Merge pull request #654 from cake-tech/CW-234-Gift-cards-filter-button-null-exception

[CW-234] gift cards filter button null exception

lib/src/screens/ionia/cards/ionia_manage_cards_page.dart

@@ -118,7 +118,7 @@ class IoniaManageCardsPage extends BasePage {
           width: 32,
           padding: EdgeInsets.all(8),
           decoration: BoxDecoration(
-            color: Colors.white.withOpacity(0.15),
+            color: Theme.of(context).textTheme!.headline6!.backgroundColor!,
             border: Border.all(
               color: Colors.white.withOpacity(0.2),
             ),

lib/src/screens/ionia/widgets/ionia_filter_modal.dart

@@ -20,7 +20,7 @@ class IoniaFilterModal extends StatelessWidget {
       padding: EdgeInsets.all(10),
       child: Image.asset(
         'assets/images/mini_search_icon.png',
-        color: Theme.of(context).accentColor,
+        color: Theme.of(context).textTheme.subtitle2!.color!,
       ),
     );
     return Scaffold(
@@ -53,7 +53,7 @@ class IoniaFilterModal extends StatelessWidget {
                           prefixIcon: searchIcon,
                           hintText: S.of(context).search_category,
                           contentPadding: EdgeInsets.only(bottom: 5),
-                          fillColor: Theme.of(context).textTheme!.subtitle1!.backgroundColor!,
+                          fillColor: Theme.of(context).primaryTextTheme!.caption!.decorationColor!.withOpacity(0.5),
                           border: OutlineInputBorder(
                             borderSide: BorderSide.none,
                             borderRadius: BorderRadius.circular(8),