.. _user_interfaces-embedding_in_qt:

user_interfaces example code: embedding_in_qt.py
================================================

[`source code <embedding_in_qt.py>`_]

::

    #! /usr/bin/env python
    
    # embedding_in_qt.py --- Simple Qt application embedding matplotlib canvases
    #
    # Copyright (C) 2005 Florent Rougon
    #
    # This file is an example program for matplotlib. It may be used and
    # modified with no restriction; raw copies as well as modified versions
    # may be distributed without limitation.
    
    import sys, os, random
    from qt import *
    
    from numpy import arange, sin, pi
    from matplotlib.backends.backend_qtagg import FigureCanvasQTAgg as FigureCanvas
    from matplotlib.figure import Figure
    
    # This seems to be what PyQt expects, according to the examples shipped in
    # its distribution.
    TRUE  = 1
    FALSE = 0
    
    progname = os.path.basename(sys.argv[0])
    progversion = "0.1"
    
    # Note: color-intensive applications may require a different color allocation
    # strategy.
    #QApplication.setColorSpec(QApplication.NormalColor)
    app = QApplication(sys.argv)
    
    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):
            self.fig = Figure(figsize=(width, height), dpi=dpi)
            self.axes = self.fig.add_subplot(111)
            # We want the axes cleared every time plot() is called
            self.axes.hold(False)
    
            self.compute_initial_figure()
    
            FigureCanvas.__init__(self, self.fig)
            self.reparent(parent, QPoint(0, 0))
    
            FigureCanvas.setSizePolicy(self,
                                       QSizePolicy.Expanding,
                                       QSizePolicy.Expanding)
            FigureCanvas.updateGeometry(self)
    
        def sizeHint(self):
            w, h = self.get_width_height()
            return QSize(w, h)
    
        def minimumSizeHint(self):
            return QSize(10, 10)
    
    
    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 = QTimer(self, "canvas update timer")
            QObject.connect(timer, SIGNAL("timeout()"), self.update_figure)
            timer.start(1000, FALSE)
    
        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 xrange(4) ]
    
            self.axes.plot([0, 1, 2, 3], l, 'r')
            self.draw()
    
    
    class ApplicationWindow(QMainWindow):
        def __init__(self):
            QMainWindow.__init__(self, None,
                                 "application main window",
                                 Qt.WType_TopLevel | Qt.WDestructiveClose)
    
            self.file_menu = QPopupMenu(self)
            self.file_menu.insertItem('&Quit', self.fileQuit, Qt.CTRL + Qt.Key_Q)
            self.menuBar().insertItem('&File', self.file_menu)
    
            self.help_menu = QPopupMenu(self)
            self.menuBar().insertSeparator()
            self.menuBar().insertItem('&Help', self.help_menu)
    
            self.help_menu.insertItem('&About', self.about)
    
            self.main_widget = QWidget(self, "Main widget")
    
            l = QVBoxLayout(self.main_widget)
            sc = MyStaticMplCanvas(self.main_widget, width=5, height=4, dpi=100)
            dc = MyDynamicMplCanvas(self.main_widget, width=5, height=4, dpi=100)
            l.addWidget(sc)
            l.addWidget(dc)
    
            self.main_widget.setFocus()
            self.setCentralWidget(self.main_widget)
    
            self.statusBar().message("All hail matplotlib!", 2000)
    
        def fileQuit(self):
            qApp.exit(0)
    
        def closeEvent(self, ce):
            self.fileQuit()
    
        def about(self):
            QMessageBox.about(self, "About %s" % progname,
    u"""%(prog)s version %(version)s
    Copyright \N{COPYRIGHT SIGN} 2005 Florent Rougon
    
    This program is a simple example of a Qt application embedding matplotlib
    canvases.
    
    It may be used and modified with no restriction; raw copies as well as
    modified versions may be distributed without limitation."""
                              % {"prog": progname, "version": progversion})
    
    
    aw = ApplicationWindow()
    aw.setCaption("%s" % progname)
    qApp.setMainWidget(aw)
    aw.show()
    sys.exit(qApp.exec_loop())
    

Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)