share: Support switching accounts

assets/l10n/app_en.arb

@@ -1117,9 +1117,9 @@
       "allChannelsPageTitle": {"type": "String", "example": "All channels"}
     }
   },
-  "sharePageTitle": "Share",
-  "@sharePageTitle": {
-    "description": "Title for the page about sharing content received from other apps."
+  "shareChooseAccountLabel": "Choose an account",
+  "@shareChooseAccountLabel": {
+    "description": "Label for the page about selecting an account to share content received from other apps."
   },
   "mainMenuMyProfile": "My profile",
   "@mainMenuMyProfile": {

lib/generated/l10n/zulip_localizations.dart

@@ -1647,11 +1647,11 @@ abstract class ZulipLocalizations {
     String allChannelsPageTitle,
   );
 
-  /// Title for the page about sharing content received from other apps.
+  /// Label for the page about selecting an account to share content received from other apps.
   ///
   /// In en, this message translates to:
-  /// **'Share'**
-  String get sharePageTitle;
+  /// **'Choose an account'**
+  String get shareChooseAccountLabel;
 
   /// Label for main-menu button leading to the user's own profile.
   ///

lib/generated/l10n/zulip_localizations_ar.dart

@@ -934,7 +934,7 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => 'Share';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => 'My profile';

lib/generated/l10n/zulip_localizations_de.dart

@@ -957,7 +957,7 @@ class ZulipLocalizationsDe extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => 'Teilen';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => 'Mein Profil';

lib/generated/l10n/zulip_localizations_en.dart

@@ -934,7 +934,7 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => 'Share';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => 'My profile';

lib/generated/l10n/zulip_localizations_fr.dart

@@ -948,7 +948,7 @@ class ZulipLocalizationsFr extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => 'Share';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => 'My profile';

lib/generated/l10n/zulip_localizations_it.dart

@@ -949,7 +949,7 @@ class ZulipLocalizationsIt extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => 'Share';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => 'Il mio profilo';

lib/generated/l10n/zulip_localizations_ja.dart

@@ -913,7 +913,7 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => '共有';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => '自分のプロフィール';

lib/generated/l10n/zulip_localizations_nb.dart

@@ -934,7 +934,7 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => 'Share';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => 'My profile';

lib/generated/l10n/zulip_localizations_pl.dart

@@ -949,7 +949,7 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => 'Udostępnij';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => 'Mój profil';

lib/generated/l10n/zulip_localizations_ru.dart

@@ -959,7 +959,7 @@ class ZulipLocalizationsRu extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => 'Поделиться';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => 'Мой профиль';

lib/generated/l10n/zulip_localizations_sk.dart

@@ -936,7 +936,7 @@ class ZulipLocalizationsSk extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => 'Share';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => 'Môj profil';

lib/generated/l10n/zulip_localizations_sl.dart

@@ -969,7 +969,7 @@ class ZulipLocalizationsSl extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => 'Deli';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => 'Moj profil';

lib/generated/l10n/zulip_localizations_uk.dart

@@ -950,7 +950,7 @@ class ZulipLocalizationsUk extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => 'Поділитися';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => 'Мій профіль';

lib/generated/l10n/zulip_localizations_zh.dart

@@ -934,7 +934,7 @@ class ZulipLocalizationsZh extends ZulipLocalizations {
   }
 
   @override
-  String get sharePageTitle => 'Share';
+  String get shareChooseAccountLabel => 'Choose an account';
 
   @override
   String get mainMenuMyProfile => 'My profile';
@@ -2014,9 +2014,6 @@ class ZulipLocalizationsZhHansCn extends ZulipLocalizationsZh {
   @override
   String get channelsEmptyPlaceholder => '您还没有订阅任何频道。';
 
-  @override
-  String get sharePageTitle => '分享';
-
   @override
   String get mainMenuMyProfile => '个人资料';
 
@@ -3127,9 +3124,6 @@ class ZulipLocalizationsZhHantTw extends ZulipLocalizationsZh {
     return '您尚未訂閱任何頻道。請前往 <z-link>$allChannelsPageTitle</z-link> 並加入一些頻道。';
   }
 
-  @override
-  String get sharePageTitle => '分享';
-
   @override
   String get mainMenuMyProfile => '我的設定檔';
 

lib/widgets/share.dart

@@ -5,15 +5,19 @@ import 'package:flutter/material.dart';
 import 'package:flutter/scheduler.dart';
 import 'package:mime/mime.dart';
 
+import '../api/core.dart';
+import '../api/route/realm.dart';
 import '../generated/l10n/zulip_localizations.dart';
 import '../host/android_intents.dart';
 import '../log.dart';
 import '../model/binding.dart';
 import '../model/narrow.dart';
+import 'action_sheet.dart';
 import 'app.dart';
 import 'compose_box.dart';
 import 'content.dart';
 import 'dialog.dart';
+import 'home.dart';
 import 'icons.dart';
 import 'message_list.dart';
 import 'recent_dm_conversations.dart';
@@ -183,6 +187,7 @@ class ShareDialog extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final globalStore = GlobalStoreWidget.of(context);
     final store = PerAccountStoreWidget.of(context);
     final designVariables = DesignVariables.of(context);
     final zulipLocalizations = ZulipLocalizations.of(context);
@@ -205,15 +210,29 @@ class ShareDialog extends StatelessWidget {
         maxLines: 1);
     }
 
