Move now works better, and the API is a lot cleaner. Now just need to make it not crash.

gui/fsm.cpp

@@ -208,6 +208,7 @@ namespace gui {
       case MOUSE_CLICK:
         mouse_action(false);
         break;
+      case MOUSE_DRAG:
       case MOUSE_MOVE: {
         if($grab_source) {
           auto& source = $status_ui.get_grab_source(*$grab_source);
@@ -218,13 +219,6 @@ namespace gui {
       case MOUSE_DRAG_START: {
           mouse_action(false);
        } break;
-      case MOUSE_DRAG: {
-        if($grab_source) {
-          auto& source = $status_ui.get_grab_source(*$grab_source);
-          source.move($router.position);
-        }
-        mouse_action(true);
-       } break;
       case MOUSE_DROP:
         mouse_action(false);
         break;

gui/guecstra.cpp

@@ -21,11 +21,20 @@ namespace guecs {
   }
 
   DinkyECS::Entity GrabSource::grab() {
-    fmt::println("grab! {}", world_entity);
     return world_entity;
   }
 
-  void GrabSource::move(sf::Vector2i position) {
-    fmt::println("move! {} to {},{}", world_entity, position.x, position.y);
+  void GrabSource::setSprite(guecs::UI& gui, DinkyECS::Entity gui_id) {
+    dbc::check(gui.has<guecs::Sprite>(gui_id), "GrabSource given sprite gui_id that doesn't exist");
+
+    auto& sp = gui.get<guecs::Sprite>(gui_id);
+    sprite = sp.sprite;
+  }
+
+  void GrabSource::move(sf::Vector2i pos) {
+    if(sprite) {
+      sprite->setPosition({
+          float(pos.x), float(pos.y)});
+    }
   }
 }

gui/guecstra.hpp

@@ -11,9 +11,11 @@ namespace guecs {
   struct GrabSource {
     DinkyECS::Entity world_entity;
     std::function<void()> commit;
+    std::shared_ptr<sf::Sprite> sprite = nullptr;
 
     DinkyECS::Entity grab();
-    void move(sf::Vector2i position);
+    void setSprite(guecs::UI& gui, DinkyECS::Entity gui_id);
+    void move(sf::Vector2i pos);
   };
 
   struct DropTarget {

gui/loot_ui.cpp

@@ -67,8 +67,11 @@ namespace gui {
             "item in inventory UI doesn't exist in world. New level?");
         auto& sprite = $level.world->get<components::Sprite>(item);
         $gui.set_init<guecs::Sprite>(id, {sprite.name});
-        $gui.set<guecs::GrabSource>(id, {
-            item, [&, id]() { return remove_slot(id); }});
+
+        guecs::GrabSource grabber{
+            item, [&, id]() { return remove_slot(id); }};
+        grabber.setSprite($gui, id);
+        $gui.set<guecs::GrabSource>(id, grabber);
       } else {
         $gui.set<guecs::DropTarget>(id, {
            [&, id](DinkyECS::Entity world_entity) -> bool { return place_slot(id, world_entity); }

gui/status_ui.cpp

@@ -89,8 +89,11 @@ namespace gui {
     if($level.world->has<components::Sprite>(world_entity)) {
       auto& sprite = $level.world->get<components::Sprite>(world_entity);
       $gui.set_init<guecs::Sprite>(gui_id, {sprite.name});
-      $gui.set<guecs::GrabSource>(gui_id, {world_entity,
-          [&, gui_id]() { return remove_slot(gui_id); }});
+      guecs::GrabSource grabber{ world_entity,
+          [&, gui_id]() { return remove_slot(gui_id); }};
+      grabber.setSprite($gui, gui_id);
+      $gui.set<guecs::GrabSource>(gui_id, grabber);
+
       contents.insert_or_assign(gui_id, world_entity);
       return true;
     } else {