python - 带有嵌入式 Matplotlib 的 PyQt - 焦点问题

Question

我想创建一个 GUI，左侧是用户输入，右侧是绘图。 应用按钮应根据输入更新绘图。现在该按钮只是清除 TextLabel。

我用 Qt Desginer 做了一个基本的布局并尝试实现 this示例。

如果没有绘图，可以使用鼠标聚焦不同的 QLineEdit 来工作，但是，如果绘图聚焦仅适用于键盘的选项卡，而不能再单击。

MyMplCanvas 类是否捕获了鼠标焦点或者为什么它不起作用？

这是代码:

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

from __future__ import unicode_literals
import random
import matplotlib
# Make sure that we are using QT5
matplotlib.use('Qt5Agg')
from PyQt5 import QtCore, QtWidgets
from numpy import arange, sin, pi
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.figure import Figure


class MyMplCanvas(FigureCanvas):
    """Ultimately, this is a QWidget (as well as a FigureCanvasAgg, etc.)."""

    def __init__(self, parent=None, width=5, height=4, dpi=100):
        fig = Figure(figsize=(width, height), dpi=dpi)
        self.axes = fig.add_subplot(111)

        self.compute_initial_figure()

        FigureCanvas.__init__(self, fig)
        self.setParent(parent)

        FigureCanvas.setSizePolicy(self,
                                   QtWidgets.QSizePolicy.Expanding,
                                   QtWidgets.QSizePolicy.Expanding)
        FigureCanvas.updateGeometry(self)

    def compute_initial_figure(self):
        pass


class MyStaticMplCanvas(MyMplCanvas):
    """Simple canvas with a sine plot."""

    def compute_initial_figure(self):
        t = arange(0.0, 3.0, 0.01)
        s = sin(2*pi*t)
        self.axes.plot(t, s)


class MyDynamicMplCanvas(MyMplCanvas):
    """A canvas that updates itself every second with a new plot."""

    def __init__(self, *args, **kwargs):
        MyMplCanvas.__init__(self, *args, **kwargs)
        timer = QtCore.QTimer(self)
        timer.timeout.connect(self.update_figure)
        timer.start(1000)

    def compute_initial_figure(self):
        self.axes.plot([0, 1, 2, 3], [1, 2, 0, 4], 'r')

    def update_figure(self):
        # Build a list of 4 random integers between 0 and 10 (both inclusive)
        l = [random.randint(0, 10) for i in range(4)]
        self.axes.cla()
        self.axes.plot([0, 1, 2, 3], l, 'r')
        self.draw()

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(852, 678)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.gridLayout_2 = QtWidgets.QGridLayout(self.centralwidget)
        self.gridLayout_2.setObjectName("gridLayout_2")
        self.horizontalLayout_2 = QtWidgets.QHBoxLayout()
        self.horizontalLayout_2.setObjectName("horizontalLayout_2")
        self.formLayout = QtWidgets.QFormLayout()
        self.formLayout.setContentsMargins(5, 5, 5, 5)
        self.formLayout.setObjectName("formLayout")
        self.label = QtWidgets.QLabel(self.centralwidget)
        self.label.setObjectName("label")
        self.formLayout.setWidget(0, QtWidgets.QFormLayout.LabelRole, self.label)
        self.lineEdit = QtWidgets.QLineEdit(self.centralwidget)
        self.lineEdit.setObjectName("lineEdit")
        self.formLayout.setWidget(0, QtWidgets.QFormLayout.FieldRole, self.lineEdit)
        self.label_2 = QtWidgets.QLabel(self.centralwidget)
        self.label_2.setObjectName("label_2")
        self.formLayout.setWidget(1, QtWidgets.QFormLayout.LabelRole, self.label_2)
        self.lineEdit_2 = QtWidgets.QLineEdit(self.centralwidget)
        self.lineEdit_2.setObjectName("lineEdit_2")
        self.formLayout.setWidget(1, QtWidgets.QFormLayout.FieldRole, self.lineEdit_2)
        self.label_3 = QtWidgets.QLabel(self.centralwidget)
        self.label_3.setObjectName("label_3")
        self.formLayout.setWidget(2, QtWidgets.QFormLayout.LabelRole, self.label_3)
        self.lineEdit_3 = QtWidgets.QLineEdit(self.centralwidget)
        self.lineEdit_3.setObjectName("lineEdit_3")
        self.formLayout.setWidget(2, QtWidgets.QFormLayout.FieldRole, self.lineEdit_3)
        self.pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.pushButton.setMinimumSize(QtCore.QSize(200, 0))
        self.pushButton.setObjectName("pushButton")
        self.formLayout.setWidget(3, QtWidgets.QFormLayout.SpanningRole, self.pushButton)
        self.horizontalLayout_2.addLayout(self.formLayout)
        self.gridLayout = QtWidgets.QGridLayout()
        self.gridLayout.setContentsMargins(5, 5, 5, 5)
        self.gridLayout.setObjectName("gridLayout")
        self.widget_2 = QtWidgets.QWidget(self.centralwidget)
        self.widget_2.setMinimumSize(QtCore.QSize(300, 300))
        self.widget_2.setObjectName("widget_2")

