diff --git a/include/ALabel.hpp b/include/ALabel.hpp
index 888c65a8..cdfcef68 100644
--- a/include/ALabel.hpp
+++ b/include/ALabel.hpp
@@ -25,7 +25,7 @@ class ALabel : public AModule {
   bool alt_ = false;
   std::string default_format_;
 
-  bool handleToggle(GdkEventButton *const &e) override;
+//todo  bool handleToggle(GdkEventButton *const &e) override;
   virtual std::string getState(uint8_t value, bool lesser = false);
 };
 
diff --git a/include/AModule.hpp b/include/AModule.hpp
index df0165cf..47f7c68f 100644
--- a/include/AModule.hpp
+++ b/include/AModule.hpp
@@ -2,7 +2,7 @@
 
 #include <glibmm/dispatcher.h>
 #include <glibmm/markup.h>
-#include <gtkmm/eventbox.h>
+//#include <gtkmm/eventbox.h>
 #include <json/json.h>
 
 #include "IModule.hpp"
@@ -28,25 +28,25 @@ class AModule : public IModule {
 
   enum SCROLL_DIR { NONE, UP, DOWN, LEFT, RIGHT };
 
-  SCROLL_DIR getScrollDir(GdkEventScroll *e);
+//  SCROLL_DIR getScrollDir(GdkEventScroll *e);
   bool tooltipEnabled();
 
   const std::string name_;
   const Json::Value &config_;
-  Gtk::EventBox event_box_;
+//  Gtk::EventBox event_box_;
 
-  virtual bool handleToggle(GdkEventButton *const &ev);
-  virtual bool handleScroll(GdkEventScroll *);
-  virtual bool handleRelease(GdkEventButton *const &ev);
+//  virtual bool handleToggle(GdkEventButton *const &ev);
+//  virtual bool handleScroll(GdkEventScroll *);
+//  virtual bool handleRelease(GdkEventButton *const &ev);
 
  private:
-  bool handleUserEvent(GdkEventButton *const &ev);
+//  bool handleUserEvent(GdkEventButton *const &ev);
   const bool isTooltip;
   std::vector<int> pid_;
   gdouble distance_scrolled_y_;
   gdouble distance_scrolled_x_;
   std::map<std::string, std::string> eventActionMap_;
-  static const inline std::map<std::pair<uint, GdkEventType>, std::string> eventMap_{
+ /* static const inline std::map<std::pair<uint, GdkEventType>, std::string> eventMap_{
       {std::make_pair(1, GdkEventType::GDK_BUTTON_PRESS), "on-click"},
       {std::make_pair(1, GdkEventType::GDK_BUTTON_RELEASE), "on-click-release"},
       {std::make_pair(1, GdkEventType::GDK_2BUTTON_PRESS), "on-double-click"},
@@ -66,7 +66,7 @@ class AModule : public IModule {
       {std::make_pair(9, GdkEventType::GDK_BUTTON_PRESS), "on-click-forward"},
       {std::make_pair(9, GdkEventType::GDK_BUTTON_RELEASE), "on-click-forward-release"},
       {std::make_pair(9, GdkEventType::GDK_2BUTTON_PRESS), "on-double-click-forward"},
-      {std::make_pair(9, GdkEventType::GDK_3BUTTON_PRESS), "on-triple-click-forward"}};
+      {std::make_pair(9, GdkEventType::GDK_3BUTTON_PRESS), "on-triple-click-forward"}};*/
 };
 
 }  // namespace waybar
diff --git a/include/bar.hpp b/include/bar.hpp
index d2cbffa0..f5c21c9c 100644
--- a/include/bar.hpp
+++ b/include/bar.hpp
@@ -1,18 +1,13 @@
 #pragma once
 
 #include <gdkmm/monitor.h>
-#include <glibmm/refptr.h>
 #include <gtkmm/box.h>
+#include <gtkmm/centerbox.h>
 #include <gtkmm/cssprovider.h>
-#include <gtkmm/main.h>
 #include <gtkmm/window.h>
-#include <json/json.h>
-
-#include <memory>
-#include <vector>
 
 #include "AModule.hpp"
-#include "group.hpp"
+//#include "group.hpp"
 #include "xdg-output-unstable-v1-client-protocol.h"
 
 namespace waybar {
@@ -91,6 +86,7 @@ class Bar {
   bool visible = true;
   bool vertical = false;
   Gtk::Window window;
+  Glib::RefPtr<Gdk::Surface> gdk_surface_;
 
   int x_global;
   int y_global;
@@ -100,13 +96,13 @@ class Bar {
 #endif
 
  private:
-  void onMap(GdkEventAny *);
+  void onMap();
   auto setupWidgets() -> void;
-  void getModules(const Factory &, const std::string &, waybar::Group *);
+//  void getModules(const Factory &, const std::string &, waybar::Group *);
   void setupAltFormatKeyForModule(const std::string &module_name);
   void setupAltFormatKeyForModuleList(const char *module_list_name);
   void setMode(const bar_mode &);
-  void onConfigure(GdkEventConfigure *ev);
+  void onConfigure(int width, int height);
   void configureGlobalOffset(int width, int height);
   void onOutputGeometryChanged();
 
@@ -120,7 +116,7 @@ class Bar {
   Gtk::Box left_;
   Gtk::Box center_;
   Gtk::Box right_;
-  Gtk::Box box_;
+  Gtk::CenterBox box_;
   std::vector<std::shared_ptr<waybar::AModule>> modules_left_;
   std::vector<std::shared_ptr<waybar::AModule>> modules_center_;
   std::vector<std::shared_ptr<waybar::AModule>> modules_right_;
diff --git a/include/client.hpp b/include/client.hpp
index 9ec29ef3..fe6552af 100644
--- a/include/client.hpp
+++ b/include/client.hpp
@@ -1,9 +1,6 @@
 #pragma once
 
