Usage of BoundsEditor in TraitsUI

Question

I want to use the BoundsEditor (in TraitsUI) for a range selection. How do I access the High and Low values? For testing I use the RangeEditor - which works as expected (on moving the slider the current value is printed). But I cannot get any values out of the BoundsEditor. Any pointers are appreciated.

I use following (simplified code):

from traits.api \
    import HasTraits, Button, Range
from traitsui.api \
    import View, Item, Group, RangeEditor
from traitsui.qt4.extra.bounds_editor import BoundsEditor

class Parameters(HasTraits):
    rgb_range = Range(0.,1.0)
    range1 = rgb_range
    range2 = rgb_range
    eval_button = Button("Eval")  

    traits_view= View(
        Item('range1')), #editor=RangeEditor()
        Item('range2', editor=BoundsEditor()),
        Item('eval_button'))


    def _range1_changed(self, value):
        print(value)

    def _range2_changed(self, *arg, **kwargs):
        print(arg)

    def _range2_changed(self, *arg, **kwargs):
        print(arg)

    def _range2_low_changed(self, *arg, **kwargs):
        print(arg)

    def _range2_high_changed(self, *arg, **kwargs):
        print(arg)

    def _eval_button_fired(self):
        print(self.range1)
        print(self.range2)


if __name__ == '__main__':
    alg = Parameters()
    alg.configure_traits() 

Answer 1

I am just beginning to learn Traits, so I am sure someone else can explain this better than me. I am using an example from http://blog.enthought.com/enthought-tool-suite/traits/new-double-slider-editor/#.VgFbYLTgtWQ. I declared variables for the low and high values, and passed these into BoundsEditor(). Then I declared functions that run when those values change. I got what I think is close to what you are looking for.

from traits.api \
    import HasTraits, Button, Range, Float
from traitsui.api \
    import View, Item, Group, RangeEditor
from traitsui.qt4.extra.bounds_editor import BoundsEditor

class Parameters(HasTraits):
    rgb_range = Range(0.,1.0)
    range1 = rgb_range
    range2 = rgb_range
    low_val = Float(0.0)
    high_val = Float(1.0)
    eval_button = Button("Eval")  

    traits_view= View(
        Item('range1', editor=RangeEditor()),
        Item('range2', editor=BoundsEditor(low_name = 'low_val', high_name = 'high_val')),
        Item('eval_button'))


    def _range1_changed(self, value):
        print(value)

    def _low_val_changed(self):
        print(self.low_val)

    def _high_val_changed(self):
        print(self.high_val)

    def _eval_button_fired(self):
        print(self.range1)
        print(self.low_val)
        print(self.high_val)

if __name__ == '__main__':
    alg = Parameters()
    alg.configure_traits()