Add gtk integration option

It is disabled by default to provide native Qt experience by default

Telegram/Resources/langs/lang.strings

@@ -2606,6 +2606,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 "ktg_net_speed_boost_big" = "Big";
 
 "ktg_settings_system" = "System";
+"ktg_settings_gtk_integration" = "GTK integration";
 
 "ktg_settings_other" = "Other";
 "ktg_profile_copy_id" = "Copy ID";

Telegram/Resources/langs/rewrites/en.json

@@ -67,6 +67,7 @@
 	"ktg_net_speed_boost_medium": "Medium",
 	"ktg_net_speed_boost_big": "Big",
 	"ktg_settings_system": "System",
+	"ktg_settings_gtk_integration": "GTK integration",
 	"ktg_settings_other": "Other",
 	"ktg_profile_copy_id": "Copy ID",
 	"ktg_profile_bot_id": "Bot ID",

Telegram/Resources/langs/rewrites/ru.json

@@ -66,6 +66,7 @@
 	"ktg_net_speed_boost_medium": "Среднее",
 	"ktg_net_speed_boost_big": "Высокое",
 	"ktg_settings_system": "Система",
+	"ktg_settings_gtk_integration": "GTK-интеграция",
 	"ktg_settings_other": "Прочие",
 	"ktg_profile_copy_id": "Копировать ID",
 	"ktg_profile_bot_id": "ID бота",

Telegram/SourceFiles/kotato/json_settings.cpp

@@ -378,6 +378,7 @@ QByteArray GenerateSettingsJson(bool areDefault = false) {
 	settings.insert(qsl("recent_stickers_limit"), RecentStickersLimit());
 	settings.insert(qsl("userpic_corner_type"), cUserpicCornersType());
 	settings.insert(qsl("always_show_top_userpic"), cShowTopBarUserpic());
+	settings.insert(qsl("gtk_integration"), cGtkIntegration());
 	settings.insert(qsl("disable_tray_counter"), cDisableTrayCounter());
 	settings.insert(qsl("use_telegram_panel_icon"), cUseTelegramPanelIcon());
 	settings.insert(qsl("custom_app_icon"), cCustomAppIcon());
@@ -620,6 +621,10 @@ bool Manager::readCustomFile() {
 		cSetShowTopBarUserpic(v);
 	});
 
+	ReadBoolOption(settings, "gtk_integration", [&](auto v) {
+		cSetGtkIntegration(v);
+	});
+
 	ReadBoolOption(settings, "disable_tray_counter", [&](auto v) {
 		cSetDisableTrayCounter(v);
 	});

Telegram/SourceFiles/kotato/settings.cpp

@@ -145,6 +145,7 @@ rpl::producer<int> RecentStickersLimitChanges() {
 
 int gUserpicCornersType = 3;
 bool gShowTopBarUserpic = false;
+bool gGtkIntegration = false;
 bool gDisableTrayCounter = false;
 bool gUseTelegramPanelIcon = false;
 int gCustomAppIcon = 0;

Telegram/SourceFiles/kotato/settings.h

@@ -101,6 +101,7 @@ void SetRecentStickersLimit(int limit);
 
 DeclareSetting(int, UserpicCornersType);
 DeclareSetting(bool, ShowTopBarUserpic);
+DeclareSetting(bool, GtkIntegration);
 DeclareSetting(bool, DisableTrayCounter);
 DeclareSetting(bool, UseTelegramPanelIcon);
 DeclareSetting(int, CustomAppIcon);

Telegram/SourceFiles/kotato/settings_menu.cpp

@@ -7,6 +7,7 @@ https://github.com/kotatogram/kotatogram-desktop/blob/dev/LEGAL
 */
 #include "kotato/settings_menu.h"
 
+#include "base/platform/base_platform_info.h"
 #include "settings/settings_common.h"
 #include "settings/settings_chat.h"
 #include "ui/wrap/vertical_layout.h"
@@ -437,6 +438,37 @@ void SetupKotatoSystem(
 	AddSkip(container);
 	AddSubsectionTitle(container, tr::ktg_settings_system());
 
+#ifndef TDESKTOP_DISABLE_GTK_INTEGRATION
+	if (Platform::IsLinux()) {
+		const auto gtkIntegrationToggled = Ui::CreateChild<rpl::event_stream<bool>>(
+			container.get());
+		AddButton(
+			container,
+			tr::ktg_settings_gtk_integration(),
+			st::settingsButton
+		)->toggleOn(
+			gtkIntegrationToggled->events_starting_with_copy(cGtkIntegration())
+		)->toggledValue(
+		) | rpl::filter([](bool enabled) {
+			return (enabled != cGtkIntegration());
+		}) | rpl::start_with_next([=](bool enabled) {
+			const auto confirmed = [=] {
+				cSetGtkIntegration(enabled);
+				::Kotato::JsonSettings::Write();
+				App::restart();
+			};
+			const auto cancelled = [=] {
+				gtkIntegrationToggled->fire(cGtkIntegration() == true);
+			};
+			Ui::show(Box<ConfirmBox>(
+				tr::lng_settings_need_restart(tr::now),
+				tr::lng_settings_restart_now(tr::now),
+				confirmed,
+				cancelled));
+		}, container->lifetime());
+	}
+#endif // !TDESKTOP_DISABLE_GTK_INTEGRATION
+
 #if defined Q_OS_MAC
 	const auto useNativeDecorationsToggled = Ui::CreateChild<rpl::event_stream<bool>>(
 		container.get());

Telegram/SourceFiles/platform/linux/specific_linux.cpp

@@ -67,7 +67,6 @@ using Platform::internal::WaylandIntegration;
 namespace Platform {
 namespace {
 
-constexpr auto kDisableGtkIntegration = "TDESKTOP_DISABLE_GTK_INTEGRATION"_cs;
 constexpr auto kIgnoreGtkIncompatibility = "TDESKTOP_I_KNOW_ABOUT_GTK_INCOMPATIBILITY"_cs;
 
 constexpr auto kDesktopFile = ":/misc/kotatogramdesktop.desktop"_cs;
@@ -583,8 +582,7 @@ bool IsStaticBinary() {
 
 bool UseGtkIntegration() {
 #ifndef TDESKTOP_DISABLE_GTK_INTEGRATION
-	static const auto Result = !qEnvironmentVariableIsSet(
+	static const auto Result = cGtkIntegration();
-		kDisableGtkIntegration.utf8());
 
 	return Result;
 #endif // !TDESKTOP_DISABLE_GTK_INTEGRATION
@@ -1008,13 +1006,6 @@ void start() {
 			"this will lead to a crash.",
 			kIgnoreGtkIncompatibility.utf8().constData());
 
-		g_message(
-			"GTK integration can be disabled by setting %s to any value. "
-			"Keep in mind that this will lead to clipboard issues "
-			"and tdesktop will be unable to get settings from GTK "
-			"(such as decoration layout, dark mode & more).",
-			kDisableGtkIntegration.utf8().constData());
-
 		qunsetenv("QT_QPA_PLATFORMTHEME");
 		qunsetenv("QT_STYLE_OVERRIDE");
 
@@ -1024,13 +1015,6 @@ void start() {
 		}
 	}
 
-	if (!UseGtkIntegration()) {
-		g_warning(
-			"GTK integration was disabled on build or in runtime. "
-			"This will lead to clipboard issues and a lack of some features "
-			"(like Auto-Night Mode or system window controls layout).");
-	}
-
 #ifdef DESKTOP_APP_USE_PACKAGED_RLOTTIE
 	g_warning(
 		"Application has been built with foreign rlottie, "