-#include <fmt/format.h>
-#include <gdk/gdk.h>
-#include <gdk/gdkwayland.h>
-#include <wayland-client.h>
+#include <gdk/wayland/gdkwayland.h>
 
 #include "bar.hpp"
 #include "config.hpp"
@@ -34,6 +31,7 @@ class Client {
 
  private:
   Client() = default;
+  Glib::RefPtr<Gio::ListModel> monitors_;
   const std::string getStyle(const std::string &style, std::optional<Appearance> appearance);
   void bindInterfaces();
   void handleOutput(struct waybar_output &output);
@@ -51,7 +49,6 @@ class Client {
   void handleMonitorRemoved(Glib::RefPtr<Gdk::Monitor> monitor);
   void handleDeferredMonitorRemoval(Glib::RefPtr<Gdk::Monitor> monitor);
 
-  Glib::RefPtr<Gtk::StyleContext> style_context_;
   Glib::RefPtr<Gtk::CssProvider> css_provider_;
   std::unique_ptr<Portal> portal;
   std::list<struct waybar_output> outputs_;
diff --git a/include/group.hpp b/include/group.hpp
index 67cf4385..87a57b81 100644
--- a/include/group.hpp
+++ b/include/group.hpp
@@ -19,7 +19,7 @@ class Group : public AModule {
   virtual Gtk::Box& getBox();
   void addWidget(Gtk::Widget& widget);
 
-  bool handleMouseHover(GdkEventCrossing* const& e);
+//  bool handleMouseHover(GdkEventCrossing* const& e);
 
  protected:
   Gtk::Box box;
diff --git a/include/modules/cffi.hpp b/include/modules/cffi.hpp
index 85f12989..e7f988fc 100644
--- a/include/modules/cffi.hpp
+++ b/include/modules/cffi.hpp
@@ -16,7 +16,7 @@ typedef struct wbcffi_module wbcffi_module;
 typedef struct {
   wbcffi_module* obj;
   const char* waybar_version;
-  GtkContainer* (*get_root_widget)(wbcffi_module*);
+//todo  GtkContainer* (*get_root_widget)(wbcffi_module*);
   void (*queue_update)(wbcffi_module*);
 } wbcffi_init_info;
 
diff --git a/include/modules/custom.hpp b/include/modules/custom.hpp
index 2c7ba8a8..e8f4e3ee 100644
--- a/include/modules/custom.hpp
+++ b/include/modules/custom.hpp
@@ -26,8 +26,8 @@ class Custom : public ALabel {
   void parseOutputRaw();
   void parseOutputJson();
   void handleEvent();
-  bool handleScroll(GdkEventScroll* e) override;
-  bool handleToggle(GdkEventButton* const& e) override;
+//todo  bool handleScroll(GdkEventScroll* e) override;
+//todo  bool handleToggle(GdkEventButton* const& e) override;
 
   const std::string name_;
   const std::string output_name_;
diff --git a/include/modules/idle_inhibitor.hpp b/include/modules/idle_inhibitor.hpp
index 22bd808f..1cb94a07 100644
--- a/include/modules/idle_inhibitor.hpp
+++ b/include/modules/idle_inhibitor.hpp
@@ -19,7 +19,7 @@ class IdleInhibitor : public ALabel {
   static bool status;
 
  private:
-  bool handleToggle(GdkEventButton* const& e) override;
+//todo  bool handleToggle(GdkEventButton* const& e) override;
   void toggleStatus();
 
   const Bar& bar_;
diff --git a/include/modules/user.hpp b/include/modules/user.hpp
index bcb03da4..13608f43 100644
--- a/include/modules/user.hpp
+++ b/include/modules/user.hpp
@@ -14,7 +14,7 @@ class User : public AIconLabel {
   virtual ~User() = default;
   auto update() -> void override;
 
-  bool handleToggle(GdkEventButton* const& e) override;
+//todo  bool handleToggle(GdkEventButton* const& e) override;
 
  private:
   util::SleeperThread thread_;
diff --git a/include/util/SafeSignal.hpp b/include/util/SafeSignal.hpp
index 458bc57e..ff1469d0 100644
--- a/include/util/SafeSignal.hpp
+++ b/include/util/SafeSignal.hpp
@@ -52,7 +52,7 @@ struct SafeSignal : sigc::signal<void(std::decay_t<Args>...)> {
   using slot_t = decltype(std::declval<signal_t>().make_slot());
   using arg_tuple_t = std::tuple<std::decay_t<Args>...>;
   // ensure that unwrapped methods are not accessible
-  using signal_t::emit_reverse;
+  using signal_t::emit;
   using signal_t::make_slot;
 
   void handle_event() {
diff --git a/include/util/portal.hpp b/include/util/portal.hpp
index 23619169..05458c7f 100644
--- a/include/util/portal.hpp
+++ b/include/util/portal.hpp
@@ -19,7 +19,7 @@ class Portal : private DBus::Proxy {
   void refreshAppearance();
   Appearance getAppearance();
 
-  typedef sigc::signal<void, Appearance> type_signal_appearance_changed;
+  typedef sigc::signal<void(Appearance)> type_signal_appearance_changed;
   type_signal_appearance_changed signal_appearance_changed() { return m_signal_appearance_changed; }
 
  private:
diff --git a/meson.build b/meson.build
index c1ae48b5..1997162a 100644
--- a/meson.build
+++ b/meson.build
@@ -1,10 +1,10 @@
 project(
     'waybar', 'cpp', 'c',
-    version: '0.9.24',
+    version: '4.1.0',
     license: 'MIT',
-    meson_version: '>= 0.50.0',
+    meson_version: '>= 1.3.0',
     default_options : [
-        'cpp_std=c++20',
+        'cpp_std=c++23',
         'buildtype=release',
         'default_library=static'
     ],
@@ -78,78 +78,23 @@ is_freebsd = host_machine.system() == 'freebsd'
 is_netbsd = host_machine.system() == 'netbsd'
 is_openbsd = host_machine.system() == 'openbsd'
 
