refactor(bar): Split GLS and raw layer-shell implementations

Extract two surface implementations from the bar class: GLSSurfaceImpl
and RawSurfaceImpl. This change allowed to remove _all_ surface type
conditionals and significantly simplify the Bar code.

The change also applies PImpl pattern to the Bar, allowing to remove
some headers and fields from `bar.hpp`.

include/bar.hpp

@@ -7,6 +7,7 @@
 #include <gtkmm/main.h>
 #include <gtkmm/window.h>
 #include <json/json.h>
+
 #include "AModule.hpp"
 #include "idle-inhibit-unstable-v1-client-protocol.h"
 #include "wlr-layer-shell-unstable-v1-client-protocol.h"
@@ -23,13 +24,35 @@ struct waybar_output {
       nullptr, &zxdg_output_v1_destroy};
 };
 
+struct bar_margins {
+  int top = 0;
+  int right = 0;
+  int bottom = 0;
+  int left = 0;
+};
+
+class BarSurface {
+ protected:
+  BarSurface() = default;
+
+ public:
+  virtual void set_exclusive_zone(bool enable) = 0;
+  virtual void set_layer(const std::string_view &layer) = 0;
+  virtual void set_margins(const struct bar_margins &margins) = 0;
+  virtual void set_position(const std::string_view &position) = 0;
+  virtual void set_size(uint32_t width, uint32_t height) = 0;
+
+  virtual ~BarSurface() = default;
+};
+
 class Bar {
  public:
   Bar(struct waybar_output *w_output, const Json::Value &);
   Bar(const Bar &) = delete;
   ~Bar() = default;
 
-  auto toggle() -> void;
+  void setVisible(bool visible);
+  void toggle();
   void handleSignal(int);
 
   struct waybar_output *output;
@@ -40,48 +63,15 @@ class Bar {
   Gtk::Window           window;
 
  private:
-  static constexpr const char *MIN_HEIGHT_MSG =
+  void onMap(GdkEventAny *);
-      "Requested height: {} exceeds the minimum height: {} required by the modules";
-  static constexpr const char *MIN_WIDTH_MSG =
-      "Requested width: {} exceeds the minimum width: {} required by the modules";
-  static constexpr const char *BAR_SIZE_MSG =
-      "Bar configured (width: {}, height: {}) for output: {}";
-  static constexpr const char *SIZE_DEFINED =
-      "{} size is defined in the config file so it will stay like that";
-  static void layerSurfaceHandleConfigure(void *, struct zwlr_layer_surface_v1 *, uint32_t,
-                                          uint32_t, uint32_t);
-  static void layerSurfaceHandleClosed(void *, struct zwlr_layer_surface_v1 *);
-
-#ifdef HAVE_GTK_LAYER_SHELL
-  /* gtk-layer-shell code */
-  void initGtkLayerShell();
-  void onConfigureGLS(GdkEventConfigure *ev);
-  void onMapGLS(GdkEventAny *ev);
-#endif
-  /* fallback layer-surface code */
-  void onConfigure(GdkEventConfigure *ev);
-  void onRealize();
-  void onMap(GdkEventAny *ev);
-  void setSurfaceSize(uint32_t width, uint32_t height);
-  /* common code */
-  void setExclusiveZone(uint32_t width, uint32_t height);
   auto setupWidgets() -> void;
   void getModules(const Factory &, const std::string &);
   void setupAltFormatKeyForModule(const std::string &module_name);
   void setupAltFormatKeyForModuleList(const char *module_list_name);
 
-  struct margins {
+  std::unique_ptr<BarSurface>                   surface_impl_;
-    int top = 0;
-    int right = 0;
-    int bottom = 0;
-    int left = 0;
-  } margins_;
-  struct zwlr_layer_surface_v1 *layer_surface_;
-  // use gtk-layer-shell instead of handling layer surfaces directly
-  bool                                          use_gls_ = false;
   uint32_t                                      width_ = 0;
   uint32_t                                      height_ = 1;
-  uint8_t                                       anchor_;
   Gtk::Box                                      left_;
   Gtk::Box                                      center_;
   Gtk::Box                                      right_;

src/bar.cpp

@@ -8,13 +8,346 @@
 #include "client.hpp"
 #include "factory.hpp"
 
