如何将平移事件从滚轮拖动改为鼠标右键拖动click+ at Pyqtgraph？

from pyqtgraph.Qt import QtGui, QtCore
import pyqtgraph as pg

class CustomPlotWidget(pg.PlotWidget):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.setMouseTracking(True)
        self.dragging = False
        self.drag_start = None

    def mousePressEvent(self, event):
        if event.button() == QtCore.Qt.RightButton:
            self.dragging = True
            self.drag_start = event.pos()

    def mouseMoveEvent(self, event):
        if self.dragging:
            delta = event.pos() - self.drag_start
            self.getViewBox().translateBy(delta.x(), delta.y())
            self.drag_start = event.pos()

    def mouseReleaseEvent(self, event):
        if event.button() == QtCore.Qt.RightButton:
            self.dragging = False

app = QtGui.QApplication([])
win = QtGui.QMainWindow()
plot_widget = CustomPlotWidget()
win.setCentralWidget(plot_widget)
win.show()