action_sheet: Add DM action sheet

Fixes #1272.

While working on the design update for the Inbox page, I noticed that
we were well-prepared to implement the DM action sheet, including a
way to show the participants of a group DM in the action sheet itself.
For that, I've used a scrollable collection of user "chips" in the
action-sheet header, with avatar, presence, and name. Discussion
ongoing for whether we like this approach or prefer to put the users
list on a separate page, as in issue #1534:
  https://chat.zulip.org/#narrow/channel/48-mobile/topic/abbreviated.20headings/near/2366774

In this commit, the action sheet can have up to two buttons:
- "View profile", for 1:1 DMs
- "Mark conversation as read", if there are unreads.

Author: chrisbobbe

assets/l10n/app_en.arb

@@ -321,6 +321,29 @@
   "@actionSheetOptionCopyTopicLink": {
     "description": "Label for copy topic link button in action sheet."
   },
+  "actionSheetTitleDm": "DMs with {user}",
+  "@actionSheetTitleDm": {
+    "description": "The title of an action sheet for a 1:1 DM conversation with another user.",
+    "placeholders": {
+      "user": {"type": "String", "example": "Alice"}
+    }
+  },
+  "actionSheetTitleSelfDm": "DMs with yourself",
+  "@actionSheetTitleSelfDm": {
+    "description": "The title of an action sheet for the 1:1 DM conversation with yourself."
+  },
+  "actionSheetTitleGroupDm": "Group DM",
+  "@actionSheetTitleGroupDm": {
+    "description": "The title of an action sheet for a group DM conversation."
+  },
+  "actionSheetOptionViewProfile": "View profile",
+  "@actionSheetOptionViewProfile": {
+    "description": "Option to view the user's profile in the action sheet for a 1:1 DM conversation."
+  },
+  "actionSheetOptionMarkDmConversationAsRead": "Mark conversation as read",
+  "@actionSheetOptionMarkDmConversationAsRead": {
+    "description": "Option to mark a DM conversation as read in the action sheet."
+  },
   "errorWebAuthOperationalErrorTitle": "Something went wrong",
   "@errorWebAuthOperationalErrorTitle": {
     "description": "Error title when third-party authentication has an operational error (not necessarily caused by invalid credentials)."

lib/generated/l10n/zulip_localizations.dart

@@ -599,6 +599,36 @@ abstract class ZulipLocalizations {
   /// **'Copy link to topic'**
   String get actionSheetOptionCopyTopicLink;
 
+  /// The title of an action sheet for a 1:1 DM conversation with another user.
+  ///
+  /// In en, this message translates to:
+  /// **'DMs with {user}'**
+  String actionSheetTitleDm(String user);
+
+  /// The title of an action sheet for the 1:1 DM conversation with yourself.
+  ///
+  /// In en, this message translates to:
+  /// **'DMs with yourself'**
+  String get actionSheetTitleSelfDm;
+
+  /// The title of an action sheet for a group DM conversation.
+  ///
+  /// In en, this message translates to:
+  /// **'Group DM'**
+  String get actionSheetTitleGroupDm;
+
+  /// Option to view the user's profile in the action sheet for a 1:1 DM conversation.
+  ///
+  /// In en, this message translates to:
+  /// **'View profile'**
+  String get actionSheetOptionViewProfile;
+
+  /// Option to mark a DM conversation as read in the action sheet.
+  ///
+  /// In en, this message translates to:
+  /// **'Mark conversation as read'**
+  String get actionSheetOptionMarkDmConversationAsRead;
+
   /// Error title when third-party authentication has an operational error (not necessarily caused by invalid credentials).
   ///
   /// In en, this message translates to:

lib/generated/l10n/zulip_localizations_ar.dart

@@ -271,6 +271,24 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
   @override
   String get actionSheetOptionCopyTopicLink => 'Copy link to topic';
 
+  @override
+  String actionSheetTitleDm(String user) {
+    return 'DMs with $user';
+  }
+
+  @override
+  String get actionSheetTitleSelfDm => 'DMs with yourself';
+
+  @override
+  String get actionSheetTitleGroupDm => 'Group DM';
+
+  @override
+  String get actionSheetOptionViewProfile => 'View profile';
+
+  @override
+  String get actionSheetOptionMarkDmConversationAsRead =>
+      'Mark conversation as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_de.dart

@@ -279,6 +279,24 @@ class ZulipLocalizationsDe extends ZulipLocalizations {
   @override
   String get actionSheetOptionCopyTopicLink => 'Link zum Thema kopieren';
 