+namespace waybar {
+static constexpr const char* MIN_HEIGHT_MSG =
+    "Requested height: {} exceeds the minimum height: {} required by the modules";
+
+static constexpr const char* MIN_WIDTH_MSG =
+    "Requested width: {} exceeds the minimum width: {} required by the modules";
+
+static constexpr const char* BAR_SIZE_MSG = "Bar configured (width: {}, height: {}) for output: {}";
+
+static constexpr const char* SIZE_DEFINED =
+    "{} size is defined in the config file so it will stay like that";
+
+#ifdef HAVE_GTK_LAYER_SHELL
+struct GLSSurfaceImpl : public BarSurface, public sigc::trackable {
+  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_monitor(window_.gobj(), output.monitor->gobj());
+    gtk_layer_set_namespace(window_.gobj(), "waybar");
+
+    window.signal_configure_event().connect_notify(
+        sigc::mem_fun(*this, &GLSSurfaceImpl::on_configure));
+  }
+
+  void set_exclusive_zone(bool enable) override {
+    if (enable) {
+      gtk_layer_auto_exclusive_zone_enable(window_.gobj());
+    } else {
+      gtk_layer_set_exclusive_zone(window_.gobj(), 0);
+    }
+  }
+
+  void set_margins(const struct bar_margins& margins) override {
+    gtk_layer_set_margin(window_.gobj(), GTK_LAYER_SHELL_EDGE_LEFT, margins.left);
+    gtk_layer_set_margin(window_.gobj(), GTK_LAYER_SHELL_EDGE_RIGHT, margins.right);
+    gtk_layer_set_margin(window_.gobj(), GTK_LAYER_SHELL_EDGE_TOP, margins.top);
+    gtk_layer_set_margin(window_.gobj(), GTK_LAYER_SHELL_EDGE_BOTTOM, margins.bottom);
+  }
+
+  void set_layer(const std::string_view& value) override {
+    auto layer = GTK_LAYER_SHELL_LAYER_BOTTOM;
+    if (value == "top") {
+      layer = GTK_LAYER_SHELL_LAYER_TOP;
+    } else if (value == "overlay") {
+      layer = GTK_LAYER_SHELL_LAYER_OVERLAY;
+    }
+    gtk_layer_set_layer(window_.gobj(), layer);
+  }
+
+  void set_position(const std::string_view& position) override {
+    auto unanchored = GTK_LAYER_SHELL_EDGE_BOTTOM;
+    vertical_ = false;
+    if (position == "bottom") {
+      unanchored = GTK_LAYER_SHELL_EDGE_TOP;
+    } else if (position == "left") {
+      unanchored = GTK_LAYER_SHELL_EDGE_RIGHT;
+      vertical_ = true;
+    } else if (position == "right") {
+      vertical_ = true;
+      unanchored = GTK_LAYER_SHELL_EDGE_LEFT;
+    }
+    for (auto edge : {GTK_LAYER_SHELL_EDGE_LEFT,
+                      GTK_LAYER_SHELL_EDGE_RIGHT,
+                      GTK_LAYER_SHELL_EDGE_TOP,
+                      GTK_LAYER_SHELL_EDGE_BOTTOM}) {
+      gtk_layer_set_anchor(window_.gobj(), edge, unanchored != edge);
+    }
+  }
+
+  void set_size(uint32_t width, uint32_t height) override {
+    width_ = width;
+    height_ = height;
+    window_.set_size_request(width_, height_);
+  };
+
+ private:
+  Gtk::Window& window_;
+  std::string  output_name_;
+  uint32_t     width_;
+  uint32_t     height_;
+  bool         vertical_ = false;
+
+  void on_configure(GdkEventConfigure* ev) {
+    /*
+     * GTK wants new size for the window.
+     * Actual resizing and management of the exclusve zone is handled within the gtk-layer-shell
+     * code. This event handler only updates stored size of the window and prints some warnings.
+     *
+     * Note: forced resizing to a window smaller than required by GTK would not work with
+     * gtk-layer-shell.
+     */
+    if (vertical_) {
+      if (width_ > 1 && ev->width > static_cast<int>(width_)) {
+        spdlog::warn(MIN_WIDTH_MSG, width_, ev->width);
+      }
+    } else {
+      if (height_ > 1 && ev->height > static_cast<int>(height_)) {
+        spdlog::warn(MIN_HEIGHT_MSG, height_, ev->height);
+      }
+    }
+    width_ = ev->width;
+    height_ = ev->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} {
+    output_ = gdk_wayland_monitor_get_wl_output(output.monitor->gobj());
+    output_name_ = output.name;
+
+    window.signal_realize().connect_notify(sigc::mem_fun(*this, &RawSurfaceImpl::on_realize));
+    window.signal_map_event().connect_notify(sigc::mem_fun(*this, &RawSurfaceImpl::on_map));
+    window.signal_configure_event().connect_notify(
+        sigc::mem_fun(*this, &RawSurfaceImpl::on_configure));
+
+    if (window.get_realized()) {
+      on_realize();
+    }
+  }
+
