Ported drag and resize code from godot's window dialog as a base for RectViewNode.

game/addons/world_generator/resources/world_gen_base_resource.gd

@@ -3,6 +3,7 @@ extends Resource
 class_name WorldGenBaseResource
 
 export(Rect2) var rect : Rect2 = Rect2(0, 0, 1, 1)
+export(bool) var locked : bool = false
 
 func get_rect() -> Rect2:
 	return rect

game/addons/world_generator/test/test_world.tres

@@ -6,25 +6,30 @@
 [sub_resource type="Resource" id=1]
 script = ExtResource( 2 )
 rect = Rect2( 0, 0, 100, 100 )
+locked = false
 zones = [  ]
 
 [sub_resource type="Resource" id=2]
 script = ExtResource( 2 )
 rect = Rect2( 0, 0, 1, 1 )
+locked = false
 zones = [  ]
 
 [sub_resource type="Resource" id=3]
 script = ExtResource( 2 )
 rect = Rect2( 0, 0, 1, 1 )
+locked = false
 zones = [  ]
 
 [sub_resource type="Resource" id=4]
 script = ExtResource( 2 )
 rect = Rect2( 0, 0, 1, 1 )
+locked = false
 zones = [  ]
 
 [resource]
 resource_name = "asdasdss"
 script = ExtResource( 1 )
 rect = Rect2( 0, 0, 1000, 1000 )
+locked = false
 continents = [ SubResource( 1 ), SubResource( 2 ), SubResource( 3 ), SubResource( 4 ) ]

game/addons/world_generator/ui/RectViewNode.gd

@@ -1,8 +1,21 @@
 tool
 extends MarginContainer
 
+enum DragType {
+	DRAG_NONE = 0,
+	DRAG_MOVE = 1,
+	DRAG_RESIZE_TOP = 1 << 1,
+	DRAG_RESIZE_RIGHT = 1 << 2,
+	DRAG_RESIZE_BOTTOM = 1 << 3,
+	DRAG_RESIZE_LEFT = 1 << 4
+};
+
 var edited_resource : WorldGenBaseResource = null
 
+var drag_type : int
+var drag_offset : Vector2
+var drag_offset_far : Vector2
+
 func _draw():
 	draw_rect(Rect2(get_position(), get_size()), Color(1, 1, 1, 1))
 
@@ -22,3 +35,118 @@ func set_edited_resource(res : WorldGenBaseResource):
 	
 	refresh()
 	
