matplotlib-devel Mailing List for matplotlib

Hello everyone,

in my programs I need the RectangleSelector. It's quiet easy to use but I 
discovered that there isn't a really easy way to switch it off once it is 
activated. I thought about  the following lines to matplotlib/widgets.py:

#--------------------------------------------------------------------------------------------
#at the beginning of RectangleSelector's __init__:
        ... docstring ...
        self.ax = ax					# like before
        self.visible = True				# like before
        self.canvas = ax.figure.canvas	# like before
        self.connect_id = []       # will contain the connection id's 
        self.active = True          #  for activation / deactivation
        self.is_active(True)
        ... snip ... 

#and an additional method:
#--------------------------------------------------------------------------------------------
def is_active(self, active):
        """ Use this to activate the RectangleSelector from your program.
        """
        self.active = active
        if active and len(self.connect_id) == 0: # you want to activate and it
                                                   #  isn't already active     
            self.connect_id.append(self.canvas.mpl_connect(
                  'motion_notify_event', self.onmove))
            self.connect_id.append(self.canvas.mpl_connect(
                  'button_press_event', self.press))
            self.connect_id.append(self.canvas.mpl_connect(
                  'button_release_event', self.release))
            self.connect_id.append(self.canvas.mpl_connect(
                  'draw_event', self.update_background))

        if not active and len(self.connect_id) != 0:  # you want to deactivate 
            for index in self.connect_id:     #  and it isn't already inactive  
                self.canvas.mpl_disconnect(index)
            self.connect_id = []
#--------------------------------------------------------------------------------------------

With  these changes you can check the following example:

#--------------------------------------------------------------------------------------------
from matplotlib.widgets import  RectangleSelector
from pylab import *

def onselect(eclick, erelease):
  'eclick and erelease are matplotlib events at press and release'
  print 'startposition : (%f,%f)'%(eclick.xdata, eclick.ydata)
  print 'endposition   : (%f,%f)'%(erelease.xdata, erelease.ydata)
  print 'used button   : ', eclick.button

def toggle_Selector(event):
    print "Key pressed."
    if event.key in ["Q", "q"] and toggle_Selector.RS.active:
        print " RectangleSelector deactivated."
        toggle_Selector.RS.is_active(False)
    if event.key in ["A", "a"] and not toggle_Selector.RS.active:
        print " RectangleSelector activated."
        toggle_Selector.RS.is_active(True)

x = arange(100)/(99.0)
y = sin(x)
fig = figure
ax = subplot(111)
ax.plot(x,y)

toggle_Selector.RS = RectangleSelector(ax, onselect,drawtype='box')
connect("key_press_event", toggle_Selector)
show()
#--------------------------------------------------------------------------------------------

I hope this is usefull to someone,
Martin

PS: Maybe the above example can replace the RectangleSelector's
docstring. I think it's easier to read and understand.