+  void set_exclusive_zone(bool enable) override {
+    exclusive_zone_ = enable;
+    if (layer_surface_) {
+      auto zone = 0;
+      if (enable) {
+        // exclusive zone already includes margin for anchored edge,
+        // only opposite margin should be added
+        if ((anchor_ & VERTICAL_ANCHOR) == VERTICAL_ANCHOR) {
+          zone += width_;
+          zone += (anchor_ & ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT) ? margins_.right : margins_.left;
+        } else {
+          zone += height_;
+          zone += (anchor_ & ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP) ? margins_.bottom : margins_.top;
+        }
+      }
+      spdlog::debug("Set exclusive zone {} for output {}", zone, output_name_);
+      zwlr_layer_surface_v1_set_exclusive_zone(layer_surface_, zone);
+    }
+  }
+
+  void set_layer(const std::string_view& layer) override {
+    layer_ = ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM;
+    if (layer == "top") {
+      layer_ = ZWLR_LAYER_SHELL_V1_LAYER_TOP;
+    } else if (layer == "overlay") {
+      layer_ = ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY;
+    }
+    // updating already mapped window
+    if (layer_surface_) {
+      if (zwlr_layer_surface_v1_get_version(layer_surface_) >=
+          ZWLR_LAYER_SURFACE_V1_SET_LAYER_SINCE_VERSION) {
+        zwlr_layer_surface_v1_set_layer(layer_surface_, layer_);
+        commit();
+      } else {
+        spdlog::warn("Unable to set layer: layer-shell interface version is too old");
+      }
+    }
+  }
+
+  void set_margins(const struct bar_margins& margins) override {
+    margins_ = margins;
+    // updating already mapped window
+    if (layer_surface_) {
+      zwlr_layer_surface_v1_set_margin(
+          layer_surface_, margins_.top, margins_.right, margins_.bottom, margins_.left);
+      commit();
+    }
+  }
+
+  void set_position(const std::string_view& position) override {
+    anchor_ = HORIZONTAL_ANCHOR | ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP;
+    if (position == "bottom") {
+      anchor_ = HORIZONTAL_ANCHOR | ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM;
+    } else if (position == "left") {
+      anchor_ = VERTICAL_ANCHOR | ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT;
+    } else if (position == "right") {
+      anchor_ = VERTICAL_ANCHOR | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
+    }
+
+    // updating already mapped window
+    if (layer_surface_) {
+      zwlr_layer_surface_v1_set_anchor(layer_surface_, anchor_);
+      commit();
+    }
+  }
+
+  void set_size(uint32_t width, uint32_t height) override {
+    width_ = width;
+    height_ = height;
+    // layer_shell.configure handler should update exclusive zone if size changes
+    window_.set_size_request(width, height);
+  };
+
+ private:
+  constexpr static uint8_t VERTICAL_ANCHOR =
+      ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP | ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM;
+  constexpr static uint8_t HORIZONTAL_ANCHOR =
+      ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
+
+  Gtk::Window&       window_;
+  std::string        output_name_;
+  uint32_t           width_;
+  uint32_t           height_;
+  uint8_t            anchor_ = HORIZONTAL_ANCHOR | ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP;
+  bool               exclusive_zone_ = true;
+  struct bar_margins margins_;
+
+  zwlr_layer_shell_v1_layer     layer_ = ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM;
+  struct wl_output*             output_ = nullptr;
+  struct wl_surface*            surface_ = nullptr;
+  struct zwlr_layer_surface_v1* layer_surface_ = nullptr;
+
+  void on_realize() {
+    auto gdk_window = window_.get_window()->gobj();
+    gdk_wayland_window_set_use_custom_surface(gdk_window);
+  }
+
+  void on_map(GdkEventAny* ev) {
+    auto client = Client::inst();
+    auto gdk_window = window_.get_window()->gobj();
+    surface_ = gdk_wayland_window_get_wl_surface(gdk_window);
+
+    layer_surface_ = zwlr_layer_shell_v1_get_layer_surface(
+        client->layer_shell, surface_, output_, layer_, "waybar");
+
+    zwlr_layer_surface_v1_set_keyboard_interactivity(layer_surface_, false);
+
