[GREEN] Add shimmer loading effect to list_sekolah.dart

lib/page/informasi/list_sekolah.dart

@@ -8,6 +8,7 @@ import 'package:bisaGo/page/informasi/detail_komunitas.dart';
 import 'package:bisaGo/page/informasi/detail_sekolah.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
+import 'package:shimmer/shimmer.dart';
 
 class ListSekolah extends StatefulWidget {
   const ListSekolah({Key key}) : super(key: key);
@@ -17,11 +18,21 @@ class ListSekolah extends StatefulWidget {
 }
 
 class _ListSekolahState extends State<ListSekolah> {
-
   /// Search Icon for textFormField
   Icon searchIcon = const Icon(Icons.search);
 
   LayananBloc layanan_bloc = LayananBloc();
+  bool _enabled = true;
+  final mockSekolah = SekolahModel.fromJson({
+    'name': 'SMA Tanjung Barat',
+    'alamat': 'Kecamatan Tanjung Barat',
+    'no_telp': '0213425367',
+    'website': 'www.tanjungbarat.co.id',
+    'jumlah_siswa': 200,
+    'status': 'IT',
+    'jenis_sekolah': 'IK',
+    'akreditasi': 'A',
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -94,14 +105,17 @@ class _ListSekolahState extends State<ListSekolah> {
                 if (snapshot.hasData) {
                   switch (snapshot.data.status) {
                     case Status.loading:
-                      return const Center(
-                        child: CircularProgressIndicator(
-                          valueColor:
-                              AlwaysStoppedAnimation<Color>(greenPrimary),
-                        ),
-                      );
+                      _enabled = true;
+                      return Column(children: [
+                        Shimmer.fromColors(
+                            baseColor: Colors.grey[300],
+                            highlightColor: Colors.grey[100],
+                            enabled: _enabled,
+                            child: makeSekolahWidget('sekolah', mockSekolah))
+                      ]);
                       break;
                     case Status.completed:
+                      _enabled = false;
                       var layanan = snapshot.data.data;
                       return Column(
                         children: layanan.map<Widget>((each) {
@@ -116,6 +130,7 @@ class _ListSekolahState extends State<ListSekolah> {
                       );
                       break;
                     case Status.error:
+                      _enabled = false;
                       return Center(
                         child: Text(snapshot.data.data.toString()),
                       );