dialog: Use Cupertino-flavored alert dialogs on iOS

lib/widgets/dialog.dart

@@ -1,3 +1,5 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 
 import '../generated/l10n/zulip_localizations.dart';
@@ -7,18 +9,29 @@ import 'app.dart';
 import 'content.dart';
 import 'store.dart';
 
-Widget _dialogActionText(String text) {
-  return Text(
-    text,
-
-    // As suggested by
-    //   https://api.flutter.dev/flutter/material/AlertDialog/actions.html :
-    // > It is recommended to set the Text.textAlign to TextAlign.end
-    // > for the Text within the TextButton, so that buttons whose
-    // > labels wrap to an extra line align with the overall
-    // > OverflowBar's alignment within the dialog.
-    textAlign: TextAlign.end,
-  );
+/// A platform-appropriate action for [AlertDialog.adaptive]'s [actions] param.
+Widget _adaptiveAction({required VoidCallback onPressed, required String text}) {
+  switch (defaultTargetPlatform) {
+    case TargetPlatform.android:
+    case TargetPlatform.fuchsia:
+    case TargetPlatform.linux:
+    case TargetPlatform.windows:
+      return TextButton(
+        onPressed: onPressed,
+        child: Text(
+          text,
+          // As suggested by
+          //   https://api.flutter.dev/flutter/material/AlertDialog/actions.html :
+          // > It is recommended to set the Text.textAlign to TextAlign.end
+          // > for the Text within the TextButton, so that buttons whose
+          // > labels wrap to an extra line align with the overall
+          // > OverflowBar's alignment within the dialog.
+          textAlign: TextAlign.end));
+
+    case TargetPlatform.iOS:
+    case TargetPlatform.macOS:
+      return CupertinoDialogAction(onPressed: onPressed, child: Text(text));
+  }
 }
 
 /// Tracks the status of a dialog, in being still open or already closed.
@@ -71,17 +84,17 @@ DialogStatus<void> showErrorDialog({
   final zulipLocalizations = ZulipLocalizations.of(context);
   final future = showDialog<void>(
     context: context,
-    builder: (BuildContext context) => AlertDialog(
+    builder: (BuildContext context) => AlertDialog.adaptive(
       title: Text(title),
       content: message != null ? SingleChildScrollView(child: Text(message)) : null,
       actions: [
         if (learnMoreButtonUrl != null)
-          TextButton(
+          _adaptiveAction(
             onPressed: () => PlatformActions.launchUrl(context, learnMoreButtonUrl),
-            child: _dialogActionText(zulipLocalizations.errorDialogLearnMore)),
-        TextButton(
+            text: zulipLocalizations.errorDialogLearnMore),
+        _adaptiveAction(
           onPressed: () => Navigator.pop(context),
-          child: _dialogActionText(zulipLocalizations.errorDialogContinue)),
+          text: zulipLocalizations.errorDialogContinue),
       ]));
   return DialogStatus(future);
 }
@@ -103,16 +116,16 @@ DialogStatus<bool> showSuggestedActionDialog({
   final zulipLocalizations = ZulipLocalizations.of(context);
   final future = showDialog<bool>(
     context: context,
-    builder: (BuildContext context) => AlertDialog(
+    builder: (BuildContext context) => AlertDialog.adaptive(
       title: Text(title),
       content: SingleChildScrollView(child: Text(message)),
       actions: [
-        TextButton(
+        _adaptiveAction(
           onPressed: () => Navigator.pop<bool>(context, null),
-          child: _dialogActionText(zulipLocalizations.dialogCancel)),
-        TextButton(
+          text: zulipLocalizations.dialogCancel),
+        _adaptiveAction(
           onPressed: () => Navigator.pop<bool>(context, true),
-          child: _dialogActionText(actionButtonText ?? zulipLocalizations.dialogContinue)),
+          text: actionButtonText ?? zulipLocalizations.dialogContinue),
       ]));
   return DialogStatus(future);
 }
@@ -164,7 +177,7 @@ class UpgradeWelcomeDialog extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     final zulipLocalizations = ZulipLocalizations.of(context);
-    return AlertDialog(
+    return AlertDialog.adaptive(
       title: Text(zulipLocalizations.upgradeWelcomeDialogTitle),
       content: SingleChildScrollView(
         child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
@@ -177,8 +190,9 @@ class UpgradeWelcomeDialog extends StatelessWidget {
               zulipLocalizations.upgradeWelcomeDialogLinkText)),
         ])),
       actions: [
-        TextButton(onPressed: () => Navigator.pop(context),
-          child: Text(zulipLocalizations.upgradeWelcomeDialogDismiss)),
+        _adaptiveAction(
+          onPressed: () => Navigator.pop(context),
+          text: zulipLocalizations.upgradeWelcomeDialogDismiss)
       ]);
   }
 }

