feat(scoreboard): Add Objective::isDisplayed method

include/endstone/detail/scoreboard/objective.h

@@ -38,6 +38,7 @@ class EndstoneObjective : public Objective {
     [[nodiscard]] Result<bool> isModifiable() const override;
     [[nodiscard]] Scoreboard &getScoreboard() const override;
     [[nodiscard]] Result<void> unregister() const override;
+    [[nodiscard]] Result<bool> isDisplayed() const override;
     [[nodiscard]] Result<DisplaySlot> getDisplaySlot() const override;
     [[nodiscard]] Result<ObjectiveSortOrder> getSortOrder() const override;
     Result<void> setDisplay(std::optional<DisplaySlot> slot) override;

include/endstone/scoreboard/objective.h

@@ -78,6 +78,13 @@ class Objective {
      */
     [[nodiscard]] virtual Result<void> unregister() const = 0;
 
+    /**
+     * @brief Gets if the objective is currently displayed in a slot.
+     *
+     * @return true if the objective is displayed
+     */
+    [[nodiscard]] virtual Result<bool> isDisplayed() const = 0;
+
     /**
      * @brief Gets the display slot this objective is displayed at.
      *

python/src/endstone/_internal/endstone_python.pyi

@@ -1382,11 +1382,16 @@ class Objective:
     def display_name(self, arg1: str) -> None:
         ...
     @property
-    def display_slot(self) -> DisplaySlot:
+    def display_slot(self) -> DisplaySlot | None:
         """
         Gets the display slot this objective is displayed at
         """
     @property
+    def is_displayed(self) -> bool:
+        """
+        Gets if the objective is currently displayed in a slot.
+        """
+    @property
     def is_modifiable(self) -> bool:
         """
         Gets if the objective's scores can be modified directly by a plugin
@@ -1410,7 +1415,7 @@ class Objective:
         Gets the scoreboard to which this objective is attached
         """
     @property
-    def sort_order(self) -> ObjectiveSortOrder:
+    def sort_order(self) -> ObjectiveSortOrder | None:
         """
         Gets and sets the sort order for this objective
         """

src/endstone_core/scoreboard/objective.cpp

@@ -84,6 +84,20 @@ Result<void> EndstoneObjective::unregister() const
         .or_else([](const auto &err) -> Result<void> { return nonstd::make_unexpected(err); });
 }
 
+Result<bool> EndstoneObjective::isDisplayed() const
+{
+    bool displayed = false;
+    return forEachDisplayObjective([&](auto /*slot*/, const auto &display) -> bool {
+               if (&display.getObjective() == &objective_) {
+                   displayed = true;
+                   return false;
+               }
+               return true;
+           })
+        .and_then([&displayed]() -> Result<bool> { return displayed; })
+        .or_else([](const auto &err) -> Result<bool> { return nonstd::make_unexpected(err); });
+}
+
 Result<DisplaySlot> EndstoneObjective::getDisplaySlot() const
 {
     std::optional<DisplaySlot> result;

src/endstone_python/scoreboard.cpp

@@ -81,10 +81,26 @@ void init_scoreboard(py::module_ &m)
                                "Gets the scoreboard to which this objective is attached",
                                py::return_value_policy::reference)
         .def("unregister", &Objective::unregister, "Unregisters this objective from the associated Scoreboard.")
-        .def_property_readonly("display_slot", &Objective::getDisplaySlot,
-                               "Gets the display slot this objective is displayed at")
-        .def_property_readonly("sort_order", &Objective::getSortOrder,
-                               "Gets and sets the sort order for this objective")
+        .def_property_readonly("is_displayed", &Objective::isDisplayed,
+                               "Gets if the objective is currently displayed in a slot.")
+        .def_property_readonly(
+            "display_slot",
+            [](const Objective &self) -> std::variant<Result<DisplaySlot>, py::none> {
+                if (self.isDisplayed().value_or(false)) {
+                    return self.getDisplaySlot();
+                }
+                return py::none();
+            },
+            "Gets the display slot this objective is displayed at")
+        .def_property_readonly(
+            "sort_order",
+            [](const Objective &self) -> std::variant<Result<ObjectiveSortOrder>, py::none> {
+                if (self.isDisplayed().value_or(false)) {
+                    return self.getSortOrder();
+                }
+                return py::none();
+            },
+            "Gets and sets the sort order for this objective")
         .def(
             "set_display",
             [](Objective &self, std::optional<DisplaySlot> slot, std::optional<ObjectiveSortOrder> order) {