from PyQt5 import QtWidgets
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QTAgg as NavigationToolbar
from matplotlib.figure import Figure

class MplCanvas(FigureCanvas):
    def __init__(self):
        self.fig = Figure()
        self.ax = self.fig.add_subplot(111)
        FigureCanvas.__init__(self, self.fig)
        FigureCanvas.setSizePolicy(self, QtWidgets.QSizePolicy.Expanding, QtWidgets.QSizePolicy.Expanding)
        FigureCanvas.updateGeometry(self)

    def clear(self):
        self.ax.clear()
        self.fig.clear()

class MplWidget(QtWidgets.QWidget):
    def __init__(self, parent = None):
        QtWidgets.QWidget.__init__(self, parent)

        self.canvas = MplCanvas()
        self.vbl = QtWidgets.QVBoxLayout()
        self.vbl.addWidget(self.canvas)
        self.setLayout(self.vbl)