Clean up more of the FSM so that it's almost nothing.Now I'll try to make a stand-alone 'dnd' state machine to handle drag and drop functionality.

gui/fsm.cpp

@@ -133,23 +133,17 @@ namespace gui {
         $loot_ui.active = false;
         state(State::IDLE);
         break;
-      case LOOT_SELECT: {
-          auto gui_id = std::any_cast<guecs::Entity>(data);
-          $grab_source = UISystem::loot_grab($loot_ui.$gui, gui_id);
-          if(!$grab_source) state(State::LOOTING);
-        } break;
-      case INV_SELECT: {
-          if($grab_source) {
-            auto gui_id = std::any_cast<guecs::Entity>(data);
-            bool dropped = UISystem::loot_drop(
-                $loot_ui.$gui, $status_ui.$gui,
-                *$grab_source, gui_id);
-
-            if(dropped) {
-              state(State::LOOTING);
-            }
-          }
-        } break;
+      case LOOT_SELECT:
+        $grab_source = UISystem::loot_grab($loot_ui.$gui, data);
+        if($grab_source) state(State::LOOTING);
+        break;
+      case INV_SELECT:
+         if(UISystem::loot_drop($loot_ui.$gui,
+               $status_ui.$gui, $grab_source, data))
+         {
+           state(State::LOOTING);
+         }
+         break;
       case MOUSE_CLICK:
         mouse_action(false);
         break;
@@ -183,23 +177,17 @@ namespace gui {
         $loot_ui.active = false;
         state(State::IDLE);
         break;
-      case LOOT_SELECT: {
-          if($grab_source) {
-            auto gui_id = std::any_cast<guecs::Entity>(data);
-            bool dropped = UISystem::loot_drop(
-                $status_ui.$gui, $loot_ui.$gui,
-                *$grab_source, gui_id);
-
-            if(dropped) {
-              state(State::LOOTING);
-            }
-          }
-        } break;
-      case INV_SELECT: {
-          auto gui_id = std::any_cast<DinkyECS::Entity>(data);
-          $grab_source = UISystem::loot_grab($status_ui.$gui, gui_id);
-          if(!$grab_source) state(State::LOOTING);
-        } break;
+      case LOOT_SELECT:
+        if(UISystem::loot_drop($status_ui.$gui,
+              $loot_ui.$gui, $grab_source, data))
+        {
+          state(State::LOOTING);
+        }
+        break;
+      case INV_SELECT:
+        $grab_source = UISystem::loot_grab($status_ui.$gui, data);
+        state(State::LOOTING);
+        break;
       case MOUSE_CLICK:
         mouse_action(false);
         break;
@@ -230,16 +218,14 @@ namespace gui {
         $loot_ui.active = false;
         state(State::IDLE);
         break;
-      case LOOT_SELECT: {
-          auto gui_id = std::any_cast<guecs::Entity>(data);
-          $grab_source = UISystem::loot_grab($loot_ui.$gui, gui_id);
-          if($grab_source) state(State::LOOT_GRAB);
-        } break;
-      case INV_SELECT: {
-          auto gui_id = std::any_cast<DinkyECS::Entity>(data);
-          $grab_source = UISystem::loot_grab($status_ui.$gui, gui_id);
-          if($grab_source) state(State::INV_GRAB);
-        } break;
+      case LOOT_SELECT:
+        $grab_source = UISystem::loot_grab($loot_ui.$gui, data);
+        if($grab_source) state(State::LOOT_GRAB);
+        break;
+      case INV_SELECT:
+        $grab_source = UISystem::loot_grab($status_ui.$gui, data);
+        if($grab_source) state(State::INV_GRAB);
+        break;
       case MOUSE_DRAG_START:
       case MOUSE_CLICK:
         mouse_action(false);

gui/uisystems.cpp

@@ -2,7 +2,9 @@
 #include "gui/guecstra.hpp"
 
 namespace UISystem {
-  std::optional<guecs::Entity> loot_grab(guecs::UI& gui, guecs::Entity gui_id) {
+  std::optional<guecs::Entity> loot_grab(guecs::UI& gui, std::any data) {
+    auto gui_id = std::any_cast<guecs::Entity>(data);
+
     if(auto source = gui.get_if<guecs::GrabSource>(gui_id)) {
       source->grab();
       return gui_id;
@@ -11,9 +13,14 @@ namespace UISystem {
     }
   }
 
-  bool loot_drop(guecs::UI& source, guecs::UI& target, guecs::Entity source_id, guecs::Entity target_id) {
+  bool loot_drop(guecs::UI& source, guecs::UI& target,
+      std::optional<guecs::Entity> source_id, std::any data)
+  {
+    if(!source_id) return false;
+    auto target_id = std::any_cast<guecs::Entity>(data);
+
     auto& drop = target.get<guecs::DropTarget>(target_id);
-    auto& grab = source.get<guecs::GrabSource>(source_id);
+    auto& grab = source.get<guecs::GrabSource>(*source_id);
 
     if(drop.commit(grab.world_entity)) {
       grab.commit();

gui/uisystems.hpp

@@ -3,8 +3,8 @@
 #include <optional>
 
 namespace UISystem {
-  std::optional<guecs::Entity> loot_grab(guecs::UI& gui, guecs::Entity gui_id);
+  std::optional<guecs::Entity> loot_grab(guecs::UI& gui, std::any data);
 
-
-  bool loot_drop(guecs::UI& source, guecs::UI& target, guecs::Entity grab_source, guecs::Entity target_id);
+  bool loot_drop(guecs::UI& source, guecs::UI& target,
+      std::optional<guecs::Entity> source_id, std::any data);
 }