refactor(github): repo screen lazy load

lib/screens/gh_repo.dart

@@ -9,6 +9,7 @@ import 'package:git_touch/widgets/app_bar_title.dart';
 import 'package:git_touch/widgets/entry_item.dart';
 import 'package:git_touch/widgets/label.dart';
 import 'package:git_touch/widgets/language_bar.dart';
+import 'package:git_touch/widgets/loading.dart';
 import 'package:git_touch/widgets/mutation_button.dart';
 import 'package:git_touch/widgets/markdown_view.dart';
 import 'package:git_touch/widgets/repo_header.dart';
@@ -16,7 +17,6 @@ import 'package:git_touch/widgets/table_view.dart';
 import 'package:github/github.dart';
 import 'package:provider/provider.dart';
 import 'package:git_touch/models/theme.dart';
-import 'package:tuple/tuple.dart';
 import 'package:git_touch/widgets/action_button.dart';
 
 class GhRepoScreen extends StatelessWidget {
@@ -25,16 +25,6 @@ class GhRepoScreen extends StatelessWidget {
   final String branch;
   GhRepoScreen(this.owner, this.name, {this.branch});
 
-  Future<GhRepoRepository> _query(BuildContext context) async {
-    var res = await context.read<AuthModel>().gqlClient.execute(GhRepoQuery(
-        variables: GhRepoArguments(
-            owner: owner,
-            name: name,
-            branchSpecified: branch != null,
-            branch: branch ?? '')));
-    return res.data.repository;
-  }
-
   String _buildWatchState(GhRepoSubscriptionState state) {
     switch (state) {
       case GhRepoSubscriptionState.IGNORED:
@@ -48,44 +38,21 @@ class GhRepoScreen extends StatelessWidget {
     }
   }
 
-  Future<String> _fetchContributors(BuildContext context) async {
-    final res = await context
-        .read<AuthModel>()
-        .ghClient
-        .getJSON('/repos/$owner/$name/stats/contributors');
-    return res.length.toString();
-  }
-
-  Future<String> _fetchReadme(BuildContext context) async {
-    try {
-      final res = await context
-          .read<AuthModel>()
-          .ghClient
-          .repositories
-          .getReadme(RepositorySlug(owner, name));
-      return res.text;
-    } catch (e) {
-      // 404
-      return null;
-    }
-  }
-
   @override
   Widget build(BuildContext context) {
     final theme = Provider.of<ThemeModel>(context);
-    return RefreshStatefulScaffold<Tuple3<GhRepoRepository, String, String>>(
+    return RefreshStatefulScaffold<GhRepoRepository>(
       title: AppBarTitle('Repository'),
       fetchData: () async {
-        final rs = await Future.wait([
-          _query(context),
-          _fetchReadme(context),
-          _fetchContributors(context),
-        ]);
-
-        return Tuple3(rs[0] as GhRepoRepository, rs[1] as String, rs[2]);
+        var res = await context.read<AuthModel>().gqlClient.execute(GhRepoQuery(
+            variables: GhRepoArguments(
+                owner: owner,
+                name: name,
+                branchSpecified: branch != null,
+                branch: branch ?? '')));
+        return res.data.repository;
       },
-      actionBuilder: (data, setState) {
-        final repo = data.item1;
+      actionBuilder: (repo, setState) {
         return ActionButton(
           title: 'Repository Actions',
           items: [
@@ -101,10 +68,7 @@ class GhRepoScreen extends StatelessWidget {
           ],
         );
       },
-      bodyBuilder: (data, setState) {
-        final repo = data.item1;
-        final readme = data.item2;
-        final contributorsCount = data.item3;
+      bodyBuilder: (repo, setState) {
         final ref = branch == null ? repo.defaultBranchRef : repo.ref;
         final license = repo.licenseInfo?.spdxId ?? repo.licenseInfo?.name;
 
@@ -329,20 +293,44 @@ class GhRepoScreen extends StatelessWidget {
                 TableViewItem(
                   leftIconData: Octicons.organization,
                   text: Text('Contributors'),
-                  rightWidget: Text(contributorsCount),
+                  rightWidget: FutureBuilder<String>(
+                    future: context
+                        .read<AuthModel>()
+                        .ghClient
+                        .getJSON('/repos/$owner/$name/stats/contributors')
+                        .then((v) => v.length.toString()),
+                    builder: (context, snapshot) {
+                      return Text(snapshot.data ?? '');
+                    },
+                  ),
                   url: '/github/$owner/$name/contributors',
                 )
               ],
             ),
-            if (readme != null)
-              Container(
-                padding: CommonStyle.padding,
-                color: theme.palette.background,
-                child: MarkdownView(
-                  readme,
-                  basePaths: [owner, name, branch ?? 'master'], // TODO:
-                ),
-              ),
+            FutureBuilder<String>(
+              future: context
+                  .read<AuthModel>()
+                  .ghClient
+                  .repositories
+                  .getReadme(RepositorySlug(owner, name))
+                  .then((file) => file.text),
+              builder: (context, snapshot) {
+                if (snapshot.connectionState == ConnectionState.waiting) {
+                  return Loading();
+                }
+                if (snapshot.hasData) {
+                  return Container(
+                    padding: CommonStyle.padding,
+                    color: theme.palette.background,
+                    child: MarkdownView(
+                      snapshot.data,
+                      basePaths: [owner, name, branch ?? 'master'], // TODO:
+                    ),
+                  );
+                }
+                return Container();
+              },
+            ),
             CommonStyle.verticalGap,
           ],
         );