UI improvements

ui/component/ModalBackdrop.gd

@@ -1,48 +1,16 @@
 class_name ModalBackdrop extends ColorRect
 
-# Tracks which overlays are currently open. Each entry must be a direct sibling
-# (child of the same parent). The backdrop repositions itself in the scene tree
-# to sit immediately below whichever open overlay has the highest tree index,
-# so only one backdrop is ever visible regardless of how many overlays are open.
-var _openOverlays:Array[Control] = []
-
 func _ready() -> void:
   visible = false
+  mouse_filter = MOUSE_FILTER_IGNORE
+  UI.FOCUS_STACK.activeLayerChanged.connect(_onActiveLayerChanged)
 
-func register(overlay:Control) -> void:
-  assert(overlay.get_parent() == get_parent(), "ModalBackdrop: overlay must be a sibling")
-  assert(overlay.has_signal("opened") and overlay.has_signal("closed"),
-    "ModalBackdrop: overlay must have opened/closed signals")
-  overlay.connect("opened", func(): _onOpened(overlay))
-  overlay.connect("closed", func(): _onClosed(overlay))
-
-func _onOpened(overlay:Control) -> void:
-  if overlay not in _openOverlays:
-    _openOverlays.append(overlay)
-  _reposition()
-
-func _onClosed(overlay:Control) -> void:
-  _openOverlays.erase(overlay)
-  _reposition()
-
-func _reposition() -> void:
-  if _openOverlays.is_empty():
+func _onActiveLayerChanged(layer:ClosableMenu) -> void:
+  if layer == null or layer.get_parent() != get_parent():
     visible = false
-    return
-  visible = true
-  var top := _topOverlay()
-  var topIdx := top.get_index()
-  var myIdx := get_index()
-  if myIdx == topIdx - 1:
-    return
-  if myIdx < topIdx:
-    get_parent().move_child(self, topIdx - 1)
+    mouse_filter = MOUSE_FILTER_IGNORE
+    z_index = 0
   else:
-    get_parent().move_child(self, topIdx)
-
-func _topOverlay() -> Control:
-  var top:Control = _openOverlays[0]
-  for overlay in _openOverlays:
-    if overlay.get_index() > top.get_index():
-      top = overlay
-  return top
+    visible = true
+    mouse_filter = MOUSE_FILTER_STOP
+    z_index = layer.z_index - 5