+  @override
+  String actionSheetTitleDm(String user) {
+    return 'DMs with $user';
+  }
+
+  @override
+  String get actionSheetTitleSelfDm => 'DMs with yourself';
+
+  @override
+  String get actionSheetTitleGroupDm => 'Group DM';
+
+  @override
+  String get actionSheetOptionViewProfile => 'View profile';
+
+  @override
+  String get actionSheetOptionMarkDmConversationAsRead =>
+      'Mark conversation as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Etwas ist schiefgelaufen';
 

lib/generated/l10n/zulip_localizations_el.dart

@@ -271,6 +271,24 @@ class ZulipLocalizationsEl extends ZulipLocalizations {
   @override
   String get actionSheetOptionCopyTopicLink => 'Copy link to topic';
 
+  @override
+  String actionSheetTitleDm(String user) {
+    return 'DMs with $user';
+  }
+
+  @override
+  String get actionSheetTitleSelfDm => 'DMs with yourself';
+
+  @override
+  String get actionSheetTitleGroupDm => 'Group DM';
+
+  @override
+  String get actionSheetOptionViewProfile => 'View profile';
+
+  @override
+  String get actionSheetOptionMarkDmConversationAsRead =>
+      'Mark conversation as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_en.dart

@@ -271,6 +271,24 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
   @override
   String get actionSheetOptionCopyTopicLink => 'Copy link to topic';
 
+  @override
+  String actionSheetTitleDm(String user) {
+    return 'DMs with $user';
+  }
+
+  @override
+  String get actionSheetTitleSelfDm => 'DMs with yourself';
+
+  @override
+  String get actionSheetTitleGroupDm => 'Group DM';
+
+  @override
+  String get actionSheetOptionViewProfile => 'View profile';
+
+  @override
+  String get actionSheetOptionMarkDmConversationAsRead =>
+      'Mark conversation as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_es.dart

@@ -271,6 +271,24 @@ class ZulipLocalizationsEs extends ZulipLocalizations {
   @override
   String get actionSheetOptionCopyTopicLink => 'Copy link to topic';
 
+  @override
+  String actionSheetTitleDm(String user) {
+    return 'DMs with $user';
+  }
+
+  @override
+  String get actionSheetTitleSelfDm => 'DMs with yourself';
+
+  @override
+  String get actionSheetTitleGroupDm => 'Group DM';
+
+  @override
+  String get actionSheetOptionViewProfile => 'View profile';
+
+  @override
+  String get actionSheetOptionMarkDmConversationAsRead =>
+      'Mark conversation as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_fr.dart

@@ -281,6 +281,24 @@ class ZulipLocalizationsFr extends ZulipLocalizations {
   String get actionSheetOptionCopyTopicLink =>
       'Copier le lien vers cette conversation';
 
+  @override
+  String actionSheetTitleDm(String user) {
+    return 'DMs with $user';
+  }
+
+  @override
+  String get actionSheetTitleSelfDm => 'DMs with yourself';
+
+  @override
+  String get actionSheetTitleGroupDm => 'Group DM';
+
+  @override
+  String get actionSheetOptionViewProfile => 'View profile';
+
+  @override
+  String get actionSheetOptionMarkDmConversationAsRead =>
+      'Mark conversation as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Une erreur s\'est produite';
 

lib/generated/l10n/zulip_localizations_he.dart

@@ -271,6 +271,24 @@ class ZulipLocalizationsHe extends ZulipLocalizations {
   @override
   String get actionSheetOptionCopyTopicLink => 'Copy link to topic';
 
+  @override
+  String actionSheetTitleDm(String user) {
+    return 'DMs with $user';
+  }
+
+  @override
+  String get actionSheetTitleSelfDm => 'DMs with yourself';
+
+  @override
+  String get actionSheetTitleGroupDm => 'Group DM';
+
+  @override
+  String get actionSheetOptionViewProfile => 'View profile';
+
+  @override
+  String get actionSheetOptionMarkDmConversationAsRead =>
+      'Mark conversation as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_hu.dart

@@ -271,6 +271,24 @@ class ZulipLocalizationsHu extends ZulipLocalizations {
   @override
   String get actionSheetOptionCopyTopicLink => 'Copy link to topic';
 
+  @override
+  String actionSheetTitleDm(String user) {
+    return 'DMs with $user';
+  }
+
+  @override
+  String get actionSheetTitleSelfDm => 'DMs with yourself';
+
+  @override
+  String get actionSheetTitleGroupDm => 'Group DM';
+
+  @override
+  String get actionSheetOptionViewProfile => 'View profile';
+
+  @override
+  String get actionSheetOptionMarkDmConversationAsRead =>
+      'Mark conversation as read';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';