How should i get mouse dragged to work?

mouse drag.gd

func _input(event):
	if self.mouse_in_grid && !mouse_has_entered:
		emit_signal("mouse_entered")
	if !self.mouse_in_grid && mouse_has_entered:
		emit_signal("mouse_exited")

	if should_ignore_mouse || !self.mouse_in_grid:
		return

	if event is InputEventMouseButton:
		var normalizedX = floor(event.position.x / cellSize.x)
		var normalizedY = floor(event.position.y / cellSize.y)
		mouse_left_is_pressed = event.pressed && event.button_index == BUTTON_LEFT #set the mouse pressed bool
		if event.pressed && event.button_index == BUTTON_LEFT:
			emit_signal("mouse_left_clicked", Vector2(normalizedX, normalizedY))
		elif event.pressed && event.button_index == BUTTON_RIGHT:
			emit_signal("mouse_right_clicked", Vector2(normalizedX, normalizedY), true)
		
	elif event is InputEventMouseMotion:
		if event.position.x >= 0 && event.position.x < (drawSize.x):
			if event.position.y >= 0 && event.position.y < drawSize.y:
				var mousePosition = get_local_mouse_position()
				if mouse_left_is_pressed:
					print("dragged")
					emit_signal("mouse_left_dragged", Vector2(normalizedX, normalizedY), false)