fix(#3239): hide cursor type change behind config flag

also, statically configure the cursor type

man/waybar-styles.5.scd.in

@@ -39,6 +39,38 @@ You can apply special styling to any module for when the cursor hovers it.
 }
 ```
 
+## Setting cursor style
+
+Most, if not all, module types support setting the `cursor` option. This is
+configured in your `config.jsonc`. If set to `true`, when hovering the module a
+"pointer"(as commonly known from web CSS styling `cursor: pointer`) style cursor
+will be shown.
+There are more cursor types to choose from by setting the `cursor` option to
+a number, see Gdk3 official docs for all possible cursor types:
+https://docs.gtk.org/gdk3/enum.CursorType.html.
+However, note that not all cursor options listed may be available on
+your system. If you attempt to use a cursor which is not available, the
+application will crash.
+
+Example of enabling pointer(`Gdk::Hand2`) cursor type on a custom module:
+
+```
+"custom/my-custom-module": {
+    ...
+    "cursor": true,
+}
+```
+
+Example of setting cursor type to `Gdk::Boat`(according to
+https://docs.gtk.org/gdk3/enum.CursorType.html#boat):
+
+```
+"custom/my-custom-module": {
+    ...
+    "cursor": 8,
+}
+```
+
 # SEE ALSO
 
 - *waybar(5)*

src/AModule.cpp

@@ -1,9 +1,13 @@
 #include "AModule.hpp"
 
 #include <fmt/format.h>
+#include <spdlog/spdlog.h>
 
 #include <util/command.hpp>
 
+#include "gdk/gdk.h"
+#include "gdkmm/cursor.h"
+
 namespace waybar {
 
 AModule::AModule(const Json::Value& config, const std::string& name, const std::string& id,
@@ -64,6 +68,16 @@ AModule::AModule(const Json::Value& config, const std::string& name, const std::
     event_box_.add_events(Gdk::SCROLL_MASK | Gdk::SMOOTH_SCROLL_MASK);
     event_box_.signal_scroll_event().connect(sigc::mem_fun(*this, &AModule::handleScroll));
   }
+
+  if (config_.isMember("cursor")) {
+    if (config_["cursor"].isBool() && config_["cursor"].asBool()) {
+      setCursor(Gdk::HAND2);
+    } else if (config_["cursor"].isInt()) {
+      setCursor(Gdk::CursorType(config_["cursor"].asInt()));
+    } else {
+      spdlog::warn("unknown cursor option configured on module {}", name_);
+    }
+  }
 }
 
 AModule::~AModule() {
@@ -91,19 +105,26 @@ auto AModule::doAction(const std::string& name) -> void {
 }
 
 void AModule::setCursor(Gdk::CursorType const& c) {
-  auto cursor = Gdk::Cursor::create(c);
   auto gdk_window = event_box_.get_window();
+  if (gdk_window) {
+    auto cursor = Gdk::Cursor::create(c);
     gdk_window->set_cursor(cursor);
+  } else {
+    // window may not be accessible yet, in this case,
+    // schedule another call for setting the cursor in 1 sec
+    Glib::signal_timeout().connect_seconds(
+        [this, c]() {
+          setCursor(c);
+          return false;
+        },
+        1);
+  }
 }
 
 bool AModule::handleMouseEnter(GdkEventCrossing* const& e) {
   if (auto* module = event_box_.get_child(); module != nullptr) {
     module->set_state_flags(Gtk::StateFlags::STATE_FLAG_PRELIGHT);
   }
-
-  if (hasUserEvents_) {
-    setCursor(Gdk::HAND2);
-  }
   return false;
 }
 
@@ -111,10 +132,6 @@ bool AModule::handleMouseLeave(GdkEventCrossing* const& e) {
   if (auto* module = event_box_.get_child(); module != nullptr) {
     module->unset_state_flags(Gtk::StateFlags::STATE_FLAG_PRELIGHT);
   }
-
-  if (hasUserEvents_) {
-    setCursor(Gdk::ARROW);
-  }
   return false;
 }