Update icon theme on the fly

Telegram/CMakeLists.txt

@@ -866,6 +866,8 @@ PRIVATE
     platform/linux/linux_gdk_helper.h
     platform/linux/linux_libs.cpp
     platform/linux/linux_libs.h
+    platform/linux/linux_xlib_helper.cpp
+    platform/linux/linux_xlib_helper.h
     platform/linux/file_utilities_linux.cpp
     platform/linux/file_utilities_linux.h
     platform/linux/launcher_linux.cpp

Telegram/SourceFiles/platform/linux/linux_libs.cpp

@@ -8,13 +8,14 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "platform/linux/linux_libs.h"
 
 #include "base/platform/base_platform_info.h"
+#include "platform/linux/linux_xlib_helper.h"
 #include "platform/linux/linux_gdk_helper.h"
 #include "platform/linux/linux_desktop_environment.h"
 #include "platform/linux/specific_linux.h"
-
-extern "C" {
-#include <X11/Xlib.h>
-}
+#include "core/sandbox.h"
+#include "core/application.h"
+#include "main/main_domain.h"
+#include "mainwindow.h"
 
 namespace Platform {
 namespace Libs {
@@ -138,7 +139,8 @@ bool setupGtkBase(QLibrary &lib_gtk) {
 
 	// gtk_init will reset the Xlib error handler, and that causes
 	// Qt applications to quit on X errors. Therefore, we need to manually restore it.
-	int (*oldErrorHandler)(Display *, XErrorEvent *) = XSetErrorHandler(nullptr);
+	internal::XErrorHandlerRestorer handlerRestorer;
+	handlerRestorer.save();
 
 	DEBUG_LOG(("Library gtk functions loaded!"));
 	gtkTriedToInit = true;
@@ -149,13 +151,40 @@ bool setupGtkBase(QLibrary &lib_gtk) {
 	}
 	DEBUG_LOG(("Checked gtk with gtk_init_check!"));
 
-	XSetErrorHandler(oldErrorHandler);
+	handlerRestorer.restore();
 
 	// Use our custom log handler.
 	g_log_set_handler("Gtk", G_LOG_LEVEL_MESSAGE, gtkMessageHandler, nullptr);
 
 	return true;
 }
+
+bool IconThemeShouldBeSet() {
+	// change the icon theme only if it isn't already set by a platformtheme plugin
+	// if QT_QPA_PLATFORMTHEME=(gtk2|gtk3), then force-apply the icon theme
+	static const auto Result = ((QIcon::themeName() == qstr("hicolor") // QGenericUnixTheme
+		&& QIcon::fallbackThemeName() == qstr("hicolor"))
+		|| (QIcon::themeName() == qstr("Adwaita") // QGnomeTheme
+		&& QIcon::fallbackThemeName() == qstr("gnome")))
+		|| IsGtkIntegrationForced();
+
+	return Result;
+}
+
+void SetIconTheme() {
+	Core::Sandbox::Instance().customEnterFromEventLoop([] {
+		if (IconThemeShouldBeSet()) {
+			DEBUG_LOG(("Set GTK icon theme"));
+			QIcon::setThemeName(gtkSetting("gtk-icon-theme-name"));
+			QIcon::setFallbackThemeName(gtkSetting("gtk-fallback-icon-theme"));
+			Platform::SetApplicationIcon(Window::CreateIcon());
+			if (App::wnd()) {
+				App::wnd()->setWindowIcon(Window::CreateIcon());
+			}
+			Core::App().domain().notifyUnreadBadgeChanged();
+		}
+	});
+}
 #endif // !TDESKTOP_DISABLE_GTK_INTEGRATION
 
 } // namespace
@@ -251,17 +280,10 @@ void start() {
 		LOAD_SYMBOL(lib_gtk, "gtk_button_set_label", gtk_button_set_label);
 		LOAD_SYMBOL(lib_gtk, "gtk_button_get_type", gtk_button_get_type);
 