test/widgets/action_sheet_test.dart

@@ -335,7 +335,7 @@ void main() {
         await tester.tap(findButtonForLabel('Mark channel as read'));
         await tester.pumpAndSettle();
         checkRequest(someChannel.streamId);
-        checkNoErrorDialog(tester);
+        checkNoDialog(tester);
       });
 
       testWidgets('request fails', (tester) async {
@@ -776,7 +776,7 @@ void main() {
         await tester.tap(findButtonForLabel('Mark as resolved'));
         await tester.pumpAndSettle();
 
-        checkNoErrorDialog(tester);
+        checkNoDialog(tester);
         checkRequest(message.id, '✔ zulip');
       });
 
@@ -791,7 +791,7 @@ void main() {
         await tester.tap(findButtonForLabel('Mark as resolved'));
         await tester.pumpAndSettle();
 
-        checkNoErrorDialog(tester);
+        checkNoDialog(tester);
         checkRequest(message.id, '✔ zulip');
       });
 
@@ -805,7 +805,7 @@ void main() {
         await tester.tap(findButtonForLabel('Mark as unresolved'));
         await tester.pumpAndSettle();
 
-        checkNoErrorDialog(tester);
+        checkNoDialog(tester);
         checkRequest(message.id, 'zulip');
       });
 
@@ -819,7 +819,7 @@ void main() {
         await tester.tap(findButtonForLabel('Mark as unresolved'));
         await tester.pumpAndSettle();
 
-        checkNoErrorDialog(tester);
+        checkNoDialog(tester);
         checkRequest(message.id, 'zulip');
       });
 

test/widgets/app_test.dart

@@ -401,14 +401,14 @@ void main() {
       check(ZulipApp.ready).value.isFalse();
       await tester.pump();
       check(findSnackBarByText(message).evaluate()).isEmpty();
-      checkNoErrorDialog(tester);
+      checkNoDialog(tester);
 
       check(ZulipApp.ready).value.isTrue();
       // After app startup, reportErrorToUserBriefly displays a SnackBar.
       reportErrorToUserBriefly(message, details: details);
       await tester.pumpAndSettle();
       check(findSnackBarByText(message).evaluate()).single;
-      checkNoErrorDialog(tester);
+      checkNoDialog(tester);
 
       // Open the error details dialog.
       await tester.tap(find.text('Details'));
@@ -493,7 +493,7 @@ void main() {
       reportErrorToUserModally(title, message: message);
       check(ZulipApp.ready).value.isFalse();
       await tester.pump();
-      checkNoErrorDialog(tester);
+      checkNoDialog(tester);
 
       check(ZulipApp.ready).value.isTrue();
       // After app startup, reportErrorToUserModally displays an [AlertDialog].

