Python-сообщество

class DiagramScene(QtGui.QGraphicsScene):
    InsertItem, InsertLine, InsertText, MoveItem  = range(4)

    itemInserted = QtCore.Signal(DiagramItem)

    textInserted = QtCore.Signal(QtGui.QGraphicsTextItem)

    itemSelected = QtCore.Signal(QtGui.QGraphicsItem)

    def __init__(self, itemMenu, parent=None):
        super(DiagramScene, self).__init__(parent)

        self.myItemMenu = itemMenu
        self.myMode = self.MoveItem
        self.myItemType = DiagramItem.Step
        self.line = None
        self.textItem = None
        self.myItemColor = QtCore.Qt.white
        self.myTextColor = QtCore.Qt.black
        self.myLineColor = QtCore.Qt.black
        self.myFont = QtGui.QFont()
     def mousePressEvent(self, mouseEvent):
        if (mouseEvent.button() != QtCore.Qt.LeftButton):
            return

        if self.myMode == self.InsertItem:
            item = DiagramItem(self.myItemType, self.myItemMenu)
            item.setBrush(self.myItemColor)
            self.addItem(item)
            item.setPos(mouseEvent.scenePos())
            self.itemInserted.emit(item)
        elif self.myMode == self.InsertLine:
            self.line = QtGui.QGraphicsLineItem(QtCore.QLineF(mouseEvent.scenePos(),
                                        mouseEvent.scenePos()))
            self.line.setPen(QtGui.QPen(self.myLineColor, 2))
            self.addItem(self.line)
        elif self.myMode == self.InsertText:
            textItem = DiagramTextItem()
            textItem.setFont(self.myFont)
            textItem.setTextInteractionFlags(QtCore.Qt.TextEditorInteraction)
            textItem.setZValue(1000.0)
            textItem.lostFocus.connect(self.editorLostFocus)
            textItem.selectedChange.connect(self.itemSelected)
            self.addItem(textItem)
            textItem.setDefaultTextColor(self.myTextColor)
            textItem.setPos(mouseEvent.scenePos())
            self.textInserted.emit(textItem)

        super(DiagramScene, self).mousePressEvent(mouseEvent)