FigureCanvaQtAgg：左右单击差异

Question

我正在尝试使用FigureCanveQtAgg将Matplotlib图形嵌入到Qt窗口中。可以很好地工作，但是当我单击该图时，我很难区分左键单击和右键单击。

这里是我所做的工作的简单版本（一段时间前我在左键单击上遇到了问题，因此我已经回答了上一个问题，并将其粘贴到了这里：How to draw a circle on a FigureCanvasQTAgg on mouse click）。

from PySide2 import QtCore, QtGui, QtWidgets

from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure

import numpy as np


class PainterCanvas(FigureCanvas):
    def __init__(self, parent=None, width=5, height=4, dpi=100):
        fig = Figure(figsize=(width, height), dpi=dpi)
        FigureCanvas.__init__(self, fig)
        self.setParent(parent)
        self._instructions = []
        self.axes = self.figure.add_subplot(111)

    def paintEvent(self, event):
        super().paintEvent(event)
        painter = QtGui.QPainter(self)
        painter.setRenderHint(QtGui.QPainter.Antialiasing, True)
        width, height = self.get_width_height()
        for x, y, rx, ry, br_color in self._instructions:
            x_pixel, y_pixel_m = self.axes.transData.transform((x, y))
            # In matplotlib, 0,0 is the lower left corner,
            # whereas it's usually the upper right
            # for most image software, so we'll flip the y-coor
            y_pixel = height - y_pixel_m
            painter.setBrush(QtGui.QColor(br_color))
            painter.drawEllipse( QtCore.QPoint(x_pixel, y_pixel), rx, ry)

    def create_oval(self, x, y, radius_x=5, radius_y=5, brush_color="red"):
        self._instructions.append([x, y, radius_x, radius_y, brush_color])
        self.update()


class MyPaintWidget(QtWidgets.QWidget):
    def __init__(self):
        super().__init__()

        self.canvas = PainterCanvas()
        self.canvas.mpl_connect("button_press_event", self._on_left_click)
        x = np.arange(0, 10, 0.1)
        y = np.cos(x)
        self.canvas.axes.plot(x, y)

        layout_canvas = QtWidgets.QVBoxLayout(self)
        layout_canvas.addWidget(self.canvas)

    def _on_left_click(self, event):
        self.canvas.create_oval(event.xdata, event.ydata, brush_color="green")


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)

    w = MyPaintWidget()
    w.show()
    sys.exit(app.exec_())

对于我当时想要的东西，它非常有用。但是，现在我需要区分左键单击和右键单击。我认为问题是因为函数mpl_connect()只能使用“ button_press_event”事件。但是，有没有办法区分左键和右键？

我要实现的是：-如果用户单击鼠标左键：它将像现在一样绘制一个绿色圆圈-如果用户右键单击：它将打开带有功能的上下文菜单

谢谢！

Answer 1

您可以使用button中event的MyPaintWidget._on_left_click属性来确定按下了哪个按钮。此属性是类型为matplotlib.backend_bases.MouseButton的枚举常量。因此，要区分左键和右键按下，您可以执行以下操作]

matplotlib.backend_bases.MouseButton