Swapping and putting back now work in the status_ui inventory, but now I need to refactor so this operation works on any inventory::Model.

gui/dnd_loot.cpp

@@ -111,10 +111,16 @@ namespace gui {
           dbc::check(worked, "Need to fix this, should be able to abort.");
           END(CLOSE);
         } break;
-      case INV_SELECT:
-        if(commit_move($status_ui.$gui, $grab_source, data)) {
-          END(CLOSE);
-        }
+      case INV_SELECT: {
+          auto drop_id = std::any_cast<guecs::Entity>(data);
+
+          if($status_ui.occupied(drop_id)) {
+            $status_ui.swap(*$grab_source, drop_id);
+            END(CLOSE);
+          } else if(commit_move($status_ui.$gui, $grab_source, data)) {
+            END(CLOSE);
+          }
+         } break;
         break;
       default:
          handle_mouse(ev, $status_ui.$gui);

gui/status_ui.cpp

@@ -135,4 +135,25 @@ namespace gui {
     $gui.remove<guecs::GrabSource>(slot_id);
     $gui.remove<guecs::Sprite>(slot_id);
   }
+
+  void StatusUI::swap(guecs::Entity gui_a, guecs::Entity gui_b) {
+    if(gui_a != gui_b) {
+      auto& inventory = $level.world->get_the<inventory::Model>();
+      auto& a_name = $slot_to_name.at(gui_a);
+      auto& b_name = $slot_to_name.at(gui_b);
+      auto a_ent = inventory.get(a_name);
+      auto b_ent = inventory.get(b_name);
+      inventory.swap(a_ent, b_ent);
+    }
+
+    update();
+  }
+
+  bool StatusUI::occupied(guecs::Entity slot) {
+    dbc::check($slot_to_name.contains(slot), "jank ass slot to name thing isn't loaded right you idiot.");
+
+    auto& inventory = $level.world->get_the<inventory::Model>();
+    auto& slot_name = $slot_to_name.at(slot);
+    return inventory.has(slot_name);
+  }
 }

gui/status_ui.hpp

@@ -26,5 +26,8 @@ namespace gui {
       void remove_slot(guecs::Entity slot_id);
       bool place_slot(guecs::Entity gui_id, DinkyECS::Entity world_entity);
       bool drop_item(DinkyECS::Entity item_id);
+
+      void swap(guecs::Entity gui_a, guecs::Entity gui_b);
+      bool occupied(guecs::Entity slot);
   };
 }