adjust text size

cupertino_gallery/lib/gallery_home.dart

@@ -7,10 +7,14 @@ class GalleryHome extends StatelessWidget {
     super.key,
     required this.onThemeChange,
     required this.isDarkMode,
+    required this.onTextSizeChange,
+    required this.textSize,
   });
 
   final ValueChanged<bool> onThemeChange;
   final bool isDarkMode;
+  final ValueChanged<double> onTextSizeChange;
+  final double textSize;
 
   @override
   Widget build(BuildContext context) {
@@ -35,6 +39,8 @@ class GalleryHome extends StatelessWidget {
               1 => SettingsPage(
                     onThemeChange: onThemeChange,
                     isDarkMode: isDarkMode,
+                    onTextSizeChange: onTextSizeChange,
+                    textSize: textSize,
                   ),
               _ => const Center(child: Text('Widgets')),
             };

cupertino_gallery/lib/main.dart

@@ -20,6 +20,7 @@ class CupertinoGalleryApp extends StatefulWidget {
 
 class _CupertinoGalleryAppState extends State<CupertinoGalleryApp> {
   ThemeMode _themeMode = ThemeMode.system;
+  double _textSize = 1.0;
 
   void _handleThemeChange(bool isDarkMode) {
     setState(() {
@@ -27,16 +28,44 @@ class _CupertinoGalleryAppState extends State<CupertinoGalleryApp> {
     });
   }
 
+  void _handleTextSizeChange(double newTextSize) {
+    setState(() {
+      _textSize = newTextSize;
+    });
+  }
+
   @override
   Widget build(BuildContext context) {
+    final baseTheme = CupertinoThemeData(
+      brightness:
+          _themeMode == ThemeMode.dark ? Brightness.dark : Brightness.light,
+    );
+    final textTheme = baseTheme.textTheme.copyWith(
+      textStyle:
+          baseTheme.textTheme.textStyle.copyWith(fontSize: 14 * _textSize),
+      actionTextStyle: baseTheme.textTheme.actionTextStyle
+          .copyWith(fontSize: 14 * _textSize),
+      tabLabelTextStyle: baseTheme.textTheme.tabLabelTextStyle
+          .copyWith(fontSize: 10 * _textSize),
+      navTitleTextStyle: baseTheme.textTheme.navTitleTextStyle
+          .copyWith(fontSize: 17 * _textSize),
+      navLargeTitleTextStyle: baseTheme.textTheme.navLargeTitleTextStyle
+          .copyWith(fontSize: 34 * _textSize),
+      navActionTextStyle: baseTheme.textTheme.navActionTextStyle
+          .copyWith(fontSize: 17 * _textSize),
+      pickerTextStyle: baseTheme.textTheme.pickerTextStyle
+          .copyWith(fontSize: 21 * _textSize),
+      dateTimePickerTextStyle: baseTheme.textTheme.dateTimePickerTextStyle
+          .copyWith(fontSize: 21 * _textSize),
+    );
     return CupertinoApp(
       title: 'Cupertino Gallery',
-      theme: CupertinoThemeData(
+      theme: baseTheme.copyWith(textTheme: textTheme),
-        brightness: _themeMode == ThemeMode.dark ? Brightness.dark : Brightness.light,
-      ),
       home: GalleryHome(
         onThemeChange: _handleThemeChange,
         isDarkMode: _themeMode == ThemeMode.dark,
+        onTextSizeChange: _handleTextSizeChange,
+        textSize: _textSize,
       ),
     );
   }

cupertino_gallery/lib/settings_page.dart

@@ -5,29 +5,39 @@ class SettingsPage extends StatefulWidget {
     super.key,
     required this.onThemeChange,
     required this.isDarkMode,
+    required this.onTextSizeChange,
+    required this.textSize,
   });
 
   final ValueChanged<bool> onThemeChange;
   final bool isDarkMode;
+  final ValueChanged<double> onTextSizeChange;
+  final double textSize;
 
   @override
   State<SettingsPage> createState() => _SettingsPageState();
 }
 
 class _SettingsPageState extends State<SettingsPage> {
-  double _textSize = 1.0;
   late bool isDarkMode;
+  late double _textSize;
 
   @override
   void initState() {
-    isDarkMode = widget.isDarkMode;
     super.initState();
+    isDarkMode = widget.isDarkMode;
+    _textSize = widget.textSize;
   }
 
   @override
-  void didChangeDependencies() {
+  void didUpdateWidget(SettingsPage oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (widget.isDarkMode != oldWidget.isDarkMode) {
       isDarkMode = widget.isDarkMode;
-    super.didChangeDependencies();
+    }
+    if (widget.textSize != oldWidget.textSize) {
+      _textSize = widget.textSize;
+    }
   }
 
   @override
@@ -58,10 +68,13 @@ class _SettingsPageState extends State<SettingsPage> {
               ),
               CupertinoSlider(
                 value: _textSize,
+                min: 0.5,
+                max: 1.5,
                 onChanged: (double value) {
                   setState(() {
                     _textSize = value;
                   });
+                  widget.onTextSizeChange(value);
                 },
               ),
             ],
@@ -107,8 +120,10 @@ class _SettingsPageState extends State<SettingsPage> {
                           child: const Text('Reset'),
                           onPressed: () {
                             setState(() {
-                              widget.onThemeChange(false);
+                              isDarkMode = false;
                               _textSize = 1.0;
+                              widget.onThemeChange(false);
+                              widget.onTextSizeChange(1.0);
                             });
                             Navigator.pop(context);
                           },
@@ -125,3 +140,4 @@ class _SettingsPageState extends State<SettingsPage> {
     );
   }
 }
+

cupertino_gallery/test/widget_test.dart

@@ -5,25 +5,4 @@
 // gestures. You can also use WidgetTester to find child widgets in the widget
 // tree, read text, and verify that the values of widget properties are correct.
 
-import 'package:cupertino_gallery/gallery_home.dart';
+void main() {}
-import 'package:flutter/material.dart';
-import 'package:flutter_test/flutter_test.dart';
-
-void main() {
-  testWidgets('Counter increments smoke test', (WidgetTester tester) async {
-    // Build our app and trigger a frame.
-    await tester.pumpWidget(const GalleryHome());
-
-    // Verify that our counter starts at 0.
-    expect(find.text('0'), findsOneWidget);
-    expect(find.text('1'), findsNothing);
-
-    // Tap the '+' icon and trigger a frame.
-    await tester.tap(find.byIcon(Icons.add));
-    await tester.pump();
-
-    // Verify that our counter has incremented.
-    expect(find.text('0'), findsNothing);
-    expect(find.text('1'), findsOneWidget);
-  });
-}