+#based on / ported from engine/scene/gui/dialogs.h and .cpp
+func _notification(p_what : int) -> void:
+	if (p_what == NOTIFICATION_MOUSE_EXIT):
+			# Reset the mouse cursor when leaving the resizable window border.
+			if (edited_resource && !edited_resource.locked && !drag_type):
+				if (get_default_cursor_shape() != CURSOR_ARROW):
+					set_default_cursor_shape(CURSOR_ARROW)
+
+#based on / ported from engine/scene/gui/dialogs.h and .cpp
+func _gui_input(p_event : InputEvent) -> void:
+	if (p_event is InputEventMouseButton) && (p_event.get_button_index() == BUTTON_LEFT):
+		var mb : InputEventMouseButton = p_event as InputEventMouseButton
+		
+		if (mb.is_pressed()):
+			# Begin a possible dragging operation.
+			drag_type = _drag_hit_test(Vector2(mb.get_position().x, mb.get_position().y))
+			
+			if (drag_type != DragType.DRAG_NONE):
+				drag_offset = get_global_mouse_position() - get_position()
+			
+			drag_offset_far = get_position() + get_size() - get_global_mouse_position()
+			
+		elif (drag_type != DragType.DRAG_NONE && !mb.is_pressed()):
+			# End a dragging operation.
+			drag_type = DragType.DRAG_NONE
+
+	if p_event is InputEventMouseMotion:
+		var mm : InputEventMouseMotion = p_event as InputEventMouseMotion
+
+		if (drag_type == DragType.DRAG_NONE):
+			# Update the cursor while moving along the borders.
+			var cursor = CURSOR_ARROW
+			if (!edited_resource.locked):
+				var preview_drag_type : int = _drag_hit_test(Vector2(mm.get_position().x, mm.get_position().y));
+				
+				var top_left : int = DragType.DRAG_RESIZE_TOP + DragType.DRAG_RESIZE_LEFT
+				var bottom_right : int = DragType.DRAG_RESIZE_BOTTOM + DragType.DRAG_RESIZE_RIGHT
+				var top_right : int = DragType.DRAG_RESIZE_TOP + DragType.DRAG_RESIZE_RIGHT
+				var bottom_left : int = DragType.DRAG_RESIZE_BOTTOM + DragType.DRAG_RESIZE_LEFT
+				
+				match (preview_drag_type):
+					DragType.DRAG_RESIZE_TOP:
+						continue
+					DragType.DRAG_RESIZE_BOTTOM:
+						cursor = CURSOR_VSIZE;
+					DragType.DRAG_RESIZE_LEFT:
+						continue
+					DragType.DRAG_RESIZE_RIGHT:
+						cursor = CURSOR_HSIZE;
+					top_left:
+						continue
+					bottom_right:
+						cursor = CURSOR_FDIAGSIZE;
+					top_right:
+						continue
+					bottom_left:
+						cursor = CURSOR_BDIAGSIZE;
+			
+			if (get_cursor_shape() != cursor):
+				set_default_cursor_shape(cursor);
+			
+		else:
+			# Update while in a dragging operation.
+			var global_pos : Vector2 = get_global_mouse_position()
+			global_pos.y = max(global_pos.y, 0) # Ensure title bar stays visible.
+
+			var rect : Rect2 = get_rect()
+			var min_size : Vector2 = get_combined_minimum_size()
+
+			if (drag_type == DragType.DRAG_MOVE):
+				rect.position = global_pos - drag_offset
+			else:
+				if (drag_type & DragType.DRAG_RESIZE_TOP):
+					var bottom : int = rect.position.y + rect.size.y
+					var max_y : int = bottom - min_size.y
+					rect.position.y = min(global_pos.y - drag_offset.y, max_y)
+					rect.size.y = bottom - rect.position.y
+				elif (drag_type & DragType.DRAG_RESIZE_BOTTOM):
+					rect.size.y = global_pos.y - rect.position.y + drag_offset_far.y
+				
+				if (drag_type & DragType.DRAG_RESIZE_LEFT):
+					var right : int = rect.position.x + rect.size.x
+					var max_x : int = right - min_size.x
+					rect.position.x = min(global_pos.x - drag_offset.x, max_x)
+					rect.size.x = right - rect.position.x
+				elif (drag_type & DragType.DRAG_RESIZE_RIGHT):
+					rect.size.x = global_pos.x - rect.position.x + drag_offset_far.x
+
+			set_size(rect.size)
+			set_position(rect.position)
+
+#based on / ported from engine/scene/gui/dialogs.h and .cpp
+func _drag_hit_test(pos : Vector2) -> int:
+	var drag_type : int = DragType.DRAG_NONE
+
+	if (!edited_resource.locked):
+		var title_height : int = 20 #get_constant("title_height", "WindowDialog")
+		var scaleborder_size : int = 10 #get_constant("scaleborder_size", "WindowDialog")
+
+		var rect : Rect2 = get_rect()
+
+		if (pos.y < (-title_height + scaleborder_size)):
+			drag_type = DragType.DRAG_RESIZE_TOP
+		elif (pos.y >= (rect.size.y - scaleborder_size)):
+			drag_type = DragType.DRAG_RESIZE_BOTTOM
+		
+		if (pos.x < scaleborder_size):
+			drag_type |= DragType.DRAG_RESIZE_LEFT
+		elif (pos.x >= (rect.size.x - scaleborder_size)):
+			drag_type |= DragType.DRAG_RESIZE_RIGHT
+
+	if (drag_type == DragType.DRAG_NONE && pos.y < 0):
+		drag_type = DragType.DRAG_MOVE
+
+	return drag_type