import sys

import numpy as np
import matplotlib
matplotlib.use('Qt4Agg')
import matplotlib.style
from matplotlib.backends.backend_qt4agg import (
    Figure,
    FigureCanvasQTAgg as FigureCanvas)
from PyQt4 import QtGui
from PyQt4.uic import loadUiType


Ui_MainWindow, QMainWindow = loadUiType('dialog.ui')

matplotlib.style.use('ggplot')


class Main(QMainWindow, Ui_MainWindow):
    def __init__(self, ):
        super(Main, self).__init__()
        self.setupUi(self)

        self.layout_mpl = QtGui.QVBoxLayout()
        self.widget_mpl.setLayout(self.layout_mpl)

        self.prepare_figure()

        # Assign callbacks
        self.button_refresh.clicked.connect(self.update_figure)

    def prepare_figure(self):
        self.fig = Figure()
        self.axes = self.fig.add_subplot(111)

        self.axes.set_xlim((0, 6))
        self.axes.set_xlabel('seq.index')
        self.axes.set_ylim((0, 100))
        self.axes.set_ylabel('observation')

        N = 5
        self.graph = self.axes.scatter(
            [] * N, [] * N, s=[np.pi*5**2] * N, color='seagreen', animated=True)

        self.canvas = FigureCanvas(self.fig)
        # w = self.widget_mpl.width()
        # h = self.widget_mpl.height()
        # self.canvas.setFixedSize(w, h)

        self.canvas.draw()
        self.layout_mpl.addWidget(self.canvas)

        self.bg = self.canvas.copy_from_bbox(self.axes.bbox)

    def update_figure(self):
        self.canvas.restore_region(self.bg)

        # Set data to be visualized
        self.graph.set_offsets([(i+1, d) for i, d in
                                enumerate(np.random.rand(5)*100)])

        # Redraw
        self.axes.draw_artist(self.graph)
        self.canvas.blit(self.axes.bbox)


if __name__ == '__main__':
    app = QtGui.QApplication(sys.argv)
    main = Main()
    main.show()
    sys.exit(app.exec_())