diff --git a/include/events/signal.hpp b/include/events/signal.hpp
index cdad4bca..efcf755e 100644
--- a/include/events/signal.hpp
+++ b/include/events/signal.hpp
@@ -5,34 +5,18 @@
 #include "components/ipc.hpp"
 #include "components/parser.hpp"
 #include "components/types.hpp"
-#include "events/types.hpp"
 #include "utils/functional.hpp"
 
 POLYBAR_NS
 
-// fwd decl {{{
-
+// fwd
 enum class mousebtn : uint8_t;
 enum class syntaxtag : uint8_t;
 enum class alignment : uint8_t;
 enum class attribute : uint8_t;
 
-// }}}
-
-#define DEFINE_SIGNAL(id, name)                        \
-  struct name : public detail::base_signal<name, id> { \
-    using base_type::base_type;                        \
-  }
-
-#define DEFINE_VALUE_SIGNAL(id, name, type)                   \
-  struct name : public detail::value_signal<name, id, type> { \
-    using base_type::base_type;                               \
-  }
-
 namespace signals {
   namespace detail {
-    // definition : signal {{{
-
     class signal {
      public:
       explicit signal() = default;
@@ -40,98 +24,161 @@ namespace signals {
       virtual size_t size() const = 0;
     };
 
-    // }}}
-    // definition : base_signal {{{
-
-    template <typename Derived, uint8_t Id>
+    template <typename Derived>
     class base_signal : public signal {
      public:
-      using base_type = base_signal<Derived, Id>;
+      using base_type = base_signal<Derived>;
 
       explicit base_signal() = default;
-
       virtual ~base_signal() {}
 
-      static uint8_t id() {
-        return Id;
-      }
-
       virtual size_t size() const override {
         return sizeof(Derived);
       };
     };
 
-    // }}}
-    // definition : value_signal {{{
-
-    template <typename Derived, uint8_t Id, typename ValueType>
-    class value_signal : public base_signal<Derived, Id> {
+    template <typename Derived, typename ValueType>
+    class value_signal : public base_signal<Derived> {
      public:
-      using base_type = value_signal<Derived, Id, ValueType>;
+      using base_type = value_signal<Derived, ValueType>;
       using value_type = ValueType;
 
-      explicit value_signal() {}
-      explicit value_signal(ValueType&& data) {
-        memcpy(m_data, &data, sizeof(data));
+      template <size_t Size = sizeof(ValueType)>
+      explicit value_signal(void* data) : m_data(data), m_size(Size) {}
+
+      template <size_t Size = sizeof(ValueType)>
+      explicit value_signal(ValueType data) : m_size(Size) {
+        m_data = new char[Size];
+        m_alloced = true;
+        memcpy(m_data, static_cast<void*>(&data), Size);
       }
 
-      virtual ~value_signal() {}
-
-      const ValueType* operator()() const {
-        return reinterpret_cast<const ValueType*>(&m_data);
+      virtual ~value_signal() {
+        if (m_alloced) {
+          delete[] static_cast<char*>(m_data);
+        }
       }
-      const ValueType* data() const {
-        return reinterpret_cast<const ValueType*>(&m_data);
+
+      void* data() const {
+        return m_data;
+      }
+      size_t size() const {
+        return m_size;
+      }
+      inline ValueType cast() const {
+        return *static_cast<ValueType*>(m_data);
       }
 
      private:
-      char m_data[sizeof(ValueType)];
+      void* m_data;
+      size_t m_size;
+      bool m_alloced{false};
     };
-
-    // }}}
   }
 
   namespace eventqueue {
-    DEFINE_SIGNAL(1, exit_terminate);
-    DEFINE_SIGNAL(2, exit_reload);
-    DEFINE_SIGNAL(3, notify_change);
-    DEFINE_SIGNAL(4, check_state);
-    DEFINE_SIGNAL(5, update);
+    struct exit_terminate : public detail::base_signal<exit_terminate> {
+      using base_type::base_type;
+    };
+    struct exit_reload : public detail::base_signal<exit_reload> {
+      using base_type::base_type;
+    };
+    struct notify_change : public detail::base_signal<notify_change> {
+      using base_type::base_type;
+    };
+    struct check_state : public detail::base_signal<check_state> {
+      using base_type::base_type;
+    };
+    struct update : public detail::base_signal<update> {
+      using base_type::base_type;
+    };
   }
 