test/widgets/compose_box_test.dart

@@ -395,7 +395,7 @@ void main() {
         await prepareWithContent(tester,
           makeStringWithCodePoints(kMaxMessageLengthCodePoints));
         await tapSendButton(tester);
-        checkNoErrorDialog(tester);
+        checkNoDialog(tester);
       });
 
       testWidgets('code points not counted unnecessarily', (tester) async {
@@ -434,7 +434,7 @@ void main() {
         await prepareWithTopic(tester,
           makeStringWithCodePoints(kMaxTopicLengthCodePoints));
         await tapSendButton(tester);
-        checkNoErrorDialog(tester);
+        checkNoDialog(tester);
       });
 
       testWidgets('code points not counted unnecessarily', (tester) async {
@@ -938,7 +938,7 @@ void main() {
       await setupAndTapSend(tester, prepareResponse: (int messageId) {
         connection.prepare(json: SendMessageResult(id: messageId).toJson());
       });
-      checkNoErrorDialog(tester);
+      checkNoDialog(tester);
     });
 
     testWidgets('ZulipApiException', (tester) async {
@@ -1078,7 +1078,7 @@ void main() {
         check(call.allowMultiple).equals(true);
         check(call.type).equals(FileType.media);
 
-        checkNoErrorDialog(tester);
+        checkNoDialog(tester);
 
         check(controller!.content.text)
           .equals('see image: [Uploading image.jpg…]()\n\n');
@@ -1137,7 +1137,7 @@ void main() {
         check(call.source).equals(ImageSource.camera);
         check(call.requestFullMetadata).equals(false);
 
-        checkNoErrorDialog(tester);
+        checkNoDialog(tester);
 
         check(controller!.content.text)
           .equals('see image: [Uploading image.jpg…]()\n\n');
@@ -1864,7 +1864,7 @@ void main() {
           UploadFileResult(url: '/path/file.jpg').toJson());
         await tester.tap(find.byIcon(ZulipIcons.attach_file), warnIfMissed: false);
         await tester.pump(Duration.zero);
-        checkNoErrorDialog(tester);
+        checkNoDialog(tester);
         check(testBinding.takePickFilesCalls()).length.equals(1);
         connection.takeRequests(); // upload request
 

test/widgets/dialog_checks.dart

@@ -1,10 +1,12 @@
 import 'package:checks/checks.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_checks/flutter_checks.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:zulip/widgets/dialog.dart';
 
-/// In a widget test, check that showErrorDialog was called with the right text.
+/// In a widget test, check that [showErrorDialog] was called with the right text.
 ///
 /// Checks for an error dialog matching an expected title
 /// and, optionally, matching an expected message. Fails if none is found.
@@ -15,24 +17,41 @@ Widget checkErrorDialog(WidgetTester tester, {
   required String expectedTitle,
   String? expectedMessage,
 }) {
-  final dialog = tester.widget<AlertDialog>(find.byType(AlertDialog));
-  tester.widget(find.descendant(matchRoot: true,
-    of: find.byWidget(dialog.title!), matching: find.text(expectedTitle)));
-  if (expectedMessage != null) {
-    tester.widget(find.descendant(matchRoot: true,
-      of: find.byWidget(dialog.content!), matching: find.text(expectedMessage)));
-  }
-
-  // TODO check "Learn more" button?
+  switch (defaultTargetPlatform) {
+    case TargetPlatform.android:
+    case TargetPlatform.fuchsia:
+    case TargetPlatform.linux:
+    case TargetPlatform.windows:
+      final dialog = tester.widget<AlertDialog>(find.bySubtype<AlertDialog>());
+      tester.widget(find.descendant(matchRoot: true,
+        of: find.byWidget(dialog.title!), matching: find.text(expectedTitle)));
+      if (expectedMessage != null) {
+        tester.widget(find.descendant(matchRoot: true,
+          of: find.byWidget(dialog.content!), matching: find.text(expectedMessage)));
+      }
+      return tester.widget(find.descendant(of: find.byWidget(dialog),
+        matching: find.widgetWithText(TextButton, 'OK')));
 