        #self.gridLayout.addWidget(self.widget_2, 0, 1, 1, 1)
        self.gridLayout.addWidget(MyDynamicMplCanvas(self.widget_2), 0, 1, 1, 1)

        self.widget_1 = QtWidgets.QWidget(self.centralwidget)
        self.widget_1.setMinimumSize(QtCore.QSize(300, 300))
        self.widget_1.setObjectName("widget_1")

        #self.gridLayout.addWidget(self.widget_1, 0, 0, 1, 1)
        self.gridLayout.addWidget(MyStaticMplCanvas(self.widget_1), 0, 0, 1, 1)

        self.widget_4 = QtWidgets.QWidget(self.centralwidget)
        self.widget_4.setMinimumSize(QtCore.QSize(300, 300))
        self.widget_4.setObjectName("widget_4")
        self.gridLayout.addWidget(self.widget_4, 1, 1, 1, 1)
        self.widget_3 = QtWidgets.QWidget(self.centralwidget)
        self.widget_3.setMinimumSize(QtCore.QSize(300, 300))
        self.widget_3.setObjectName("widget_3")
        self.gridLayout.addWidget(self.widget_3, 1, 0, 1, 1)
        self.horizontalLayout_2.addLayout(self.gridLayout)
        self.gridLayout_2.addLayout(self.horizontalLayout_2, 0, 0, 1, 1)
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 852, 20))
        self.menubar.setObjectName("menubar")
        self.menuDatei = QtWidgets.QMenu(self.menubar)
        self.menuDatei.setObjectName("menuFile")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)
        self.menubar.addAction(self.menuDatei.menuAction())

        self.retranslateUi(MainWindow)
        self.pushButton.clicked.connect(self.label.clear)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.label.setText(_translate("MainWindow", "TextLabel"))
        self.label_2.setText(_translate("MainWindow", "TextLabel"))
        self.label_3.setText(_translate("MainWindow", "TextLabel"))
        self.pushButton.setText(_translate("MainWindow", "Apply"))
        self.menuDatei.setTitle(_translate("MainWindow", "File"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

Answer 1

该问题是由位于布局顶部的 self.widget_1 和 self.widget_2 引起的，阻止了鼠标事件的传播。

这个想法是用 Canvas 替换 self.widget_1 和 self.widget_2 ，如下所示:

...
self.gridLayout = QtWidgets.QGridLayout()
self.gridLayout.setContentsMargins(5, 5, 5, 5)
self.gridLayout.setObjectName("gridLayout")
self.widget_2 = MyDynamicMplCanvas(self.centralwidget) # <---
self.widget_2.setMinimumSize(QtCore.QSize(300, 300))
self.widget_2.setObjectName("widget_2")
self.gridLayout.addWidget(self.widget_2, 0, 1, 1, 1)
# self.gridLayout.addWidget(MyDynamicMplCanvas(self.widget_2), 0, 1, 1, 1)
self.widget_1 = MyStaticMplCanvas(self.centralwidget) # <---
self.widget_1.setMinimumSize(QtCore.QSize(300, 300))
self.widget_1.setObjectName("widget_1")
self.gridLayout.addWidget(self.widget_1, 0, 0, 1, 1)
# self.gridLayout.addWidget(MyStaticMplCanvas(self.widget_1), 0, 0, 1, 1)
self.widget_4 = QtWidgets.QWidget(self.centralwidget)
self.widget_4.setMinimumSize(QtCore.QSize(300, 300))
self.widget_4.setObjectName("widget_4")
self.gridLayout.addWidget(self.widget_4, 1, 1, 1, 1)
self.widget_3 = QtWidgets.QWidget(self.centralwidget)
self.widget_3.setMinimumSize(QtCore.QSize(300, 300))
self.widget_3.setObjectName("widget_3")
self.gridLayout.addWidget(self.widget_3, 1, 0, 1, 1)
...