arrow.py

from PySide2.QtWidgets import QApplication, QWidget, QMainWindow, QLabel, QAction,\
QStatusBar, QMenuBar, QLineEdit, QPushButton, QSlider, QScrollArea, QVBoxLayout,\
QHBoxLayout, QDockWidget, QToolBar, QMenu, QLayout, QSizePolicy, QListWidget, QListWidgetItem,\
QGraphicsLineItem, QGraphicsWidget
from PySide2.QtCore import Qt, QSize, QLineF, QPoint, QRectF
from PySide2.QtGui import QIcon, QFont, QPainter, QPen

from b_asic import Signal

class Arrow(QGraphicsLineItem):

    def __init__(self, source, destination, window, parent=None):
        super(Arrow, self).__init__(parent)
        self.source = source
        self.signal = Signal(source.port, destination.port)
        self.destination = destination
        self._window = window
        self.moveLine()
        self.source.moved.connect(self.moveLine)
        self.destination.moved.connect(self.moveLine)

    def contextMenuEvent(self, event):
        menu = QMenu()
        menu.addAction("Delete", self.remove)
        menu.exec_(self.cursor().pos())

    def remove(self):
        self.signal.remove_destination()
        self.signal.remove_source()
        self._window.scene.removeItem(self)
        self._window.signalList.remove(self)

    def moveLine(self):
        self.setPen(QPen(Qt.black, 3))
        self.setLine(QLineF(self.source.operation.x()+self.source.x()+14,\
             self.source.operation.y()+self.source.y()+7.5,\
             self.destination.operation.x()+self.destination.x(),\
             self.destination.operation.y()+self.destination.y()+7.5))