Matplotlib and PySide

pytobias

Hello,

I'm trying to embed a matplotlib figure within QMainWindow using pyside. In the following example a rectangle is plotted and now I want to have it draggable by using mouse-commands. Why is the following code not working? If I use the DraggableRectangle-Class without Qt it works quite well.

@import numpy as np
import matplotlib.pyplot as plt
import sys

from PySide import QtCore, QtGui
import matplotlib
matplotlib.use('Qt4Agg')
matplotlib.rcParams['backend.qt4']='PySide'
import matplotlib.pyplot as plt
from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg as FigureCanvas

class DraggableRectangle:
def init(self, rect):
self.rect = rect
self.press = None

def connect(self):
    'connect to all the events we need'
    self.cidpress = self.rect.figure.canvas.mpl_connect(
        'button_press_event', self.on_press)
    self.cidrelease = self.rect.figure.canvas.mpl_connect(
        'button_release_event', self.on_release)
    self.cidmotion = self.rect.figure.canvas.mpl_connect(
        'motion_notify_event', self.on_motion)

def on_press(self, event):
    'on button press we will see if the mouse is over us and store some data'
    if event.inaxes != self.rect.axes: return

    contains, attrd = self.rect.contains(event)
    if not contains: return
    print 'event contains', self.rect.xy
    x0, y0 = self.rect.xy
    self.press = x0, y0, event.xdata, event.ydata

def on_motion(self, event):
    'on motion we will move the rect if the mouse is over us'
    if self.press is None: return
    if event.inaxes != self.rect.axes: return
    x0, y0, xpress, ypress = self.press
    dx = event.xdata - xpress
    dy = event.ydata - ypress
    #print 'x0=%f, xpress=%f, event.xdata=%f, dx=%f, x0+dx=%f'%(x0, xpress, event.xdata, dx, x0+dx)
    self.rect.set_x(x0+dx)
    self.rect.set_y(y0+dy)

    self.rect.figure.canvas.draw()


def on_release(self, event):
    'on release we reset the press data'
    self.press = None
    self.rect.figure.canvas.draw()

def disconnect(self):
    'disconnect all the stored connection ids'
    self.rect.figure.canvas.mpl_disconnect(self.cidpress)
    self.rect.figure.canvas.mpl_disconnect(self.cidrelease)
    self.rect.figure.canvas.mpl_disconnect(self.cidmotion)

class MainWindow(QtGui.QMainWindow):
def init(self, parent=None):
super(MainWindow, self).init(parent)

    self.setGeometry(100, 100, 1000, 600)

    self.fig = plt.Figure((16, 4))
    self.fig.subplots_adjust(0.01, 0.01, 0.99, 0.99)
    self.canvas = FigureCanvas(self.fig)
    self.subplot = self.fig.add_subplot(111)
    self.subplot.set_axis_off()
    self.press = None

    self.rect = plt.Rectangle((0.5,0.5), 0.3, 0.3, edgecolor='r', facecolor='green', picker=10)
    self.subplot.add_patch(self.rect)

    self.setCentralWidget(self.canvas)

    dr = DraggableRectangle(self.rect)
    dr.connect()

def main():
app = QtGui.QApplication(sys.argv)
form = MainWindow()
form.show()
app.exec_()

main()@

Thank you for your help in advance!