user [nfc]: Move getDisplayEmailFor method to lib/api/model/model.dart

Moved getDisplayEmailFor method which gets
the user's real email address to
lib/api/model/model.dart and
refactored usages to remove duplication.

Author: fombalang

lib/api/model/model.dart

@@ -1,5 +1,6 @@
 import 'package:json_annotation/json_annotation.dart';
 
+import '../../model/store.dart';
 import 'events.dart';
 import 'initial_snapshot.dart';
 import 'reaction.dart';
@@ -305,6 +306,34 @@ enum UserRole{
   int? toJson() => apiValue;
 }
 
+/// The given user's real email address, if known, for displaying in the UI.
+///
+/// Returns null if self-user isn't able to see [user]'s real email address.
+String? getDisplayEmailFor(User user, {required PerAccountStore store}) {
+  if (store.account.zulipFeatureLevel >= 163) { // TODO(server-7)
+    // A non-null value means self-user has access to [user]'s real email,
+    // while a null value means it doesn't have access to the email.
+    // Search for "delivery_email" in https://zulip.com/api/register-queue.
+    return user.deliveryEmail;
+  } else {
+    if (user.deliveryEmail != null) {
+      // A non-null value means self-user has access to [user]'s real email,
+      // while a null value doesn't necessarily mean it doesn't have access
+      // to the email, ....
+      return user.deliveryEmail;
+    } else if (store.emailAddressVisibility == EmailAddressVisibility.everyone) {
+      // ... we have to also check for [PerAccountStore.emailAddressVisibility].
+      // See:
+      //   * https://github.com/zulip/zulip-mobile/pull/5515#discussion_r997731727
+      //   * https://chat.zulip.org/#narrow/stream/378-api-design/topic/email.20address.20visibility/near/1296133
+      return user.email;
+    } else {
+      return null;
+    }
+  }
+}
+
+
 /// As in `streams` in the initial snapshot.
 ///
 /// Not called `Stream` because dart:async uses that name.

lib/widgets/profile.dart

@@ -3,11 +3,9 @@ import 'dart:convert';
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/zulip_localizations.dart';
 
-import '../api/model/initial_snapshot.dart';
 import '../api/model/model.dart';
 import '../model/content.dart';
 import '../model/narrow.dart';
-import '../model/store.dart';
 import 'app_bar.dart';
 import 'content.dart';
 import 'message_list.dart';
@@ -36,32 +34,6 @@ class ProfilePage extends StatelessWidget {
       page: ProfilePage(userId: userId));
   }
 
-  /// The given user's real email address, if known, for displaying in the UI.
-  ///
-  /// Returns null if self-user isn't able to see [user]'s real email address.
-  String? _getDisplayEmailFor(User user, {required PerAccountStore store}) {
-    if (store.account.zulipFeatureLevel >= 163) { // TODO(server-7)
-      // A non-null value means self-user has access to [user]'s real email,
-      // while a null value means it doesn't have access to the email.
-      // Search for "delivery_email" in https://zulip.com/api/register-queue.
-      return user.deliveryEmail;
-    } else {
-      if (user.deliveryEmail != null) {
-        // A non-null value means self-user has access to [user]'s real email,
-        // while a null value doesn't necessarily mean it doesn't have access
-        // to the email, ....
-        return user.deliveryEmail;
-      } else if (store.emailAddressVisibility == EmailAddressVisibility.everyone) {
-        // ... we have to also check for [PerAccountStore.emailAddressVisibility].
-        // See:
-        //   * https://github.com/zulip/zulip-mobile/pull/5515#discussion_r997731727
-        //   * https://chat.zulip.org/#narrow/stream/378-api-design/topic/email.20address.20visibility/near/1296133
-        return user.email;
-      } else {
-        return null;
-      }
-    }
-  }
 
   @override
   Widget build(BuildContext context) {
@@ -72,7 +44,7 @@ class ProfilePage extends StatelessWidget {
       return const _ProfileErrorPage();
     }
 
-    final displayEmail = _getDisplayEmailFor(user, store: store);
+    final displayEmail = getDisplayEmailFor(user, store: store);
     final items = [
       Center(
         child: Avatar(userId: userId, size: 200, borderRadius: 200 / 8)),