settings: Add browser preference setting ui

The translation for the label is taken from zulip-mobile. The user
facing string refers to "in in-app browser" when the actual value is
`UrlLaunchMode.platformDefault`. This is consistent with the behavior
the user sees when the link is a HTTP URL on Android and iOS, which
should cover the majority of use cases of this setting (and probably
what the user would expect).

The UI currently does not have a design, and is made to be as simple as
possible to implement for now.

Fixes: #1228

Signed-off-by: Zixuan James Li <[email protected]>

Author: PIG208

assets/l10n/app_en.arb

@@ -803,6 +803,10 @@
   "@themeSettingSystem": {
     "description": "Label for system theme setting."
   },
+  "openLinksWithInAppBrowser": "Open links with in-app browser",
+  "@openLinksWithInAppBrowser": {
+    "description": "Label for toggling setting to open links with in-app browser"
+  },
   "pollWidgetQuestionMissing": "No question.",
   "@pollWidgetQuestionMissing": {
     "description": "Text to display for a poll when the question is missing"

lib/generated/l10n/zulip_localizations.dart

@@ -1173,6 +1173,12 @@ abstract class ZulipLocalizations {
   /// **'System'**
   String get themeSettingSystem;
 
+  /// Label for toggling setting to open links with in-app browser
+  ///
+  /// In en, this message translates to:
+  /// **'Open links with in-app browser'**
+  String get openLinksWithInAppBrowser;
+
   /// Text to display for a poll when the question is missing
   ///
   /// In en, this message translates to:

lib/generated/l10n/zulip_localizations_ar.dart

@@ -628,6 +628,9 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
   @override
   String get themeSettingSystem => 'System';
 
+  @override
+  String get openLinksWithInAppBrowser => 'Open links with in-app browser';
+
   @override
   String get pollWidgetQuestionMissing => 'No question.';
 

lib/generated/l10n/zulip_localizations_en.dart

@@ -628,6 +628,9 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
   @override
   String get themeSettingSystem => 'System';
 
+  @override
+  String get openLinksWithInAppBrowser => 'Open links with in-app browser';
+
   @override
   String get pollWidgetQuestionMissing => 'No question.';
 

lib/generated/l10n/zulip_localizations_ja.dart

@@ -628,6 +628,9 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
   @override
   String get themeSettingSystem => 'System';
 
+  @override
+  String get openLinksWithInAppBrowser => 'Open links with in-app browser';
+
   @override
   String get pollWidgetQuestionMissing => 'No question.';
 

lib/generated/l10n/zulip_localizations_nb.dart

@@ -628,6 +628,9 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
   @override
   String get themeSettingSystem => 'System';
 
+  @override
+  String get openLinksWithInAppBrowser => 'Open links with in-app browser';
+
   @override
   String get pollWidgetQuestionMissing => 'No question.';
 

lib/generated/l10n/zulip_localizations_pl.dart

@@ -628,6 +628,9 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
   @override
   String get themeSettingSystem => 'System';
 
+  @override
+  String get openLinksWithInAppBrowser => 'Open links with in-app browser';
+
   @override
   String get pollWidgetQuestionMissing => 'Brak pytania.';
 

lib/generated/l10n/zulip_localizations_ru.dart

@@ -628,6 +628,9 @@ class ZulipLocalizationsRu extends ZulipLocalizations {
   @override
   String get themeSettingSystem => 'System';
 
+  @override
+  String get openLinksWithInAppBrowser => 'Open links with in-app browser';
+
   @override
   String get pollWidgetQuestionMissing => 'Нет вопроса.';
 

lib/generated/l10n/zulip_localizations_sk.dart

@@ -628,6 +628,9 @@ class ZulipLocalizationsSk extends ZulipLocalizations {
   @override
   String get themeSettingSystem => 'System';
 
+  @override
+  String get openLinksWithInAppBrowser => 'Open links with in-app browser';
+
   @override
   String get pollWidgetQuestionMissing => 'Bez otázky.';
 

lib/widgets/settings.dart

@@ -2,6 +2,7 @@ import 'package:drift/drift.dart' hide Column;
 import 'package:flutter/material.dart';
 
