Fleshes out settings screen with groups, items, and navigation (#43)

veggieseasons/lib/screens/settings.dart

@@ -3,19 +3,208 @@
 // found in the LICENSE file.
 
 import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
+import 'package:scoped_model/scoped_model.dart';
+import 'package:veggieseasons/data/preferences.dart';
+import 'package:veggieseasons/data/veggie.dart';
 import 'package:veggieseasons/styles.dart';
+import 'package:veggieseasons/widgets/settings_group.dart';
+import 'package:veggieseasons/widgets/settings_item.dart';
 
-class SettingsScreen extends StatelessWidget {
+class VeggieCategorySettingsScreen extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
+    final model = ScopedModel.of<Preferences>(context, rebuildOnChange: true);
+    final currentPrefs = model.preferredCategories;
+
     return CupertinoPageScaffold(
       navigationBar: CupertinoNavigationBar(
-        middle: Text('Settings'),
+        middle: Text('Preferred Categories'),
+        previousPageTitle: 'Settings',
       ),
       backgroundColor: Styles.scaffoldBackground,
-      child: Center(
-        child: Text('Not yet implemented.'),
+      child: FutureBuilder<Set<VeggieCategory>>(
+        future: currentPrefs,
+        builder: (context, snapshot) {
+          final items = <SettingsItem>[];
+
+          for (final category in VeggieCategory.values) {
+            CupertinoSwitch toggle;
+
+            // It's possible that category data hasn't loaded from shared prefs
+            // yet, so display it if possible and fall back to disabled switches
+            // otherwise.
+            if (snapshot.hasData) {
+              toggle = CupertinoSwitch(
+                value: snapshot.data.contains(category),
+                onChanged: (value) {
+                  if (value) {
+                    model.addPreferredCategory(category);
+                  } else {
+                    model.removePreferredCategory(category);
+                  }
+                },
+              );
+            } else {
+              toggle = CupertinoSwitch(
+                value: false,
+                onChanged: null,
+              );
+            }
+
+            items.add(SettingsItem(
+              label: veggieCategoryNames[category],
+              content: toggle,
+            ));
+          }
+
+          return ListView(
+            children: [
+              SettingsGroup(
+                items: items,
+              ),
+            ],
+          );
+        },
+      ),
+    );
+  }
+}
+
+class CalorieSettingsScreen extends StatelessWidget {
+  static const max = 1000;
+  static const min = 2600;
+  static const step = 200;
+
+  @override
+  Widget build(BuildContext context) {
+    final model = ScopedModel.of<Preferences>(context, rebuildOnChange: true);
+
+    return CupertinoPageScaffold(
+      navigationBar: CupertinoNavigationBar(
+        previousPageTitle: 'Settings',
+      ),
+      backgroundColor: Styles.scaffoldBackground,
+      child: ListView(
+        children: [
+          FutureBuilder<int>(
+            future: model.desiredCalories,
+            builder: (context, snapshot) {
+              final steps = <SettingsItem>[];
+
+              for (int cals = max; cals < min; cals += step) {
+                steps.add(
+                  SettingsItem(
+                    label: cals.toString(),
+                    icon: SettingsIcon(
+                      icon: Styles.checkIcon,
+                      foregroundColor: snapshot.hasData && snapshot.data == cals
+                          ? CupertinoColors.activeBlue
+                          : Styles.transparentColor,
+                      backgroundColor: Styles.transparentColor,
+                    ),
+                    onPress: snapshot.hasData
+                        ? () => model.setDesiredCalories(cals)
+                        : null,
+                  ),
+                );
+              }
+
+              return SettingsGroup(
+                items: steps,
+                header: SettingsGroupHeader('Available calorie levels'),
+                footer: SettingsGroupFooter('These are used for serving '
+                    'calculations'),
+              );
+            },
+          ),
+        ],
+      ),
+    );
+  }
+}
+
+class SettingsScreen extends StatelessWidget {
+  Widget _buildCaloriesItem(BuildContext context, Preferences prefs) {
+    return SettingsItem(
+      label: 'Calorie Target',
+      icon: SettingsIcon(
+        backgroundColor: Styles.iconBlue,
+        icon: Styles.calorieIcon,
+      ),
+      content: FutureBuilder<int>(
+        future: prefs.desiredCalories,
+        builder: (context, snapshot) {
+          return Row(
+            children: <Widget>[
+              Text(snapshot.data?.toString() ?? ''),
+              SizedBox(width: 8.0),
+              SettingsNavigationIndicator(),
+            ],
+          );
+        },
+      ),
+      onPress: () {
+        Navigator.of(context).push(
+          CupertinoPageRoute(
+            builder: (context) => CalorieSettingsScreen(),
+            title: 'Calorie Target',
+          ),
+        );
+      },
+    );
+  }
+
+  Widget _buildCategoriesItem(BuildContext context, Preferences prefs) {
+    return SettingsItem(
+      label: 'Preferred Categories',
+      subtitle: 'What types of veggies you prefer!',
+      icon: SettingsIcon(
+        backgroundColor: Styles.iconGold,
+        icon: Styles.preferenceIcon,
+      ),
+      content: SettingsNavigationIndicator(),
+      onPress: () {
+        Navigator.of(context).push(
+          CupertinoPageRoute(
+            builder: (context) => VeggieCategorySettingsScreen(),
+            title: 'Preferred Categories',
+          ),
+        );
+      },
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final prefs = ScopedModel.of<Preferences>(context, rebuildOnChange: true);
+
+    return CupertinoPageScaffold(
+      child: Container(
+        color: Styles.scaffoldBackground,
+        child: CustomScrollView(
+          slivers: <Widget>[
+            CupertinoSliverNavigationBar(
+              largeTitle: Text('Settings'),
+            ),
+            SliverSafeArea(
+              top: false,
+              sliver: SliverList(
+                delegate: SliverChildListDelegate(
+                  <Widget>[
+                    SettingsGroup(
+                      items: [
+                        _buildCaloriesItem(context, prefs),
+                        _buildCategoriesItem(context, prefs),
+                      ],
+                    ),
+                  ],
+                ),
+              ),
+            ),
+          ],
+        ),
       ),
     );
   }