   namespace ipc {
-    DEFINE_VALUE_SIGNAL(20, command, string);
-    DEFINE_VALUE_SIGNAL(21, hook, string);
-    DEFINE_VALUE_SIGNAL(22, action, string);
+    struct command : public detail::value_signal<command, string> {
+      using base_type::base_type;
+    };
+    struct hook : public detail::value_signal<hook, string> {
+      using base_type::base_type;
+    };
+    struct action : public detail::value_signal<action, string> {
+      using base_type::base_type;
+    };
   }
 
   namespace ui {
-    DEFINE_SIGNAL(50, tick);
-    DEFINE_VALUE_SIGNAL(51, button_press, string);
-    DEFINE_VALUE_SIGNAL(52, visibility_change, bool);
-    DEFINE_VALUE_SIGNAL(53, dim_window, double);
-    DEFINE_SIGNAL(54, shade_window);
-    DEFINE_SIGNAL(55, unshade_window);
+    struct tick : public detail::base_signal<tick> {
+      using base_type::base_type;
+    };
+    struct button_press : public detail::value_signal<button_press, string> {
+      using base_type::base_type;
+    };
+    struct visibility_change : public detail::value_signal<visibility_change, bool> {
+      using base_type::base_type;
+    };
+    struct dim_window : public detail::value_signal<dim_window, double> {
+      using base_type::base_type;
+    };
+    struct shade_window : public detail::base_signal<shade_window> {
+      using base_type::base_type;
+    };
+    struct unshade_window : public detail::base_signal<unshade_window> {
+      using base_type::base_type;
+    };
+  }
+
+  namespace ui_tray {
+    struct mapped_clients : public detail::value_signal<mapped_clients, size_t> {
+      using base_type::base_type;
+    };
   }
 
   namespace parser {
-    using parser_t = polybar::parser;
-
-    DEFINE_VALUE_SIGNAL(70, change_background, uint32_t);
-    DEFINE_VALUE_SIGNAL(71, change_foreground, uint32_t);
-    DEFINE_VALUE_SIGNAL(72, change_underline, uint32_t);
-    DEFINE_VALUE_SIGNAL(73, change_overline, uint32_t);
-    DEFINE_VALUE_SIGNAL(74, change_font, uint8_t);
-    DEFINE_VALUE_SIGNAL(75, change_alignment, alignment);
-    DEFINE_VALUE_SIGNAL(76, offset_pixel, int16_t);
-    DEFINE_VALUE_SIGNAL(77, attribute_set, attribute);
-    DEFINE_VALUE_SIGNAL(78, attribute_unset, attribute);
-    DEFINE_VALUE_SIGNAL(79, attribute_toggle, attribute);
-    DEFINE_VALUE_SIGNAL(80, action_begin, action);
-    DEFINE_VALUE_SIGNAL(81, action_end, mousebtn);
-    DEFINE_VALUE_SIGNAL(82, write_text_ascii, uint16_t);
-    DEFINE_VALUE_SIGNAL(83, write_text_unicode, uint16_t);
-    DEFINE_VALUE_SIGNAL(84, write_text_string, parser_t::packet);
+    struct change_background : public detail::value_signal<change_background, uint32_t> {
+      using base_type::base_type;
+    };
+    struct change_foreground : public detail::value_signal<change_foreground, uint32_t> {
+      using base_type::base_type;
+    };
+    struct change_underline : public detail::value_signal<change_underline, uint32_t> {
+      using base_type::base_type;
+    };
+    struct change_overline : public detail::value_signal<change_overline, uint32_t> {
+      using base_type::base_type;
+    };
+    struct change_font : public detail::value_signal<change_font, uint8_t> {
+      using base_type::base_type;
+    };
+    struct change_alignment : public detail::value_signal<change_alignment, alignment> {
+      using base_type::base_type;
+    };
+    struct offset_pixel : public detail::value_signal<offset_pixel, int16_t> {
+      using base_type::base_type;
+    };
+    struct attribute_set : public detail::value_signal<attribute_set, attribute> {
+      using base_type::base_type;
+    };
+    struct attribute_unset : public detail::value_signal<attribute_unset, attribute> {
+      using base_type::base_type;
+    };
+    struct attribute_toggle : public detail::value_signal<attribute_toggle, attribute> {
+      using base_type::base_type;
+    };
+    struct action_begin : public detail::value_signal<action_begin, action> {
+      using base_type::base_type;
+    };
+    struct action_end : public detail::value_signal<action_end, mousebtn> {
+      using base_type::base_type;
+    };
+    struct write_text_ascii : public detail::value_signal<write_text_ascii, uint16_t> {
+      using base_type::base_type;
+    };
+    struct write_text_unicode : public detail::value_signal<write_text_unicode, uint16_t> {
+      using base_type::base_type;
+    };
+    struct write_text_string : public detail::value_signal<write_text_string, polybar::parser::packet> {
+      using base_type::base_type;
+    };
   }
 }
 
