Use class instantiators for block background scripts

https://phabricator.endlessm.com/T35538

Author: dylanmccall

addons/block_code/drag_manager/drag.gd

@@ -1,6 +1,7 @@
 @tool
 extends Control
 
+const Background = preload("res://addons/block_code/ui/blocks/utilities/background/background.gd")
 const BlockCanvas = preload("res://addons/block_code/ui/block_canvas/block_canvas.gd")
 const Constants = preload("res://addons/block_code/ui/constants.gd")
 const InstructionTree = preload("res://addons/block_code/instruction_tree/instruction_tree.gd")
@@ -189,8 +190,7 @@ func _update_preview():
 
 	if target_snap_point:
 		# Make preview block
-		_preview_block = Control.new()
-		_preview_block.set_script(preload("res://addons/block_code/ui/blocks/utilities/background/background.gd"))
+		_preview_block = Background.new()
 
 		_preview_block.color = Color(1, 1, 1, 0.5)
 		_preview_block.custom_minimum_size = _block.get_global_rect().size

addons/block_code/ui/blocks/control_block/control_block.gd

@@ -2,8 +2,10 @@
 class_name ControlBlock
 extends Block
 
+const Background = preload("res://addons/block_code/ui/blocks/utilities/background/background.gd")
 const Constants = preload("res://addons/block_code/ui/constants.gd")
 const DragDropArea = preload("res://addons/block_code/ui/blocks/utilities/drag_drop_area/drag_drop_area.gd")
+const Gutter = preload("res://addons/block_code/ui/blocks/utilities/background/gutter.gd")
 
 @export var block_formats: Array = []
 @export var statements: Array = []
@@ -104,9 +106,8 @@ func format():
 		row.custom_minimum_size.y = 30
 		row.size_flags_horizontal = Control.SIZE_SHRINK_BEGIN
 
-		var bg := Control.new()
+		var bg := Background.new()
 		bg.name = "Background"
-		bg.set_script(preload("res://addons/block_code/ui/blocks/utilities/background/background.gd"))
 		bg.color = color
 		if i != 0:
 			bg.shift_top = Constants.CONTROL_MARGIN
@@ -144,9 +145,8 @@ func format():
 		snap_container.custom_minimum_size.y = 30
 		snap_container.size_flags_horizontal = Control.SIZE_SHRINK_BEGIN
 
-		var snap_gutter := Control.new()
+		var snap_gutter := Gutter.new()
 		snap_gutter.name = "Background"
-		snap_gutter.set_script(preload("res://addons/block_code/ui/blocks/utilities/background/gutter.gd"))
 		snap_gutter.custom_minimum_size.x = Constants.CONTROL_MARGIN
 		snap_gutter.size_flags_horizontal = Control.SIZE_SHRINK_BEGIN
 		snap_gutter.size_flags_vertical = Control.SIZE_EXPAND_FILL
@@ -161,11 +161,10 @@ func format():
 
 		%Rows.add_child(snap_container)
 
-	var bg := Control.new()
+	var bg := Background.new()
 	bg.size_flags_horizontal = Control.SIZE_SHRINK_BEGIN
 	bg.custom_minimum_size.x = 100
 	bg.custom_minimum_size.y = 30
-	bg.set_script(preload("res://addons/block_code/ui/blocks/utilities/background/background.gd"))
 	bg.color = color
 	bg.shift_top = Constants.CONTROL_MARGIN
 	%Rows.add_child(bg)