Slightly improved appearing of usernames list.

Telegram/SourceFiles/api/api_user_names.cpp

@@ -199,5 +199,28 @@ Data::Usernames Usernames::FromTL(const MTPVector<MTPUsername> &usernames) {
 	) | ranges::views::transform(UsernameFromTL) | ranges::to_vector;
 }
 
+void Usernames::requestToCache(not_null<PeerData*> peer) {
+	_tinyCache = {};
+	if (const auto user = peer->asUser()) {
+		if (user->usernames().empty()) {
+			return;
+		}
+	} else if (const auto channel = peer->asChannel()) {
+		if (channel->usernames().empty()) {
+			return;
+		}
+	}
+	const auto lifetime = std::make_shared<rpl::lifetime>();
+	*lifetime = loadUsernames(
+		peer
+	) | rpl::start_with_next([=, id = peer->id](Data::Usernames usernames) {
+		_tinyCache = std::make_pair(id, std::move(usernames));
+		lifetime->destroy();
+	});
+}
+
+Data::Usernames Usernames::cacheFor(PeerId id) {
+	return (_tinyCache.first == id) ? _tinyCache.second : Data::Usernames();
+}
 
 } // namespace Api

Telegram/SourceFiles/api/api_user_names.h

@@ -33,6 +33,9 @@ public:
 		not_null<PeerData*> peer,
 		const std::vector<QString> &usernames);
 
+	void requestToCache(not_null<PeerData*> peer);
+	[[nodiscard]] Data::Usernames cacheFor(PeerId id);
+
 	static Data::Usernames FromTL(const MTPVector<MTPUsername> &usernames);
 
 private:
@@ -47,6 +50,8 @@ private:
 	};
 	base::flat_map<Key, Entry> _toggleRequests;
 	base::flat_map<Key, mtpRequestId> _reorderRequests;
+	// Used for a seamless display of usernames list.
+	std::pair<Key, Data::Usernames> _tinyCache;
 
 };
 

Telegram/SourceFiles/boxes/peers/edit_peer_info_box.cpp

@@ -635,7 +635,7 @@ void Controller::showEditPeerTypeBox(
 	});
 	_typeDataSavedValue->hasLinkedChat
 		= (_linkedChatSavedValue.value_or(nullptr) != nullptr);
-	_navigation->parentController()->show(
+	const auto box = _navigation->parentController()->show(
 		Box<EditPeerTypeBox>(
 			_navigation,
 			_peer,
@@ -644,6 +644,10 @@ void Controller::showEditPeerTypeBox(
 			_typeDataSavedValue,
 			error),
 		Ui::LayerOption::KeepOther);
+	box->boxClosing(
+	) | rpl::start_with_next([peer = _peer] {
+		peer->session().api().usernames().requestToCache(peer);
+	}, box->lifetime());
 }
 
 void Controller::showEditLinkedChatBox() {
@@ -740,6 +744,9 @@ void Controller::fillPrivacyTypeButton() {
 			: tr::lng_manage_peer_channel_type)(),
 		_privacyTypeUpdates.events(
 		) | rpl::map([=](Privacy flag) {
+			if (flag == Privacy::HasUsername) {
+				_peer->session().api().usernames().requestToCache(_peer);
+			}
 			return (flag == Privacy::HasUsername)
 				? (hasLocation
 					? tr::lng_manage_peer_link_permanent

Telegram/SourceFiles/boxes/peers/edit_peer_usernames_list.cpp

@@ -113,6 +113,13 @@ UsernamesList::UsernamesList(
 : RpWidget(parent)
 , _show(show)
 , _peer(peer) {
+	{
+		auto &api = _peer->session().api();
+		const auto usernames = api.usernames().cacheFor(_peer->id);
+		if (!usernames.empty()) {
+			rebuild(usernames);
+		}
+	}
 	load();
 }
 

Telegram/SourceFiles/settings/settings_information.cpp

@@ -48,6 +48,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "window/window_peer_menu.h"
 #include "apiwrap.h"
 #include "api/api_peer_photo.h"
+#include "api/api_user_names.h"
 #include "core/file_utilities.h"
 #include "base/call_delayed.h"
 #include "base/unixtime.h"
@@ -445,12 +446,19 @@ void SetupRows(
 			"internal:edit_username" });
 		return result;
 	});
+	session->api().usernames().requestToCache(session->user());
 	AddRow(
 		container,
 		std::move(label),
 		std::move(value),
 		tr::lng_context_copy_mention(tr::now),
-		[=] { controller->show(Box(UsernamesBox, session)); },
+		[=] {
+			const auto box = controller->show(Box(UsernamesBox, session));
+			box->boxClosing(
+			) | rpl::start_with_next([=] {
+				session->api().usernames().requestToCache(session->user());
+			}, box->lifetime());
+		},
 		{ &st::settingsIconMention, kIconLightOrange });
 
 	AddSkip(container);