Add typing, renaming, convenience methods/properties

b_asic/GUI/arrow.py

@@ -5,12 +5,12 @@ from qtpy.QtGui import QPainterPath, QPen
 from qtpy.QtWidgets import QGraphicsPathItem, QMenu
 
 from b_asic.GUI._preferences import GRID, LINECOLOR, PORTHEIGHT, PORTWIDTH
-from b_asic.GUI.port_button import PortButton
 from b_asic.signal import Signal
 
 if TYPE_CHECKING:
     from b_asic.GUI.drag_button import DragButton
     from b_asic.GUI.main_window import MainWindow
+    from b_asic.GUI.port_button import PortButton
     from b_asic.port import InputPort, OutputPort
 
 
@@ -34,8 +34,8 @@ class Arrow(QGraphicsPathItem):
 
     def __init__(
         self,
-        source_port_button: PortButton,
-        destination_port_button: PortButton,
+        source_port_button: "PortButton",
+        destination_port_button: "PortButton",
         window: "MainWindow",
         signal: Optional[Signal] = None,
         parent=None,
@@ -102,7 +102,7 @@ class Arrow(QGraphicsPathItem):
         self._source_port_button._operation_button.operation = source
 
     def set_destination_operation(self, destination: "Operation"):
-        """Set operation of the source DragButton"""
+        """Set operation of the destination DragButton"""
         self._destination_port_button._operation_button.operation = destination
 
     def remove(self):