From df14515927bd13d62cd6cc7b45c98e47038f705a Mon Sep 17 00:00:00 2001
From: 23rd <23rd@vivaldi.net>
Date: Sun, 8 Feb 2026 11:02:17 +0300
Subject: [PATCH] Added ability to check if peer can be added to specific
 filter.

---
 Telegram/SourceFiles/boxes/choose_filter_box.cpp | 11 +++++++++++
 Telegram/SourceFiles/boxes/choose_filter_box.h   |  1 +
 2 files changed, 12 insertions(+)

diff --git a/Telegram/SourceFiles/boxes/choose_filter_box.cpp b/Telegram/SourceFiles/boxes/choose_filter_box.cpp
index da0be24a9a..f713eacd94 100644
--- a/Telegram/SourceFiles/boxes/choose_filter_box.cpp
+++ b/Telegram/SourceFiles/boxes/choose_filter_box.cpp
@@ -216,6 +216,17 @@ bool ChooseFilterValidator::canAdd() const {
 	return false;
 }
 
+bool ChooseFilterValidator::canAdd(FilterId filterId) const {
+	Expects(filterId != 0);
+
+	const auto list = _history->owner().chatsFilters().list();
+	const auto i = ranges::find(list, filterId, &Data::ChatFilter::id);
+	if (i != end(list)) {
+		return !i->contains(_history);
+	}
+	return false;
+}
+
 bool ChooseFilterValidator::canRemove(FilterId filterId) const {
 	Expects(filterId != 0);
 
diff --git a/Telegram/SourceFiles/boxes/choose_filter_box.h b/Telegram/SourceFiles/boxes/choose_filter_box.h
index 84417d6ec7..d551b47727 100644
--- a/Telegram/SourceFiles/boxes/choose_filter_box.h
+++ b/Telegram/SourceFiles/boxes/choose_filter_box.h
@@ -26,6 +26,7 @@ public:
 	};
 
 	[[nodiscard]] bool canAdd() const;
+	[[nodiscard]] bool canAdd(FilterId filterId) const;
 	[[nodiscard]] bool canRemove(FilterId filterId) const;
 	[[nodiscard]] LimitData limitReached(
 		FilterId filterId,