+    zwlr_layer_surface_v1_set_anchor(layer_surface_, anchor_);
+    zwlr_layer_surface_v1_set_margin(
+        layer_surface_, margins_.top, margins_.right, margins_.bottom, margins_.left);
+    set_surface_size(width_, height_);
+    set_exclusive_zone(exclusive_zone_);
+
+    static const struct zwlr_layer_surface_v1_listener layer_surface_listener = {
+        .configure = on_surface_configure,
+        .closed = on_surface_closed,
+    };
+    zwlr_layer_surface_v1_add_listener(layer_surface_, &layer_surface_listener, this);
+
+    wl_surface_commit(surface_);
+    wl_display_roundtrip(client->wl_display);
+  }
+
+  void on_configure(GdkEventConfigure* ev) {
+    /*
+     * GTK wants new size for the window.
+     *
+     * Prefer configured size if it's non-default.
+     * If the size is not set and the window is smaller than requested by GTK, request resize from
+     * layer surface.
+     */
+    auto tmp_height = height_;
+    auto tmp_width = width_;
+    if (ev->height > static_cast<int>(height_)) {
+      // Default minimal value
+      if (height_ > 1) {
+        spdlog::warn(MIN_HEIGHT_MSG, height_, ev->height);
+      }
+      /*
+      if (config["height"].isUInt()) {
+        spdlog::info(SIZE_DEFINED, "Height");
+      } else */
+      tmp_height = ev->height;
+    }
+    if (ev->width > static_cast<int>(width_)) {
+      // Default minimal value
+      if (width_ > 1) {
+        spdlog::warn(MIN_WIDTH_MSG, width_, ev->width);
+      }
+      /*
+      if (config["width"].isUInt()) {
+        spdlog::info(SIZE_DEFINED, "Width");
+      } else */
+      tmp_width = ev->width;
+    }
+    if (tmp_width != width_ || tmp_height != height_) {
+      set_surface_size(tmp_width, tmp_height);
+    }
+  }
+
+  void commit() {
+    if (window_.get_mapped()) {
+      wl_surface_commit(surface_);
+    }
+  }
+
+  void set_surface_size(uint32_t width, uint32_t height) {
+    /* If the client is anchored to two opposite edges, layer_surface.configure will return
+     * size without margins for the axis.
+     * layer_surface.set_size, however, expects size with margins for the anchored axis.
+     * This is not specified by wlr-layer-shell and based on actual behavior of sway.
+     */
+    bool vertical = (anchor_ & VERTICAL_ANCHOR) == VERTICAL_ANCHOR;
+    if (vertical && height > 1) {
+      height += margins_.top + margins_.bottom;
+    }
+    if (!vertical && width > 1) {
+      width += margins_.right + margins_.left;
+    }
+    spdlog::debug("Set surface size {}x{} for output {}", width, height, output_name_);
+    zwlr_layer_surface_v1_set_size(layer_surface_, width, height);
+  }
+
+  static void on_surface_configure(void* data, struct zwlr_layer_surface_v1* surface,
+                                   uint32_t serial, uint32_t width, uint32_t height) {
+    auto o = static_cast<RawSurfaceImpl*>(data);
+    if (width != o->width_ || height != o->height_) {
+      o->width_ = width;
+      o->height_ = height;
+      o->window_.set_size_request(o->width_, o->height_);
+      o->window_.resize(o->width_, o->height_);
+      o->set_exclusive_zone(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_);
+      wl_surface_commit(o->surface_);
+    }
+    zwlr_layer_surface_v1_ack_configure(surface, serial);
+  }
+
+  static void on_surface_closed(void* data, struct zwlr_layer_surface_v1* /* surface */) {
+    auto o = static_cast<RawSurfaceImpl*>(data);
+    if (o->layer_surface_) {
+      zwlr_layer_surface_v1_destroy(o->layer_surface_);
+      o->layer_surface_ = nullptr;
+    }
+  }
+};
+
+};  // namespace waybar
+
 waybar::Bar::Bar(struct waybar_output* w_output, const Json::Value& w_config)
     : output(w_output),
       config(w_config),
-      surface(nullptr),
       window{Gtk::WindowType::WINDOW_TOPLEVEL},
-      layer_surface_(nullptr),
-      anchor_(ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP),
       left_(Gtk::ORIENTATION_HORIZONTAL, 0),
       center_(Gtk::ORIENTATION_HORIZONTAL, 0),
       right_(Gtk::ORIENTATION_HORIZONTAL, 0),
@@ -29,32 +362,22 @@ waybar::Bar::Bar(struct waybar_output* w_output, const Json::Value& w_config)
   center_.get_style_context()->add_class("modules-center");
   right_.get_style_context()->add_class("modules-right");
 