-thread_dep = dependency('threads')
-fmt = dependency('fmt', version : ['>=8.1.1'], fallback : ['fmt', 'fmt_dep'])
-spdlog = dependency('spdlog', version : ['>=1.10.0'], fallback : ['spdlog', 'spdlog_dep'], default_options : ['external_fmt=enabled'])
+jsoncpp = dependency('jsoncpp', version : ['>=1.9.4'], fallback : ['jsoncpp', 'jsoncpp_dep'])
 wayland_client = dependency('wayland-client')
 wayland_cursor = dependency('wayland-cursor')
 wayland_protos = dependency('wayland-protocols')
-gtkmm = dependency('gtkmm-3.0', version : ['>=3.22.0'])
-dbusmenu_gtk = dependency('dbusmenu-gtk3-0.4', required: get_option('dbusmenu-gtk'))
-giounix = dependency('gio-unix-2.0', required: (get_option('dbusmenu-gtk').enabled() or
-                                                get_option('logind').enabled() or
-                                                get_option('upower_glib').enabled() or
-                                                get_option('mpris').enabled()))
-jsoncpp = dependency('jsoncpp', version : ['>=1.9.2'], fallback : ['jsoncpp', 'jsoncpp_dep'])
-sigcpp = dependency('sigc++-2.0')
-libinotify = dependency('libinotify', required: false)
-libepoll = dependency('epoll-shim', required: false)
-libinput = dependency('libinput', required: get_option('libinput'))
-libnl = dependency('libnl-3.0', required: get_option('libnl'))
-libnlgen = dependency('libnl-genl-3.0', required: get_option('libnl'))
-upower_glib = dependency('upower-glib', required: get_option('upower_glib'))
-pipewire = dependency('libpipewire-0.3', required: get_option('pipewire'))
-playerctl = dependency('playerctl', version : ['>=2.0.0'], required: get_option('mpris'))
-libpulse = dependency('libpulse', required: get_option('pulseaudio'))
-libudev = dependency('libudev', required: get_option('libudev'))
-libevdev = dependency('libevdev', required: get_option('libevdev'))
-libmpdclient = dependency('libmpdclient', required: get_option('mpd'))
-xkbregistry = dependency('xkbregistry')
-libjack = dependency('jack', required: get_option('jack'))
-libwireplumber = dependency('wireplumber-0.4', required: get_option('wireplumber'))
+sigcpp = dependency('sigc++-3.0', version: ['>=3.4.0'])
+gtkmm = dependency('gtkmm-4.0', version : ['>=4.12.0'])
+giounix = dependency('gio-unix-2.0', version: ['>=2.76.4'])
+spdlog = dependency('spdlog', version : ['>=1.10.0'], fallback : ['spdlog', 'spdlog_dep'], default_options : ['external_fmt=enabled'])
 
-libsndio = compiler.find_library('sndio', required: get_option('sndio'))
-if libsndio.found()
-    if not compiler.has_function('sioctl_open', prefix: '#include <sndio.h>', dependencies: libsndio)
-        if get_option('sndio').enabled()
-            error('libsndio is too old, required >=1.7.0')
-        else
-            warning('libsndio is too old, required >=1.7.0')
-            libsndio = dependency('', required: false)
-        endif
-    endif
-endif
+gtk_layer_shell = dependency('gtk4-layer-shell-0',
+                             version : ['>=1.0.2'],
+                             required: get_option('gtk-layer-shell'),
+                             fallback : ['gtk4-layer-shell', 'gtk_layer_shell'],
+                             default_options : ['vapi=false'])
 
-gtk_layer_shell = dependency('gtk-layer-shell-0',
-        required: get_option('gtk-layer-shell'),
-        fallback : ['gtk-layer-shell', 'gtk_layer_shell_dep'])
-systemd = dependency('systemd', required: get_option('systemd'))
-
-cpp_lib_chrono = compiler.compute_int('__cpp_lib_chrono', prefix : '#include <chrono>')
-have_chrono_timezones = cpp_lib_chrono >= 201611
-
-if have_chrono_timezones
-   code = '''
-#include <chrono>
-using namespace std::chrono;
-int main(int argc, char** argv) {
-   const time_zone* tz;
-   return 0;
-}
-'''
-   if not compiler.links(code)
-      have_chrono_timezones = false
-   endif
-endif
-
-if have_chrono_timezones
-  tz_dep = declare_dependency()
-else
-  tz_dep = dependency('date',
-      required: false,
-      default_options : [ 'use_system_tzdb=true' ],
-      modules : [ 'date::date', 'date::date-tz' ],
-      fallback: [ 'date', 'tz_dep' ])
+if gtk_layer_shell.found()
+    add_project_arguments('-DHAVE_GTK_LAYER_SHELL', language: 'cpp')
 endif
 
 prefix = get_option('prefix')
@@ -159,47 +104,18 @@ conf_data.set('prefix', prefix)
 
 add_project_arguments('-DSYSCONFDIR="/@0@"'.format(join_paths(prefix, sysconfdir)), language : 'cpp')
 
