From 42254d774d96f8929d150b0f9066f5bb379afafa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=CE=B6eh=20Matt?= <5415177+ZehMatt@users.noreply.github.com>
Date: Sun, 12 Sep 2021 18:24:55 +0300
Subject: [PATCH] Allow game actions to store custom data instead of using
 inheritance

---
 src/openrct2-ui/windows/TopToolbar.cpp     |  5 +++--
 src/openrct2/actions/BannerPlaceAction.cpp | 24 ++--------------------
 src/openrct2/actions/BannerPlaceAction.h   | 10 ++-------
 src/openrct2/actions/GameAction.h          | 15 ++++++++++++++
 4 files changed, 22 insertions(+), 32 deletions(-)

diff --git a/src/openrct2-ui/windows/TopToolbar.cpp b/src/openrct2-ui/windows/TopToolbar.cpp
index 2de7cecde5..a55bf14190 100644
--- a/src/openrct2-ui/windows/TopToolbar.cpp
+++ b/src/openrct2-ui/windows/TopToolbar.cpp
@@ -1983,11 +1983,12 @@ static void window_top_toolbar_scenery_tool_down(const ScreenCoordsXY& windowPos
             CoordsXYZD loc{ gridPos, z, direction };
             auto primaryColour = gWindowSceneryPrimaryColour;
             auto bannerPlaceAction = BannerPlaceAction(loc, selectedScenery, primaryColour);
-            bannerPlaceAction.SetCallback([=](const GameAction* ga, const BannerPlaceActionResult* result) {
+            bannerPlaceAction.SetCallback([=](const GameAction* ga, const GameActions::Result* result) {
                 if (result->Error == GameActions::Status::Ok)
                 {
+                    auto data = result->GetData<BannerPlaceActionResult>();
                     OpenRCT2::Audio::Play3D(OpenRCT2::Audio::SoundId::PlaceItem, result->Position);
-                    context_open_detail_window(WD_BANNER, result->bannerId);
+                    context_open_detail_window(WD_BANNER, data.bannerId);
                 }
             });
             GameActions::Execute(&bannerPlaceAction);
diff --git a/src/openrct2/actions/BannerPlaceAction.cpp b/src/openrct2/actions/BannerPlaceAction.cpp
index 88e6860d27..5fcc570d31 100644
--- a/src/openrct2/actions/BannerPlaceAction.cpp
+++ b/src/openrct2/actions/BannerPlaceAction.cpp
@@ -18,26 +18,6 @@
 
 using namespace OpenRCT2;
 
-BannerPlaceActionResult::BannerPlaceActionResult()
-    : GameActions::Result(GameActions::Status::Ok, STR_CANT_POSITION_THIS_HERE)
-{
-}
-
-BannerPlaceActionResult::BannerPlaceActionResult(GameActions::Status err)
-    : GameActions::Result(err, STR_CANT_POSITION_THIS_HERE)
-{
-}
-
-BannerPlaceActionResult::BannerPlaceActionResult(GameActions::Status err, rct_string_id msg)
-    : GameActions::Result(err, STR_CANT_POSITION_THIS_HERE, msg)
-{
-}
-
-BannerPlaceActionResult::BannerPlaceActionResult(GameActions::Status err, rct_string_id title, rct_string_id message)
-    : GameActions::Result(err, title, message)
-{
-}
-
 BannerPlaceAction::BannerPlaceAction(const CoordsXYZD& loc, ObjectEntryIndex bannerType, colour_t primaryColour)
     : _loc(loc)
     , _bannerType(bannerType)
@@ -117,6 +97,7 @@ GameActions::Result::Ptr BannerPlaceAction::Query() const
         return MakeResult(GameActions::Status::InvalidParameters, STR_CANT_POSITION_THIS_HERE);
     }
     res->Cost = bannerEntry->price;
+
     return res;
 }
 
@@ -155,8 +136,7 @@ GameActions::Result::Ptr BannerPlaceAction::Execute() const
     banner->colour = _primaryColour;
     banner->position = TileCoordsXY(_loc);
 
-    res->bannerId = banner->id;
-
+    res->SetData(BannerPlaceActionResult{ banner->id });
     auto* bannerElement = TileElementInsert<BannerElement>({ _loc, _loc.z + (2 * COORDS_Z_STEP) }, 0b0000);
     Guard::Assert(bannerElement != nullptr);
 
diff --git a/src/openrct2/actions/BannerPlaceAction.h b/src/openrct2/actions/BannerPlaceAction.h
index c4195a18ca..5de3d37e82 100644
--- a/src/openrct2/actions/BannerPlaceAction.h
+++ b/src/openrct2/actions/BannerPlaceAction.h
@@ -11,18 +11,12 @@
 
 #include "GameAction.h"
 
-class BannerPlaceActionResult final : public GameActions::Result
+struct BannerPlaceActionResult
 {
-public:
-    BannerPlaceActionResult();
-    BannerPlaceActionResult(GameActions::Status err);
-    BannerPlaceActionResult(GameActions::Status err, rct_string_id msg);
-    BannerPlaceActionResult(GameActions::Status err, rct_string_id title, rct_string_id message);
-
     BannerIndex bannerId = BANNER_INDEX_NULL;
 };
 
-DEFINE_GAME_ACTION(BannerPlaceAction, GameCommand::PlaceBanner, BannerPlaceActionResult)
+DEFINE_GAME_ACTION(BannerPlaceAction, GameCommand::PlaceBanner, GameActions::Result)
 {
 private:
     CoordsXYZD _loc;
diff --git a/src/openrct2/actions/GameAction.h b/src/openrct2/actions/GameAction.h
index 856470f356..03ee95fe5f 100644
--- a/src/openrct2/actions/GameAction.h
+++ b/src/openrct2/actions/GameAction.h
@@ -16,6 +16,7 @@
 #include "../localisation/StringIds.h"
 #include "../world/Map.h"
 
+#include <any>
 #include <array>
 #include <functional>
 #include <memory>
@@ -130,6 +131,7 @@ namespace GameActions
         CoordsXYZ Position = { LOCATION_NULL, LOCATION_NULL, LOCATION_NULL };
         money32 Cost = 0;
         ExpenditureType Expenditure = ExpenditureType::Count;
+        std::any ResultData;
 
         Result() = default;
         Result(GameActions::Status error, rct_string_id message);
@@ -140,6 +142,19 @@ namespace GameActions
 
         std::string GetErrorTitle() const;
         std::string GetErrorMessage() const;
+
+        // It is recommended to use strong types since a type alias such as 'using MyType = uint32_t'
+        // is still just uint32_t, this guarantees the data is associated with the correct type.
+        template<typename T> void SetData(const T&& data)
+        {
+            ResultData = std::forward<const T&&>(data);
+        }
+
+        // This function will throw std::bad_any_cast if the type mismatches.
+        template<typename T> T GetData() const
+        {
+            return std::any_cast<T>(ResultData);
+        }
     };
 
     class ConstructClearResult final : public Result