Can´t add text from a Qtextedit to a matplotlib "stickynote"

Question

I´m trying to add some text for a note in a matplotlib plot, and i want to get that text from a QTextEdit, which is in a QDialog that pops-up with a button in the toolbar.

This is my code so far:

class TextoMatplotlib(QDialog):
    def __init__(self):
      QDialog.__init__(self)
      uic.loadUi("insertartextoenMatplotlib.ui", self) # Created in QtDesigner
      #Matplotlib figure
      fig = plt.figure(1, figsize=(5,5))
      fig.clf()
      ax = fig.add_subplot(111)
      ax.plot()
      self.connect(self.textEdit, SIGNAL("returnPressed()"),self.InsertText) 

Here is the method that i want to connect with the QTextEdit (it´s all in the same class):

     def InsertText(self):
       nota.insertPlainText(self.textEdit.text())
       nota.setText('')

       notes = ax.annotate(nota, xy=(), bbox = dict(facecolor="red"))
       listadenotas = []
       for note in notes:
          nota = DraggableNote(note)
          nota.connect()
          listadenotas.append(nota)

class DraggableNote:
    def __init__(self, note):
      self.note = nota
      self.press = None

    def connect(self):
      self.cidpress = self.note.figure.canvas.mpl_connect(
          "button_pressed_event", self.on_press)
      self.cidrelease = self.note.figure.canvas.mpl_connect(
          "button_release_event", self.on_release)
      self.cidmotion = self.note.figure.canvas.mpl_connect(
          "motion_notify_event", self.on_motion)

    def on_press(self, event):
      if event.inaxes != self.note.axes:
          return
      contains, attrd = self.note.contains(event)

      if not contains:
          return
          x0, y0 = self.note.xy
          self.press = x0, y0, event.xdata, event.ydata

    def on_motion(self, event):

      if self.press is None:
          return
      if event.inaxes != self.note.axes:
          return
      x0, y0, xpress, ypress = self.press
      dx = event.xdata - xpress
      dy = event.ydata - ypress

      self.note.set_x(x0+dx)
      self.note.set_y(y0+dy)

      self.note.figure.canvas.draw()

  def on_release(self, event):

      self.press = None
      self.note.figure.canvas.draw()

  def disconnect(self):
      self.note.figure.canvas.mpl_disconnect(self.cidpress)
      self.note.figure.canvas.mpl_disconnect(self.cidrelease)
      self.note.figure.canvas.mpl_disconnect(self.cidmotion)

I´ve got the "DraggableNote" class from an example in the Matplotlib documentation.

I don´t know where the problem is. I may have copy/paste it wrong in here, but the indentation is correct. Sorry if there is a mistake of that kind.

I hope you can help me. Thank you for your answers.

------------------------------ EDIT------------------------------------------

I tried to make it more easier. This is what i´ve done:

class TextoMatplotlib(QDialog):
    def __init__(self):
      QDialog.__init__(self)
      uic.loadUi("insertartextoenMatplotlib2.ui", self) 

      self.setWindowTitle("Insertar Nota")
      self.setMinimumSize(250, 120)
      self.setMaximumSize(250, 120)
      self.label.setText("Insertar texto: ")

      x = np.arange(0, 5, 0.1);
      y = np.sin(x)

      fig, ax = plt.subplots()
      ax.plot(x,y)

      nota = self.textEdit.toPlainText()
      self.connect(self.textEdit, SIGNAL("returnPressed()"), self.insertText)

    def insertText(self):
      note = ax.annotate(nota, xy=(2, 0), bbox=dict(facecolor='yellow'))  
      note.draggable()

It still does not work. I really don´t know what i´m missing here