diff --git a/include/events/signal_emitter.hpp b/include/events/signal_emitter.hpp
index 85fbbf1c..f651c6e4 100644
--- a/include/events/signal_emitter.hpp
+++ b/include/events/signal_emitter.hpp
@@ -2,8 +2,6 @@
 
 #include "common.hpp"
 #include "events/signal_receiver.hpp"
-#include "utils/factory.hpp"
-#include "utils/mixins.hpp"
 
 POLYBAR_NS
 
@@ -55,8 +53,8 @@ class signal_emitter {
 
  protected:
   template <typename Signal>
-  uint8_t id() const {
-    return Signal::id();
+  std::type_index id() const {
+    return typeid(Signal);
   }
 
   template <typename Receiver, typename Signal>
@@ -70,7 +68,7 @@ class signal_emitter {
     attach<Receiver, Next, Signals...>(s);
   }
 
-  void attach(signal_receiver_interface* s, uint8_t id) {
+  void attach(signal_receiver_interface* s, std::type_index id) {
     g_signal_receivers[id].emplace(s->priority(), s);
   }
 
@@ -85,7 +83,7 @@ class signal_emitter {
     detach<Receiver, Next, Signals...>(s);
   }
 
-  void detach(signal_receiver_interface* d, uint8_t id) {
+  void detach(signal_receiver_interface* d, std::type_index id) {
     try {
       auto& prio_map = g_signal_receivers.at(id);
       const auto& prio_sink_pair = prio_map.equal_range(d->priority());
diff --git a/include/events/signal_fwd.hpp b/include/events/signal_fwd.hpp
index 10888b7c..2b331eea 100644
--- a/include/events/signal_fwd.hpp
+++ b/include/events/signal_fwd.hpp
@@ -4,10 +4,16 @@
 
 POLYBAR_NS
 
+class signal_emitter;
+class signal_receiver_interface;
 template <uint8_t Priority, typename Signal, typename... Signals>
 class signal_receiver;
 
 namespace signals {
+  namespace detail {
+    class signal;
+  }
+
   namespace eventqueue {
     struct exit_terminate;
     struct exit_reload;
@@ -28,6 +34,9 @@ namespace signals {
     struct shade_window;
     struct unshade_window;
   }
+  namespace ui_tray {
+    struct mapped_clients;
+  }
   namespace parser {
     struct change_background;
     struct change_foreground;
diff --git a/include/events/signal_receiver.hpp b/include/events/signal_receiver.hpp
index 3fa39d0c..2b584f13 100644
--- a/include/events/signal_receiver.hpp
+++ b/include/events/signal_receiver.hpp
@@ -2,6 +2,8 @@
 