-		// change the icon theme only if it isn't already set by a platformtheme plugin
-		// if QT_QPA_PLATFORMTHEME=(gtk2|gtk3), then force-apply the icon theme
-		if (((QIcon::themeName() == qstr("hicolor") // QGenericUnixTheme
-			&& QIcon::fallbackThemeName() == qstr("hicolor"))
-			|| (QIcon::themeName() == qstr("Adwaita") // QGnomeTheme
-			&& QIcon::fallbackThemeName() == qstr("gnome")))
-			|| IsGtkIntegrationForced()) {
-			DEBUG_LOG(("Set GTK icon theme"));
-			QIcon::setThemeName(gtkSetting("gtk-icon-theme-name"));
-			QIcon::setFallbackThemeName(gtkSetting("gtk-fallback-icon-theme"));
-		}
+		SetIconTheme();
+
+		const auto settings = gtk_settings_get_default();
+		g_signal_connect(settings, "notify::gtk-icon-theme-name", G_CALLBACK(SetIconTheme), nullptr);
 	} else {
 		LOG(("Could not load gtk-3 or gtk-x11-2.0!"));
 	}

Telegram/SourceFiles/platform/linux/linux_xlib_helper.cpp

@@ -0,0 +1,40 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#include "platform/linux/linux_xlib_helper.h"
+
+#ifndef TDESKTOP_DISABLE_GTK_INTEGRATION
+extern "C" {
+#include <X11/Xlib.h>
+}
+
+namespace Platform {
+namespace internal {
+
+class XErrorHandlerRestorer::Private {
+public:
+	Private() {}
+	int (*oldErrorHandler)(Display *, XErrorEvent *);
+};
+
+XErrorHandlerRestorer::XErrorHandlerRestorer()
+: _private(std::make_unique<Private>()) {
+}
+
+XErrorHandlerRestorer::~XErrorHandlerRestorer() = default;
+
+void XErrorHandlerRestorer::save() {
+	_private->oldErrorHandler = XSetErrorHandler(nullptr);
+}
+
+void XErrorHandlerRestorer::restore() {
+	XSetErrorHandler(_private->oldErrorHandler);
+}
+
+} // namespace internal
+} // namespace Platform
+#endif // !TDESKTOP_DISABLE_GTK_INTEGRATION

Telegram/SourceFiles/platform/linux/linux_xlib_helper.h

@@ -0,0 +1,29 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#pragma once
+
+#ifndef TDESKTOP_DISABLE_GTK_INTEGRATION
+namespace Platform {
+namespace internal {
+
+class XErrorHandlerRestorer {
+public:
+	XErrorHandlerRestorer();
+	~XErrorHandlerRestorer();
+
+	void save();
+	void restore();
+
+private:
+	class Private;
+	const std::unique_ptr<Private> _private;
+};
+
+} // namespace internal
+} // namespace Platform
+#endif // !TDESKTOP_DISABLE_GTK_INTEGRATION

Telegram/SourceFiles/platform/linux/main_window_linux.cpp

@@ -519,7 +519,8 @@ void MainWindow::setSNITrayIcon(int counter, bool muted) {
 		_sniTrayIcon->setToolTipIconByName(iconName);
 	} else if (IsIndicatorApplication()) {
 		if (!IsIconRegenerationNeeded(counter, muted)
-			&& !_sniTrayIcon->iconName().isEmpty()) {
+			&& _trayIconFile
+			&& _sniTrayIcon->iconName() == _trayIconFile->fileName()) {
 			return;
 		}
 
@@ -532,7 +533,8 @@ void MainWindow::setSNITrayIcon(int counter, bool muted) {
 		}
 	} else {
 		if (!IsIconRegenerationNeeded(counter, muted)
-			&& !_sniTrayIcon->iconPixmap().isEmpty()) {
+			&& !_sniTrayIcon->iconPixmap().isEmpty()
+			&& _sniTrayIcon->iconName().isEmpty()) {
 			return;
 		}