-  if (config["position"] == "right" || config["position"] == "left") {
+  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);
+    vertical = true;
+
     height_ = 0;
     width_ = 1;
   }
   height_ = config["height"].isUInt() ? config["height"].asUInt() : height_;
   width_ = config["width"].isUInt() ? config["width"].asUInt() : width_;
 
-  if (config["position"] == "bottom") {
+  struct bar_margins margins_;
-    anchor_ = ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM;
-  } else if (config["position"] == "left") {
-    anchor_ = ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT;
-  } else if (config["position"] == "right") {
-    anchor_ = ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
-  }
-  if (anchor_ == ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM ||
-      anchor_ == ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP) {
-    anchor_ |= ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT | ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT;
-  } else if (anchor_ == ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT ||
-             anchor_ == ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT) {
-    anchor_ |= ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP | ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM;
-    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);
-    vertical = true;
-  }
 
   if (config["margin-top"].isInt() || config["margin-right"].isInt() ||
       config["margin-bottom"].isInt() || config["margin-left"].isInt()) {
@@ -102,210 +425,51 @@ waybar::Bar::Bar(struct waybar_output* w_output, const Json::Value& w_config)
   }
 
 #ifdef HAVE_GTK_LAYER_SHELL
-  use_gls_ = config["gtk-layer-shell"].isBool() ? config["gtk-layer-shell"].asBool() : true;
+  bool use_gls = config["gtk-layer-shell"].isBool() ? config["gtk-layer-shell"].asBool() : true;
-  if (use_gls_) {
+  if (use_gls) {
-    initGtkLayerShell();
+    surface_impl_ = std::make_unique<GLSSurfaceImpl>(window, *output);
-    window.signal_map_event().connect_notify(sigc::mem_fun(*this, &Bar::onMapGLS));
-    window.signal_configure_event().connect_notify(sigc::mem_fun(*this, &Bar::onConfigureGLS));
-  }
-#endif
-
-  if (!use_gls_) {
-    window.signal_realize().connect_notify(sigc::mem_fun(*this, &Bar::onRealize));
-    window.signal_map_event().connect_notify(sigc::mem_fun(*this, &Bar::onMap));
-    window.signal_configure_event().connect_notify(sigc::mem_fun(*this, &Bar::onConfigure));
-  }
-  window.set_size_request(width_, height_);
-  setupWidgets();
-
-  if (!use_gls_ && window.get_realized()) {
-    onRealize();
-  }
-  window.show_all();
-}
-
-#ifdef HAVE_GTK_LAYER_SHELL
-void waybar::Bar::initGtkLayerShell() {
-  auto gtk_window = window.gobj();
-  // this has to be executed before GtkWindow.realize
-  gtk_layer_init_for_window(gtk_window);
-  gtk_layer_set_keyboard_interactivity(gtk_window, FALSE);
-  auto layer = config["layer"] == "top" ? GTK_LAYER_SHELL_LAYER_TOP : GTK_LAYER_SHELL_LAYER_BOTTOM;
-  gtk_layer_set_layer(gtk_window, layer);
-  gtk_layer_set_monitor(gtk_window, output->monitor->gobj());
-  gtk_layer_set_namespace(gtk_window, "waybar");
-
-  gtk_layer_set_anchor(gtk_window,
-                       GTK_LAYER_SHELL_EDGE_LEFT,
-                       (anchor_ & ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT) ? TRUE : FALSE);
-  gtk_layer_set_anchor(gtk_window,
-                       GTK_LAYER_SHELL_EDGE_RIGHT,
-                       (anchor_ & ZWLR_LAYER_SURFACE_V1_ANCHOR_RIGHT) ? TRUE : FALSE);
-  gtk_layer_set_anchor(gtk_window,
-                       GTK_LAYER_SHELL_EDGE_TOP,
-                       (anchor_ & ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP) ? TRUE : FALSE);
-  gtk_layer_set_anchor(gtk_window,
-                       GTK_LAYER_SHELL_EDGE_BOTTOM,
-                       (anchor_ & ZWLR_LAYER_SURFACE_V1_ANCHOR_BOTTOM) ? TRUE : FALSE);
-
-  gtk_layer_set_margin(gtk_window, GTK_LAYER_SHELL_EDGE_LEFT, margins_.left);
-  gtk_layer_set_margin(gtk_window, GTK_LAYER_SHELL_EDGE_RIGHT, margins_.right);
-  gtk_layer_set_margin(gtk_window, GTK_LAYER_SHELL_EDGE_TOP, margins_.top);
-  gtk_layer_set_margin(gtk_window, GTK_LAYER_SHELL_EDGE_BOTTOM, margins_.bottom);
-
-  setExclusiveZone(width_, height_);
-}
-
-void waybar::Bar::onConfigureGLS(GdkEventConfigure* ev) {
-  /*
-   * GTK wants new size for the window.
-   * Actual resizing and management of the exclusve zone is handled within the gtk-layer-shell code.