-  return tester.widget(
-    find.descendant(of: find.byWidget(dialog),
-      matching: find.widgetWithText(TextButton, 'OK')));
+    case TargetPlatform.iOS:
+    case TargetPlatform.macOS:
+      final dialog = tester.widget<CupertinoAlertDialog>(find.byType(CupertinoAlertDialog));
+      tester.widget(find.descendant(matchRoot: true,
+        of: find.byWidget(dialog.title!), matching: find.text(expectedTitle)));
+      if (expectedMessage != null) {
+        tester.widget(find.descendant(matchRoot: true,
+          of: find.byWidget(dialog.content!), matching: find.text(expectedMessage)));
+      }
+      return tester.widget(find.descendant(of: find.byWidget(dialog),
+        matching: find.widgetWithText(CupertinoDialogAction, 'OK')));
+  }
 }
 
-// TODO(#996) update this to check for per-platform flavors of alert dialog
-void checkNoErrorDialog(WidgetTester tester) {
-  check(find.byType(AlertDialog)).findsNothing();
+/// Checks that there is no dialog.
+/// Fails if one is found.
+void checkNoDialog(WidgetTester tester) {
+  check(find.byType(Dialog)).findsNothing();
+  check(find.bySubtype<AlertDialog>()).findsNothing();
+  check(find.byType(CupertinoAlertDialog)).findsNothing();
 }
 
 /// In a widget test, check that [showSuggestedActionDialog] was called
@@ -49,19 +68,35 @@ void checkNoErrorDialog(WidgetTester tester) {
   required String expectedMessage,
   String? expectedActionButtonText,
 }) {
-  final dialog = tester.widget<AlertDialog>(find.byType(AlertDialog));
-  tester.widget(find.descendant(matchRoot: true,
-    of: find.byWidget(dialog.title!), matching: find.text(expectedTitle)));
-  tester.widget(find.descendant(matchRoot: true,
-    of: find.byWidget(dialog.content!), matching: find.text(expectedMessage)));
+  switch (defaultTargetPlatform) {
+    case TargetPlatform.android:
+    case TargetPlatform.fuchsia:
+    case TargetPlatform.linux:
+    case TargetPlatform.windows:
+      final dialog = tester.widget<AlertDialog>(find.bySubtype<AlertDialog>());
+      tester.widget(find.descendant(matchRoot: true,
+        of: find.byWidget(dialog.title!), matching: find.text(expectedTitle)));
+      tester.widget(find.descendant(matchRoot: true,
+        of: find.byWidget(dialog.content!), matching: find.text(expectedMessage)));
 
-  final actionButton = tester.widget(
-    find.descendant(of: find.byWidget(dialog),
-      matching: find.widgetWithText(TextButton, expectedActionButtonText ?? 'Continue')));
+      final actionButton = tester.widget(find.descendant(of: find.byWidget(dialog),
+        matching: find.widgetWithText(TextButton, expectedActionButtonText ?? 'Continue')));
+      final cancelButton = tester.widget(find.descendant(of: find.byWidget(dialog),
+        matching: find.widgetWithText(TextButton, 'Cancel')));
+      return (actionButton, cancelButton);
 
-  final cancelButton = tester.widget(
-    find.descendant(of: find.byWidget(dialog),
-      matching: find.widgetWithText(TextButton, 'Cancel')));
+    case TargetPlatform.iOS:
+    case TargetPlatform.macOS:
+      final dialog = tester.widget<CupertinoAlertDialog>(find.byType(CupertinoAlertDialog));
+      tester.widget(find.descendant(matchRoot: true,
+        of: find.byWidget(dialog.title!), matching: find.text(expectedTitle)));
+      tester.widget(find.descendant(matchRoot: true,
+        of: find.byWidget(dialog.content!), matching: find.text(expectedMessage)));
 
-  return (actionButton, cancelButton);
+      final actionButton = tester.widget(find.descendant(of: find.byWidget(dialog),
+        matching: find.widgetWithText(CupertinoDialogAction, expectedActionButtonText ?? 'Continue')));
+      final cancelButton = tester.widget(find.descendant(of: find.byWidget(dialog),
+        matching: find.widgetWithText(CupertinoDialogAction, 'Cancel')));
+      return (actionButton, cancelButton);
+  }
 }