-if systemd.found()
-  user_units_dir = systemd.get_pkgconfig_variable('systemduserunitdir')
-
-  configure_file(
-    configuration: conf_data,
-    input: './resources/waybar.service.in',
-    output: '@BASENAME@',
-    install_dir: user_units_dir
-  )
-endif
-
 src_files = files(
-    'src/factory.cpp',
-    'src/AModule.cpp',
-    'src/ALabel.cpp',
-    'src/AIconLabel.cpp',
-    'src/AAppIconLabel.cpp',
-    'src/modules/custom.cpp',
-    'src/modules/disk.cpp',
-    'src/modules/idle_inhibitor.cpp',
-    'src/modules/image.cpp',
-    'src/modules/load.cpp',
-    'src/modules/temperature.cpp',
-    'src/modules/user.cpp',
-    'src/ASlider.cpp',
-    'src/main.cpp',
-    'src/bar.cpp',
-    'src/client.cpp',
-    'src/config.cpp',
-    'src/group.cpp',
-    'src/util/portal.cpp',
-    'src/util/enum.cpp',
-    'src/util/prepare_for_sleep.cpp',
-    'src/util/ustring_clen.cpp',
-    'src/util/sanitize_str.cpp',
-    'src/util/rewrite_string.cpp',
-    'src/util/gtk_icon.cpp',
-    'src/util/regex_collection.cpp'
+     'src/main.cpp',
+     'src/client.cpp',
+     'src/bar.cpp',
+     'src/config.cpp',
+     'src/util/portal.cpp',
+     'src/util/prepare_for_sleep.cpp',
+#    'src/AModule.cpp',
 )
 
 inc_dirs = ['include']
+<<<<<<< HEAD
 
 if is_linux
     add_project_arguments('-DHAVE_CPU_LINUX', language: 'cpp')
@@ -399,45 +315,23 @@ if cava.found()
    src_files += 'src/modules/cava.cpp'
 endif
 
+=======
+>>>>>>> luka/gtk4
 subdir('protocol')
 
-app_resources = []
-subdir('resources/icons')
-
 executable(
     'waybar',
-    [src_files, app_resources],
+    [src_files],
     dependencies: [
-        thread_dep,
-        client_protos,
-        wayland_client,
-        fmt,
-        spdlog,
+        gtk_layer_shell,
+        gtkmm,
+        giounix,
         sigcpp,
         jsoncpp,
+        wayland_client,
         wayland_cursor,
-        gtkmm,
-        dbusmenu_gtk,
-        giounix,
-        libinput,
-        libnl,
-        libnlgen,
-        upower_glib,
-        pipewire,
-        playerctl,
-        libpulse,
-        libjack,
-        libwireplumber,
-        libudev,
-        libinotify,
-        libepoll,
-        libmpdclient,
-        libevdev,
-        gtk_layer_shell,
-        libsndio,
-        tz_dep,
-		xkbregistry,
-        cava
+        client_protos,
+        spdlog
     ],
     include_directories: inc_dirs,
     install: true,
@@ -448,6 +342,7 @@ install_data(
     './resources/style.css',
     install_dir: sysconfdir + '/xdg/waybar'
 )
+<<<<<<< HEAD
 
 scdoc = dependency('scdoc', version: '>=1.9.2', native: true, required: get_option('man-pages'))
 
@@ -558,3 +453,5 @@ if clangtidy.found()
         ] + src_files)
 endif
 
+=======
+>>>>>>> luka/gtk4
diff --git a/src/bar.cpp b/src/bar.cpp
index 1ffe2ef6..ae9c6524 100644
--- a/src/bar.cpp
+++ b/src/bar.cpp
@@ -1,15 +1,13 @@
 #ifdef HAVE_GTK_LAYER_SHELL
-#include <gtk-layer-shell.h>
+#include <gtk4-layer-shell.h>
 #endif
 
 #include <spdlog/spdlog.h>
 
-#include <type_traits>
-
 #include "bar.hpp"
 #include "client.hpp"
-#include "factory.hpp"
-#include "group.hpp"
+//#include "factory.hpp"
+//#include "group.hpp"
 #include "wlr-layer-shell-unstable-v1-client-protocol.h"
 
 #ifdef HAVE_SWAY
@@ -108,17 +106,16 @@ void from_json(const Json::Value& j, std::map<Key, Value>& m) {
 
 #ifdef HAVE_GTK_LAYER_SHELL
 struct GLSSurfaceImpl : public BarSurface, public sigc::trackable {
-  GLSSurfaceImpl(Gtk::Window& window, struct waybar_output& output) : window_{window} {
+  GLSSurfaceImpl(Gtk::Window& window, struct waybar_output& output)
+      : window_{window} {
     output_name_ = output.name;
     // this has to be executed before GtkWindow.realize
     gtk_layer_init_for_window(window_.gobj());
-    gtk_layer_set_keyboard_interactivity(window.gobj(), FALSE);
+    gtk_layer_set_keyboard_mode(window.gobj(), GTK_LAYER_SHELL_KEYBOARD_MODE_NONE);
     gtk_layer_set_monitor(window_.gobj(), output.monitor->gobj());
     gtk_layer_set_namespace(window_.gobj(), "waybar");
 
-    window.signal_map_event().connect_notify(sigc::mem_fun(*this, &GLSSurfaceImpl::onMap));
-    window.signal_configure_event().connect_notify(
-        sigc::mem_fun(*this, &GLSSurfaceImpl::onConfigure));
+    window.signal_map().connect(sigc::mem_fun(*this, &GLSSurfaceImpl::onMap));
   }
 
   void setExclusiveZone(bool enable) override {
@@ -148,13 +145,12 @@ struct GLSSurfaceImpl : public BarSurface, public sigc::trackable {
 
   void setPassThrough(bool enable) override {
     passthrough_ = enable;
-    auto gdk_window = window_.get_window();
-    if (gdk_window) {
+    if (gdk_surface_) {
       Cairo::RefPtr<Cairo::Region> region;
       if (enable) {
         region = Cairo::Region::create();
       }
-      gdk_window->input_shape_combine_region(region, 0, 0);
+      gdk_surface_->set_input_region(region);
     }
   }
 