 #include <map>
 #include <unordered_map>
+#include <typeindex>
+#include <typeinfo>
 
 #include "common.hpp"
 
@@ -45,6 +47,6 @@ class signal_receiver : public signal_receiver_interface,
   }
 };
 
-using signal_receivers_t = std::unordered_map<uint8_t, signal_receiver_interface::prio_map>;
+using signal_receivers_t = std::unordered_map<std::type_index, signal_receiver_interface::prio_map>;
 
 POLYBAR_NS_END
diff --git a/src/components/bar.cpp b/src/components/bar.cpp
index f6e45e45..96651f95 100644
--- a/src/components/bar.cpp
+++ b/src/components/bar.cpp
@@ -514,7 +514,7 @@ void bar::handle(const evt::leave_notify&) {
   if (!m_opts.dimmed) {
     m_taskqueue->defer_unique("window-dim", 3s, [&](size_t) {
       m_opts.dimmed = true;
-      m_sig.emit(dim_window{double{m_opts.dimvalue}});
+      m_sig.emit(dim_window{m_opts.dimvalue});
     });
   }
 }
@@ -722,8 +722,8 @@ bool bar::on(const sig_ui::tick&) {
 }
 
 bool bar::on(const sig_ui::dim_window& sig) {
-  m_opts.dimmed = *sig.data() != 1.0;
-  set_wm_window_opacity(m_connection, m_opts.window, *sig.data() * 0xFFFFFFFF);
+  m_opts.dimmed = sig.cast() != 1.0;
+  set_wm_window_opacity(m_connection, m_opts.window, sig.cast() * 0xFFFFFFFF);
   m_connection.flush();
   return false;
 }
diff --git a/src/components/controller.cpp b/src/components/controller.cpp
index aada0aef..b408f79e 100644
--- a/src/components/controller.cpp
+++ b/src/components/controller.cpp
@@ -531,7 +531,7 @@ bool controller::on(const sig_ev::check_state&) {
  * Process ui button press event
  */
 bool controller::on(const sig_ui::button_press& evt) {
-  string input{*evt()};
+  string input{evt.cast()};
 
   if (input.empty()) {
     m_log.err("Cannot enqueue empty input");
@@ -546,7 +546,7 @@ bool controller::on(const sig_ui::button_press& evt) {
  * Process ipc action messages
  */
 bool controller::on(const sig_ipc::action& evt) {
-  string action{*evt()};
+  string action{evt.cast()};
 
   if (action.empty()) {
     m_log.err("Cannot enqueue empty ipc action");
@@ -562,7 +562,7 @@ bool controller::on(const sig_ipc::action& evt) {
  * Process ipc command messages
  */
 bool controller::on(const sig_ipc::command& evt) {
-  string command{*evt()};
+  string command{evt.cast()};
 
   if (command.empty()) {
     return false;
@@ -583,7 +583,7 @@ bool controller::on(const sig_ipc::command& evt) {
  * Process ipc hook messages
  */
 bool controller::on(const sig_ipc::hook& evt) {
-  string hook{*evt()};
+  string hook{evt.cast()};
 
   for (const auto& block : m_modules) {
     for (const auto& module : block.second) {
diff --git a/src/components/parser.cpp b/src/components/parser.cpp
index 562140e8..04993cff 100644
--- a/src/components/parser.cpp
+++ b/src/components/parser.cpp
@@ -184,7 +184,7 @@ size_t parser::text(string&& data) {
       }
 
       pkt.length = len;
-      m_sig.emit(write_text_string{move(pkt)});
+      m_sig.emit(write_text_string{static_cast<void*>(&pkt)});
     }
 
     if (pos > 0) {
diff --git a/src/components/renderer.cpp b/src/components/renderer.cpp
index 1580c7fe..d906a9d4 100644
--- a/src/components/renderer.cpp
+++ b/src/components/renderer.cpp
@@ -530,7 +530,7 @@ void renderer::debug_hints() {
 #endif
 