-   * This event handler only updates stored size of the window and prints some warnings.
-   *
-   * Note: forced resizing to a window smaller than required by GTK would not work with
-   * gtk-layer-shell.
-   */
-  if (vertical) {
-    if (width_ > 1 && ev->width > static_cast<int>(width_)) {
-      spdlog::warn(MIN_WIDTH_MSG, width_, ev->width);
-    }
-  } else {
-    if (height_ > 1 && ev->height > static_cast<int>(height_)) {
-      spdlog::warn(MIN_HEIGHT_MSG, height_, ev->height);
-    }
-  }
-  width_ = ev->width;
-  height_ = ev->height;
-  spdlog::info(BAR_SIZE_MSG, width_, height_, output->name);
-}
-
-void waybar::Bar::onMapGLS(GdkEventAny* ev) {
-  /*
-   * Obtain a pointer to the custom layer surface for modules that require it (idle_inhibitor).
-   */
-  auto gdk_window = window.get_window();
-  surface = gdk_wayland_window_get_wl_surface(gdk_window->gobj());
-}
-
-#endif
-
-void waybar::Bar::onConfigure(GdkEventConfigure* ev) {
-  /*
-   * GTK wants new size for the window.
-   *
-   * Prefer configured size if it's non-default.
-   * If the size is not set and the window is smaller than requested by GTK, request resize from
-   * layer surface.
-   */
-  auto tmp_height = height_;
-  auto tmp_width = width_;
-  if (ev->height > static_cast<int>(height_)) {
-    // Default minimal value
-    if (height_ > 1) {
-      spdlog::warn(MIN_HEIGHT_MSG, height_, ev->height);
-    }
-    if (config["height"].isUInt()) {
-      spdlog::info(SIZE_DEFINED, "Height");
-    } else {
-      tmp_height = ev->height;
-    }
-  }
-  if (ev->width > static_cast<int>(width_)) {
-    // Default minimal value
-    if (width_ > 1) {
-      spdlog::warn(MIN_WIDTH_MSG, width_, ev->width);
-    }
-    if (config["width"].isUInt()) {
-      spdlog::info(SIZE_DEFINED, "Width");
-    } else {
-      tmp_width = ev->width;
-    }
-  }
-  if (tmp_width != width_ || tmp_height != height_) {
-    setSurfaceSize(tmp_width, tmp_height);
-  }
-}
-
-void waybar::Bar::onRealize() {
-  auto gdk_window = window.get_window()->gobj();
-  gdk_wayland_window_set_use_custom_surface(gdk_window);
-}
-
-void waybar::Bar::onMap(GdkEventAny* ev) {
-  auto gdk_window = window.get_window()->gobj();
-  surface = gdk_wayland_window_get_wl_surface(gdk_window);
-
-  auto client = waybar::Client::inst();
-  // owned by output->monitor; no need to destroy
-  auto wl_output = gdk_wayland_monitor_get_wl_output(output->monitor->gobj());
-  auto layer =
-      config["layer"] == "top" ? ZWLR_LAYER_SHELL_V1_LAYER_TOP : ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM;
-  layer_surface_ = zwlr_layer_shell_v1_get_layer_surface(
-      client->layer_shell, surface, wl_output, layer, "waybar");
-
-  zwlr_layer_surface_v1_set_keyboard_interactivity(layer_surface_, false);
-  zwlr_layer_surface_v1_set_anchor(layer_surface_, anchor_);
-  zwlr_layer_surface_v1_set_margin(
-      layer_surface_, margins_.top, margins_.right, margins_.bottom, margins_.left);
-  setSurfaceSize(width_, height_);
-  setExclusiveZone(width_, height_);
-
-  static const struct zwlr_layer_surface_v1_listener layer_surface_listener = {
-      .configure = layerSurfaceHandleConfigure,
-      .closed = layerSurfaceHandleClosed,
-  };
-  zwlr_layer_surface_v1_add_listener(layer_surface_, &layer_surface_listener, this);
-
-  wl_surface_commit(surface);
-  wl_display_roundtrip(client->wl_display);
-}
-
-void waybar::Bar::setExclusiveZone(uint32_t width, uint32_t height) {
-#ifdef HAVE_GTK_LAYER_SHELL
-  if (use_gls_) {
-    if (visible) {
-      spdlog::debug("Enable auto exclusive zone for output {}", output->name);
-      gtk_layer_auto_exclusive_zone_enable(window.gobj());
-    } else {
-      spdlog::debug("Disable exclusive zone for output {}", output->name);
-      gtk_layer_set_exclusive_zone(window.gobj(), 0);
-    }
   } else
 #endif
   {
-    auto zone = 0;
+    surface_impl_ = std::make_unique<RawSurfaceImpl>(window, *output);
-    if (visible) {
-      // exclusive zone already includes margin for anchored edge,
-      // only opposite margin should be added
-      if (vertical) {
-        zone += width;
-        zone += (anchor_ & ZWLR_LAYER_SURFACE_V1_ANCHOR_LEFT) ? margins_.right : margins_.left;
-      } else {
-        zone += height;
-        zone += (anchor_ & ZWLR_LAYER_SURFACE_V1_ANCHOR_TOP) ? margins_.bottom : margins_.top;
-      }
-    }
-    spdlog::debug("Set exclusive zone {} for output {}", zone, output->name);
-    zwlr_layer_surface_v1_set_exclusive_zone(layer_surface_, zone);
-  }
   }
 