@@ -195,15 +191,19 @@ struct GLSSurfaceImpl : public BarSurface, public sigc::trackable {
 
  private:
   Gtk::Window& window_;
+  Glib::RefPtr<Gdk::Surface> gdk_surface_;
   std::string output_name_;
   uint32_t width_;
   uint32_t height_;
   bool passthrough_ = false;
   bool vertical_ = false;
 
-  void onMap(GdkEventAny* ev) { setPassThrough(passthrough_); }
+  void onMap() {
+    gdk_surface_ = window_.get_surface();
+    gdk_surface_->signal_layout().connect(sigc::mem_fun(*this, &GLSSurfaceImpl::onConfigure));
+    setPassThrough(passthrough_); }
 
-  void onConfigure(GdkEventConfigure* ev) {
+  void onConfigure(int width, int height) {
     /*
      * GTK wants new size for the window.
      * Actual resizing and management of the exclusve zone is handled within the gtk-layer-shell
@@ -213,30 +213,30 @@ struct GLSSurfaceImpl : public BarSurface, public sigc::trackable {
      * gtk-layer-shell.
      */
     if (vertical_) {
-      if (width_ > 1 && ev->width > static_cast<int>(width_)) {
-        spdlog::warn(MIN_WIDTH_MSG, width_, ev->width);
+      if (width_ > 1 && width > static_cast<int>(width_)) {
+        spdlog::warn(MIN_WIDTH_MSG, width_, width);
       }
     } else {
-      if (height_ > 1 && ev->height > static_cast<int>(height_)) {
-        spdlog::warn(MIN_HEIGHT_MSG, height_, ev->height);
+      if (height_ > 1 && height > static_cast<int>(height_)) {
+        spdlog::warn(MIN_HEIGHT_MSG, height_, height);
       }
     }
-    width_ = ev->width;
-    height_ = ev->height;
+    width_ = width;
+    height_ = height;
     spdlog::info(BAR_SIZE_MSG, width_, height_, output_name_);
   }
 };
 #endif
 
 struct RawSurfaceImpl : public BarSurface, public sigc::trackable {
-  RawSurfaceImpl(Gtk::Window& window, struct waybar_output& output) : window_{window} {
+  RawSurfaceImpl(Gtk::Window& window, struct waybar_output& output)
+      : window_{window}, gdk_surface_{window_.get_surface()} {
     output_ = gdk_wayland_monitor_get_wl_output(output.monitor->gobj());
     output_name_ = output.name;
 
-    window.signal_realize().connect_notify(sigc::mem_fun(*this, &RawSurfaceImpl::onRealize));
-    window.signal_map_event().connect_notify(sigc::mem_fun(*this, &RawSurfaceImpl::onMap));
-    window.signal_configure_event().connect_notify(
-        sigc::mem_fun(*this, &RawSurfaceImpl::onConfigure));
+    window.signal_realize().connect(sigc::mem_fun(*this, &RawSurfaceImpl::onRealize));
+    window.signal_map().connect(sigc::mem_fun(*this, &RawSurfaceImpl::onMap));
+    gdk_surface_->signal_layout().connect(sigc::mem_fun(*this, &RawSurfaceImpl::onConfigure));
 
     if (window.get_realized()) {
       onRealize();
@@ -294,13 +294,12 @@ struct RawSurfaceImpl : public BarSurface, public sigc::trackable {
     passthrough_ = enable;
     /* GTK overwrites any region changes applied directly to the wl_surface,
      * thus the same GTK region API as in the GLS impl has to be used. */
-    auto gdk_window = window_.get_window();
-    if (gdk_window) {
+    if (gdk_surface_) {
       Cairo::RefPtr<Cairo::Region> region;
       if (enable) {
         region = Cairo::Region::create();
       }
-      gdk_window->input_shape_combine_region(region, 0, 0);
+      gdk_surface_->set_input_region(region);
     }
   }
 
@@ -345,6 +344,7 @@ struct RawSurfaceImpl : public BarSurface, public sigc::trackable {
       std::unique_ptr<zwlr_layer_surface_v1, deleter_fn<zwlr_layer_surface_v1_destroy>>;
 
   Gtk::Window& window_;
+  Glib::RefPtr<Gdk::Surface> gdk_surface_;
   std::string output_name_;
   uint32_t configured_width_ = 0;
   uint32_t configured_height_ = 0;
@@ -361,18 +361,16 @@ struct RawSurfaceImpl : public BarSurface, public sigc::trackable {
   layer_surface_ptr layer_surface_;
 
   void onRealize() {
-    auto gdk_window = window_.get_window()->gobj();
-    gdk_wayland_window_set_use_custom_surface(gdk_window);
+    gtk_layer_init_for_window(window_.gobj());
   }
 
-  void onMap(GdkEventAny* ev) {
+  void onMap() {
     static const struct zwlr_layer_surface_v1_listener layer_surface_listener = {
         .configure = onSurfaceConfigure,
         .closed = onSurfaceClosed,
     };
     auto client = Client::inst();
-    auto gdk_window = window_.get_window()->gobj();
-    surface_ = gdk_wayland_window_get_wl_surface(gdk_window);
+    surface_ = gdk_wayland_surface_get_wl_surface(gdk_surface_->gobj());
 
     layer_surface_.reset(zwlr_layer_shell_v1_get_layer_surface(client->layer_shell, surface_,
                                                                output_, layer_, "waybar"));
@@ -391,7 +389,7 @@ struct RawSurfaceImpl : public BarSurface, public sigc::trackable {
     wl_display_roundtrip(client->wl_display);
   }
 
