges="layoutDirection|locale|keyboardHidden|orientation|screenSize" >
 
             <!-- App URLs -->

F-Droid/res/values/strings.xml

@@ -258,6 +258,9 @@
     <string name="empty_installed_app_list">No apps installed.\n\nThere are apps on your device, but they are not available from F-Droid. This could be because you need to update your repositories, or the repositories genuinely don\'t have your apps available.</string>
     <string name="empty_available_app_list">No apps in this category.\n\nTry selecting a different category or updating your repositories to get a fresh list of apps.</string>
     <string name="empty_can_update_app_list">All apps up to date.\n\nCongratulations! All of your apps are up to date (or your repositories are out of date).</string>
+    <string name="empty_search_installed_app_list">No matching installed applications.</string>
+    <string name="empty_search_available_app_list">No matching applications available.</string>
+    <string name="empty_search_can_update_app_list">No matching applications for update.</string>
 
     <string name="requesting_root_access_body">Requesting root access…</string>
     <string name="root_access_denied_title">Root access denied</string>

F-Droid/src/org/fdroid/fdroid/views/fragments/AppListFragment.java

@@ -14,6 +14,7 @@ import android.support.v4.content.Loader;
 import android.text.TextUtils;
 import android.view.View;
 import android.widget.AdapterView;
+import android.widget.TextView;
 
 import org.fdroid.fdroid.AppDetails;
 import org.fdroid.fdroid.Preferences;
@@ -64,6 +65,10 @@ public abstract class AppListFragment extends ListFragment implements
 
     protected abstract Uri getDataUri(String query);
 
+    protected abstract int getEmptyMessage();
+
+    protected abstract int getNoSearchResultsMessage();
+
     /**
      * Subclasses can choose to do different things based on when a user begins searching.
      * For example, the "Available" tab chooses to hide its category spinner to make it clear
@@ -84,6 +89,14 @@ public abstract class AppListFragment extends ListFragment implements
         // Do nothing by default.
     }
 
+    /**
+     * Utility function to set empty view text which should be different
+     * depending on whether search is active or not.
+     */
+    private void setEmptyText(int resId) {
+        ((TextView) getListView().getEmptyView()).setText(resId);
+    }
+
     @Override
     public void onActivityCreated(Bundle savedInstanceState) {
         super.onActivityCreated(savedInstanceState);
@@ -177,15 +190,18 @@ public abstract class AppListFragment extends ListFragment implements
 
     /**
      * Notifies the subclass via {@link AppListFragment#onSearch()} and {@link AppListFragment#onSearchStopped()}
-     * about whether or not a search is taking place.
+     * about whether or not a search is taking place and changes empty message
+     * appropriately.
      * @return True if a user is searching.
      */
     private boolean updateSearchStatus() {
         if (TextUtils.isEmpty(searchQuery)) {
             onSearchStopped();
+            setEmptyText(getEmptyMessage());
             return false;
         } else {
             onSearch();
+            setEmptyText(getNoSearchResultsMessage());
             return true;
         }
     }

F-Droid/src/org/fdroid/fdroid/views/fragments/AvailableAppsFragment.java

@@ -176,6 +176,16 @@ public class AvailableAppsFragment extends AppListFragment implements
         return AppProvider.getSearchUri(query);
     }
 
+    @Override
+    protected int getEmptyMessage() {
+        return R.string.empty_available_app_list;
+    }
+
+    @Override
+    protected int getNoSearchResultsMessage() {
+        return R.string.empty_search_available_app_list;
+    }
+
     private void setCurrentCategory(String category) {
         currentCategory = category;
         Utils.debugLog(TAG, "Category '" + currentCategory + "' selected.");

F-Droid/src/org/fdroid/fdroid/views/fragments/CanUpdateAppsFragment.java

@@ -28,10 +28,21 @@ public class CanUpdateAppsFragment extends AppListFragment {
         return AppProvider.getCanUpdateUri();
     }
 
+    @Override
     protected Uri getDataUri(String query) {
         return AppProvider.getSearchCanUpdateUri(query);
     }
 
+    @Override
+    protected int getEmptyMessage() {
+        return R.string.empty_can_update_app_list;
+    }
+
+    @Override
+    protected int getNoSearchResultsMessage() {
+        return R.string.empty_search_can_update_app_list;
+    }
+
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         return inflater.inflate(R.layout.can_update_app_list, container, false);

F-Droid/src/org/fdroid/fdroid/views/fragments/InstalledAppsFragment.java

@@ -28,10 +28,21 @@ public class InstalledAppsFragment extends AppListFragment {
         return AppProvider.getInstalledUri();
     }
 
+    @Override
     protected Uri getDataUri(String query) {
         return AppProvider.getSearchInstalledUri(query);
     }
 
+    @Override
+    protected int getEmptyMessage() {
+        return R.string.empty_installed_app_list;
+    }
+
+    @Override
+    protected int getNoSearchResultsMessage() {
+        return R.string.empty_search_installed_app_list;
+    }
+
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
         return inflater.inflate(R.layout.installed_app_list, container, false);