-void waybar::Bar::setSurfaceSize(uint32_t width, uint32_t height) {
+  if (config["layer"].isString()) {
-  /* If the client is anchored to two opposite edges, layer_surface.configure will return
+    surface_impl_->set_layer(config["layer"].asString());
-   * size without margins for the axis.
+  }
-   * layer_surface.set_size, however, expects size with margins for the anchored axis.
+  surface_impl_->set_exclusive_zone(true);
-   * This is not specified by wlr-layer-shell and based on actual behavior of sway.
+  surface_impl_->set_margins(margins_);
+  surface_impl_->set_position(position);
+  surface_impl_->set_size(width_, height_);
+
+  window.signal_map_event().connect_notify(sigc::mem_fun(*this, &Bar::onMap));
+
+  setupWidgets();
+  window.show_all();
+}
+
+void waybar::Bar::onMap(GdkEventAny*) {
+  /*
+   * Obtain a pointer to the custom layer surface for modules that require it (idle_inhibitor).
    */
-  if (vertical && height > 1) {
+  auto gdk_window = window.get_window()->gobj();
-    height += margins_.top + margins_.bottom;
+  surface = gdk_wayland_window_get_wl_surface(gdk_window);
 }
-  if (!vertical && width > 1) {
+
-    width += margins_.right + margins_.left;
+void waybar::Bar::setVisible(bool value) {
+  visible = value;
+  if (!visible) {
+    window.get_style_context()->add_class("hidden");
+    window.set_opacity(0);
+  } else {
+    window.get_style_context()->remove_class("hidden");
+    window.set_opacity(1);
   }
-  spdlog::debug("Set surface size {}x{} for output {}", width, height, output->name);
+  surface_impl_->set_exclusive_zone(visible);
-  zwlr_layer_surface_v1_set_size(layer_surface_, width, height);
 }
 
