And the new GraphicsSignal class

b_asic/scheduler-gui/graphics_signal.py

+from typing     import Optional
+
+from qtpy.QtWidgets import QGraphicsItem, QGraphicsPathItem
+from qtpy.QtGui import QPainterPath, QPen
+from qtpy.QtCore    import Qt, QPointF
+
+# B-ASIC
+from b_asic.signal import Signal
+from graphics_component_item    import GraphicsComponentItem
+
+class GraphicsSignal(QGraphicsPathItem):
+    _path: Optional[QPainterPath] = None
+    _src_operation: GraphicsComponentItem
+    _dest_operation: GraphicsComponentItem
+    _signal: Signal
+    def __init__(self,
+                 src_operation: GraphicsComponentItem,
+                 dest_operation: GraphicsComponentItem,
+                 signal: Signal, pen: Optional[QPen] = None,
+                 parent: Optional[QGraphicsItem] = None):
+        super().__init__(parent=parent)
+        self._src_operation = src_operation
+        self._dest_operation = dest_operation
+        self._signal = signal
+        if pen is None:
+            pen = QPen(Qt.black)
+            pen.setWidthF(0.03)
+        self.setPen(pen)
+        self.update_path()
+
+    def update_path(self):
+        """
+        Create a new path after moving connected operations.
+        """
+        source_point = self._src_operation.get_port_location(
+            f"out{self._signal.source.index}")
+        dest_point = self._dest_operation.get_port_location(
+            f"in{self._signal.destination.index}")
+        path = QPainterPath()
+        path.moveTo(source_point)
+        source_x = source_point.x()
+        source_y = source_point.y()
+        dest_x = dest_point.x()
+        dest_y = dest_point.y()
+        if abs(source_x - dest_x) <= 0.1:
+            ctrl_point1 = QPointF(source_x + 0.5, source_y)
+            ctrl_point2 = QPointF(source_x - 0.5, dest_y)
+        else:
+            mid_x = (source_x + dest_x)/2
+            ctrl_point1 = QPointF(mid_x, source_y)
+            ctrl_point2 = QPointF(mid_x, dest_y)
+
+        path.cubicTo(ctrl_point1, ctrl_point2, dest_point)
+        self.setPath(path)