+    final hasMultipleAccounts =
+      List<int>.unmodifiable(globalStore.accountIds).length > 1;
+
     return DefaultTabController(
       length: 2,
       child: Column(children: [
         Row(children: [
-          SizedBox.square(
-            dimension: 42,
-            child: Padding(
-              padding: const EdgeInsets.all(7),
-              child: RealmContentNetworkImage(realmIconUrl))),
+          GestureDetector(
+            onTap: hasMultipleAccounts
+              ? () {
+                ChooseAccountForShareDialog.show(
+                  pageContext: context,
+                  selectedAccountId: store.accountId,
+                  sharedFiles: sharedFiles,
+                  sharedText: sharedText);
+              }
+              : null,
+            child: SizedBox.square(
+              dimension: 42,
+              child: Padding(
+                padding: const EdgeInsets.all(7),
+                child: RealmContentNetworkImage(realmIconUrl))),
+          ),
           Expanded(child: TabBar(
             labelStyle: labelStyle,
             labelColor: designVariables.iconSelected,
@@ -266,3 +285,127 @@ class ShareDialog extends StatelessWidget {
       ]));
   }
 }
+
+class ChooseAccountForShareDialog extends StatefulWidget {
+  const ChooseAccountForShareDialog({
+    super.key,
+    required this.sharedFiles,
+    required this.sharedText,
+  });
+
+  final Iterable<FileToUpload>? sharedFiles;
+  final String? sharedText;
+
+  static void show({
+    required BuildContext pageContext,
+    required int selectedAccountId,
+    required Iterable<FileToUpload>? sharedFiles,
+    required String? sharedText,
+  }) async {
+    unawaited(showModalBottomSheet<void>(
+      context: pageContext,
+      // Clip.hardEdge looks bad; Clip.antiAliasWithSaveLayer looks pixel-perfect
+      // on my iPhone 13 Pro but is marked as "much slower":
+      //   https://api.flutter.dev/flutter/dart-ui/Clip.html
+      clipBehavior: Clip.antiAlias,
+      useSafeArea: true,
+      isScrollControlled: true,
+      builder: (_) {
+        return SafeArea(
+          minimum: const EdgeInsets.only(bottom: 16),
+          child: ChooseAccountForShareDialog(
+            sharedFiles: sharedFiles,
+            sharedText: sharedText));
+      }));
+  }
+
+  @override
+  State<ChooseAccountForShareDialog> createState() => _ChooseAccountForShareDialogState();
+}
+
+class _ChooseAccountForShareDialogState extends State<ChooseAccountForShareDialog> {
+  late List<int> accountIds;
+  bool _hasUpdatedAccountsOnce = false;
+
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+
+    final globalStore = GlobalStoreWidget.of(context);
+    accountIds = List.unmodifiable(globalStore.accountIds);
+
+    if (_hasUpdatedAccountsOnce) return;
+    _hasUpdatedAccountsOnce = true;
+
+    for (final accountId in accountIds) {
+      final account = globalStore.getAccount(accountId);
+      if (account == null) continue;
+
+      unawaited(() async {
+        final GetServerSettingsResult serverSettings;
+        final connection = globalStore.apiConnection(
+          realmUrl: account.realmUrl,
+          zulipFeatureLevel: null);
+        try {
+          serverSettings = await getServerSettings(connection);
+        } catch (_) {
+          return;
+        } finally {
+          connection.close();
+        }
+
+        if (globalStore.getAccount(accountId) != null) {
+          await globalStore.updateRealmData(
+            accountId,
+            realmName: serverSettings.realmName,
+            realmIcon: serverSettings.realmIcon);
+        }
+      }());
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final globalStore = GlobalStoreWidget.of(context);
+    final zulipLocalizations = ZulipLocalizations.of(context);
+
+    final content = SliverList.builder(
+      itemCount: accountIds.length,
+      itemBuilder: (context, index) {
+        final accountId = accountIds[index];
+        final account = globalStore.getAccount(accountId);
+        if (account == null) {
+          return const SizedBox.shrink();
+        }
+
+        return ListTile(
+          onTap: () {
+            // First change home page account to the selected account.
+            HomePage.navigate(context, accountId: accountId);
+            // Then push a new share dialog for the selected account.
+            ShareDialog.show(
+              pageContext: context,
+              initialAccountId: accountId,
+              sharedFiles: widget.sharedFiles,
+              sharedText: widget.sharedText);
+          },
+          leading: AspectRatio(
+            aspectRatio: 1,
+            child: account.realmIcon != null
+              ? Image.network(
+                  account.realmUrl.resolveUri(account.realmIcon!).toString(),
+                  headers: userAgentHeader())
+              : null),
+          title: Text(account.realmName ?? account.realmUrl.toString()),
+          subtitle: Text(account.email));
+      });
+
+    return DraggableScrollableModalBottomSheet(
+      header: Padding(
+        padding: const EdgeInsets.only(top: 8),
+        child: BottomSheetHeader(title: zulipLocalizations.shareChooseAccountLabel)),
+      contentSliver: SliverPadding(
+        padding: const EdgeInsets.symmetric(horizontal: 8),
+        sliver: content));
+  }
+}