+void waybar::Bar::toggle() { setVisible(!visible); }
+
 // Converting string to button code rn as to avoid doing it later
 void waybar::Bar::setupAltFormatKeyForModule(const std::string& module_name) {
   if (config.isMember(module_name)) {
@@ -367,50 +531,6 @@ void waybar::Bar::handleSignal(int signal) {
   }
 }
 
-void waybar::Bar::layerSurfaceHandleConfigure(void* data, struct zwlr_layer_surface_v1* surface,
-                                              uint32_t serial, uint32_t width, uint32_t height) {
-  auto o = static_cast<waybar::Bar*>(data);
-  if (width != o->width_ || height != o->height_) {
-    o->width_ = width;
-    o->height_ = height;
-    o->window.set_size_request(o->width_, o->height_);
-    o->window.resize(o->width_, o->height_);
-    o->setExclusiveZone(width, height);
-    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);
-    wl_surface_commit(o->surface);
-  }
-  zwlr_layer_surface_v1_ack_configure(surface, serial);
-}
-
-void waybar::Bar::layerSurfaceHandleClosed(void* data, struct zwlr_layer_surface_v1* /*surface*/) {
-  auto o = static_cast<waybar::Bar*>(data);
-  if (o->layer_surface_) {
-    zwlr_layer_surface_v1_destroy(o->layer_surface_);
-    o->layer_surface_ = nullptr;
-  }
-  o->modules_left_.clear();
-  o->modules_center_.clear();
-  o->modules_right_.clear();
-}
-
-auto waybar::Bar::toggle() -> void {
-  visible = !visible;
-  if (!visible) {
-    window.get_style_context()->add_class("hidden");
-    window.set_opacity(0);
-  } else {
-    window.get_style_context()->remove_class("hidden");
-    window.set_opacity(1);
-  }
-  setExclusiveZone(width_, height_);
-  if (!use_gls_) {
-    wl_surface_commit(surface);
-  }
-}
-
 void waybar::Bar::getModules(const Factory& factory, const std::string& pos) {
   if (config[pos].isArray()) {
     for (const auto& name : config[pos]) {