 import '../generated/l10n/zulip_localizations.dart';
+import '../model/binding.dart';
 import '../model/database.dart';
 import '../model/settings.dart';
 import 'app_bar.dart';
@@ -23,6 +24,7 @@ class SettingsPage extends StatelessWidget {
       appBar: ZulipAppBar(
         title: Text(zulipLocalizations.settingsPageTitle)),
       body: Column(children: [
+        const _BrowserPreferenceSetting(),
         const _ThemeSetting(),
       ]));
   }
@@ -54,3 +56,31 @@ class _ThemeSetting extends StatelessWidget {
       ]);
   }
 }
+
+class _BrowserPreferenceSetting extends StatelessWidget {
+  const _BrowserPreferenceSetting();
+
+  void _handleChange(BuildContext context, bool newOpenLinksWithInAppBrowser) {
+    GlobalStoreWidget.of(context).updateGlobalSettings(
+      GlobalSettingsCompanion(browserPreference: Value(
+        newOpenLinksWithInAppBrowser ? BrowserPreference.embedded
+                                     : BrowserPreference.external)));
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final zulipLocalizations = ZulipLocalizations.of(context);
+    // On Android and iOS, an in-app browser will be used for HTTP URLs if the
+    // launch mode is [UrlLaunchMode.platformDefault], which is consistent with
+    // the user-facing "Open links with in-app browser" label.  In practice,
+    // external browsers/apps can still be used for other types of links, but
+    // those links aren't common in normal usage.
+    final openLinksWithInAppBrowser =
+      GlobalStoreWidget.of(context).globalSettings.urlLaunchMode
+      == UrlLaunchMode.platformDefault;
+    return SwitchListTile.adaptive(
+      title: Text(zulipLocalizations.openLinksWithInAppBrowser),
+      value: openLinksWithInAppBrowser,
+      onChanged: (newValue) => _handleChange(context, newValue));
+  }
+}

test/flutter_checks.dart

@@ -82,6 +82,10 @@ extension RadioListTileChecks<T> on Subject<RadioListTile<T>> {
   Subject<bool> get checked => has((x) => x.checked, 'checked');
 }
 
+extension SwitchListTileChecks<T> on Subject<SwitchListTile> {
+  Subject<bool> get value => has((x) => x.value, 'value');
+}
+
 extension TextChecks on Subject<Text> {
   Subject<String?> get data => has((t) => t.data, 'data');
   Subject<TextStyle?> get style => has((t) => t.style, 'style');

test/widgets/settings_test.dart

@@ -25,6 +25,51 @@ void main() {
     await tester.pump();
   }
 
+  group('BrowserPreference', () {
+    Finder useInAppBrowserSwitchFinder = find.ancestor(
+      of: find.text('Open links with in-app browser'),
+      matching: find.byType(SwitchListTile));
+
+    void checkSwitchAndGlobalSettings(WidgetTester tester, {
+      required bool checked,
+      required BrowserPreference? expectedBrowserPreference,
+    }) {
+      check(tester.widget<SwitchListTile>(useInAppBrowserSwitchFinder))
+        .value.equals(checked);
+      check(testBinding.globalStore)
+        .globalSettings.browserPreference.equals(expectedBrowserPreference);
+    }
+
+    testWidgets('smoke', (tester) async {
+      await testBinding.globalStore.updateGlobalSettings(
+        eg.globalSettings(
+          browserPreference: BrowserPreference.external).toCompanion(false));
+      await prepare(tester);
+      checkSwitchAndGlobalSettings(tester,
+        checked: false, expectedBrowserPreference: BrowserPreference.external);
+
+      await tester.tap(useInAppBrowserSwitchFinder);
+      await tester.pump();
+      checkSwitchAndGlobalSettings(tester,
+        checked: true, expectedBrowserPreference: BrowserPreference.embedded);
+    });
+
+    testWidgets('use platform-specific default browser preference', (tester) async {
+      await prepare(tester);
+      bool useInAppBrowserExpected = defaultTargetPlatform == TargetPlatform.android;
+      checkSwitchAndGlobalSettings(tester,
+        checked: useInAppBrowserExpected, expectedBrowserPreference: null);
+
+      await tester.tap(useInAppBrowserSwitchFinder);
+      await tester.pump();
+      useInAppBrowserExpected = !useInAppBrowserExpected;
+      checkSwitchAndGlobalSettings(tester,
+        checked: useInAppBrowserExpected,
+        expectedBrowserPreference: useInAppBrowserExpected
+          ? BrowserPreference.embedded : BrowserPreference.external);
+    }, variant: TargetPlatformVariant({TargetPlatform.android, TargetPlatform.iOS}));
+  });
+
   group('ThemeSetting', () {
     Finder findRadioListTileWithTitle(String title) => find.ancestor(
       of: find.text(title),