Add "show" button for last seen hidden.

Telegram/SourceFiles/info/info.style

@@ -304,6 +304,9 @@ InfoProfileCover {
 	status: FlatLabel;
 	statusLeft: pixels;
 	statusTop: pixels;
+	showLastSeen: RoundButton;
+	showLastSeenPosition: point;
+	showLastSeenVisible: bool;
 	rightSkip: pixels;
 }
 infoProfilePhotoInnerSize: 72px;
@@ -334,6 +337,14 @@ infoProfileCover: InfoProfileCover {
 	status: infoProfileStatus;
 	statusLeft: 109px;
 	statusTop: 58px;
+	showLastSeen: RoundButton(defaultActiveButton) {
+		width: -12px;
+		height: 20px;
+		textTop: 2px;
+		font: font(11px semibold);
+	}
+	showLastSeenPosition: point(4px, 56px);
+	showLastSeenVisible: true;
 	rightSkip: 20px;
 }
 infoProfileMegagroupCover: InfoProfileCover(infoProfileCover) {

Telegram/SourceFiles/info/profile/info_profile_cover.cpp

@@ -26,6 +26,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "history/view/media/history_view_sticker_player.h"
 #include "lang/lang_keys.h"
 #include "ui/controls/userpic_button.h"
+#include "ui/widgets/buttons.h"
 #include "ui/widgets/labels.h"
 #include "ui/text/text_utilities.h"
 #include "base/unixtime.h"
@@ -323,6 +324,7 @@ Cover::Cover(
 	: nullptr)
 , _name(this, _st.name)
 , _status(this, _st.status)
+, _showLastSeen(this, tr::lng_status_lastseen_show(), _st.showLastSeen)
 , _refreshStatusTimer([this] { refreshStatusText(); }) {
 	_peer->updateFull();
 
@@ -333,6 +335,8 @@ Cover::Cover(
 		_status->setAttribute(Qt::WA_TransparentForMouseEvents);
 	}
 
+	setupShowLastSeen();
+
 	_badge->setPremiumClickCallback([=] {
 		if (const auto panel = _emojiStatusPanel.get()) {
 			panel->show(_controller, _badge->widget(), _badge->sizeTag());
@@ -361,6 +365,34 @@ Cover::Cover(
 	}
 }
 
+void Cover::setupShowLastSeen() {
+	const auto user = _peer->asUser();
+	if (_st.showLastSeenVisible
+		&& user
+		&& !user->isSelf()
+		&& !user->isBot()
+		&& !user->isServiceUser()
+		&& user->session().premiumPossible()) {
+		rpl::combine(
+			user->session().changes().peerFlagsValue(
+				user,
+				Data::PeerUpdate::Flag::OnlineStatus),
+			Data::AmPremiumValue(&user->session())
+		) | rpl::start_with_next([=] {
+			_showLastSeen->setVisible(
+				(user->onlineTill == kOnlineHidden)
+				&& !user->session().premium()
+				&& user->session().premiumPossible());
+		}, _showLastSeen->lifetime());
+	} else {
+		_showLastSeen->hide();
+	}
+
+	_showLastSeen->setClickedCallback([=] {
+		::Settings::ShowPremium(_controller, u"lastseen_hidden"_q);
+	});
+}
+
 void Cover::setupChildGeometry() {
 	widthValue(
 	) | rpl::start_with_next([this](int newWidth) {
@@ -577,6 +609,11 @@ void Cover::refreshStatusGeometry(int newWidth) {
 	auto statusWidth = newWidth - _st.statusLeft - _st.rightSkip;
 	_status->resizeToWidth(statusWidth);
 	_status->moveToLeft(_st.statusLeft, _st.statusTop, newWidth);
+	const auto left = _st.statusLeft + _status->textMaxWidth();
+	_showLastSeen->moveToLeft(
+		left + _st.showLastSeenPosition.x(),
+		_st.showLastSeenPosition.y(),
+		newWidth);
 }
 
 } // namespace Info::Profile

Telegram/SourceFiles/info/profile/info_profile_cover.h

@@ -20,6 +20,7 @@ class UserpicButton;
 class FlatLabel;
 template <typename Widget>
 class SlideWrap;
+class RoundButton;
 } // namespace Ui
 
 namespace HistoryView {
@@ -126,6 +127,7 @@ private:
 		Role role,
 		rpl::producer<QString> title);
 
+	void setupShowLastSeen();
 	void setupChildGeometry();
 	void initViewers(rpl::producer<QString> title);
 	void refreshStatusText();
@@ -149,6 +151,7 @@ private:
 	object_ptr<TopicIconButton> _iconButton;
 	object_ptr<Ui::FlatLabel> _name = { nullptr };
 	object_ptr<Ui::FlatLabel> _status = { nullptr };
+	object_ptr<Ui::RoundButton> _showLastSeen = { nullptr };
 	//object_ptr<CoverDropArea> _dropArea = { nullptr };
 	base::Timer _refreshStatusTimer;