 bool renderer::on(const change_background& evt) {
-  const uint32_t color{*evt()};
+  const uint32_t color{evt.cast()};
 
   if (m_colors[gc::BG] == color) {
     m_log.trace_x("renderer: ignoring unchanged background color(#%08x)", color);
@@ -545,7 +545,7 @@ bool renderer::on(const change_background& evt) {
 }
 
 bool renderer::on(const change_foreground& evt) {
-  const uint32_t color{*evt()};
+  const uint32_t color{evt.cast()};
 
   if (m_colors[gc::FG] == color) {
     m_log.trace_x("renderer: ignoring unchanged foreground color(#%08x)", color);
@@ -560,7 +560,7 @@ bool renderer::on(const change_foreground& evt) {
 }
 
 bool renderer::on(const change_underline& evt) {
-  const uint32_t color{*evt()};
+  const uint32_t color{evt.cast()};
 
   if (m_colors[gc::UL] == color) {
     m_log.trace_x("renderer: ignoring unchanged underline color(#%08x)", color);
@@ -574,7 +574,7 @@ bool renderer::on(const change_underline& evt) {
 }
 
 bool renderer::on(const change_overline& evt) {
-  const uint32_t color{*evt()};
+  const uint32_t color{evt.cast()};
 
   if (m_colors[gc::OL] == color) {
     m_log.trace_x("renderer: ignoring unchanged overline color(#%08x)", color);
@@ -588,7 +588,7 @@ bool renderer::on(const change_overline& evt) {
 }
 
 bool renderer::on(const change_font& evt) {
-  const uint8_t font{*evt()};
+  const uint8_t font{evt.cast()};
 
   if (m_fontindex == font) {
     m_log.trace_x("renderer: ignoring unchanged font index(%i)", static_cast<uint8_t>(font));
@@ -602,7 +602,7 @@ bool renderer::on(const change_font& evt) {
 }
 
 bool renderer::on(const change_alignment& evt) {
-  auto align = static_cast<const alignment&>(*evt());
+  auto align = static_cast<const alignment&>(evt.cast());
 
   if (align == m_alignment) {
     m_log.trace_x("renderer: ignoring unchanged alignment(%i)", static_cast<uint8_t>(align));
@@ -616,30 +616,30 @@ bool renderer::on(const change_alignment& evt) {
 }
 
 bool renderer::on(const offset_pixel& evt) {
-  shift_content(*evt());
+  shift_content(evt.cast());
   return true;
 }
 
 bool renderer::on(const attribute_set& evt) {
-  m_log.trace_x("renderer: attribute_set(%i, %i)", static_cast<uint8_t>(*evt()), true);
-  m_attributes |= 1U << static_cast<uint8_t>(*evt());
+  m_log.trace_x("renderer: attribute_set(%i, %i)", static_cast<uint8_t>(evt.cast()), true);
+  m_attributes |= 1U << static_cast<uint8_t>(evt.cast());
   return true;
 }
 
 bool renderer::on(const attribute_unset& evt) {
-  m_log.trace_x("renderer: attribute_unset(%i, %i)", static_cast<uint8_t>(*evt()), true);
-  m_attributes &= ~(1U << static_cast<uint8_t>(*evt()));
+  m_log.trace_x("renderer: attribute_unset(%i, %i)", static_cast<uint8_t>(evt.cast()), true);
+  m_attributes &= ~(1U << static_cast<uint8_t>(evt.cast()));
   return true;
 }
 
 bool renderer::on(const attribute_toggle& evt) {
-  m_log.trace_x("renderer: attribute_toggle(%i)", static_cast<uint8_t>(*evt()));
-  m_attributes ^= 1U << static_cast<uint8_t>(*evt());
+  m_log.trace_x("renderer: attribute_toggle(%i)", static_cast<uint8_t>(evt.cast()));
+  m_attributes ^= 1U << static_cast<uint8_t>(evt.cast());
   return true;
 }
 
