WindowServer: Propagate theme change to the applet area

Fixes: #6056

Userland/Services/WindowServer/AppletManager.cpp

@@ -152,11 +152,29 @@ void AppletManager::relayout()
     if (m_window->rect() == rect)
         return;
     m_window->set_rect(rect);
+
+    repaint();
+
+    WindowManager::the().tell_wm_listeners_applet_area_size_changed(rect.size());
+}
+
+void AppletManager::repaint()
+{
+    if (!m_window) {
+        return;
+    }
+
+    auto rect = Gfx::IntRect { { 0, 0 }, m_window->size() };
+
     if (!rect.is_empty()) {
         Gfx::Painter painter(*m_window->backing_store());
-        painter.fill_rect({ { 0, 0 }, rect.size() }, WindowManager::the().palette().window());
+        painter.fill_rect(rect, WindowManager::the().palette().window());
     }
-    WindowManager::the().tell_wm_listeners_applet_area_size_changed(rect.size());
+}
+
+void AppletManager::did_change_theme()
+{
+    repaint();
 }
 
 void AppletManager::remove_applet(Window& applet)

Userland/Services/WindowServer/AppletManager.h

@@ -52,7 +52,10 @@ public:
     Window* window() { return m_window; }
     const Window* window() const { return m_window; }
 
+    void did_change_theme();
+
 private:
+    void repaint();
     void draw_applet(const Window& applet);
     void set_hovered_applet(Window*);
 

Userland/Services/WindowServer/WindowManager.cpp

@@ -1525,6 +1525,7 @@ bool WindowManager::update_theme(String theme_path, String theme_name)
         return IterationDecision::Continue;
     });
     MenuManager::the().did_change_theme();
+    AppletManager::the().did_change_theme();
     auto wm_config = Core::ConfigFile::open("/etc/WindowServer/WindowServer.ini");
     wm_config->write_entry("Theme", "Name", theme_name);
     wm_config->sync();