-  void onConfigure(GdkEventConfigure* ev) {
+  void onConfigure(int width, int height) {
     /*
      * GTK wants new size for the window.
      *
@@ -401,26 +399,26 @@ struct RawSurfaceImpl : public BarSurface, public sigc::trackable {
      */
     auto tmp_height = height_;
     auto tmp_width = width_;
-    if (ev->height > static_cast<int>(height_)) {
+    if (height > static_cast<int>(height_)) {
       // Default minimal value
       if (height_ > 1) {
-        spdlog::warn(MIN_HEIGHT_MSG, height_, ev->height);
+        spdlog::warn(MIN_HEIGHT_MSG, height_, height);
       }
       if (configured_height_ > 1) {
         spdlog::info(SIZE_DEFINED, "Height");
       } else {
-        tmp_height = ev->height;
+        tmp_height = height;
       }
     }
-    if (ev->width > static_cast<int>(width_)) {
+    if (width > static_cast<int>(width_)) {
       // Default minimal value
       if (width_ > 1) {
-        spdlog::warn(MIN_WIDTH_MSG, width_, ev->width);
+        spdlog::warn(MIN_WIDTH_MSG, width_, width);
       }
       if (configured_width_ > 1) {
         spdlog::info(SIZE_DEFINED, "Width");
       } else {
-        tmp_width = ev->width;
+        tmp_width = width;
       }
     }
     if (tmp_width != width_ || tmp_height != height_) {
@@ -460,7 +458,6 @@ struct RawSurfaceImpl : public BarSurface, public sigc::trackable {
       o->width_ = width;
       o->height_ = height;
       o->window_.set_size_request(o->width_, o->height_);
-      o->window_.resize(o->width_, o->height_);
       o->setExclusiveZone(o->exclusive_zone_);
       spdlog::info(BAR_SIZE_MSG, o->width_ == 1 ? "auto" : std::to_string(o->width_),
                    o->height_ == 1 ? "auto" : std::to_string(o->height_), o->output_name_);
@@ -480,17 +477,18 @@ struct RawSurfaceImpl : public BarSurface, public sigc::trackable {
 waybar::Bar::Bar(struct waybar_output* w_output, const Json::Value& w_config)
     : output(w_output),
       config(w_config),
-      window{Gtk::WindowType::WINDOW_TOPLEVEL},
+      window{Gtk::Window()},
       x_global(0),
       y_global(0),
       margins_{.top = 0, .right = 0, .bottom = 0, .left = 0},
-      left_(Gtk::ORIENTATION_HORIZONTAL, 0),
-      center_(Gtk::ORIENTATION_HORIZONTAL, 0),
-      right_(Gtk::ORIENTATION_HORIZONTAL, 0),
-      box_(Gtk::ORIENTATION_HORIZONTAL, 0) {
+      left_(Gtk::Orientation::HORIZONTAL, 0),
+      center_(Gtk::Orientation::HORIZONTAL, 0),
+      right_(Gtk::Orientation::HORIZONTAL, 0),
+      box_{} {
   window.set_title("waybar");
   window.set_name("waybar");
   window.set_decorated(false);
+  window.set_child(box_);
   window.get_style_context()->add_class(output->name);
   window.get_style_context()->add_class(config["name"].asString());
   window.get_style_context()->add_class(config["position"].asString());
@@ -498,12 +496,13 @@ waybar::Bar::Bar(struct waybar_output* w_output, const Json::Value& w_config)
   auto position = config["position"].asString();
 
   if (position == "right" || position == "left") {
-    left_ = Gtk::Box(Gtk::ORIENTATION_VERTICAL, 0);
-    center_ = Gtk::Box(Gtk::ORIENTATION_VERTICAL, 0);
-    right_ = Gtk::Box(Gtk::ORIENTATION_VERTICAL, 0);
-    box_ = Gtk::Box(Gtk::ORIENTATION_VERTICAL, 0);
+    left_.set_orientation(Gtk::Orientation::VERTICAL);
+    center_.set_orientation(Gtk::Orientation::VERTICAL);
+    right_.set_orientation(Gtk::Orientation::VERTICAL);
+    box_.set_orientation(Gtk::Orientation::VERTICAL);
     vertical = true;
-  }
+  } else
+    box_.set_orientation(Gtk::Orientation::HORIZONTAL);
 
   left_.get_style_context()->add_class("modules-left");
   center_.get_style_context()->add_class("modules-center");
@@ -564,7 +563,6 @@ waybar::Bar::Bar(struct waybar_output* w_output, const Json::Value& w_config)
     margins_ = {.top = gaps, .right = gaps, .bottom = gaps, .left = gaps};
   }
 
-  window.signal_configure_event().connect_notify(sigc::mem_fun(*this, &Bar::onConfigure));
   output->monitor->property_geometry().signal_changed().connect(
       sigc::mem_fun(*this, &Bar::onOutputGeometryChanged));
 
@@ -602,7 +600,7 @@ waybar::Bar::Bar(struct waybar_output* w_output, const Json::Value& w_config)
     setVisible(false);
   }
 
-  window.signal_map_event().connect_notify(sigc::mem_fun(*this, &Bar::onMap));
+  window.signal_map().connect(sigc::mem_fun(*this, &Bar::onMap));
 
 #if HAVE_SWAY
   if (auto ipc = config["ipc"]; ipc.isBool() && ipc.asBool()) {
@@ -622,7 +620,7 @@ waybar::Bar::Bar(struct waybar_output* w_output, const Json::Value& w_config)
 #endif
 
   setupWidgets();
-  window.show_all();
+  window.show();
 
   if (spdlog::should_log(spdlog::level::debug)) {
     // Unfortunately, this function isn't in the C++ bindings, so we have to call the C version.
@@ -673,13 +671,14 @@ void waybar::Bar::setMode(const struct bar_mode& mode) {
   surface_impl_->commit();
 }
 