 bool renderer::on(const action_begin& evt) {
-  auto a = static_cast<const action&>(*evt());
+  auto a = static_cast<const action&>(evt.cast());
   action_block action{};
   action.button = a.button;
   action.align = m_alignment;
@@ -658,7 +658,7 @@ bool renderer::on(const action_begin& evt) {
 }
 
 bool renderer::on(const action_end& evt) {
-  auto btn = static_cast<const mousebtn&>(*evt());
+  auto btn = static_cast<const mousebtn&>(evt.cast());
   int16_t clickable_width{0};
 
   for (auto action = m_actions.rbegin(); action != m_actions.rend(); action++) {
@@ -695,19 +695,19 @@ bool renderer::on(const action_end& evt) {
 }
 
 bool renderer::on(const write_text_ascii& evt) {
-  const uint16_t data[1]{*evt()};
+  const uint16_t data[1]{evt.cast()};
   draw_textstring(data, 1);
   return true;
 }
 
 bool renderer::on(const write_text_unicode& evt) {
-  const uint16_t data[1]{*evt()};
+  const uint16_t data[1]{evt.cast()};
   draw_textstring(data, 1);
   return true;
 }
 
 bool renderer::on(const write_text_string& evt) {
-  auto pkt = static_cast<const parser::packet&>(*evt());
+  auto pkt = *static_cast<const parser::packet*>(evt.data());
   draw_textstring(pkt.data, pkt.length);
   return true;
 }
diff --git a/src/events/signal_emitter.cpp b/src/events/signal_emitter.cpp
index 0a87b8d7..e153944b 100644
--- a/src/events/signal_emitter.cpp
+++ b/src/events/signal_emitter.cpp
@@ -1,4 +1,5 @@
 #include "events/signal_emitter.hpp"
+#include "utils/factory.hpp"
 
 POLYBAR_NS
 
diff --git a/src/x11/tray_manager.cpp b/src/x11/tray_manager.cpp
index 36912804..f39bd5e4 100644
--- a/src/x11/tray_manager.cpp
+++ b/src/x11/tray_manager.cpp
@@ -1093,10 +1093,11 @@ void tray_manager::handle(const evt::map_notify& evt) {
     m_log.trace("tray: Received map_notify");
     m_log.trace("tray: Set client mapped");
     find_client(evt->window)->mapped(true);
-
-    if (mapped_clients() > m_opts.configured_slots) {
+    size_t clientcount{mapped_clients()};
+    if (clientcount > m_opts.configured_slots) {
       reconfigure();
     }
+    m_sig.emit(signals::ui_tray::mapped_clients{clientcount});
   }
 }
 
@@ -1111,7 +1112,8 @@ void tray_manager::handle(const evt::unmap_notify& evt) {
   } else if (m_activated && is_embedded(evt->window)) {
     m_log.trace("tray: Received unmap_notify");
     m_log.trace("tray: Set client unmapped");
-    find_client(evt->window)->mapped(true);
+    find_client(evt->window)->mapped(false);
+    m_sig.emit(signals::ui_tray::mapped_clients{mapped_clients()});
   }
 }
 
@@ -1121,7 +1123,7 @@ void tray_manager::handle(const evt::unmap_notify& evt) {
  * toggle the tray window whenever the visibility of the bar window changes.
  */
 bool tray_manager::on(const visibility_change& evt) {
-  bool visible{*evt()};
+  bool visible{evt.cast()};
   size_t clients{mapped_clients()};
 
   m_log.trace("tray: visibility_change (state=%i, activated=%i, mapped=%i, hidden=%i)", visible,
@@ -1146,7 +1148,7 @@ bool tray_manager::on(const visibility_change& evt) {
 
 bool tray_manager::on(const dim_window& evt) {
   if (m_activated) {
-    wm_util::set_wm_window_opacity(m_connection, m_tray, *evt.data() * 0xFFFFFFFF);
+    wm_util::set_wm_window_opacity(m_connection, m_tray, evt.cast() * 0xFFFFFFFF);
     m_connection.flush();
   }
   // let the event bubble