Clear vector lines from cards when they're not being dragged

The events which can indicate a drag stop are varied:
- Drag a card into another on the table (tryObjectEnterContainer)
- Drag multiple cards into another on the table (onCollisionEnter, tryObjectEnterContainer)
- Group multiple cards while holding them (tryObjectEnterContainer)

src/core/Global.ttslua

@@ -184,6 +184,14 @@ function onObjectSearchEnd(object, playerColor)
   end
 end
 
+-- Pass object enter container events to the PlayArea to clear vector lines from dragged cards.
+-- This requires the try method as cards won't exist any more after they enter a deck, so the lines
+-- can't be cleared.
+function tryObjectEnterContainer(container, object)
+  playAreaAPI.tryObjectEnterContainer(container, object)
+  return true
+end
+
 function drawEncountercard(params)
   local position = params[1]
   local rotation = params[2]

src/core/PlayArea.ttslua

@@ -103,7 +103,12 @@ function onCollisionEnter(collisionInfo)
   if shouldSpawnTokens(card) then
     tokenManager.spawnForCard(card)
   end
-  draggingGuids[card.getGUID()] = nil
+  -- If this card was being dragged, clear the dragging connections.  A multi-drag/drop may send
+  -- the dropped card immediately into a deck, so this has to be done here
+  if draggingGuids[card.getGUID()] ~= nil then
+    card.setVectorLines(nil)
+    draggingGuids[card.getGUID()] = nil
+  end
   maybeTrackLocation(card)
 end
 
@@ -202,6 +207,18 @@ function maybeUntrackLocation(card)
   end
 end
 
+-- Global event handler, delegated from Global.  Clears any connection lines from dragged cards
+-- before they are destroyed by entering a deck.  Removal of the card from the dragging list will
+-- be handled during the next onUpdate() call.
+function tryObjectEnterContainer(params)
+  for draggedGuid, _ in pairs(draggingGuids) do
+    local draggedObj = getObjectFromGUID(draggedGuid)
+    if draggedObj ~= nil then
+      draggedObj.setVectorLines(nil)
+    end
+  end
+end
+
 -- Builds a list of GUID to GUID connection information based on the currently tracked locations.
 -- This will update the connection information and store it in the locationConnections data member,
 -- but does not draw those connections.  This should often be followed by a call to

src/core/PlayAreaApi.ttslua

@@ -48,5 +48,12 @@ do
     getObjectFromGUID(PLAY_AREA_GUID).call("setLimitSnapsByType", matchCardTypes)
   end
 
+  -- Receiver for the Global tryObjectEnterContainer event.  Used to clear vector lines from dragged
+  -- cards before they're destroyed by entering the container
+  PlayAreaApi.tryObjectEnterContainer = function(container, object)
+    getObjectFromGUID(PLAY_AREA_GUID).call("tryObjectEnterContainer",
+        { container = container, object = object })
+  end
+
   return PlayAreaApi
 end