-void waybar::Bar::onMap(GdkEventAny*) {
+void waybar::Bar::onMap() {
   /*
    * Obtain a pointer to the custom layer surface for modules that require it (idle_inhibitor).
    */
-  auto gdk_window = window.get_window()->gobj();
-  surface = gdk_wayland_window_get_wl_surface(gdk_window);
-  configureGlobalOffset(gdk_window_get_width(gdk_window), gdk_window_get_height(gdk_window));
+  gdk_surface_ = window.get_surface();
+  surface = gdk_wayland_surface_get_wl_surface(gdk_surface_->gobj());
+  configureGlobalOffset(gdk_surface_->get_width(), gdk_surface_->get_height());
+  gdk_surface_->signal_layout().connect(sigc::mem_fun(*this, &Bar::onConfigure));
 }
 
 void waybar::Bar::setVisible(bool value) {
@@ -739,6 +738,8 @@ void waybar::Bar::handleSignal(int signal) {
   }
 }
 
+// todo gtkmm4
+/*
 void waybar::Bar::getModules(const Factory& factory, const std::string& pos,
                              waybar::Group* group = nullptr) {
   auto module_list = group ? config[pos]["modules"] : config[pos];
@@ -754,7 +755,7 @@ void waybar::Bar::getModules(const Factory& factory, const std::string& pos,
           auto class_name = hash_pos != std::string::npos ? ref.substr(hash_pos + 1) : "";
 
           auto vertical = (group ? group->getBox().get_orientation() : box_.get_orientation()) ==
-                          Gtk::ORIENTATION_VERTICAL;
+                          Gtk::Orientation::VERTICAL;
 
           auto group_module = new waybar::Group(id_name, class_name, config[ref], vertical);
           getModules(factory, ref, group_module);
@@ -791,40 +792,39 @@ void waybar::Bar::getModules(const Factory& factory, const std::string& pos,
     }
   }
 }
-
+*/
 auto waybar::Bar::setupWidgets() -> void {
-  window.add(box_);
-  box_.pack_start(left_, false, false);
+  box_.set_start_widget(left_);
   if (config["fixed-center"].isBool() ? config["fixed-center"].asBool() : true) {
     box_.set_center_widget(center_);
   } else {
-    box_.pack_start(center_, true, false);
+    box_.set_start_widget(center_);
   }
-  box_.pack_end(right_, false, false);
-
+  box_.set_end_widget(right_);
   // Convert to button code for every module that is used.
   setupAltFormatKeyForModuleList("modules-left");
   setupAltFormatKeyForModuleList("modules-right");
   setupAltFormatKeyForModuleList("modules-center");
 
-  Factory factory(*this, config);
-  getModules(factory, "modules-left");
-  getModules(factory, "modules-center");
-  getModules(factory, "modules-right");
+// todo gtkmm4
+//  Factory factory(*this, config);
+//  getModules(factory, "modules-left");
+//  getModules(factory, "modules-center");
+//  getModules(factory, "modules-right");
   for (auto const& module : modules_left_) {
-    left_.pack_start(*module, false, false);
+    left_.prepend(*module);
   }
   for (auto const& module : modules_center_) {
-    center_.pack_start(*module, false, false);
+    center_.prepend(*module);
   }
   std::reverse(modules_right_.begin(), modules_right_.end());
   for (auto const& module : modules_right_) {
-    right_.pack_end(*module, false, false);
+    right_.append(*module);
   }
 }
 
-void waybar::Bar::onConfigure(GdkEventConfigure* ev) {
-  configureGlobalOffset(ev->width, ev->height);
+void waybar::Bar::onConfigure(int width, int height) {
+  configureGlobalOffset(width, height);
 }
 
 void waybar::Bar::configureGlobalOffset(int width, int height) {
diff --git a/src/client.cpp b/src/client.cpp
index 066247e7..3f65b2fa 100644
--- a/src/client.cpp
+++ b/src/client.cpp
@@ -5,6 +5,7 @@
 #include <iostream>
 
 #include "gtkmm/icontheme.h"
+#include "gtkmm/application.h"
 #include "idle-inhibit-unstable-v1-client-protocol.h"
 #include "util/clara.hpp"
 #include "util/format.hpp"
@@ -181,14 +182,15 @@ const std::string waybar::Client::getStyle(const std::string &style,
 
 auto waybar::Client::setupCss(const std::string &css_file) -> void {
   css_provider_ = Gtk::CssProvider::create();
-  style_context_ = Gtk::StyleContext::create();
 
   // Load our css file, wherever that may be hiding
-  if (!css_provider_->load_from_path(css_file)) {
-    throw std::runtime_error("Can't open style file");
+  try {
+    css_provider_->load_from_path(css_file);
+  } catch (const Glib::Error& e) {
+    spdlog::error("{}", e.what());
   }
   // there's always only one screen
-  style_context_->add_provider_for_screen(Gdk::Screen::get_default(), css_provider_,
+  Gtk::StyleContext::add_provider_for_display(Gdk::Display::get_default(), css_provider_,
                                           GTK_STYLE_PROVIDER_PRIORITY_USER);
 }
 
@@ -204,13 +206,20 @@ void waybar::Client::bindInterfaces() {
     throw std::runtime_error("Failed to acquire required resources.");
   }
   // add existing outputs and subscribe to updates
-  for (auto i = 0; i < gdk_display->get_n_monitors(); ++i) {
-    auto monitor = gdk_display->get_monitor(i);
-    handleMonitorAdded(monitor);
+//  auto monitors{gdk_display->get_monitors()};
+  for (guint i{0}; i < monitors_->get_n_items(); ++i) {
+    handleMonitorAdded(std::dynamic_pointer_cast<Gdk::Monitor>(monitors_->get_object(i)));
   }
-  gdk_display->signal_monitor_added().connect(sigc::mem_fun(*this, &Client::handleMonitorAdded));
-  gdk_display->signal_monitor_removed().connect(
-      sigc::mem_fun(*this, &Client::handleMonitorRemoved));
+
+  monitors_->signal_items_changed().connect([=, this](const guint& position, const guint& removed, const guint& added){
+    for (auto i{removed}; i > 0; --i) {
+      handleMonitorRemoved(std::dynamic_pointer_cast<Gdk::Monitor>(monitors_->get_object(position + i)));
+    }
+
+    for (auto i{added}; i > 0; --i) {
+      handleMonitorAdded(std::dynamic_pointer_cast<Gdk::Monitor>(monitors_->get_object(position + i)));
+    }
+  });
 }
 
 int waybar::Client::main(int argc, char *argv[]) {
@@ -243,13 +252,8 @@ int waybar::Client::main(int argc, char *argv[]) {
   if (!log_level.empty()) {
     spdlog::set_level(spdlog::level::from_str(log_level));
   }
-  gtk_app = Gtk::Application::create(argc, argv, "fr.arouillard.waybar",
-                                     Gio::APPLICATION_HANDLES_COMMAND_LINE);
-
-  // Initialize Waybars GTK resources with our custom icons
-  auto theme = Gtk::IconTheme::get_default();
-  theme->add_resource_path("/fr/arouillard/waybar/icons");
-
+  gtk_app = Gtk::Application::create("fr.arouillard.waybar",
+                                     Gio::Application::Flags::HANDLES_COMMAND_LINE);
   gdk_display = Gdk::Display::get_default();
   if (!gdk_display) {
     throw std::runtime_error("Can't find display");
@@ -257,7 +261,13 @@ int waybar::Client::main(int argc, char *argv[]) {
   if (!GDK_IS_WAYLAND_DISPLAY(gdk_display->gobj())) {
     throw std::runtime_error("Bar need to run under Wayland");
   }
+
+  // Initialize Waybars GTK resources with our custom icons
+  auto theme{Gtk::IconTheme::get_for_display(gdk_display)};
+  theme->add_resource_path("/fr/arouillard/waybar/icons");
+
   wl_display = gdk_wayland_display_get_wl_display(gdk_display->gobj());
+  monitors_ = gdk_display->get_monitors();
   config.load(config_opt);
   if (!portal) {
     portal = std::make_unique<waybar::Portal>();
@@ -272,6 +282,7 @@ int waybar::Client::main(int argc, char *argv[]) {
   gtk_app->hold();
   gtk_app->run();
   bars.clear();
+
   return 0;
 }
 
diff --git a/src/main.cpp b/src/main.cpp
index ff446ffc..1ffc40bd 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -108,11 +108,11 @@ int main(int argc, char* argv[]) {
 
     delete client;
     return ret;
+  } catch (const Glib::Error& e) {
+    spdlog::error("{}", static_cast<std::string>(e.what()));
+    return 1;
   } catch (const std::exception& e) {
     spdlog::error("{}", e.what());
     return 1;
-  } catch (const Glib::Exception& e) {
-    spdlog::error("{}", static_cast<std::string>(e.what()));
-    return 1;
   }
 }
diff --git a/src/util/portal.cpp b/src/util/portal.cpp
index 50c646c5..1f3f94ad 100644
--- a/src/util/portal.cpp
+++ b/src/util/portal.cpp
@@ -36,7 +36,7 @@ auto fmt::formatter<waybar::Appearance>::format(waybar::Appearance c, format_con
 }
 
 waybar::Portal::Portal()
-    : DBus::Proxy(DBus::Connection::get_sync(DBus::BusType::BUS_TYPE_SESSION), PORTAL_BUS_NAME,
+    : DBus::Proxy(DBus::Connection::get_sync(DBus::BusType::SESSION), PORTAL_BUS_NAME,
                   PORTAL_OBJ_PATH, PORTAL_INTERFACE),
       currentMode(Appearance::UNKNOWN) {
   refreshAppearance();
diff --git a/subprojects/gtk-layer-shell.wrap b/subprojects/gtk-layer-shell.wrap
deleted file mode 100644
index 555fbcb6..00000000
--- a/subprojects/gtk-layer-shell.wrap
+++ /dev/null
@@ -1,5 +0,0 @@
-[wrap-file]
-directory = gtk-layer-shell-0.4.0
-source_filename = gtk-layer-shell-0.4.0.tar.gz
-source_hash = 52fd74d3161fefa5528585ca5a523c3150934961f2284ad010ae54336dad097e
-source_url = https://github.com/wmww/gtk-layer-shell/archive/v0.4.0/gtk-layer-shell-0.4.0.tar.gz
diff --git a/subprojects/gtk4-layer-shell.wrap b/subprojects/gtk4-layer-shell.wrap
new file mode 100644
index 00000000..cd3e1cfb
--- /dev/null
+++ b/subprojects/gtk4-layer-shell.wrap
@@ -0,0 +1,9 @@
+[wrap-file]
+directory = gtk4-layer-shell-1.0.2
+source_filename = gtk4-layer-shell-1.0.2.tar.gz
+source_hash = 55fa593241cad200fcb2b647b4dcc0d5d5516792e21a5b65662f010e224d7a73
+#source_hash = a3a827845612fa15de30734eb29c01db329c32f8e279d8bc5251facc69220b86
+source_url = https://github.com/wmww/gtk4-layer-shell/archive/v1.0.2/gtk4-layer-shell-1.0.2.tar.gz
+
+[provide]
+gtk-layer-shell = gtk_layer_shell